What would you motor guys do?

I'd get those head gaskets done now !

Even if you intend on doing more work in the future. Just put the heads you are using now back on for the time being.

It's a pretty straight forward job and you can check out a few things in preparation for your big rebuild such as bolting your new headers to the edelbrock heads and you can have a look at the bores and see what the cylinder wear is like. You may ultimately need to build a whole motor not just put the Edelbrock heads on what you've got.

Don't use the old rocker arms off your original heads, i'd say they are stuffed by now. Maybe get some roller rockers.

the block deck surfaces need to be checked for warpage before you do anything, the head deck surfaces need to be checked if you plan to re-install them

IMO you'll see an overall performance decrease if you replace 351C 4V heads with Edelbrock 2V heads. you may notice a slight low end improvement but there's no way the midrange & up will be comparable

definitely get the head gaskets repaired before any(more) damage is done to the block & heads! have your factory iron heads vacuum checked for valve seal, maybe even dis-assembled & inspected for valve guide wear? consider new 1 piece stainless steel valves to prevent a head separation catastrophe, have new stem seals installed & put them back on with the Airgap manifold if you think it'll fit under the cover or maybe you don't mind if it doesn't?

or just slap the Eddy heads on it & go...

hopefully you don't find warpage on the engine block deck surfaces or it has to come out for machining. IIRC up to .006" warpage is allowable with composition gaskets as a repair, only .003" allowable with stamped shim stell gaskets. if using MLS check manufacturers info for proper surface finish requirements & warpage allowance

your headers will bolt up to the Eddy heads but you'll need to verify that they'll seal by comparing each side to a gasket. the heads may allow use of a 4V exhaust gasket that will seal on the headers, 2V gaskets may not have enough material on one side of the 4V header ports to get the job done... check it out

The block has to be prepared for the alloy heads. It is best to expect it will need to be machined flatter, and the surface of the decks will need to be smoother in order to use the multi-layer-steel (MLS) head gaskets people typically use with alloy heads. In other words, you can't bolt on the Ed heads unless the block has to be machined anyway.

The seepage of coolant could be caused by (1) warped block, (2) warped heads, (3) bad head gaskets, or (4) a combination of two or all three. I'll tell you what I would do.

Remove the heads and check the block's decks for flat-ness (warpage).

(1) If the decks are OK:

I'd put the Ed heads on eBay & sell them, use the money to purchase a refurbished pair of iron Australian 302C heads, those are the small (2V) port heads with the 58cc quench combustion chambers. Installation of these heads is not as fussy as the alloy heads, no block prep is required. Installing them will raise the compression of your Pantera's motor to 10:1, as-is, even with the factory dished pistons.

Install the iron 302C heads, the Edelbrock Air Gap intake, and rock n roll.

(2) If the decks ARE NOT OK, out comes the motor.

I know you're not financially ready for this. But if the block's deck are warped & need repair, your only other option is to install head gaskets and hope for the best. Remember Murphy's Law?

This would be the time to have the decks flattened and surfaced to be used with alloy heads and MLS gaskets. With the block completely apart you'll need some parts to re-assemble it. Throw in a few more parts and some crank work and you'll have the short block rebuilt, now, 2 years earlier than planned. The parts you'll need, off the top of my head, include flat top pistons and rings, bearings, timing set, valves, rod nuts, crank prep and balancing.

The heads that are on the motor now will need to be checked for warpage too. That will help you decide whether to keep them or replace them.

You then have the choice to (1) use the Ed heads, or (2) sell the Ed heads and use the funds to partially pay for the machine work and parts.

With the block prepared for alloy heads, and with flat top pistons installed, the motor shall be prepared to go in what ever direction you decide to go when you are ready to finish the project at a later date.

-G

Okay,

I got up this morning and tore into the motor. It looks new inside. Looks to be bored over .020" and has what I would consider to be flat top pistons. You can see honing marks in the cylinder walls.

