Holley carburettor adjustment needed

Hi Rene -

My first picture (handwritten) is how I had my Holley 4150 (List 4609, 735 CFM) set up during the initial phase of my ownership.  The typed data is how the same carb is currently set up.  It starts good, idles good, runs great.

I have drilled my throttle plates (you can see one of the holes in the picture).  All four throttle plates are drilled.

I’m running a 358 ci (351C bored .040” over), a George Pence recommended Bullet cam.  Compression is 10:1.  I am also running the Blue Thunder manifold.

My buddy Wade helped me set this all up, drilled the throttle plates, and we eventually converted this carb to 4-corner idle by drilling, and installing needle valves in the secondary throttle plate..  nevertheless…

It seems to me if your car won’t even run on start up, and doesn’t idle when you open the secondaries all the way up, very small holes (.136”) in your throttle plates will not solve your problems.

I would be thinking about something like ignition timing. But that’s just me.

I hope this information is helpful to you.

Rocky

Hi Rene,

a Holley carburettor is more tolerant than a Weber in terms of adjustments. A new holley is pre-tuned at the factory and runs as it is, and your engine should start, without backfiring, and not stall below 1800 rpm, the choice of jets, nozzles and power valve, cams, etc. .. are for optimized settings. I think it is necessary to recheck the firing order, recheck the connections and the plugs on the carburettor and on the intake pipe, etc ... before drilling holes in the butterflies and returning the secondary back to adjustment of origin.

When I had a weird problem similar to what you are describing - a lot of smoke, could only keep it running at high rpms etc, it was the distributor cap that had been put on crooked. It messed up the rotor. Worth a quick check.

Thank you for your answers, I will check the whole ignition system before changing the carburetor permanently.

You probably have the wrong Holley carb. I am not specifically familiar with the one that you have but it may be that it has the reverse idle system used to get the idle mixture to 14.6 at idle.

A generic 3310 will probably be the easiest for you to use. It's 780cfm and jetted for a 5 to 5.7L v8, so all you should have to do is bolt it on and idle it down.

What you are also describing in the issues with the carb that you are trying to use now is a symptom of a BIG vacuum leak. So check all of the usual places plus the special Pantera places like the power brake vacuum line (all the way to the front).

...If it has Backfired Through the CARB...Just One Time, You have a Blown 'Power Valve' RUBBER Diaphragm on the Primary Metering Block. Too Much Fuel, Flooding Out! If it is a 'Double-Pumper', there is also a Power Valve on the Secondary Metering Block! Check/Test these by Removing and Sucking on them...No Kidding, they should 'Hold' the Vacuum.

MJ

Marlin is correct. Yes on the power valve as the source if the diaphram is ruptured. . It can be blown out by a backfire while starting but it will also flood the engine since the primary bowl will then dump directly into intake manifold.

The current crop of pv's is so bad, of the ones I've tested around 50% are bad right out of the box. Don't suck on them. Get a Moroso pv tester. If you run Holleys, you need one.

SOME new Holleys, but not all,  have a check valve built into the base plate but they are not 100% effective.

There is only one Holley double-pumper that uses a pv in the secondaries. That is a 4181, 850cfm. The others are all just one and it is installed in the primary metering block.

as doug said, it could be a leak on the air intakes for brake assist, pcv, etc. I think the best thing to do first is to disconnect all those hoses that go to the intake and to the Holleyand put caps in place and do a test.

If you don't already have it, a link in french for the Holley settings:

CARBURATEUR AMERICAIN REGLAGE (free.fr)

@dipascale posted:

as doug said, it could be a leak on the air intakes for brake assist, pcv, etc. I think the best thing to do first is to disconnect all those hoses that go to the intake and to the Holleyand put caps in place and do a test.

If you don't already have it, a link in french for the Holley settings:

CARBURATEUR AMERICAIN REGLAGE (free.fr)

Thank you very much for the link, I think it will help me a lot.

I found a first "leak" of depression, the PCV ME Wagner valve which I haven't adjusted yet since it needs a stable idle, I plugged it and it's going a little bit better.
I'm going to check the power valve because in addition to the backfire there are explosions in the exhaust and flames that come out when I keep the engine speed a little high, not when I release the accelerator but while I hold it a little open.

Thank you for all your advice

@rene4406 posted:

Thank you very much for the link, I think it will help me a lot.

I found a first "leak" of depression, the PCV ME Wagner valve which I haven't adjusted yet since it needs a stable idle, I plugged it and it's going a little bit better.
I'm going to check the power valve because in addition to the backfire there are explosions in the exhaust and flames that come out when I keep the engine speed a little high, not when I release the accelerator but while I hold it a little open.

Thank you for all your advice

Yes, the pcv system uses 3-4 inches of vacuum to make it work. I think that you need to hook up a vacuum gauge to help diagnostics.

My vacuum gauge was destroyed by a backfire, I ordered another one.

If you have fire, explosion & flames, it’s not a carburetor problem….

…or a mild vacuum leak!

Especially if it’s coming out the exhaust…

Good luck, have you checked the roll pin in your distributor?

Rocky

as Rocky, if the firing order is OK and if there are flames in the exhaust, I will rather opt  for a lack of advance.

I rechecked the firing order and the connection of the spark plug wires, everything is OK.
It is true that the engine runs better when the vacuum advance is connected and therefore there is more advance.
It seems to me that a really too rich mixture can also cause explosions at the exit of the exhaust when the overflow of gasoline which could not burn in the cylinders comes into contact with the outside air.

Thanks again for all your advice.

@dipascale posted:

as Rocky, if the firing order is OK and if there are flames in the exhaust, I will rather opt  for a lack of advance.

... OR an exhaust valve or valves not seating. What type of camshaft is installed in the engine? Is it a solid lifter or hydraulic lifter?

302 Fords have a history of spark plug wires #7 and # 8 cross firing to the extent that the Ford Engine Assembly Manual shows that they must be separated in the wiring loom on the valve cover. Other Ford engines are not immune from that issue as well.

A problem with the distributor cap such as a crack or the wrong rotor is not out of the question also.

