Head gasket?

jm29henry

jm29henry

Well-known member
Which is more preferred and why a copper head gasket or a composite head gasket. And what it the difference in torque specks . Thank you for your help joe.
 
I prefer a copper one, not sure why.The first two torqueings, I go to 60 lbs, subsequent torqueings are 55Lbs. Maybe it's wrong, but it seems to be working. I don't slop Permatex all over it either! Just a seal around each Cylinder and water passages.
Terry
 
I never use anything but the copper head gasket. Use copper spray as a sealant.
 
I have always used the composite gasket. First the old Felpro’s , now the Best.
Never had trouble either. The key is flat flat flat
The composite is definitely harder to remove.
 
I used composite and always smear on a very light coating of wheel bearing grease. I learned that trick when I was a young, know-it-all shade tree mechanic working on flathead V8's because it made it easier when had to remove them later.
I must have forgotten a lot over the years because I am always asking questions???
"Enjoy the adventure..." Chap
 
The typical issue with people who have composite head gasket issues is the engine machinist used poor methods/equipment when resurfacing the deck or the head thus causing the RA finish to be poor. This allowed coolant to weep under the gasket.
 
Ill go into the weeds with this..Fixed timing is a cause of head gasket failure.

Why? when you set your spark lever in one spot and drive,the only time the timing is correct is at the rpm the lever is set at..any other rpm,say accelerating for instance,or idling,the timing is either too far advanced or retarded (depending on engine RPM) raising and lowering combustion chamber temperatures..this alteration of temperatures expands or contracts the head,forcing the head gasket beyond its ability to seal.
 
Jack Shaft said:
Ill go into the weeds with this..Fixed timing is a cause of head gasket failure.

Why? when you set your spark lever in one spot and drive,the only time the timing is correct is at the rpm the lever is set at..any other rpm,say accelerating for instance,or idling,the timing is either too far advanced or retarded (depending on engine RPM) raising and lowering combustion chamber temperatures..this alteration of temperatures expands or contracts the head,forcing the head gasket beyond its ability to seal.
Click to expand...

This is certainly plausible as a theory, but I'm curious what evidence you have that improper timing -> wide temperature swings in the head -> gasket failure. Like, what forensic traces in a gasket failure tell you that it was due to improper timing?
 
Back in the 1950s I was taught a copper head gasket w/a thin coating of chassis grease. but now I prefer a copper head gasket w/a coating of aluminum spray paint.
 
Best #509 is available as a copper or composite gasket, same part number. I prefer copper because when and if removal is needed, the comp is a bear to get completely off. Other racers that I know use the composite, saying they have better luck with it. Copper seems to require torqueing more often when new than the comp. Like Katy, I use silver paint, a light coat, let dry, then a heavier coat dry until tacky, then install. Copper coat never dries, so is a bit slippery, paint acts as a glue, so is more apt to stay in place.
 
Thank you all for all of the great help and information. I really do appreciate all of you for taking your time and really trying to help a fellow model A owner. I have decided to go with the copper and I will use copper spray . Is 55 foot lb correct for the final torque of the head bolts?
 
jm29henry said:
Thank you all for all of the great help and information. I really do appreciate all of you for taking your time and really trying to help a fellow model A owner. I have decided to go with the copper and I will use copper spray . Is 55 foot lb correct for the final torque of the head bolts?
Click to expand...

55 Ftlb is plenty if you have a standard head. I run a 5.5:1 head and use the same though I have heard some say they like to bump it to 57 or 8 with a high compression head
 
alexiskai said:
This is certainly plausible as a theory, but I'm curious what evidence you have that improper timing -> wide temperature swings in the head -> gasket failure. Like, what forensic traces in a gasket failure tell you that it was due to improper timing?
Click to expand...

No forensics, just logic guided by experience.Improper timing can raise combustion temperature,higher combustion temperature put more expansion stress on the head and studs. Accuracy in timing and coolant temperature control (thermostat) provides both stability in combustion temperature and coolant temperature,meaning the head is under less stress from fluctuating temperature.Exhaust manifold gasket failure and manifold warping will also be eased by consistent combustion chamber temperature.Do you have to do this for a successful experience with a model a? no,the A engine in stock form yields an excellent service life properly maintained. I enjoy getting peak performance and efficiency from the L head 200 cu in four cylinder engine.
 
Perfect.! I was wondering?The two head bolts that holds the upper radiator inlet is 45 lb for those two head bolts proper.
 
Torque the water outlet studs to 55 lbs too. I don't use a gasket on the upper outlet fitting. I file both surfaces until they are flat, flat, flat. Then I put a very thin smear of silicone gasket material on the head and torque it down. Never had a leak or broken an ear off doing it this way.

I put two light coats of the copper coat spray on the head gasket. Letting each coat get very tacky. Put the head on while the second coat is still tacky.

Be sure that the head gasket drops on easily before spraying on the copper coat. No fun fumbling around trying to get a sticky gasket to slide down onto misaligned head studs.

I'm very careful to spray the copper coat from the inside out to keep the outer edge clean leaving a crisp white gasket edge. Does nothing for performance but looks nice. If you get too much copper coat on and it squeezes out leave it alone until it is dry and shave the globs off with a sharp knife or razor blade. Try it while it is wet and it will make a smeary mess all over things.

Do not be afraid to torque the head multiple (many) times especially early on while cycling it through heating and cooling.

It will take a while for it to settle in and stay put at 55.

You can't torque it too many times. But you can torque it too much.
 
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