The heads of the intake valves have the Ford logo on them. The cumbustion chambers are domed.

Does any of this change any of the previous recommendations?







Steve

Chuck the valves. Get 1 pcs. stainless valves. I've been there and so have many others. Its not pretty when they go but it is expensive.

I found a post by George that said the 73-74 years had the open chamber heads with the smaller 2V valves. I measured my valves and yes they measure 2.04" and 1.65". So my iron heads are less than desirable. I called a friend and described my pistons to him. He said that they are actually dished pistons because of the slight recess in the top.

T.Solo, did you find the source of the water leaks ?

Geroge's suggestion of the reconditioned Aussie 302c heads and the Air gap manifold is a good option !!

Those are the dished pistons and the open chamber heads. It's an 8:1 engine.

I would suggest that if you are going to do something that you go with a rebuilt set of the 71 4v closed chamber heads, ported and with one piece stainless valves.



Actually the iron heads don't need a lot of work. The valve pockets need the cast in restrictor rings removed. That detail clearly shows in the Ford Boss 302 Off Highway booklet cross section of the heads.

You can get those "reasonably" because seems like everyone wants aluminum these days?



The heads and pistons you have are consistent with a 73 CJ Cleveland. This also means you have the 73 CJ camshaft.

I would change that cam. It is 4 degrees retarded on the timing marks.

Use a hydraulic lifter cam if you want but go to something with at least 236 degrees at .050 and you really want something around .585 lift or better.

This will be a pretty healthy 10:1 engine and you definitely will feel the crispness in it vs what you now have.



Pull off those head gaskets and look for sepage marks around the water ports where you were seeing leaks.

Actually one of you pictures shows evidence of something happening around the lower rear water ports. This is where you were seeing leakage.

The heads themselves show surface pitting on the flat surfaces. Those heads should be milled to clean that up. I would think at least .010" but that depends on how deep the worst pits are.

It is possible that a couple of those pits are holed through from the inside as a result of a bad casting and casting flash getting dislodged?



Chances are it is just the head gaskets themselves.

Many actually will "rot" out around the water passages neat the corner head bolts, oh and use new head bolts and make sure you use the Fel-pro gaskets and torque them down in sequence as the shop manual indicates.



It is entirely possible and most likely, when that engine was apart to go .020 over, the heads weren't torqued down properly.

The Clevelands need to be really tight on the head bolts.



I personally wouldn't use the Aussie 2v heads unless they were fully ported but then if you were going to spend that money, there are better heads to use.

That much porting isn't cheap to do.

Those are just good if you want to spend the least amount on a rebuild and get additional street grunt.


Even ported, those will fall on their face under head to head comparisons with a closed chamber 4v and the right camshaft.

quote:

Originally posted by PanteraDoug:
It is entirely possible and most likely, when that engine was apart to go .020 over, the heads weren't torqued down properly.

The Clevelands need to be really tight on the head bolts.

Thanks Doug,

I noticed when removing the head bolts that the rear seemed to require less torque to remove. I theorized that the motor was rebuilt and sent down the road never having had the head bolts retorqued.

Today I'm going to clean up the deck surface and attempt to check for warpage as suggested. I'll report back on that.

I'm interested in replacing the cam since I'm this far into it. should I consider going hydraulic roller? Does this require machining? Is there any oiling modification required or that I should be considering with the top off the engine?

Steve

quote:

Originally posted by T.Solo:

quote:

Originally posted by PanteraDoug:
It is entirely possible and most likely, when that engine was apart to go .020 over, the heads weren't torqued down properly.

The Clevelands need to be really tight on the head bolts.

Thanks Doug,

I noticed when removing the head bolts that the rear seemed to require less torque to remove. I theorized that the motor was rebuilt and sent down the road never having had the head bolts retorqued.

Today I'm going to clean up the deck surface and attempt to check for warpage as suggested. I'll report back on that.

I'm interested in replacing the cam since I'm this far into it. should I consider going hydraulic roller? Does this require machining? Is there any oiling modification required or that I should be considering with the top off the engine?

