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Preparing Cylinder head for Gasket


GrahamPaige29

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Hi guys.  Sorry I ask so many "dumb" questions but I'm a beginner.  I am almost ready to install the news gasket and head on my '29 Graham Paige.  The block and head are nice and straight.  I'm wondering if you guys "dress" the head and block surfaces in some way before putting the gasket on.  I've seen guys run a very flat sharpening stone over the surfaces to clean them up a bit.  I did go over them with a razor blade to clean off some gunk.  Do you believe in that sticky gasket spray or is it just a messy waste to time?  Thanks.

 

 

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Stone it and you'll have grit where you don't want it when your trying to get it clean to assemble.

 

Just wipe down the mating surfaces with solvent to get rid of any traces of oil and dirt. Then spray the gasket with this Permatex Copper Spray-A-Gasket.  https://www.permatex.com/products/gasketing/gasket-sealants/permatex-copper-spray-a-gasket-hi-temp-sealant/ 

 

Paul

Edited by PFitz (see edit history)
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Yes. Use a thin bladed putty knife to work in under the gasket to loosen it.  Works faster if you can warm it up.  Then just use solvent to clean off the Copper Spray-A-Gasket on both the engine and the gasket.  

 

If you can get spare gaskets, I'd recommend that you do so.  If your car is going to be a driver, it's good to have spares on hand whenever possible. Parts of that era are becoming tougher, and tougher to find as stocks dry up and as there are fewer and few cars that vintage being restored, parts manufactures are moving on to making parts for later makes of cars. So, who knows what parts for your car will be available in future.   

 

Paul

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BTW.  The silver you sometimes find on old copper gaskets ,.... that's most likely because many old mechanics used rattle-can silver engine enamel spray paint before the spray gasket sealers became popular. Works well if the head and block are within spec for being straight.

 

Paul

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3 hours ago, GrahamPaige29 said:

Sorry I ask so many "dumb" questions but I'm a beginner.

 

No such thing as a "dumb" question! Just because you don't know is not "dumb". Everyone has to learn, somehow.

 

I am surprised Paul suggested a "sealer" on a new gasket, but I am a learner on training wheels too. My understanding, from reading these various fora, is that the spray would be used on a USED gasket. Maybe Paul has detected the block and head are not machined and recommended it to deal with any asperities?

 

 

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I don't know how similar your engine is to the 1936-41 Graham engine... MoToR's Manual 1947 has a tightening sequence for that motor. The torque (for Aluminium head) is 41 to 44 lb.ft.. Bring up in stages. Final tightening after a run and when completely cool. It looks like the pattern is different. From your block it looks like you have 22 studs? The later one has 20. Note also, I don't know the size of the studs in this later motor and whether yours are similar.

Edited by Spinneyhill (see edit history)
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If your head is still off, it is very worthwhile to get it refaced. Just a lick across it on a milling machine to ensure that it is perfectly flat. The long 6 & 8 cylinder heads can vary a bit over their length.

 

The point of all this is that the gasket will have a far easier job of sealing if it is matched against at least one flat surface, instead of two uneven ones. Machining is not difficult and should not cost much.  It will greatly improve your chances of achieving a good seal.

 

By all means follow the correct tightening sequence if you have it, but otherwise, follow the simple rule of starting in the middle and working outwards, tightening it down in stages. Above all, make sure that you re-torque the head after a few minutes (and after a cup of tea :-)), again after it has run for a few minutes and again after a few days. Essentially, keep re-torgueing it until it does not 'go up' any further with subsequent torgueing.

 

As for gasket sealer, you will hear many different views. On these older engines, I would tend to use something like Red Hermatite or Wellseal, particularly on the side facing the surface which has not been machined (ie the block face).

 

Adam..

Edited by Alfa (see edit history)
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I rebuilt a 1926 Packard straight eight years ago and did have the head surfaced before assembly. But I had a terrible time getting a good seal. Went through three headgaskets if I recall right. 

Anyway a friend who rebuilds professionally said that it is tough to get a good seal  on long engines like that Packard. He recommended Hylomar spray as a gasket sealer. 

Worked great and I always use it on everything. 

--Scott

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Olsen's Gaskets had the Graham head gaskets last time I needed one.  The Copper Gasket spray is the ticket, its not a permanent adhesive, it will come apart with some work.  I built a head remover for my Grahams, it is a 1/2 inch piece of plate steel that sits on the head studs.  I broke out some old spark plugs and put carriage bolts in them.  So you thread in the broken spark plug with the carriage bolt, stud up (its a flat head so the bolts don't fall in) set the plate steel on (with holes for the carriage bolts) thread on nuts and extract the head.  I have not had to use a wrench to get mine off yet just finger tighten the nuts.  The slow movement lets you keep the head perpendicular to the block and lots of time to keep the gasket moving the right direction.  2x on surfacing the head before you install it!!!  Might want to do the exhaust and intake manifold while you are there.  The shop I use has a large belt sander device to clean them up.   On the Graham head the only bolt that is tight is the center bolt the rest are oversized holes.  I put anti seize in the head holes to make sure the next time the head comes off, it is an easy job.  Try not to get anti seize on the head bolt where the nut is, it can mess up the torque.

 

Good Luck!

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