1936 Series 70 V8 Head Gaskets

[cwickadee]

Hi,
My '36 is getting hot after 5 miles. No compression problems except a little low in two cylinders and the plugs are clean but saw a little leakage from gaskets. I tried but couldn't torque the head bolts down anymore. I do know there is oil in the coolant so there is definitely a leak somewhere. I have original gaskets from Olsens. First, we can find no torque specs anywhere even with all the engine info, only from 1947 on. Anybody know the ballpark? Do we need to replace the bolts, too? The gaskets seem to be coated with asbestos or some other annealing metal. Do we anneal them or are they self-annealing while driving? Some boards recommend using sealants like Hylomar but is this for not-so-flat heads in dire situations or the right way to do it? Any other advice would be greatly appreciated. Does anybody know a local in the Portland Oregon area who might have an interest?
Thanks,
Carol

[KenZ]

I had some experience with my 1936 running hot.  Think the torque specs for the head bolts are 60-70 foot lbs.  Someone else will probably have a reference. Replacing the head bolts is the best practice, but I have utilized original bolts that are carefully inspected with success, but you run the risk of breaking them when torqueing or breaking loose.  Olsen is a very reputable supplier of gaskets, so they should be good.  The gaskets I received from Olsen were copper and I just put a light coat of grease on them. Have you checked the surfaces for flatness?  Are you loosing coolant?  How low is the compression? Also, ignition timing can effect engine temp.  The 1936 engines are very similar to the later model flathead but are different.  I ended up installing a later model flathead (tank engine) since the original engine had a cracked valve seat and I was loosing water.  BTW, I have set of good heads (cheap) for the one year only 1936 engine if you get to that point. Lots of info on the website regarding hot running flatheads.  Good Luck!   

[Ron Parker]

There are no oil passages to the heads. If there is oil in the water there must be water in the oil.In the center of the block there is a coolant crossover passage way that has on oil passage drilled in it for the lifter oil supply. It could be corrosion or a crack there or in the cylinder water jackets. I have had some success with block sealers. I tested old corroded head bolts and they broke at 150 foot pounds. They are very hard and do not stretch. Ron Parker

[cwickadee]

Thanks for the stellar advice. :-) After I spent too much time obsessively scrubbing my head bolts, I realized the ends had corroded off in the coolant. We tapped and drilled out the few ends that were still in the block and will have to clean out all the crud but she will be nice and healthy and ready to roll!
The head gaskets didn't look too bad but there was a fair amount of blowback around the bolt holes. Some were less than 70 lbs. but might have loosened. The heads were nice and flat, not even 0.003 across each head :-). Heck, I'm used to nanometers, hundredths in something this old is great! Heads smooth, one bolt hole had some corrosion, that's it.
I looked for sources for bolts, but we only found modern ones. I really don’t know where to look and tried a few suppliers like Terrill but they are no more. Head bolt suppliers, anybody??
Regardless of the authenticity question of using new parts in an old vehicle, is there any reason new bolts wouldn’t work if they are the right grade of steel and can be torqued to the correct torque ft/lb.?
Back to cleaning my heads. I feel like Rosie the Riveter out there. My Dad took the princess to the beauty shop but I think he should have taken her in for the colonoscopy first. If we can find the bolts locally we might get her back together in the next couple of days.
Thanks again, Carol

[Bob Schuman]

For head bolts, Grade 8 bolts of the right length should be available at industrial supply houses or better auto parts stores such as NAPA. The heads will have a 5/8" hex vs. the 11/16" hex on the originals, with the five radial bars indicating Grade 8, which can be ground off if desired. Carefully measure the depth of each bolt hole from the deck surface-you want bolts that engage the full thread in the block, but do not bottom in the hole. If a bolt is too long and bottoms in its hole, when you torque it you may crack the block and then have an 800 lb. piece of scrap iron.