Cam Bullet Racing "GeorgesP" spec, hydraulic roller tappets tuned with very little play, almost like solids.

@rene4406 posted:

Cam Bullet Racing "GeorgesP" spec, hydraulic roller tappets tuned with very little play, almost like solids.

Are you SURE that the valves are closing COMPLETELY? Incorrect valve adjustments are one of the things I would be looking at.

I always prefered solids where I could measure the clearances with a feeler gauge rather then ATTEMPTING to pre-load hydraulic lifters correctly. I always had difficulty with "high performance" hydraulic lifters. They are always a "bear" for me to get right.

I checked the powervalve "by mouth" and it is not destroyed, probably because my carburettor has a protective valve.
I closed the secondary a little so that the progression slot looks like a square.

I increased the lead.

The engine only starts by screwing the idle screw on the primary hands almost fully, when it is running I can loosen the screw up to 1400/1500 rpm, below there is backfire and the engine stalls.

At 1500 revs it takes 36° in advance with the depression connected, backfire below and the engine stalls

The depression is 16 inches, which seems like a lot to me with a cam that has a 285° intake

The engine accelerates slightly when I remove the vacuum gauge and therefore create an additional air intake.

You are kind of isolating this to the carburetor. From your latest post, the carburetor idle circuit is not operating at all.

Is this a new carb or used one being re-applied?

You might want to message Drew Pojedinec on Facebook.

afscarbs.com Web page.

airfuelspart on facebook.

He is one of the most knowledgeable and helpful people that I know of on Holley carburetors. He has mentioned previously that he has brand new Holley carburetors that have had internal problems and incomplete machining and assembly procedures too common to be called rare.

For the moment, try another carburetor.

It is a brand new carburetor.

I have another one that was running when I ran the engine outside the car, a Holley 4160 600 CFM with vacuum primaries, if the same backfires occur I will blow the membrane and gas supply is different as well as the accelerator cable. I'll see if I can adapt it easily.

Recently I had a defective new ngk spark plug, without really believing it, maybe changing the 8 spark plugs. Yes, for me too the depression value of 16 in seems high to me but you measured it at 1500 rpm and not at 800-1000 rpm for your information, with a bullet cam with 226°int and 234°exh @ .050 and a 58° crossover I only have 11-12 of vacuum at 900 rpm. If the engine accelerates with an additional air intake, it is too rich.

@rene4406 posted:

It is a brand new carburetor.

I have another one that was running when I ran the engine outside the car, a Holley 4160 600 CFM with vacuum primaries, if the same backfires occur I will blow the membrane and gas supply is different as well as the accelerator cable. I'll see if I can adapt it easily.

Just get it on the engine. Worry about the details later. If it runs with no problems and will idle then the only component defective has to be the new carburetor. If it is new, it has a warranty on it.

Hopefully you can return it locally and not from someone like Summit and need to deal with shipping and Customs again.

In a way, I hope that it is the carb, so that you stop pulling everything else apart.

Again, a generic 3310 is probably what you want. Originally it was a Chevy Z28 carb but is used in many generic forms now.

Rocky's 4609 is actually a version of the 3310. The original application for it was a '69 Ford 428. It was intended to have good street manners and reasonable fuel economy (for a 7L).  Rocky it is worth a few dollars stock to the Mustang group. I wouldn't go drilling on it any more if I were you.

I've run that set up before and frankly don't know why you drilled the throttle plates. That's a modification for a "radical cam" to get it to idle the engine on a street driven car?

The Pantera throttle adapter will work on many old and current Holley throttle levers. It is not rocket science to adapt them.

The 3310 is a 780cfm, vacuum secondary. Originally was a manual choke on the Chevy but is easily converted to an automatic one and it is the "old" type of idle screw adjustment. Not a newer type reverse idle screw adjustment.

There is also a Ford version of that carb on the 69-70 Boss 302 so neither one is too big for a 5.7L.

It is not a terrible idea to get everything running on an 1850. It is a little small and will lack upper mid range and high rpm power but it will be very responsive up to about 4500 rpm or so and is on the lean side so it is good for running in the engine and not worrying about the piston rings not sealing because of too much fuel.

I would actually expect George's cam to produce 16-17 inches of vacuum at idle. That was part of the intention of his design.

I get almost 14 with my Webers on an individual runner manifold and a .606" lift, 244 @.050 so 11-12 means there is a leak in the system somewhere OR the ignition system does not have enough initial advance.

The Boss 302 from the factory used 16 degrees initial advance so that is really a factory engineering admission that the Cleveland heads need some unique timing. That initial timing is really a separate factor from the camshaft timing. In my view any performance "Cleveland" head engine should use at least 14 degrees initial.

I hope some of this helps.

So trouble shooting 101 - you say the engine ran "outside" the car?  Did it run well?  If yes, then what did you change when it was then installed in the car?  These are really pretty simple devices.  Make sure everything is connected, all vacuum ports either plugged or connected and put the old carb that it ran with (assuming it ran well) back on and start it.  You do not need an accelerator cable - screw all of that.  Just hand prime and try to start it.  If you have changed a bunch of stuff since the time the motor was last run, then you have to go backward to see what may have affected this.  OBTW, the picture at the top of this tread certainly is not a new cab with all the black carbon buildup on it.  A base properly tuned 351C at idle should pull approximately 17.00 inches of mercury (vacuum).  The vacuum gauge needle should be rock solid - no fluctuations.   Depending upon what you read (once you get the thing even running) will tell you much more as to what else might not be right (timing, vacuum leaks, plugs, etc.).  A motor that is backfiring that much and flames out the exhaust sounds like either a massive fuel leak from the top end or a stuck value that is causing major running issues.

Perhaps you can walk us through the progression of the motor and how it ran outside the car and then the installation and what changed.  

Here to help if we can.

Pat -

Agree with you, and the suggestions to just pop the old carb on and run it. Rene can fill the bowls through the air vent with a squirt bottle.

Thats my carb in the picture, not Rene’s.

