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Head gasket????
Posted: Thu Feb 10, 2022 10:51 am
by Dan Hatch
Anyone use a steel head gasket on a Z head?
Thanks Dan
Re: Head gasket????
Posted: Thu Feb 10, 2022 10:45 pm
by Craig Leach
Seems head gaskets have turned into a big topic lately, Copper vs modern vs steel. Mostly because of he lack of availability of copper head gaskets. I have used steel & modern ( with silicone ) when I was a automotive mechanic some 45 years ago and don't remember any supplier having copper head gaskets. Aluminum heads where not real popular back then but still delt with them. I don't seem to understand what the issue is, the purose of a gasket is to conform to two surfaces to make a seal. And the manufacture should make them for that pupose. The only trouble I have had with head gaskets on model T's has been my fault for not making sure the mating surfaces where good enough and I fallowed up on retorquing properly. Something that never happened on modern engines I worked on as they where better designed than a model T.
So the question is what is the problem with model T's & head gaskets? Including aluminium heads for said engine. As I understand there is two reasons for head gasket failures. Lack of conformity & errosion as they dont have enough combustion pressure to make a gasket fail. So If you have a copper & brass radiator a iron block, a aluminium head with out good grownding of the electrical system the aluminium head will be the sacrificial metal in the system. The PH of the liquid in the cooling system will retard or advance the proccess of electrolysis. I'm thinking atleast some form of anti-corrosion coolant should be used. I have had good results with all types of head gaskets, but I don't have any aluminium heads on my T's.
Craig
Re: Head gasket????
Posted: Thu Feb 10, 2022 11:25 pm
by ModelTWoods
I don't remember the post, or the date of it, but Iseen to remember a previous post on the subject that concluded that copper head gaskets were the best for sealing a Z head.
Re: Head gasket????
Posted: Fri Feb 11, 2022 9:44 am
by DanTreace
Dan
Have replaced busted gasket on Z head on tour, all that was avail. was a new steel gasket, sealed with high metallic content alum spray paint. Worked fine, still running.
While the Instruction Sheet with the Z head recommends using a new copper gasket, the key word is "new"! You don't want to reuse a head gasket that has already been crushed in torque of the head bolts to seal it.
The reasons head gaskets fail, and normally at the center bolts, is the narrow gap between cylinders with Ford design (which you can't fix).
But you can minimize this with a new gasket so it will crush and seal, and be sure to use the Ford Method, after running down all the head bolts, of starting your torque sequence at the center of the head, to seal the midline of the head, then random out to the edges. That will clamp the center of the head first, and help prevent gasket failure. Of course the head and block surfaces should be true, flat, and the alum head without warp.
Re: Head gasket????
Posted: Fri Feb 11, 2022 9:52 am
by TXGOAT2
I'd think it would be a good idea to avoid boring a T engine over .040 if possible. Would a properly-done sleeve job to standard bore restore the original sealing surface? Besides the close bore spacing, most T blocks have a century of corrosion in the water jackets.
Re: Head gasket????
Posted: Fri Feb 11, 2022 11:02 am
by DanTreace
Would agree, keep to .040" for best results.
Also, have never placed a head gasket dry. Have always use good sealer, Permatex Copper gasket sealant, or quality alum spray paint with lots of metallic content, on both sides of the head gasket. No failures using good torque sequence too.