Head Gasket Failure - Dino 308

Probable causes for lost compression/overheating: Head gasket, cracked/warped head, cracked/warped block. Have you had the block checked for cracks? There are a few ways of doing it, ranging from a dye to some sort of electromagnetic powder being used on iron blocks... Other than those reasons, if all of them check up fine, I'm stumped. Valves/rings would cause the low compression but not the overheating... I'd say, if you're not going to check the block for cracks, just use a Ferrari head gasket as OEM is usually the way to go, and put it all back together. As for the linear height, couldn't really help you there. Good luck with whatever it is, I hope it's a cheap and quick fix.


-Tom

 

Hi
Bummer.
The shop manual has all the dimensions and tolerances you need to check the height of the sleeves. You can download it from http://dino308gt4.com.
If the sleeves are too low, then several things can happen such as compression will leak into the water jacket, etc.

Gerrit
http://dino308gt4.com

 

You need the correct liner protrusion because the aluminum block expands differently than the iron liners. If its not correct you should fix it. I dont not believe any way exists to alter liner protrusion than by adjusting deck hieght through milling? This would require milling the blocks head surface, the deck, requiring full and total disassembly of the engine/block including liner and head stud removal. You have the motor out and the heads off, no sense Mickey Mousing it at this point.

Elring is the OEM manufacture for Ferrari head gaskets. So you supplied the parts, big deal, they accepted them, they assembled it. They should at least be willing to redo the labor end to correct this, you supply more parts. Outside of a set of head gaskets and a set of new rings and some gaskets etc., it shouldnt be overly difficult to repair. Just make sure you crack check everything, including the liners and block, even if at your expense. In the end, no matter who pays, your the one who has to live with it.

 

If the gasket is "good" (no pictures) and there is no evidence of leakage. Usually if a head gasket is leaking it is visually apparent on examination. One has to consider a cracked liner or head. Apparently you have checked this.

As far as deck height goes, were liners replaced? If not their relative height to the block should not have changed significantly from new.

 

Good day Seane,

I noticed in your initial pic that there is some sort of Orange residue around one of the coolant holes. Was some sort of sealant (silicone, etc) used with the Head Gasket? If so, then this could of caused the issue you describe, as the sealant does not allow the planed surfaces (head /block) to form a tight seal (I was always taught not to use any sealant with head gaskets for this very reason). Ensure that the head and block surfaces are perfectly clean before assembly, as any surface irregularity will prevent the head gasket from doing its job.

Cheers,

Sam

 

OK. This may sound stupid.

When you pulled the heads did some of the bolts seem loose?

It is a common but unspoken practice to re-torque head bolts on older Ferrari engines every so often.

I've seen one or two heads bolts that seemed hand tight on a bank that all the rest were near spec. This will cause oil in the anti freeze, dripping oil on the ground, adjacent cylinder common compression readings, and so on. All with perfectly good head gaskets.

 

I agree with 2NA, if there are no signs of leakage (soot and burn marks?) past the fire ring on the gasket I would (unfortunately) put my money on a cracked head.

You can check it reasonably well with a dye penetrant and a spray on white powder afterwards.

Hope it's just the gasket though..

Richard

 

Questions questions.

2NA is correct, liner protrusion doesnt change that much.

Mark is correct, the head stud nuts may have been loose.

A liner could be cracked, though doubtful unless overheated.

Block could be cracked from same causes, or from freezing with plain water.

Did you find the leak area before pulling the motor? Did the head gasket show any signs of leakage anywhere? Gasket material on the block surface is pretty normal, no concern. More pictures might help us.

I guess all any of us can offer with any validity, is that liner protrusion is a spec given in the service manual, and should be checked and or corrected before assembling. If anyone wants to put a motor together using a different spec than is given in the manual, they do so at thier own risk.

But loose head studs nuts. My first 308 had over half the nuts so loose I could turn them off with my fingers. Loosest GD head nuts I have ever seen and it leaked nothing anywhere. The ones I couldnt turn with my fingers were almost as loose. I bet I turned em all three full turns or better before they tightened to torque, but I didnt count.