Steve

I am a believer in going as simple as possible. For most people, they don't need the benefits of a roller lifter camshaft.

In the past, the durability of those components has not been what it should have been.

The roller lifter assemblies are heavier and have more components to them to fail.



I would use an ordinary hydraulic lifter camshaft. With anti-pump up lifters and better springs. I used to turn mine to 7,200rpm with no problems.

The main advantage to the roller lifter is that you can use a more radical camshaft profile and have a close to stock idle.

To me, there is always a price to pay, or a trade off if you prefer that term. The trade off to a roller is less expected life out of the valve train, and if it breaks in the middle of nowhere, then make sure you at least have cell phone connection?

The trade off to a hydraulic lifter cam generally is less upper rpm available. Text book would be about 6,500 rpm upper limit.

You can go with triple spring like I had but the there is a trade off to that as well.

I now run solid lifter cams. It is simpler.



Considering the amount of pitting that I see in your photos, it could be that the heads were sanded down with 60 grit paper and put on.

That should show on the surface using even a simple straight edge like a carpenters framing square as a "not flat surface".

The blue Fel-pro head gaskets are good, but not that good to positively seal the low spots.

You can have those heads "resurfaced" pretty cheap, without taking them apart. Shops do that all the time.

I'd strongly recommend that to you if you are going to reuse those heads.



Chances are the block was resurfaced when they did the .020 over bore. It usually is?

Wipe down the surfaces of the block with a solvent to make sure that all traces of the old head gaskets and oil are gone, and DO NOT sand it with anything at all.



The Cleveland heads need to be re-torqued after at least one run where the engine gets nice and hot, then is allowed to cool all the way down, like overnight. Check the intake manifold bolts too. Guaranty they loosen up.

Then go back and check the head bolts that they are at 110 ft-lbs.

Once you do that, it will set the gaskets permanently there and the bolts won't loosen up any more.

Theoretically those head gaskets are one torque cold, but not so in my experiences.



What you have experienced is what happens if YOU DON'T DO THAT. It just makes a problem down the road.

Do it right the first time and you won't ever have to do it again.

Put new head bolts in, AND MAKE SURE YOU RUN A TAP IN THE BLOCK AND CLEAN OUT THE DEBRIS THE TAP SHAVED OUT!

Then you'll be good to go.



Incidentally, Chevies don't take that much torque on the head bolts. GM uses a softer grade of cast iron then Ford and that much torque warps the block and heads. Ford uses nodular iron on just about everything.

That's one reason that hardened valve seats get recommended for heads using todays pump gas, i.e., that the seats are too soft, but that really doesn't apply to Fords, just Chebbies and the other also ran GM's.

You have to keep Chevy guys away from Fords. They think they know everything?

quote:
I have a small budget but considering I don't need to come out of pocket to buy the heads I'm sitting pretty good.

quote:
I would suggest that if you are going to do something that you go with a rebuilt set of the 71 4v closed chamber heads, ported and with one piece stainless valves.

I agree the iron 4v closed chamber heads are the ones to get, but they will make your brand new headers obsolete as the headers i imagine will be to suit 2v ports, The 4v heads will also make you new Airgap manifold obsolete as it too is for 2v heads.

Given you are on a budget and engine rebuilds have a habit of going out of control, a reconditioned set of Aussie 302c will give new new heads pretty cheaply, they will give you new valves and springs, they will raise the compression to 10:1 even with your existing pistons, you can utilize your new headers, you can utilize your air gap inlet manifold, you get new head gaskets (ie: fix the water leak) and you'll be up and running again pretty quickly and with not too much expense.

With the cam, i'd use what you have got, but with the thought that if you by a new timing set you can reset the cam timing 4 degrees advanced so the cam timing is straight up (0 degrees). That will improve the cam quite a bit and give you a new timing chain.

