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got a 57 235. which head gasket should I use? fiber face or copper? and what kind of oil in the engine?
Thanks
Fatback
 

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Depends on the machining process of the block and head.
Fifty years ago the typical surface was done with a large round flat spinning grind wheel - trued flat. This left a fairly rough surface and copper was required. the roughness would chap the copper - broaching it into the grooves left from the grind stone. By the mid 70's surfaces were done with a wheel with several pieces of grindstone trued together - although still stone and fairly rough as the edge of the stone was doing the work it left shallower grooves and composite gaskets worked better - but copper was still the choice for the long heads that tended to warp more. By the mid 90's most machine shops started using carbides and the surface was then milled to within 100 microns of perfectly smooth and copper just does not seal as well at that level - requiring a composite.
So to answer your question - was the BLOCK milled with carbide or stone? Rarely have I found an old in service block that needed milling - they usually have enough stress relief in the water cavity that in service they run well within the few thou tolerance. However the head is usualy a different story. Your gonna have to play detective to determine if its ever seen a surface job and how! Clean it up and check it with a flatbar and feeler guage. If its very litle warpage and you can descern rounded looking marks down the surface - its either factory or ground so either would work. If the head is perfectly flat (which would indicate its been milled since OEM built) and there are NO marks visible - or if you sent it in for a mill and they used carbide - it would probably serve better to use composite.

Oil - not arguing Zody but I wonder why you would reccomend 50 without knowing the bearing clearances or operating oil temp range?

30 for .0010 to .0014, 40 for .0015 - .0020, 50 for .0021 and up (serviceable max at .0029) operating range max 240 oil temp. You can run wider clearance for the viscosity if the oil temp is lower than 200. What happens if you run a high vol pump or high vis oil with lower clearance is that the oil which not only lubricates but removes heat - does not spill off fast enough to REMOVE the heat so the journal runs hotter - and thus has a shorter life and fails easier. And HIGH ZINC oil!
 

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No worries John...

Just a great believer of sticking to mineral oils in the old fashion stock engines, some detergent oils run so thin when hot, when the old type engines rely on oil pressure & not so much oil flow as modern engines... I have always run 20/50 in all my pre 70 amerian motors for the past 30 yrs or so, never had a problem :tu
 

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Sounds good. Curious tho - do the oils you get over there follow SAE formulae? here even in mineral blends 20-50 now has just as much detergent as as 10-40 or 10-30. Unless we go higher dollar and buy specific old car formula the zinc is practically non existant! (I tend to agree in staying off the syns in old cars). If using a straight weight I would not go above 40 tho.

I do use 20-50 in old cars - when the bearings are down to their final stages of life span - if oil pressure is below 15psi hot at idle (providing of course it climbs at least 10 per thousand RPM - without the climb we just cross our fingers and wait for knocks lol). And here I would use a straight 50 - as long as oil psi is not above 40 cold with it.
 

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head gasket

I'm rebuilding a 235 for a truck of mine. I'm thinking the composite for myself as it may be a little more forgiving of inperfections (if I don't resurface the head). The composite material head gaskets are used for many of racing engine and if it's good for them its good for the 235. :happy0030:

I also agree with the other post about machining for copper. Either way you would probably be ok, but copper kit costs $20 or so more.
 

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Head gaskets

Back in 65 when about all the head gaskets you could get from Chevrolet were metal shim type, we used to coat them with aluminum spray paint and install them while still wet. One engine we built was being protested and they wanted to take the head off to measure bore and stroke ( It was a .030 over 327) , after removing all the head bolts they couldn't get the head off even using a crow bar in the port.
 

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Back in 65 when about all the head gaskets you could get from Chevrolet were metal shim type, we used to coat them with aluminum spray paint and install them while still wet. One engine we built was being protested and they wanted to take the head off to measure bore and stroke ( It was a .030 over 327) , after removing all the head bolts they couldn't get the head off even using a crow bar in the port.
So did you win the protest? :sign0020:
 
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