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I am putting my '36 207 cylinder head back on the engine. The head is fresh from the machine shop and has been surfaced. The block has not been surfaced. I am using a NORS copper and asbestos head gasket. What are your thoughts as to the best gasket sealer to use? Thanks.

Mike

I have never used a sealer on any head gasket and had no leakage problems

On a head gasket I do not usually use anything. If you feel you must use something some of the spray copper coat would not hurt a thing. Use a couple of old head bolts with the bolt head turned down to the nominal bolt size as alignment studs. Cut a slot in the top with a hack saw for easy removal.

Hi Mike

I sprayed copper coat on both sides of my 46 head gasket and had excellent results. Nothing oozed out of the edges when done, and no leaks whatsoever.
I look at it as inexpensive insurance against having to tear everything down for a do over in the event of a miserable little seep somewhere.

I've always used a little something on head gaskets.
I used to use a thin gasket shellac, but I really liked the way the spray on stuff worked and how easy it was to control the amount and the evenness of coverage.

Thanks for the input, everyone. I cut the heads off a couple of 1/2 inch bolts so I can use them for guides. I have chased the threads in the block and cleaned the bolts on my wire brush wheel. I will use some anti-seize on the bolts. Am I forgetting anything?

Mike

I used a screw driver and air to blow the bolt holes out in the block after cleaning just to be sure the head bolts didn't bottom out before they had the head tightened down.

Hi Mike,

Unless there are specific instructions from the manufacturer of the head gasket I do like to use a thin coat of the spray copper coat. Maybe it is just “mental security”. I also like that it helps keep the head gasket in place as you lower the head on to the block, even when you use a couple of guide studs.

I agree with your practice of chasing the threads in the block. After I chase the threads I do spray some brake cleaner down the holes to wash any dirt or fine shavings out of the threads. I use a thin screwdriver with a rag wrapped around it to soak up whatever in in the bottom of the hole. Then let the threads dry.

I do agree that there should be some type of lubricant on the bolt threads. I prefer a very light coat of engine oil. Anti-seize is pretty slippery so it makes it easy to over-tighten the bolt. You can also end up with a puddle or ring of anti-seize at the top of the threads unless you really control how much you use. Oil will tend to flow down through the threads.

We all have our preferences for doing tasks like these. You are definitely taking all the right steps so I know the results will be great.

It is also great to know that you are making progress.

I use engine oil on the threads as well.

I also only oil the bolt itself, as oil or anti seize in the bottom of the hole can cause a "hydraulic lock" which will prevent the bolt from tightening down on the head, or worse yet cause a small crack down there.

I often use a product called "Hollymar" spray on copper head gaskets though I also have not used anything with no adverse results. Thread cleaning is a must and oiling the threads is highly recommended.
Tony

I agree with Gene, here. After all the thing is called a "gasket" and thus it will do its job without any help from any other "helper" sealer. With proper head bolt reach and torque the gasket is designed to form and fill any slight imperfections that may be on the head or block. If the head and block surfaces are so screwed up that the gasket alone will not serve then you have a problem that no sealer will serve any worthwhile purpose except prolonging an eventual leak of compression.

Why in the world do we keep over-thinking these things. Just make sure that block and head are smooth and the dang gasket alone will do just fine. No stinkin' sealer needed here.

Don't think that owing to no problems after using a sealer that it had anything to do with such success. It didn't. It's hard to prove a negative: that's why we mislead ourselves here.

Best,

Charlie

Charlie,
As always, thank you for your thoughtful and sensitive response.

Mike

I decided to "go commando" and not use a sealer. After chasing the threads in the block and blowing them clean, I put a dab of anti seize on the first few threads of each bolt and every one of them turned down to touch the head with my fingers.
It was too late to continue with torquing so it will wait until another time. Is 70-75 ft. lbs. the right number?

Mike

Hi Mike

I just deleted a post as I gave the spec for a 216, which was different than your number, then realized you are working on a 207.
And I don't recall what I torqued my 1929 to, so I guess I'm no help at all. :-)

I dont know the correct torque is but 70ftlb sounds a little over tight for those old bolts and block, (newer grade 8 bolts yes they will handle it) I wouldnt go much over 55lbft.
Tony

the notes i have from this site is as below:

Cylinder Head Bolt OLD: 55 to 65 ft-lb
Cylinder Head Bolt NEW: 65 to 75 ft-lb

That is what i used on my 1929 as i am rebuilding it now. i did 70ft-lb and did so in three steps. and followed the torque sequence in the repair manual.

I used a NEW set from TFS

Thanks for the wake-up call, guys. I should have known better than 70/75. The bolts were new old stock about 10 years ago, but they have had a busy life. This will be their 4th torquing.

Mike

From some charts I viewed on supplier sites lubricated bolt torque is about half of dry specs.

generally specified torque specs for hardware is DRY (Clean & Dry) ANY film, liquid, dry compound, tape, etc alters the specification as it alters the mating surface of the hardware.in the field we tell them clean and dry for torque.

Hi Steve

My charts (John Deere etc) have oiled torques closer to 3/4 of dry.
And I always oil threads. Always.

Two reasons for this.

First of course is that things don't rust together and can be taken apart if needed.
And no, they don't fall apart by themselves more easily. In fact quite the opposite, by way of my second reason.

Second, no matter how clean dry threads are, the frictional characteristics can and do vary considerably from bolt to bolt.
Because we are overcoming the friction of the threads before we even begin to torque in any bolt stretch, the TRUE tightness can vary quite a bit with dry threads.
This is why some engine manufacturers gave bolt stretch specifications instead of final torque specs for critical bolts.
And so some bolts may in fact not really be that tight at all when done. These are the bolts that eventually work loose.
My 1942-46 Chevrolet Service Manual quite clearly specifies oiled threads for both mains and connecting rods. And they stay put, even without pal nuts.
I don't think I've ever had an oiled and torqued bolt come loose

I do however torque slowly and with a steady motion, as you can more easily over run the torque if you go too fast.

I just torqued the used head bolts on a 1932 engine to 60 ft-lbs oiled. Did the tightening to each value 30 to 60 by 10 ft.-lbs steps. Tightened and loosened at least 3 times at each step. My key is that the wrench ended in the same position as the last time. I was taught that by an old timer many, many years ago. What he explained was that the imperfections in the threads will be flattened out each time they pass by each other. I have found that re torquing basically doesn't change much after the engine has been run.