Under Spec Head Fix?

exit64 · Post by **exit64** » Mon May 15, 2006 10:49 pm

Well being the glutton for punishment that I am and since the 1970 1600 is running well enough to be considered road worthy, I am going to start back up on my true love, my 67.5 1600. I have the original numbers matching block and all the guts to put her back together except that the head I bought is .010 underspec. I was talking to the machinist at the local hot rod shop and he said "no problem, just make a copper shim". He walked me through the steps of how to aneal the copper so that I could use it for this purpose. Any of you guys tried this or should I just find a head that is within specs? Am I just going to be wasting time that I should be putting into the fun stuff like sanding and cleaning parts?
Thanks,
Mike

Post by **spl310** » Mon May 15, 2006 11:01 pm

Well, it is up to you, but you have a few choices. First, you can put U20 or even H20 pistons in the engine. The R are domed, the U are flat and the H are dished. I wasn't a math major, so I can't help on how much each will change compression. If you want a copper shim, PAECO may already have them made up. Try at your own risk - I have heard some complaints, but nothing specific. The final option is to find a head. I just so happen to have a complete, good running 67.5 1600 engine in the garage...

keith0alan · Post by **keith0alan** » Tue May 16, 2006 8:53 am

The first thing to try is this. Sit the head on the engine with no head gasket. Turn the crank. If the pistons do not hit the head you are fine. If it does you can tell by how much it bumps up the thickness of shim you need.

If you want a real workout you can find where the pistons are hitting and carefully sandpaper flapwheel/ die grinder on the face of the head to reshape the combustion chambers. While you are doing that measure the volume of the combustion chambers and even them up. Since the head was warped they will be different sizes. Sounds like a lot of work since good used ones are not that hard to find, but, they are getting harder to find and someday will be all used up.

keith

Post by **dbrick** » Tue May 16, 2006 11:43 pm

LLook up on the net how to "clay" an engine. Basically you put it together, with or without the head gasket, no bolts a strip of clay or silly putty on top of the piston and rotate the motor. clay crushes, you can slice the clay where it hits and directly measure the clearance. Sort of giant size plastigauge.

nomadtrash · Post by **nomadtrash** » Thu May 18, 2006 8:31 pm

I think cincity sells thick copper headgaskets for the R16.

Post by **dbrick** » Thu May 18, 2006 10:16 pm

Dean at Fairlady lists one, part #1174, others may be selling the same part.