Then all you need are some roller rocker arms. Chuck the old ones in the bin. There are some reasonably priced sets around that will bolt up to the 302c head's rocker pedestals without any mods and if you look hard you may even come across some that are 1.8:1 ratio rather than the standard 1.73:1, that will open the valves a fraction further without a cam change.

With these few things done you can drive your car around while you plan and save for the big engine build, because believe me no matter what you do now in 6 months or a year you'll be saying: Mmmmm...i wish i had done this or i wish i had done that or i wish i had used this part or that part, or i wish i had got a new block or what ever ect.

For you it sounds best to do a economy fix up now and plan for a more coordinated engine build from scratch for later on or i can see you spending $5000.00 now and in a year second guessing yourself.



Then again i might be completely wrong ??/

quote:

Originally posted by T.Solo:

I'm interested in replacing the cam since I'm this far into it. should I consider going hydraulic roller? Does this require machining? Is there any oiling modification required or that I should be considering with the top off the engine?

Steve

Roller cams are more expensive, that's their biggest drawback. They tend to float the valves earlier, but we can make compensations for that aspect by selecting the right parts. The cams are more expensive, the lifters are more expensive, the springs are more expensive. The distributor drive gear must be replaced with a gear costing $70.

I would warn you to resist the temptation for what is called "job creep". The goal is to repair the leaking heads.

The valves in the OEM 4V heads need replacement. I think that should be done now. That is job creep too, but I believe it can be justified, due to the risk of re-using the factory valves. I assumed your preference is 2V heads, indicated by your plans to use the Ed heads at a future date. So the Australian 302C heads make sense, as a means to accomplish 6 things at once: (1) fix the leaking gaskets (2) spend as little money as possible (3) convert the motor to 2V heads without having to machine the block for alloy heads & MLS gaskets (4) replace the factory valves (5) raise the compression (6) utilize the 2V intake manifold you have on hand. The iron 302C heads will alloy you to re-use the factory rocker arms, another cost savings. I have no problem with using the factory rocker arms. The 302C heads are compatible with any 2V or 4V headers.

Raising the compression to 10:1 will boost the motor's output by about 20 horsepower. But the increase in compression will improve the "pep" of the motor, it will "feel" more like a 50 horsepower increase. I doubt there is significant power difference between using the 2V heads and 4V heads with a camshaft like the factory Cobra Jet cam (theoretical lift = 0.481"/0.490"); especially if the 2V heads are given a nice 3 angle valve job as they are put together. The real difference between 2V and 4V heads shall be the power band. The motor's power band will be skewed towards lower rpm by the 2V heads, something many people prefer. And the motor's high rpm "pull" will be blunted by the 2V heads, something I would personally miss.

Assuming the pistons in your Pantera's motor have 8cc dished domes, here's the compression you can expect using the various iron quench chamber heads:

1971 4V, D1AE casting, 66cc chambers = 9.3:1
1970 4V, D0AE casting, 63cc chambers = 9.6:1
302C, ARD1AE casting, 58cc chambers = 10.1:1

The 4V heads can be milled to 58cc, but then the chambers would be too small if the motor was updated with flat top pistons further down the road. You could also elect to just keep the 8cc dished pistons. You can see the dishes are so shallow they are virtually flat tops anyway.

On top of the 302C heads, you could install a multi-key-way camshaft timing set, and use it to advance the factory cam by 4 degrees (assuming the motor is still equipped with a factory cam!). Re-calibrate the ignition for 20 degrees centrifugal advance and 16 to 18 degrees initial advance. I'm not sure what carburetor the motor is currently equipped with. If its equipped with the Motorcraft 4300D spread bore, then the motor will need a new Holley bolt pattern carburetor, so this will be an opportunity to install a nice 650cfm to 750 cfm four barrel street-performance carburetor. If the motor is still equipped with a 40 year old factory crankshaft damper replace it with a Romac #0203 damper. These few changes will make the motor feel like a whole new motor.

There's an abundance of info on related topics in sticky #3

-G