Rocky

The only element that has changed since he was outside the car for a few minutes is the carburettor and that's why I was interested in him from the start. There is also that it now has to drive the gearbox in neutral but without the wheels and there is the full exhaust.
The engine started easily and ran not too badly, in any case much better than now but only a few tens of seconds because there was no cooling, only the full water and the closed circuit swirl tank overflowed quickly. I still managed to set the initial advance to 10°.

There was no backfire.

Since then it has remained a year and a half without turning, the valves are made of stainless steel but could the cast iron seats rust and no longer be watertight?

The new carburettor is all black and full of soot from backfires.

I have to unscrew the 4 idle mixture screws by about 1.5/2 turns and screw the idle speed screw all the way in for it to start, once started I can unscrew the idle speed screw and it runs better when I close the idle mixture screws almost full wealth. If before trying to start I open the primaries just once to get a slight squirt from the accelerator pump, I'm sure to have a backfire on the first turn of the starter.

I also thought about changing the spark plugs and I'm going to check the clearance between the rocker arms and the valves before temporarily fitting the old carb.

The valves and seats will be fine after sitting. I doubt that there is any problem there.

This likely is all just a bad carburetor. Get the engine running and hooked up on the 4150/4160.  Then work on the new carb.

You do realize that you must set the fuel level on the new carb? The factory procedure puts the level too high and will flow out of the sight plugs as delivered new. That is better with gasolene not containing Ethanol. Here we generally have 10% Ethanol in the gas and it tends to expand the fuel level. At that factory set level, the carburetor will flood the engine.

You want the level just under the sight plug hole. I use an electric fuel pump to provide the pressure with the engine off/ Also you do not want more then 5 psi pressure.

The Pantera should also use an angled spacer under the carb. I think it is 12°? In US built cars the engines were installed in that era on an angle. The intake maniolds were angle cut under the carb to make it sit level.

The drive train in the Pantera unlike the US cars is installed level, so you need to compensate with the angled spacer under the carb to make the carb sit level. I mention that here because that does effect the fuel level adjustment in the fuel bowls.

Thank you Doug and Patt for the information of vacuum value 16-17 in, on my side I will recheck the advance and a possible air intake because on my new Holley 4150 (0-4779), I had problems when opening the secondary, I had backfires in the carburettor, the needle under the secondary nozzle was glued (storage too long?) and the gasoline did not come out or little from the nozzle, I may be damaged the pcv valve or other, I will recheck all that.

Thank you for all these leads.

I have a BlueThunder "Pantera" manifold and so the carburetor is horizontal. There is a half inch spacer.

I set the fuel pressure to 6 PSI and checked to make sure the fuel wasn't overflowing through the level hole. As I write this I realize that I only checked one side, I'm going to check the other.

I find it hard to imagine that the carburetor is the only one responsible for the countless backfires.
I modified the advance 10 times in both directions and it doesn't change much.
I will measure the compression, if a valve is no longer tight I will detect it easily.

If everything is good, all I will have to do is try with the old carburetor.

I purchased this carburetor along with several other parts from an Australian supplier. For certain parts he clearly told me that they were Chinese equipment, not for the carburetor which he assured me was indeed a Holley. Have you heard of Chinese copies?

@rene4406 posted:

Thank you for all these leads.

I have a BlueThunder "Pantera" manifold and so the carburetor is horizontal. There is a half inch spacer.

I set the fuel pressure to 6 PSI and checked to make sure the fuel wasn't overflowing through the level hole. As I write this I realize that I only checked one side, I'm going to check the other.

I find it hard to imagine that the carburetor is the only one responsible for the countless backfires.
I modified the advance 10 times in both directions and it doesn't change much.
I will measure the compression, if a valve is no longer tight I will detect it easily.

If everything is good, all I will have to do is try with the old carburetor.

I purchased this carburetor along with several other parts from an Australian supplier. For certain parts he clearly told me that they were Chinese equipment, not for the carburetor which he assured me was indeed a Holley. Have you heard of Chinese copies?

I have not heard of Chinese Holley copies. I have been told that there have been issues with Holley reproductions of specific "historical carburetors". I HAVE had issues with new needle and seat assemblies. Exactly where they are made is not indicated even in Holley bubble wrapped packages.

I believe the issues are with the emulsion tubes either missing, incomplete or not correctly installed. Those are under the brass plugs in the main body and not normally customer accessible.  YOU should leave them alone. That is a rare occurrence but it has happened enough to notice it.

It was also said that there have been issues with the idle transfer slots on one or two that would effect the idle of the carb. My Holley specialist recommendation was not to send the carb to him for investigation but to return it to Holley under the warranty.

I personally have had the biggest issues with the Viton inlet needle and seats. Sometimes the brass floats colapsing.

The needle and seat seems to have an issue with the Ethanol in the fuel and tend to stick CLOSED after sitting for too long a period of time. What is that amount of time? It is not specific but could happen as soon as two weeks as the fuel in the bowls evaporates.

I have had issues with the old brass type floats and change those to the newer Nitrofil black plastic floats in the carbs that I use.

What will happen with a Holley if the inlet valve sticks closed or you loose fuel flow to the carb, if it is over a certain throttle opening like in WIDE OPEN THROTTLE, the engine will backfire violently. It is powerful enough to blow a hole in a cast piston and possibly even on a forged piston, break what we refer to as the upper piston ring lands, i.e., the small amount of piston just above the top ring.

So most of these Holley issues are now seen by engines that sit dormant after having been run, carbs that have sat new for too long in the box generally in a warehouse where temps run well over 100°F and floats that have not been re-adjusted at first new installation time. Also, heed the caution not to use more then 5 psi at anytime.

Rene: in the US we often see those temperatures in warehouses in the southwest US in the summer. Texas, Arizona, Nevada and even southern California desert areas. Those areas have many storage facilities because of the low tax rates. I can personally verify that temperatures within those warehouses often go to 135°F. Some of the components of items stored there under those conditions are vulnerable to heat exposure.

