#1493 motor update

Suggest you run it for a while, make sure it has good brakes and the car is sorted out before you tear into the motor.

Even in Europe, isn't it difficult to find places for sustained speeds of 130+?

Rocky

Hi Rocky, the car seems to be very well sorted out and handling felt great when I test drove it.
It has Pantera East Wilwood brakes, Pantera East height adjustable Koni's, 17" wheels, Centerforce clutch, Pantera Performance aluminum radiator, Ansa GTS headers and exhaust...so should be ready to be driven .
There are various spots to drive over 200Kmh (120+Mph) legally, so would not like to be the one left behind...would be nice to know that engine is up to it!

I think it is unlikely that you have .846 fifth gear ratio. That is also the ratio of fourth gear.

From what is written in the book it would be following:
/1 gearing: 2.42, 1.47, 1.09, .96, .846; 4.22 final ratio
/2 gearing: 2.23, 1.47, 1.04, .846, .705; 4.22 final ratio

Does someone know if this is correct?

quote:

if I am correct , my /1 ZF would have .846 fifth gear

Yours should have the .705 fifth gear ratio. My #1490 has it. There is a placard attached to the side of the ZF that shows the ratios. The earlier 71's had the .846 fifth gear. Your build date should be 5/71.

The "'72 in the papers" probably means that your car was first registered in '72.

John

Note the -1 stamped in the placard.

John

Hi John, perfect, thanks for this info!
So, our cars were just #3 apart!
Can not check the placard as the car is in the shipping container; would you mind letting me know what are the other ratios on your gearbox?

Oh, thanks, just seen the photo with all the ratios!
Cheers

Would really appreciate if someone could comment on the potential longevity of 351C as per specs from the first post...would really like to know if I could plan some longer trips or would be better to change to hydraulic lifters.
As well, what would be expected power; I know it might be hard to say without the cam spec?

A custom grind camshaft will have an ID number stamped or ground into the face of the front bearing lobe.

You need to strip the engine down to see it though.

Personally I am not a fan of "roller camshafts". They carry a lot of additional weight, i.e., rotating mass and the only way to deal with that is with increased valve spring pressures.

I personally would prefer a lighter and less complicated (less parts) to the lifter assemblies.

A lot of people have just good things to say about hydraulic roller lifter camshafts.

If it was me and I was so unsure about the existing camshaft I would replace it with a solid lifter grind.

You already mentioned that your engine has lifter bushings installed. That usually is done for oil restriction to the valve train for engines that are intended to be run over 7,000rpm.

It is controversial for sure and I'm not looking to open that debate up again.

I don't know if you can run a hydraulic camshaft now because of the bushings.



The benefit to the roller cam, if all the specs are the same as a regular flat lifter cam, is that the lifter lobe ramp is steeper on the roller and opens the valve faster than a flat lifter camshaft can.

That gives the engine more "energy" and makes it feel peppier.

In the past roller lifter valve trains have had issues with longevity in street driven engines.
Durability has been vastly improved though since "Detroit" has gone to them in regular production vehicles.

Apparently some of that technology has trickled down enough to make aftermarket cams much more dependable.

One issue with aftermarket camshafts though is so many components are being made "offshore" for the cam companies that quality control, at least in my mind, can be a concern.

Sounds like you are using CHI heads which really have a great reputation.

I do know that some of the older "original Ford heads" needed to be machined for lifter assembly clearance.

That shouldn't be a matter to you though. Your engine is built and running.

My solution would be to change the cam to something I new.

The main concern on ANY CAMSHAFT now for LONGEVITY is going to be the spring pressures.

The higher the pressures, the shorter the life expectancy is going to be.

Again, you don't even know what the spring pressures are in your engine but with solid roller lifters they could be over 400 pounds open.

You are really relying on the quality of the spring with pressures that high.

I like to stay 350 or under. That is usually a dual spring, one inner, one outer, with a dampener.

Hi Doug, thanks a lot for very specific feedback!

Yes, the heads are CHI, 3V version.

I dag again trough all the receipts to try and find more info on the valve train.
I found some receipts that could give some clew to what is actually in there, all of this are from 2002/2003:

From PI: Aluminum heads-$1995, Valves SS Exh & Int (Use old springs, retainers and locks) - $900, Intake manifold - $525, Oil Pan 10gt w pickup - $400

From Precision Proformance: Solid cams + lifters (custom grind) - $275, Dual roller chain - $57

Then, there is a much older invoice from 1997 from Pantera Specialists for Roller rockers - $275

From all this I think the cams might actually not be a roller but regular flat lifter; not sure about that.
From all the documentation I know that originally my engine was built with 351C 4V iron heads, hydraulic lifters and Sig Erson 351C High Flow cams (540 lift intake and 550 lift exhaust), so that means it was working well with hydraulic lifters despite the oiling modification.

