VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Blown Head Gasket

I had the symptoms of a blown head gasket so I tore her down to check and sure enough a small piece between cylinder 4 and 5 had blown out. I have been told this was some what of a problem on the early six cylinders. I have never used any head gasket sealer in the past but I am going to try the copper spray type that is made for head gaskets. I am going to torque the head bolts to 85lbs just like I did the first time. Does anyone have any other ideas on the issue? Both my head and block were milled so I know the surface is good.

What type of head gasket did you use the first time? Was it one of those junk "Teflon" head gaskets that the dealers were selling years ago?

Be sure to use a head gasket with the crimped steel edges on the head gasket around the water jacket holes, the combustion chamber openings and the sections on the gasket between the cylinders.

:) :)

Its the Filling Station Copper one.

Matt,
The 85 lbs torque sounds high especially if you are using original head bolts. Search newer than 3 years older than 2 years under 1929-32 forum the topic RE:31 head bolts in Nov. 2004. There is also info on torque on Bill's 1931chevrolet.com website.

Matt,
If you used 85 ft.lbs. on original head bolts then you are really lucky you did not break most of them. I can guarantee that several if not all are streached. The easiest way to check is with a thread gage or die or lay two bolts side by side. All the thread grooves must line up perfectly. If not replace the bolt(s). All that is needed is 60 ft. lbs. or so if the head and block are reasonably straight.

I have had it at 85# for 5000 miles and none have broken. Some time back there was a decision on this subject and I am sure the result of that conversation was to put them at 85#. I can always loosen them up and re-torque. What do you think?

I would not suggest messing with the head bolts unless you have other evidence that you have an exhaust leak or cracked head. If you ever loosen or take them out I surely would check for streaching. It is also possible that you do not have original head bolts. If so they likely will take higher torque than the originals.

Although Chevrolet manuals did not list a torque rating till in the '40's the 216 was rated at only 70 to 80 Ft. pounds.85 sounds like its excessive.If you ever remove the head again I would suggest replacing the head bolts with new ones.The torque figure given is for bolts with oiled threads also.

A common problem with the early Chevrolet models is air entrainment. It mainly comes from air drawn past the packing on the shaft of the water pump. It will occur even if there is no evidence of liquid leakage. Another source is air mixed into the coolant if the level in the radiator gets too low. This problem results in gas bubbles in the coolant and foaming of water/antifreeze mixtures. Looks the same as a cracked head to most people.

I can relate a recent experience to help illustrate the air entrainment problem. The "bosses" '31 fire truck recently received an engine transplant. In fact it was the rebuilt original engine. During the process the water pump was also rebuilt using the original type lead foil packing. In October the truck participated in the VCCA Southern Fall Tour in Kerrville, TX. It had been drive a total of 6 miles prior to the tour and run on an engine test stand for a total of a couple of hours over a six month period. No over heating was noted. On the first days tour over heating was noted after about 40 miles. As the speed increased the temperature indicated on the gage increased and interestingly also increased on downgrades. Air entrainment was immediately suspected. I have written extensively on the whys and wherefores in other postings so will not repeat here. The bottom line is that it it took two additional days of touring and tightening the packing nut to get the cooling problem fixed. The last day, which incidently included the longest and steepest climbing and decending not coolant was lost and the temperature gage remained safely in the middle of the range. Oh yes, for those who might be trying to think of another explaination the air temperatures on all days were approximately the same, 60s in the mornings and 80s in the pm.

Subman576
I also think 85 would be a bit tight especially with original bolts and castings. I dont know of any petrol engine head torqued down tighter than 75lbft with oiled threads and head.
I would be at least checking the head and block (between bolt holes) is straight and preferably taking a light skim again. As another posting suggested the bolts are probably stretched now so I would be replacing them as well.
I also use a product (dont know if it is available there) called "holymar" in a rattle can to aid the sealing.
Tony

The best thing I've found to seal head gaskets is good old fashioned silver frost paint.All you need to do is let the paint sit on the shelf until the heavier aluminium "sludge" settles out from the oil "carrier",coat the block lightly,put the gasket on,put a light coat on the head face of the gasket.
Then just tighten all the head bolts to specs,and the silver frost will fill any gaps or void spaces,and cure once the engine is up and running.Taking the head off(if needed)is a snack,as the paint doesn't stick everything together,just seals.
Using this,you can seal up a new gasket with no leaks,or re-use a 2nd hand gasket if needed.

I have some NORS gaskets if you need one. bwbugay@aol.com