I've had items come out of there that have "peel off stickers or decals" installed by the factory that now are baked on because of the excessive heat. Australia has become an area where excessive heat occurs regularly as well. So just mentioning these factors in order to give a greater understanding of the variables and to point out that consumers can not assume that because an item is 100% new, it is 100% perfect. This is all part of the new world that we all live in and we all need to be educated and informed consumers now.

Probably the "best solution" with a Holley is to have a spare that is known by you to be good when you used it. That you will need to compare the carb in question to while the engine is running.

If it is dry, i.e., no fuel in it, turn it upside down and listen for the floats, both of them to drop. You WILL hear them and that is enough to ensure that the inlet valves are working. They will not need to be re-adjusted. You can leave the floats alone.

Someone mentioned Weber carbs. Usually on a V8 engine that is referring to a 48 IDA. I have quite a bit of experience with them and actually find them to be much easier and very dependable to deal with verses the Holley carbs.

The issue with them is that people attempt to apply their Holley knowledge to them and they are just a different train of engineering thought and the two trains of thought often do not match.

It's not working yet but I'm making progress.

I measured the compression, everything is OK, between 12 and 12.5 bars on all cylinders. So no problem with valve clearance or sealing.

I installed my old carburetor, it runs a little better, I was able to lower the idle speed to 1100 rpm BUT there are still backfires.

I carefully observed the advance point with a brand new strobe lamp that I just bought, mine was 35 years old and starting to get tired, and I noticed instability and especially flashes corresponding to the spark other cylinders. The explanation for the backfire surely comes from there and moreover the wiring of the ignition box (Pertronix 510) is part of what has changed since the tests outside the car since it is now the definitive wiring.

So I have to look at the ignition side and to begin with could you confirm that my igniter (Chinese replica) is indeed a Magnetic Trigger type

Yes, magnetic sensor, you must have a resistance generally between 300 and 1000 Ohm between the 2 wires of the blue sensor. if I may, I would not have put a Chinese distributor on an engine prepared like yours.

I don't know which stroboscopic lamp you just bought but you have to take quality lamps otherwise you risk having difficulty measuring or instability.

I don't remember reading it but are you sure that the ring on the balancer hasn't rotated? Mis-timed engine could explain much.

The 4v 351-c balancer is notorious for it.

You could try advancing the distributor until the engine smooths out. You could be running now up to something like 45° retarded. Having the outer ring rotated out of sync won't imbalance the engine significantly. The counter balance is on the inner hub. The balancer could have rotated since the time you ran the engine on the stand and the time you started it in the car.

Those things are just "glued on" and with age the glue dries up and fails. If the glue has dried up just the inertia of the engine starting up can shift the ring. Then you would be timing the engine to the wrong spot even though the markings would indicate they are correct.

It sounds like the motor is 180 degrees out.   Further, that is not a Pertronix ignitor.  Not sure what it is.....

That looks like a magnetic pickup for a Duraspark.

John

The damper is new but I still checked against another TDC mark that I made very precisely between the flywheel and the clutch bell when I assembled the engine, nothing has moved.

The ignitor was sold to me as a Chinese copy of a Duraspark by the same Australian who sold me the carburetor, according to him they are well built..... I will measure the resistance of the solenoid.

My strobe light is an Equus 590-51:

https://www.getgoods.com/at-en...a18dd52cb4cde350a915

It was very stable when I used it the first time, the phase shift displayed corresponded exactly to the graduations on the damper. Now it's unstable, so car ignition system or strobe light??? Tomorrow I will try it with another car where I am sure the ignition works correctly.

It seems that if I had shifted the ignition by 180° the engine would not work at all?

I don't know what is going on with it either. I am stumped also.

Did you verify that the roll pin holding the distributor drive gear is not damaged?

Agree that if 180 degrees out it will not run at all.

It's new and I put two inside each other, but it's a possibility.

I haven't replaced the spark plug wires, I may do so, what do you recommend? Rubber? Silicon? What diameter?

Rene, maybe the connection of the pertronix box in the car, I think for example who should not connect the original blue/black wire which goes from the coil to the rev counter.

@dipascale posted:

Rene, maybe the connection of the pertronix box in the car, I think for example who should not connect the original blue/black wire which goes from the coil to the rev counter.

The blue wire from the rev counter is connected to a specific wire on the box, in fact it doesn't work but I'll see about that later.

I will try with the old point distributor since the Pertronix 510 box can work with it, so I will check if the new Chinese distributor is responsible or not; moreover I will be able to adjust the advance easily at the stop without needing the stroboscopic lamp.

I don't know the Pertronix but on an MSD box we need an adapter for the rev counter and I don't know if this is the case on the Pertronix, in doubt, I will disconnect the blue wire from the rev counter.

There are several possible wiring of the tachometer with the Pertronix but I will fix this problem when the engine is running properly.

@rene4406 posted:

It's new and I put two inside each other, but it's a possibility.

There isn't much left to examine.

There are only a few things that will affect the firing of the ignition. You have already looked at most. The distributor cam gear is left to examine.

With all camshaft manufacturers there is always the possibility that the camshaft itself was not indexed  properly before it was ground. I have had issues with aftermarket camshafts.

In my case it was Compcams and that simply had to do with insufficient "quality control" in setting up the camshaft blank before it was ground and the company only spot checking one out of three finished camshafts before shipping them.

With a custom grind, theoretically the procedure is different and it is all set up and indexed by a technician.  We just don't know the procedure Bullet cams would use to actually grind the lobs though.

It might be better to set it into a program and let the computer run the machine through a CNC procedure or that might have pitfalls as well.

To find an error in the ground profile at this point though would mean "indexing the cam", which is an SOB if you ask me, but I begrudgingly agree that it is necessary to verify the cam is "right on".

I calibrated the cam with a graduated disk and a dial gauge on the pushers to determine the maximum lift. I really have very few doubts on this point.

I'm going to focus on the ignition.

I tried with the old point igniter, no big improvement, always backfiring so it's not the igniter. On the other hand, with the old carburetor, the engine reacts to the adjustment of the mixture screws.