If I would decide to replace the cams with something that should not give me troubles what would be the best recommendation considering my heads, carburetor and intake?
Would it be best to go back to High Flow setup or there is something you would recommend?

Recommending cams is very controversial at least.

There have been several threads on that subject here on this forum.

The most scientific is to let someone like Dan Jones recommend a cam based upon the specific criteria of your engine. The reason I say that is he has a pretty good computer program that really narrows down the needs and can dial in on a cam really accurately.

How an engine runs with specific camshafts is also really a matter of taste. Some want it to be quiet like a Lincoln and some accept the rump, rump idle that makes it sound like a 5.7 liter Harley Davidson?

What exactly is wrong with the camshaft that you have in there now? I would think if it is running alright now, leave it alone.

Doing a camshaft change in a Pantera is not fun.

You really need to take off the rear deck for engine access, and the bulkhead cover as well.

There is a lot to consider and you may be gaining very little for the effort required?

The 3v CHI heads are going to have more specific cam requirements of which I am not familar with.

Why don't you give the Byer's Brothers down at Precision Proformance a call and see if they have any info on the cam that they sold for you car?

That's where to really start.

71HI, if you have some money left from your purchase, save it for a dash-2 ZF. Your 'dash-1' is actually what Lloyd Butfoy at RBT Transmissions calls a 'dash 1-1/2' since a true dash-1 ZF is only found in the Mangusta. What you have is a Pantera differential case flipped upside-down from the GT-40/Mangusta style, with a Pantera 4.22:1 ring & pinion inside, and a Mangusta transmission & gears bolted on. The factory did this on not-very-many preproduction prototype '71s before ZF got all the new tooling finished to Fords liking for production cars, in mid-1971.

About half the guts of transition ZFs are specific to the early Pantera and the Mangusta/GT-40, and very few spare parts are available. The mainshaft is longer, the clutch spline is 1-1/16"-10 while dash-2 clutch discs are 1-1/8"-10 so clutch discs are different, the bellhousing is a smaller and lighter sand-cast unit with two small access holes and fewer bolts, and several of the gears inside are different. As you noticed, the rear ZF mount is different, too. The ZF may even have a non-clutch-type LSD inside, for which NO replacement parts are available. If ANYTHING goes wrong with that box, a normal ZF rebuild isn't going to be as "cheap" as on a dash-2, if it's even possible. A few used parts will of course be available but possible interchanges that fit the early box are not well known outside of RBT. Call him sometime and ask about all this. I am not a real expert although I've worked on both types.

If your transition ZF is shifting OK and not noisy or dripping, drive it (carefully) as-is until you find a dash-2 you can afford and have that checked over. Then swap the ZFs- they are bolt-ins. Note you will also need a later bellhousing, cross-shaft and all the internal clutch release parts too as they're specific to each type of bellhousing. You'll need a later clutch disc as well. Your clutch slave cylinder and bracket may work as-is.

As for your lifter bushings, it depends entirely on what size oil holes are in the bushings as to whether hydraulic lifters will be noisy or not at low rpms. Some engine shops install bushings to blueprint lifter bores, which are often not perfectly positioned in any production engine, and available blocks nowadays often have worn lifter bores. A bunch of worn lifter bores contribute to low oil pressures; bushings can correct both problems. For racing, I'm told an 0.090" oil hole is often used in bushings while for street use, maybe 0.120" or slightly larger gives more oil flow for hydraulics. Stock was about 0.375"! Bushing holes can be opened up with a complete engine teardown.

You'll need to dig into the motor to find what actual size oil holes are in the bushings, but bottom line- if there's no rattling noise at idle with hydraulics- either roller or flat tappet, you're likely good to go. Doesn't Hawaii still have a state-wide 45 mph limit?

Hi, thanks for advice, yes, will probably just keep current cams and see how it goes; main thing was that I was planning on some longer distance trips in Europe and did not want to be standing on the side of the road
When car arrives to Europe will have access to Dyno to measure HP and torque on the wheels, so will report what I find out.

ZF feels really good for now and shifts smooth, even from 2nd to 1st; it has a side mount kit installed already. I do like the fact that my ZF/1 ratios are same as used in Euro spec GTS with the shorter 4th gear, so let's hope there will be no need for rebuilding it soon! In order to keep ZF running well, apart from being gentle with the stick, what are recommended practices (slave cylinder adjustment, any modifications to the linkage, best oil to use and how frequent to change it, any additives, how much oil to fill after change,...)?