| Author | Message | ||
| Timothy Fulmer (Tf308)
New member Username: Tf308 Post Number: 46 Registered: 5-2002 |
It looks like I have 2 studes that are holding the head on. They are the center studes on the intake side. I have used 2 snapon prybars welded together to pry on the head where it overhangs on the driver side of the motor. It seems like I am making very slow progress. Since this is not a mating surface it seems safe. What do you guys think? | ||
| C.C.ofAtlanta (Atlantaman)
Member Username: Atlantaman Post Number: 265 Registered: 3-2002 |
PS this always helps too-- 1) remove cams so all valves are shut. 2) make an air hose rig to attach to all 4 spark plug holes and pressurize the cyls slowly and leave under pressure-- this should help the solvents seep into the old gasket and add a little internal lifting force | ||
| C.C.ofAtlanta (Atlantaman)
Member Username: Atlantaman Post Number: 264 Registered: 3-2002 |
I was told a while back to put a few drops of battery acid around each stud and it would eat away all the corrosion in a day or two but have never tried it.. now i think this was on iron motors too--not sure how it would react with aluminum | ||
| jeff ryerson (Atheyg)
Member Username: Atheyg Post Number: 518 Registered: 8-2002 |
Harbor Freight sells a 4 ton portapower kit for $69, I have one and use it on my equipment all the time and they are invaluable, they have many attachments and should take the heads off in no time | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 218 Registered: 7-2003 |
There's a wurth product called Rost off.... It is sensational and has very high creeping properties. It's great for separating crusty exhaust systems too. Also, Try using a mechanics pneumatic chisel/hammer with a nylon pad on the underside of the head somewhere. They hit about 10 times per second.....and never miss! Try doing it all back up again. You may have moved it a little and shuffle up and down again my help loosen it. If you're going for a rebuild...try hyraulicing the cylinders and turning the engine to try to lift the head, or at least put extra pressure on it. Remove the cams of course, so two cylinders can work together. Panel shops will have "portopowers" or the emergency services call the jaws of life....but basically, a wedge spreader thing that works hydraulically. Roll your sleeves up, show your teeth, growl a bit, and use all the bad language your mother told you not to, that's the last resort though! | ||
| Mark Eberhardt (Me_k)
Member Username: Me_k Post Number: 756 Registered: 5-2002 |
I tried about all the things Verell mentioned....I got so disgusted I decide that one way or the other, they were coming off...it took me 7 hours with hardened steel wedges and a 5 lbs hammer to get the rear head off, the front took about 11 hours. I damaged a cylinder liner, but everything else was good. Good luck!!! | ||
| '75 308 GT4 (Peter)
Advanced Member Username: Peter Post Number: 3150 Registered: 12-2000 |
Verell, he loves his Corvette... Ehhh, end-of-story...  That doesn't mean one can't ask him tech advise. Afterall, an engine is an engine! Thinking about it, I'm quite sure this process won't work for a QV. I remember Bret cursing his, saying that the studs lie under the cam bearing journals... Hard for a plate with bolts to push off. | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1201 Registered: 5-2001 |
Thanx Peter, That's one of the plates. I just couldn't remember the specifics as to how it worked: The plate is about 1/2" thick. It bolts to the cam & valve cover studs, then the long bolts are threaded into the plate & press down on the head studs. Nice piece of machine work to get all the holes in the right places! Btw, any chance Ed will ever come back to the fold. He was a great technical resource, always very helpful. | ||
| '75 308 GT4 (Peter)
Advanced Member Username: Peter Post Number: 3148 Registered: 12-2000 |
This is the thread that Verell is talking about: 308 head removal plate Performed by my good friend, Ed Gault... | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1197 Registered: 5-2001 |
Keep tapping on each of the studs with the drift. Tap sideways on each stud from all directsions. Tap just above where the studs enter the head. Keep the stud-head joint well soaked w/PB blaster. Remember, penetrants soak into corrosion at a rate of only a couple of mm/day. Cut some thin oak wedges (think door shims - long & slim) and drive the tips into the head gasket seam. Search the archives for a 'head pulling plate'. There are a couple of descriptions of how people made them. Somehow the plate either mounts to the studs, then several bolts pull up on the head. Or maybe it attaches to the head, then bolts press down on the studs. A couple of years ago I remember some posts where it was mentioned that it took a couple of weeks to slowly pull the well seized head of a classic V-12. Locate a source of liquid nitrogen. Pour it over each of the studs to chill it down & shrink it. Alternate chilling with heating. BTW, most propane torches just can't put out enough heat to cause the necessary expansion. Get an acetylene torch to do the heating. One desperate FChat member found thin steel tubes that were barely large enough to fit over the studs. He then cut saw teeth on the bottom of the tube & used it to saw down thu the corrosion. Of course this also opened up the holes the studs fit thru. Hope these are useful. Try searching the archives for combinations of 'head' 'removing' 'stuck' 'seized' 'studs'. Above all, patience. Say to yourself "I'll do this somehow w/o damaging the head & it may take weeks". | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1709 Registered: 4-2002 |
This is a VERY common problem. It seems corrosion around the studs is the culprit. Just wait, the suggestions will follow. Violence is often the answer. | ||
| Timothy Fulmer (Tf308)
New member Username: Tf308 Post Number: 44 Registered: 5-2002 |
Does anyone have any suggestions? All the nuts are off the studs (ten total). I have used every penetrant known to man (PB Blaster, Liquid Wrench, Kroil). I cut angle iron and have suspended it with the motor and trans attached for the last 2 days. I have beat it with a 5 pound mallet and red oak wood. I have heated the studs with a propane torch. The bottom exhaust studs allow the penetrant to go through, but 4 of the top intake studs dont let any go through. Oh, and I have hit the studs with a brass drift. I am about to pull out the 44 magnum and shoot it! Any ideas? This is a 84 308QV w. 23K miles. |