I checked my strobe light on another car and it works perfectly. On the Pantera, instability manifests itself when there are misfires, which is normal. So all that remains is the ignition box, new but......., the spark plug wires and the spark plugs. I'm going to change the spark plugs and spark plug wires and if that still doesn't work there will only be the ignition box left.

Still to confirm:

Distributor cam gear slipped

Distributor cap bad , rotor bad

95% of carburetor problems are ignition related.

@panterapatt posted:

Still to confirm:

Distributor cam gear slipped

Distributor cap bad , rotor bad

Changing distributor would have solved the problem

@rene4406 posted:

Changing distributor would have solved the problem

The translation is not clear. Is the problem fixed with changing the distributor?

@panteradoug posted:

The translation is not clear. Is the problem fixed with changing the distributor?

No!

I wrote previously that replacing the distributor did not fix the problem and as the gear and the cap are part of the distributor I wrote that replacing it would have fix the problem if it had been the one or the other.

Sometimes here we get blind to the actual problem. Often we can have a friend come and look for what they see the issue is. Fresh eyes can help.

@panteradoug posted:

Sometimes here we get blind to the actual problem. Often we can have a friend come and look for what they see the issue is. Fresh eyes can help.

You are right but I don't have a friend close to me with good mechanical knowledge.

I put in new spark plugs and activated the "multispark" function of the Pertronix box, there is an improvement, there are fewer misfires but there are still backfires and explosions. in the exhaust.
Among the old spark plugs there were some that looked almost okay and others that were very black and when I plug my strobe light into different spark plug wires, some are much less stable than others.
I am now almost certain that the ignition is the fault and I will order a new spark plug wire harness and igniter cap. My current spark plug wires may not be suitable for a "high performance" ignition like the Pertronix. I half believe it but I don't see what else to change apart from the box itself.

I can ONLY react to what POSSIBLY might be causing the misfiring and when you get to the point that ALL ELSE has been eliminated, then I will suggest again that the camshaft is the issue, being ground with the wrong firing order like a 1960's 289-302 firing order.

You would have to have degreed EVERY cylinder in order to discover that. Normally no one does that, just degrees in #1.

More and more it indicates TO ME that the camshaft itself was ground with the wrong firing order AND THAT THE IGNITION IS FIRING CORRECTLY.

IF THAT IS SO, you are not getting "backfires", you are hearing the spark plugs fire while the valves are still open. That is why some have suggested that the distributor is installed 180° out of phase. It certainly CAN be the answer.

I have a "friend" who is now retired but once sold aftermarket Ford racing parts and complete engines.

He once sold a 427 Ford engine to someone who had the distributor installed "backwards" or more correctly described as 180° out of phase. He had to accept the engine in return because he was accused of selling a "defective" engine.

The fact of the matter is that SOME engines are capable of running that way , on 4 cylinders, while most are not. I do not know if a 351C is or not. I never had to find that out.

I DO NOT like that answer either BUT just as Shelock Holes once said, "when all other possibilities are eliminated, what remains must be the answer".

You have already done so many things I can't keep up with what has been done and what has not.

You can actually test the theory that of the distributor being out of phase by 180° by changing the rotor in the distributor.

Ford rotors are made in two ways. One with the locking tab on the rotor pointer side, the other opposite the pointer. Whichever rotor you have now, find one with the opposite orientation, install it and see if the engine fires correctly then.

It can not hurt at this point.

Since it appears to me that I am not contributing to this discussion positively at this point, I will now retire from commenting in it at all and just wish and hope for the best.

All the ideas are good in principle and I study them all.

But do you think the engine could run at 1100 rpm with little misfire, even if there is some, with a cam or an offset igniter?

I can check the camshaft and the correct orientation of the distributor by removing the cylinder head covers and watching that the valves open and close at the correct time relative to the position of the distributor finger. I could also just offset the spark plug wires in the igniter head.

Before, I might reassemble the old breaker ignition system, without the Pertronix box, I just need to redo some temporary wiring to connect the ballast.

Thanks for your help

@rene4406 posted:

All the ideas are good in principle and I study them all.

But do you think the engine could run at 1100 rpm with little misfire, even if there is some, with a cam or an offset igniter?

I can check the camshaft and the correct orientation of the distributor by removing the cylinder head covers and watching that the valves open and close at the correct time relative to the position of the distributor finger. I could also just offset the spark plug wires in the igniter head.

Before, I might reassemble the old breaker ignition system, without the Pertronix box, I just need to redo some temporary wiring to connect the ballast.

Thanks for your help

I know I said I will stay out of it but since your reply was so quick I will answer.

If the camshaft is ground with the wrong firing order, you can not adjust for that.

The valve opening timing is to the piston travel position. If the cam is wrong then there should be some concern for valves hitting the pistons and as a result some being bent.

I don't have a camshaft calculator program to graph the position the valves would be in if the cam is mis-ground but if it is wrong then I'm thinking that only the valves in two cylinders would be wrong and it makes it more likely that your engine can run on only six cylinders.

At this point I would not place a large bet on that scenario but long shots do come in. $20 on a 100 to 1 is a nice prize.

Compression on all cylinders is good, so I'm sure none of the valves are bent but that doesn't completely rule out a camshaft fault. For example, there may be an error of 180° on the cam (360° on the crankshaft) for one or more cylinders, the valves do not touch the pistons but the spark occurs at the wrong time. It's not totally impossible.

@rene4406 posted:

Compression on all cylinders is good, so I'm sure none of the valves are bent but that doesn't completely rule out a camshaft fault. For example, there may be an error of 180° on the cam (360° on the crankshaft) for one or more cylinders, the valves do not touch the pistons but the spark occurs at the wrong time. It's not totally impossible.

The likeliness or the percentage of probability is growing steadily in that direction.

Degreeing the cam presumes that all of the lobes for all of the cylinders are in proper relationship to each other. It does not provide for one or more lobes being ground out of sync with the others.

The only way I can see to confirm the likeliness of that scenario is to install another camshaft. Can we make this any more difficult?

I had an issue with a new camshaft here. It was replaced as a "courtesy" to me. It was missing a part of one of the distributor gear drive teeth. It was not acknowledged by the manufacturer as a warranty defect. It was brand new in the box.