You are at a cross roads, and none of us can help you make your decision. Either way I would check the heads for leaks. But you either put new gaskets on it and reinstall it and take your chances, or you pull it completely apart and correct your liner protrusion, and check the block and liners over for cracks. I see no other avenues. Myself, I would pull it apart. You have it out, the heads are off, in three or four hours you could have it entirely disassembled.

 

Yes studs can be taken out, biggest problem usually is years of crud/ oxidation as a result of regular water being used in the colling system and not DI water.

Your picture above shows white/ yellow residue in the hole where the stud inserts into the block (this is oxidation).

If your heads came off with relative ease you might be lucky.

If not there is a risk that your studs may need to be drilled out and replaced with one off ones made to order....... I know others who have had to do this (it is very very very expensive to do! (talk to Ron at Superformance before you do anything)

It is worth getting a very fine screwdriver (jewler type) or small dremel with a very fine drill bit and cleaning the crud out from around the base of each stud (you will be surprised how deep the hole is before you reach metal of the stud) and then immersing each stud in penetrating oil for a couple of days (to let capillary action take place) then use a good quality stud remover with an impact gun to release the studs that wont come out with a hand wrench.

I do know of overheating causing temporary leaks, luck of the draw as to whether they come back, usually requires a rebuild though.


By the way there is a head gasket dressing you can get (name escapes me at the moment, brown mollasses looking) that Rolls Royce and Rover use (both cars are known to have leaky head joints). Use this on both sides of the head gasket when you are doing the rebuild, it is specifically designed to prevent "minor" leaks at the joint in case of overheating / slightly imperfect surfaces. Very cheap and good insurance, Also recommeded in a Forza magazine for rebuilding old 308 engine blocks which can leak when rebuilt!!

Does not go solid so getting your heads apart again is not an issue, need to be sure you dont get any on the fire rings!

 

I don't know the specifics of your motor so I may be way off but.........Most motors I have rebuilt I replaced the head bolts or studs. Broken studs can be drilled out and (hopefully) a helicoil(replacement female thread) exists in the correct size. This procedure is a common occurence in machine shops.

At the very least you should 'chase' all the threads you can get at and use new nuts. Dinged up threads will never torque correctly. The reason for replacing the studs or bolts is bolt stretch. Each type of bolt has an allowable bolt stretch and a finite number of times they will hold the correct torque.

Replacing a sleeve or liner in most blocks involves drilling out the sleeve with a block boring machine to fit the new sleeve. Then putting the sleeve in the freezer and the block in the steam cleaner. Then it's time for ye olde sledge hammer, block of wood, and a quick prayer. It's more fun to be the guy swinging the sledge than the guy trying to hold the sleeve and block of wood.

I agree with some of the others. The shop should be on the hook for some of this. What ever is done, Magna-flux the block and heads. It should be relatively inexpensive to do that.

 

I have seen more than a couple Ferrari motors, as well as other makes with a stud sheared off at the block surface. They are steel studs threaded into aluminum, and of all the things you really do not want to snap off, thats the one. I would leave it alone if at all possible.

 

DO NOT UNDER ANY CIRCUMSTANCES TRY TO REMOVE THE STUDS!!!!

Unless you really know what you're doing.

You could break them off or damage the threads in the block.

If they need to be replaced let an EXPERT handle it.

It is possible that you don't have a serious problem. If the heads checked out OK (sounds like they did) and your liners are how their supposed to be. You could clean it up and put it back together with new gaskets.

If it ain't broke, don't fix it!

 

These motors are built far differently than most run of mill stuff. The studs are very hard, harder than drill bits I am told. For thier size, and the load they carry, they are twice as heavy as need be or what you would find in other motors of simular displacement. They dont get replaced as a normal course, and removal just isnt normally done unless the block surface really has to be milled. Milling that would then require milling the tops of the liners. The studs dont really stretch.

The motors are not "sleeved" in the sense your familiar with. They use a wet liner that is a lathe turned section of cast steel. It fits rather snug, but is basically pushed down in to the bottom of the block and seals at the bottom of the water jacket with an o-ring and locates around the top of the block by recessed machining of the block deck surface. It is entirely open around the whole water jacketed area.

