Technical 292 Y Block Head Gasket

I have a 292 Y Block in my 59 Ford Custom 300. I noticed increased water coming out the exhaust on driverside. I'm guessing I have a bad head gasket, running out the exhaust valve. Also noticed a decrease in collant volume from the radiator.

I was told if I ever needed to replace the head gasket on a Y Block the heads will need to be machined. Wondering if thats true?

 

Mine didn’t.. I’ve have both heads off to install better valve seals. I cover all holes with paper towels and used a razor blade and a vacuum running all the time. I cleaned the head side with a wire brush on a drill. I used gaskets from “Best” and the intakes with the exhaust crossover restrictors.
You must put on the head gaskets correctly. “Top” only means top for one the other goes upside down. There must be a corner of the gasket at the top on the front on both sides if correct . I’ll include a photos for both sides the right one didn’t get painted… The 3rd one is showing both heads off in the car.

 

Have you pressure tested the cooling system to find out exactly where the leak is? Are you using anti-freeze or straight water? Does it misfire? Any plugs fouled or discolored? Could be a cracked head, block, head gasket. Several things can be the problem.

 

I have not pressure tested it yet. I planned on doing that next.

 

Machining the heads not necessarily true unless the head gasket was installed incorrectly at some point and the head warped, as mine was. Heads needed work and the block needed to be stitched to repair a crack. As already mentioned, very important to have head gasket correctly installed, corners to the inside at the front!

 

To find out if your heads need to be milled for flatness, use a machinists straight edge or surface plate long enough to accommodate the length of the head and a feeler gauge. Using a feeler gauge you need to have about .003" variance or less anywhere on the mating surface on the head. These heads are pretty finicky about flatness especially using the original style thin steel head gaskets. Be very thorough about removing any sign of old sealant,etc. Coat the gaskets with shellac or Spray-A-Gasket when installing. Be sure you tighten the bolts to the proper torque and in the specified sequence.Very important with these. While it's apart inspect carefully for cracks, pits or other imperfections on the heads and the block.

 

Re-torquing the head and some Barr’s leak might solve the problem, worth a try. I’d only do one bolt at a time, pull it , clean the threads , oil threads and reinstall. Will be a pita for 2 of the bolts as the valve train interferes.

 

FWIW, I think Ted Eaton has had better luck with the Best’s head gaskets than the FelPro’s. Jimmy Six might recall, it was up recently at yblocksforever. Take a close look at the rear cylinders, seems to be more common there than the front. On either side.

 

Ted recommends Best as almost every one doing yblocks. I have used Fel Pro that are black without any problem since I had them once. Fords like early Chevrolets used shim style that guys painted silver and you needed every thing really flat and true. The multi layer or graphite style with stainless fire rings are pretty bullet proof and can stand a few thousandths off perfect. My GMC 6’s use Bests and have an o-ring in the head and a receiver groove in the block. I install the upside so the open edge of the stainless will go into the block groove. Just works for me and 14-1 compression.

 

Have a machine shop check them. While the heads
are off do the diesel fuel check of the valves.

 

One thing to consider about these engines is the head to intake manifold relationship. If you mill very much off the head it will change the the depth if the angle where the intake runners fit the head. Head gaskets that are too thick will do the same thing. Lower the head and the manifold will sit higher in relation to the ports. Raise the head and it will sit lower. This will cause a slight to moderate port alignment mismatch and could affect the air flow and cause leaks. I remember the problems folks had with this in the past (long ago). To correct it the manifold runners would need to be machined in order for the ports to match properly if the heads are milled too much.

 

The factory uses a .021 head gasket and the new gaskets are .051

 

With a Y block mill the intake side of the head that way the intake can still be used with other heads. It's been a few years but as I remember for ever .010 off the face you take .018 off the intake side. This applys if both heads are cut if just trueing the head it should not be needed.

 

Gambler, go to eatonbalancing.com, send an email to Ted Eaton, and ask about registering for y-blocksforever.com forum.