Here in the US the situation on "legal damages" I found to be frustrating at least.

IF for instance a "painter" charges you $20 to paint your front door white but it turns out pink and you hire a new painter to paint it white but he charges you $100, the original painter is only liable for the $20 he charged you.

So by the same token, if you paid Bullet cams $400 for the cam, it destroys your engine and it costs you $10,000 to replace it, in a US court Bullet AT MOST would be liable for the $400.

It isn't me, that's as we say here "that's the law".

I am purely speculating on this but I'd guess that the cam physically fits a 351c but I think they ground the lobes on the 289 firing order? Did I say that before? Well, it's worth repeating.

This is all bumming me out also. I am going to wind up arguing with the Referee and getting thrown out of the game. I just hope I don't hit him and they call the Police and arrest me?

Just thinking on how to troubleshoot… “If the cam is ground for a 351C or 289…”

it would seem to me, you could just manually turn the engine over, and watch the valves.

At TDC for each cylinder (which you could monitor via distributor position) both the intake and exhaust will be closed (valves all the way up).

351C’s firing order is 1-3-7-2-6-5-4-8

Ford 289 engine is 1-5-4-2-6-3-7-8

You might not notice this if you were doing your compression checks just based on spring position.

Anyway, the difference ought to show up within about a rotation or two of the crankshaft.  Seems like a pretty easy check that you may have already completed.

It certainly would be good to confirm before camshaft removal.

Good luck

Rocky

And all that is needed to change from one firing order to the other is to change the location of 4 plug wires

You are a smart man, Forest!

@rene4406 posted:

All the ideas are good in principle and I study them all.

But do you think the engine could run at 1100 rpm with little misfire, even if there is some, with a cam or an offset igniter?

I can check the camshaft and the correct orientation of the distributor by removing the cylinder head covers and watching that the valves open and close at the correct time relative to the position of the distributor finger. I could also just offset the spark plug wires in the igniter head.

Before, I might reassemble the old breaker ignition system, without the Pertronix box, I just need to redo some temporary wiring to connect the ballast.

Thanks for your he

lp

I don't want to offend anyone and especially not those who are trying to help me but it is obvious that it is not necessary to replace the cam with another to check it and that you just have to observe the valves open and close for two revolutions of the crankshaft. This is actually what I considered in my post above.

Today I'm going to install the whole old original point, capacitor and coil ignition system that worked well when I bought the car almost 6 years ago.

I doubt that anyone would be offended here. I'm not. It is obvious that you are not a novice at this but it appears that something out of the ordinary is occurring and we are just adding wine and beer to the festival. None of it will go to waste even though there was already plenty on hand.

It is only speculation on my part that if the cam was mis-ground to another firing order that it would be more likely that it would be to something similar in the same family like another Ford, rather then say a BMW.

Could it be as simple as the cam dowl being installed 180° wrong? That would really be far fetched?

I'm not sure if Occam's Razor applies here?

Incidentally, the reason that Ford changed the 289 to the 351 firing order was really a strange one in that very late in the 289-302's history the engine began to experience crankshaft failures. Failures in that the crankshaft would break in two.

There experimentally, their solution would be to change the crankshaft loading by changing the firing order without attempting to "redesign the wheel", so to speak. So even if this is the cause of the trouble here, and the engine runs on the 289 firing order, it would not be advisable to run it extensively with that.

Additionally, even if this is the issue, I would expect Bullet Cams to react to this with something like "YOU are full of 'do-do", WE don't make mistakes like that. It must be YOU who is mistaken", and why not? To admit a mistake like that to me would make them "totally disqualified".

Long shots do come in. I have never bet on them before the fact, only acknowledged them too late!

Almost Eureca, almost Victory

With the old ignition system, the engine runs well on all 8 cylinders! There are still some backfires at startup and if I want to reduce the idle too much, below 1100 rpm, it messes up, then a big backfire and it stalls but with a cam that has 60° crossover and vacuum advance which no longer works (the old membrane of the old igniter is pierced), this is perhaps normal. The spark plugs, even the new ones, worked with poor ignition and some may already be more or less out of service, I will order a new set.

So either the Pertronix box is malfunctioning, or the spark plug wires are not suitable for too powerful ignition and create crossfires. I'm going to start with a new spark plug wire harness, I'm thinking of buying these:
https://www.summitracing.com/parts/pnx-808280
because I can buy them from a seller in France.

And if it still malfunctions I will just have to change the box wich is brand new but as I bought it almost 5 years ago, there is no point in hoping to have it changed under warranty.

@rene4406 posted:

Almost Eureca, almost Victory

With the old ignition system, the engine runs well on all 8 cylinders! There are still some backfires at startup and if I want to reduce the idle too much, below 1100 rpm, it messes up, then a big backfire and it stalls but with a cam that has 60° crossover and vacuum advance which no longer works (the old membrane of the old igniter is pierced), this is perhaps normal. The spark plugs, even the new ones, worked with poor ignition and some may already be more or less out of service, I will order a new set.

So either the Pertronix box is malfunctioning, or the spark plug wires are not suitable for too powerful ignition and create crossfires. I'm going to start with a new spark plug wire harness, I'm thinking of buying these:
https://www.summitracing.com/parts/pnx-808280
because I can buy them from a seller in France.

And if it still malfunctions I will just have to change the box wich is brand new but as I bought it almost 5 years ago, there is no point in hoping to have it changed under warranty.

Fords have always had a susceptibility to cross firing through the spark plug wires. It isn't normally this radical though.

For instance, the Ford shop manual on the '68 302s shows that you must keep spark plug wire #7 and #8 at opposite ends of the loom on the valve cover.

That is with the '60s versions of the spark plug wire materials though. The current thick 7, 8 and 9mm silicone covered wires should not have those issues.

