Another 308 Engine Teardown Question??

1) use big 5lb rubber mallet.

2) put nuts on loose again with about 0.25" gap to the head. use cherry picker to hang engine by the head in question. Overnight pressure of this action usually does the trick.

3) you should not have taken the cams off first. since you can hand rotate (36mm nut on dampner) the engine with cam on but headnuts on with almost no gap and the compression upon turning the engine loosens the head. Becareful interferrence design and you can bend valves if not careful since stuff is not tight. This just lossens the seal to the head and then the head peals off pretty easy.

 

Welcome to ferrari head hell! Many on this board have had this problem (me not included, I was lucky). Some even have built a custom head removal jig to press it out. Trick 1 by Billy above is good, hope that works. Trick 3 is pretty neat too.

If the corrosion is too bad and nothing moves, my suggestion is to use a heavy hammer, with a 6" hard plastic stick (forgot the name of the material), pick an edge, pound on it with the hammer / plastic stick, use wood wedges once you have made some head way, and continue to the other side.

If that does not work, well, my friend, you will have to build yourself a head removal thingymajig.

 

Do a search at the old site on something like "308 head plate" (and mode, whole words only) and you should get some threads like this:

http://www.ferrarichat.com/discus/messages/256120/247.html

It's typically not easy -- BTDT.

Those "plugs" with the female hex drive do not need to be removed.

 

Briefly speaking, you are right. You do not remove or replace those studs, there is no reason to. Getting them out would involve having to retap and insert helicoils into the block. I saw one 308 block done where the aluminum was galvanized to the steel stud threads when it was pulled out and thereby destroys the inner threads in the block.

 

I always replace head studs and nuts, as well as rod bolts and nuts when I rebuild, as these stretch.

 

Controversy on the head studs. Generally good idea, but I've heard of some of the 'experts' that will re-use them one time only, as they do tend to present problems removing them.

 

That is expected, that is why part of the 30K is to retorque the head nuts. After a rebuild, a retorque is strongly suggested after only 6K miles as well as checking/adjusting valve clearances. Stud stretching is minimal and virtually eliminated via the retorque.

 

I also had to use a puller, similar to the one in the thread referenced above. My story is here:

http://www.jb330gt.com/HeadPulling.htm

Cheers,
Jon

 

I would try NOT to remove the head studs if at all possible. They screw into the block 14mm x 1.5mm pitch is what I remember. They don't come out easy and sometimes will just freeze in place. You need a pretty expensive stud puller.

But, if you need to resurface the decks of the block, or redo the liner-to-deck distance (0.001-0.0015 inch) then you must remove the studs. There is no way out. I would reuse them again, but that is just me, not looking for a debate.

 

i was lucky w/rope. cams removed so no bent valves. stuff as much as you can down (bdc) 3 & 4. turn crank. the same w/6 &7. good luck

 

YES My bad...cam belt off does not equal cam off. ;-)

 

Seeing as the shanks of the studs are not in direct contact with the head, they should not corrode, but if a catalyst of some-sorts gets in there, like coolant, it could corrode. Obviously, there could be problems with the threads in the block.

I didn't have any corrosion on mine, but decided to smear a very thin coating of anti-seize on the shank of the stud to eliminate any chances of sticking for - hopefully a long time from now - future removal. Don't get the anti-sieze on the threads as it will throw-off proper torque values (allowing the nut to spin easier, allowing more torque to be applied).

 

Sorry to hear. Take pictures, post, and let us see your progress.

 

I have heard of the rope method working on larger bore engines...

 

A couple of suggestions I might make here. On head removal, I Knocked the porcelan out of 4 spark plugs, welded a short length of tube to them and threaded it to fit an air line fitting. This manifolds into a chamber topped with a 3/4" ball valve, so when I open it 175 lbs of air blasts the head up. BTW, the cams are removed first so that all of the valves are closed and the air pressure pushes against the pistons equally. Works great.
IMO, the corrosion is often the byproduct of too many short trips, causeing condensation to accumulate in the heads. As oil floats on water by nature, travelling down the studs is a natural. I'm right in the middle of one of those blocks right now, and after trying the heating method, I found success by carefulldrilling a small hole that lines up with the small chamber below the studs end, as there is a small pocket there due to they never tap all the way down. Carefull line up is important, and an 1/8" drill bit is just right. Drop PB Blaster down the hole withthe block upside down, and it gets directly to those frozen threads.
HTH