These are the reasons an older V12 Ferrari can reportedly approach $50k or more for an overhaul. Not only are the parts very expensive, but with the block worth so much money, your machining has to not only be extremely precise, but well thought out. You just dont start shaving off .010 and cranking head studs out out of the block without other considerations. And in many cases, like with a Dino today, the original motor is something you would prefer to keep with the car for obvious reasons, so first you need to asses whats really needed to keep from harming it. IMHO I would leave well enough alone.

I would take care to preserve the motor as it sits presently. Myself, I have become of the mind that I want every bit of metal to remain on its surfaces as long as possible. You cant put back shaved off material. While helicoils work very well, in the area that the head studs are threaded I would prefer to keep as much material down there as long as possible. Drilling it and retapping it larger surely isnt going to make the block any stronger. If you surely cant trust the threads on that stud, you will have no alternative than trying to remove it, but I would judiciously soak it with something for at least two weeks before making any attempts to turn it whatsoever. If it snaps off in the block after siezing up your going to really be up the creek without a paddle.

As far as the shop that did the work is concerned, they didnt let it overheat, and they are not responsible. Thats not counting the fact its been a year. How long is a shop supposed to guarantee thier work these days?

 

<~~What he said

 

I agree with all of the above, speak to Ron at Superformance before you start down any road on removing studs etc.

I would just go with the head gasket dressing as a belt and braces for any leaks.

It is only by exception that Superformance remove the studs.

There are many 308 engines that have been rebuilt multiple times for racing that never have the block studs removed.

 

Thanks for the education. If the studs are very beefy and not normally a problem then I would agree and leave them. But I would chase the threads. Whomever told you the studs are harder than any drill bit must not have ever heard of the word "carbide".

How long a shop guarentees their work is always a good discussion. In this case it seems the cause of overheat is not quite certain. I think that's a good discussion to have with any shop before doing work. In the case of my buddies shop, I have seen him magna-flux or pressure check heads, intakes, blocks, and check other components without hesitation and try to give the customer a few ideas on what else they can check. He never charges for this. It's part of his reputation. Hopefully Seane's shop is willing to at least have the conversation.

 

The original Ferrari head gasket is a fairly thick old style composition unit. The sleeves protrude from the block to add more compression to the gasket fire ring.

I attached a photo of a used 308 sleeve so you can see that it is indeed one piece.

I make the sleeves for Nick's 3.5 liter and Mark Lewis 4 liter 308 engines. The ductile iron sleeves I make are made to work with modern multi layer steel gaskets available from Cometic. You would not however be able to use the MLS gasket without getting rid of the sleeve protrusion. The decks would have to be milled perfectly flat.

I would leave the studs alone unless the upper threads are damaged. I have to remove the studs to sleeve these blocks. It is not something I look forward to doing. Most are corroded in place requiring WD 40, heat, Snap on collet style stud remover, and a good air wrench. I have yet to break a stud but some come out very hard.

Do not chase the block threads. Clean them. If you run a tap in the block, the threads will be too loose and may pull when you torque up the studs. Mark Lewis has several sets of brand new A1 Technology studs in stock if you indeed have to replace them. I had these made for his four liter project that is still in the works. You can contact him through the 4 liter thread.

You must back off the nuts one at a time then bring back to spec in order when retorquing the heads. Do not assume they are correct just because you see no movement when you pull them up with a torque wrench. The breakaway torque will exceed what the nut is actually torqued to and give you a false reading.

Have someone put a precision straight edge across the top of the sleeves to ensure they are all at the same level. I doubt you got the engine hot enough to cause any damage. The pistons would be scuffed if that were the case.

Steve

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The sleeve I have here has a .004" step in the flange. I don't know why they machined two steps in the flange. The outer step is so small that they could have left it off.

File the bad thread in the bad spot with a three sided file. You should be able to clean it up so the nut goes on with your fingers.

I back off one nut a turn then torque it back up. I do one at a time so the gasket is not disturbed.

Steve