R & R Cyl Heads on a 2.7?

[sam77rs]

Can I remove the cylinder heads on a 2.7, clean 'em up, and put 'em back on? Some one said if you do that without putting case savers in the block, even if none of the head studs are pulled, they WILL pull out when you try to torque them up. Really?

OK, a bit of info. This is a 1977 911 ROW car with 77,228 miles on it. Engine is 911/81. PO back dated it to Webers 10 years ago and did a very sloppy job. He said it never ran right, so he just parked it and went on to other things. About 3 yrs ago he put about 4 gals of gas in the tank and tried to start it. No way. So he just left it (with 4 gals of gas in the tank).

The tail pipe looks like a stove pipe. So much black soot, you wouldn't believe it. Obiviously the carbs are WAY too rich. The combustion chambers are full of carbon, and the exhaust valves won't close. You can hear them going "whoosh - whoosh" when you crank the engine over.

So can I just pull the heads off, clean 'em up, put 'em back on, clean the carbs up, jet 'em down, and get this thing running?

[john walker's workshop]

the whoosh noise is probably compression leaking between heads and cylinders. the typical 2.7 loose head thing. generally speaking, there's not much hope in doing just a valve job on a 2.7 without a can-o-worms opening up. pulled head studs, worn head to cylinder surfaces, worn case at the cylinder bases, worn mainline, etc. you could try to retorque the heads. they either torque up or the studs pull.

[sam77rs]

Thanks John,
I guess I need to take the motor apart and see what I've got. I'm sure the whoosh noise is the exhaust valves because the only place you can hear it is if you stick your ear in the exhaust pipe. And the engine is simply not making any compression.

Maybe I'm an optimist, but I have hopes for this engine because, being a 911/81, it never had any thermal reactors. so maybe it didn't get as hot as other 2.7's. Plus it only has 77,228 miles on it.

I know there are people who say: "The only way to fix a magnesium motor is to swap it out for an aluminum one", however, there are plenty of cool mag motors out there that are doing just fine.

Another question: If I take the cyl heads off, and I DO find them full of carbon like I suspect, is it necessary that I replace the sealing ring between the cylinder and case before I put the heads back on? It would be nice if I didn't have to remove the jugs, but, if I do, OK so be it.

As a side note, many, many, years ago, we used to remove heads, clean 'em, and put 'em back on without removing the jugs. And if a stud pulled, we had a drill bit that was about 20 in long, that we would insert through the hole in the head. We'd drill out the case, and install a case saver by threading it onto a long rod with a hex on top, and tightening it into place. Then remove the rod and install the stud. Did it all the time. The Parts Dept at the Dealership had these tools. Guess I just revealed how old I am, LOL.

[Walt Fricke]

Sam - I'd take John's advice - torque all the head stud nuts to see if they will hold torque. Long ago a mechanic told me that with used 2.7s that's what he'd do when asked to check them out for customers. If one didn't torque, he'd advise at least putting in case savers. But if they all held torque, he figured run the motor and check periodically. Sufficient onto the day is the evil thereof. This kind of approach commends itself to guys who aren't intimidated by pulling a motor, so they don't have that aversion to ever having to do anything over.

If even just one is bad, I think you'd be ahead of the game by pulling the Ps and Cs off as well - this will mean you can decarbon those piston crowns efficiently, maybe rering (if Nikasil jugs), and generally look at things. John has a lot more experience than most dealing with rebuilding well used motors, but I think you will find the copper seals under the cylinders are OK (not that expensive to replace, though). Not that much extra work. For me, pulling and reinstalling and resetting all the rockers is the big time consumer.

My SC started off as a '77 Euro also. I did the case savers and switched to Dilivars (or what I thought were Dilivars), but largely because in the late '80s that's what we all did, need it or not. And I had the motor apart due to missing a shift on the track - valves needed replacing.

[sam77rs]

Thanks Walt & John,
I will take your advice and try to tighten the head stud nuts first.

Have a Happy Holiday !!