A few thoughts from 10,000 miles away, Rene-

1- Bullet Cams is one of the easiest, most willing-to-work-with-you companies in the whole aftermarket world. Call them and ask for the owner Mike Jones. Be sure they realize this is an overseas call-

Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
(704)489-2449

2- have you checked the cam chain? I've seen them worn out on a 351-C in 20,000 miles and a severe cam retard can cause odd issues

3- with incorrect cam possibilities, there are reverse-rotation cams made for dual engined boats, cams ground with GM's so-called '4-7 cylinder swap' that on a Ford V-8 is a 2-8 cylinder swap with corresponding ignition wires involved

4- The Pertronix box is the only electronic ignition I've ever found that can only partially fail but still run the engine.

Is the problem fixed?

I think so but I haven't been able to verify it yet.

I think the spark plug wire harness creates cross fires and/or misfires especially with modern high voltage an high energy ignition. I spotted a damaged and "burnt" spot on the wire that connects the coil to the igniter.

I bought a new harness but I haven't had time to fit it yet and I have to bring the car back to my bodybuilder on Monday to redo the paint he missed the first time.

I will only be able to check when I have the car again in a month.........or more.

A simple but revealing test is to fire up the engine with the engine cover up or open, in a dark garage with the lights off. If you have crossfires or other high-voltage leaks, it wil look like a fireworks display around the engine wiring. Sometimes you need a second person to watch while you put the engine under load by putting it in gear and slipping the clutch for just a few seconds. Mark the 'hot' areas and fix as required the next morning.

@bosswrench posted:

A simple but revealing test is to fire up the engine with the engine cover up or open, in a dark garage with the lights off. If you have crossfires or other high-voltage leaks, it wil look like a fireworks display around the engine wiring. Sometimes you need a second person to watch while you put the engine under load by putting it in gear and slipping the clutch for just a few seconds. Mark the 'hot' areas and fix as required the next morning.

This has always been the fast way to check the wires but caution, if you have Webers with open stacks, firing the engine up in the dark will either char you for life or terrify you about driving the car.

The Weber light show in the dark is better then the aurora boriallis.

Be careful on who you invite to see this. There might be someone in the group who will turn you in to the secret police as a threat to society for running Weber carbs.

I had a similar problem. My car suddenly didn't want to start anymore.

After some searching I found out that i didn't have 12V at the coil (Petronix Ignitor 3 with Flamethrower 3 coil). After fixing that the engine still didn't run but backfired. The engine itself was fine with good compression.

After several months and a lot of ideas that were all wrong (including changing the Ignitor module, plug wires, cap, rotor, plugs...), I finally decided to get rid of the pertronix completely and changed to a used Mallory Distributor a friend had lying around. Car started immediately and runs without issues.

Last time I ever use Pertronix.

Funny sidenote: with the pertronix my tach never worked properly, despite using adapter boxes etc., with the mallory it works fine.

@GeorgS posted:

I had a similar problem. My car suddenly didn't want to start anymore.

After some searching I found out that i didn't have 12V at the coil (Petronix Ignitor 3 with Flamethrower 3 coil). After fixing that the engine still didn't run but backfired. The engine itself was fine with good compression.

After several months and a lot of ideas that were all wrong (including changing the Ignitor module, plug wires, cap, rotor, plugs...), I finally decided to get rid of the pertronix completely and changed to a used Mallory Distributor a friend had lying around. Car started immediately and runs without issues.

Last time I ever use Pertronix.

Funny sidenote: with the pertronix my tach never worked properly, despite using adapter boxes etc., with the mallory it works fine.

I suppose that it has to be acknowledged that not everyone who posts or asks questions or for help here are not very versed, but for quite some time the lack of dependability of MSD ignition systems have generally been referred to as Might Suddenly Die.

At times this seems like talking to a 12 year old cautioned about setting off fireworks and constantly has them going off in their hands? I don't get that?

It is true that MSD company has been sold several times and may or may not increased their dependability level but the common knowledge of experienced "street rodders" is don't use them, they suck and you are going to get stuck on the road somewhere at some time. Period. End of story.

It is VERY COMMON for racers to replace the MSD cpu three or four times a racing season. They are no more dependable in street use.

There are better alternatives to them but you need more then casual knowledge to determine that.

Support MSD as you will but if it goes off in your hands it is gonna' hurt. That seems to be a need to know?

Interesting

The alternatives to Pertronix and MSD, is it Ford Duraspark? But there are fewer features, no rev limiter, no start retard and no multi-spark.

I went with ICE Ignition. Has worked well so far.

@rene4406 posted:

Interesting

The alternatives to Pertronix and MSD, is it Ford Duraspark? But there are fewer features, no rev limiter, no start retard and no multi-spark.

Pantera=Electronics has a nice one with the features you are looking for. It is designed for the Pantera.

https://www.pantera-electronics.com/eis.htm

"The alternatives to Pertronix and MSD, is it Ford Duraspark? But there are fewer features, no rev limiter, no start retard and no multi-spark."

Duraspark does have start retard, it's the white wire.

@panteradoug posted:

Pantera=Electronics has a nice one with the features you are looking for. It is designed for the Pantera.

https://www.pantera-electronics.com/eis.htm

If I have to replace my Pertronix, I will look at it with interest

@rene4406 posted:

If I have to replace my Pertronix, I will look at it with interest

You might want to inquire with Jon as to his stock on his ignition systems. He has been having difficulty obtaining components such as chips and some are sporadically out of stock with no know date for more?

I do not know if that situation has changed but the current on line listing would suggest items that are available.

@rene4406 posted:

Interesting

The alternatives to Pertronix and MSD, is it Ford Duraspark? But there are fewer features, no rev limiter, no start retard and no multi-spark.

You can find articles/threads that the durapark has problems at higher RPMs, I have no experience with that myself.

@Panterdoug: i don't understand your reply about MSD issues to my Pertronix problems. I assume you refer to Mallory belongs to MSD. The Distributor I have is an older system, pre-MSD.

@GeorgS posted:

You can find articles/threads that the durapark has problems at higher RPMs, I have no experience with that myself.

@Panterdoug: i don't understand your reply about MSD issues to my Pertronix problems. I assume you refer to Mallory belongs to MSD. The Distributor I have is an older system, pre-MSD.

I apologise for creating confusion. I was referring to the MSD. Not the Petronix. It was just a suggestion from me that if a person was going to look for another system from what they had, consider the reported MSD failure rates,

I have used Petronix in another vehicle and no longer do. I actually went back to an original dual point distributor for that car. I had no issues with the Petronix but for my application, it had limitations.

I have read reports though that some users of Petronixs were carrying new spare units with them. Whether that was for lack of faith in it's dependability or actual bad experiences with them, I personally can not say.

The Pantera, because of the location and lack of access to the distributor, has unique considerations, I have found the Motorcraft point-less distributor to be 100% dependable over a period of 40 plus years. The only issue that I had with it was integrating the Ford control box for it to the Pantera tachometer. That is a general PITA and I found that the Pantera-Electronics Ignition Controller device as a great simple and dependable solution. That I have been using since 2007.

I hope that this clears up the confusion that I created for you but if you have further questions for me, I will attempt to answer them with my experiences.

I found the cause of my problems!
A beginner's or senile person's mistake and since I'm not a beginner....it means I'm becoming senile!

I checked the firing order on the distributor head several times, I checked several times that the wires were correctly connected to the correct spark plugs BUT, I trusted my memory for the numbering of the cylinders and I was so sure of myself that I never checked even though it was very easy since the numbers are in 1/2'' digits on my intake manifold.
And I numbered:
4
                          5
3
                          6
2
                          7
1
                          8

instead of

4
                         8
3
                         7
2
                         6
1
                         5

And so the spark instead of occurring on cylinder 7 occurred on cylinder 6 which had the intake valve open and the same between cylinders 5 and 8 with the intake of cylinder 8 open.

What is surprising is that the cylinders on the driver's side cylinder bank still worked, certainly very poorly, but it was indeed burnt gases coming out of the exhaust.

I'm now impatiently waiting for my car to come back from the body shop to put everything back in order and check that it starts like clockwork and that there is no more backfire.

I still have little consolation, it allowed me to learn a little more about modern electronic ignitions and the precautions to take when wiring.

Hey, that is great news.  Live and learn!

Congratulations.

This has been an interesting thread!

I hope that you have truly found the smoking gun!

In New England we say ‘Dawn breaks on Marblehead’.
Long story.

@rene4406 posted:

I found the cause of my problems!
A beginner's or senile person's mistake and since I'm not a beginner....it means I'm becoming senile!

I checked the firing order on the distributor head several times, I checked several times that the wires were correctly connected to the correct spark plugs BUT, I trusted my memory for the numbering of the cylinders and I was so sure of myself that I never checked even though it was very easy since the numbers are in 1/2'' digits on my intake manifold.
And I numbered:
4
                          5
3
                          6
2
                          7
1
                          8

instead of

4
                         8
3
                         7
2
                         6
1
                         5

And so the spark instead of occurring on cylinder 7 occurred on cylinder 6 which had the intake valve open and the same between cylinders 5 and 8 with the intake of cylinder 8 open.

What is surprising is that the cylinders on the driver's side cylinder bank still worked, certainly very poorly, but it was indeed burnt gases coming out of the exhaust.

I'm now impatiently waiting for my car to come back from the body shop to put everything back in order and check that it starts like clockwork and that there is no more backfire.

I still have little consolation, it allowed me to learn a little more about modern electronic ignitions and the precautions to take when wiring.

If it were true that you learn by making mistakes, then by now I should be a genius. Join the club.

I picked up 4406 today from the body shop. I swapped the cables of spark plugs 5 and 8 then 6 and 7. With the old carburetor and the points ignition it starts like clockwork, no more backfire and a stable idle. It's surprising how much better it works when the spark plug wires are all plugged into the right place.

I put the new carburetor back in and it runs properly although it still needs to be adjusted.

Tomorrow I replace the breaker ignition with the Pertronix.

...You messed up again, in your Drawing!! The #1 Cylinder is ALWAYS the Most FORWARD to the FRONT, Cylinder! Congrats on finding your blunder.

MJ

P.S.   Cable #'s 5 and 6 should always be Fully Insulated From each other, as they fire One after the Other, and are Prone to 'Cross-Fire'!!

If you are installing a Pertronix ignitor module into your distributor, it must have a SWITCHED 12v source.  Do not connect it to anything but that.   And not a full time on 12V source.  

@marlinjacka posté :

...Tu as encore raté ton dessin !! Le cylindre n°1 est TOUJOURS le plus EN AVANT vers l’AVANT, cylindre ! Félicitations pour avoir trouvé votre erreur.

MJ

Les câbles PS n° 5 et 6 doivent toujours être entièrement isolés l'un de l'autre, car ils tirent l'un après l'autre et sont sujets aux « tirs croisés » !!

It was on the right bank that I made a mistake by numbering the cylinder closest to me #8 instead of 5 then 7 instead of 6, 6 instead of 7 and finally 5 instead of 8. A true beginner's mistake.

@panterapatt posted:

If you are installing a Pertronix ignitor module into your distributor, it must have a SWITCHED 12v source.  Do not connect it to anything but that.   And not a full time on 12V source.  

I reinstalled the Pertronix ignition and the engine runs but much less well than with the points ignition, there are misfires.

It is not a module in the distributor but a complete box. It doesn't change anything about the switched +12V, I connected the electric choke to the same wire and it's an error because the box indicates an error code "switched 12V low". I am going to redo the wiring with a large section wire dedicated to the switched + 12V of the Pertronix box and another for the choke.
The two wires which transmit the signal from the igniter to the box run parallel to the high voltage wire between the coil and the distributor, I think this is also an error and I will modify the routing and put twisted wires between the igniter and the box .
I will also replace the old copper spark plug wires with "Pertronix" wires and route them neatly on supports, at the moment they are not fixed and there may be cross fires.

When everything is done properly I think it will go much better.

New Pertronix spark plug wires installed on brackets:

The engine ran fine with the points igniter and old spark plug wires, but poorly with the Pertronix ignition and old wires. It works great with the new helically wound conductor wires. Pertronix should clarify that its system is not intended to work with solid core wires.