Is .040 the compressed thickness of the head gaskets? Or does that make much difference? Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Daniel:

The rule of thumb you are looking for is take 1.5 times the amount taken off the head surface off the intake surface.  Like Ted said, up to .025 don't worry about it.

John

John - "The Hoosier Hurricane"

As rules go, the heads (or deck) can be milled 0.025" without being concerned about the intake match when using composite head gaskets.

Lorena, Texas (South of Waco)

Ted, thanks for the opinions. This being my first all out build, I believe I am going to go with the composite gaskets anyway. I will look to mill a little more off the heads to give me the compression I want. Where can I find the rule of thumb for milling the intake surface of the head when the bottom is cleaned up?

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

My own preference leans towards the composition gaskets due to better water jacket seal and depending upon the brand, not needing to be retorqued after the initial fireup.  FelPro is my brand of choice for the Y.

But if using a small bore, there are some advantages to using a steel gasket in that the quench area between the head and deck where the gasket is inset is smaller and thereby a smaller area for detonation to propogate.  And the steel gaskets do offer some marginal compression ratio increase in lieu of decking and/or milling the heads if looking for a quick way to do this without the machine work.  The mandatory use of some kind of sealer on the steel gaskets to prevent any water weepage and the necessary retorque after warm up typically keeps me away from them though.

Lorena, Texas (South of Waco)

Ted - just reread RB's earlier post and saw he indicated the piston/HEAD GASKET/deck clearance. my fault on that one. thanks for the clear up. By the way, do you favor the composition gaskets?

RB - thanks for all those specs. It gives a man something to consider - didn't want to have to reinvent the wheel here. I have been "collecting" a few parts here and there - scrounging for blocks, etc. I believe I will have all that I need real soon - would like to find one more usable G head. So far I have tinkered, tuned, and tore up Y blocks...never did an all out rebuild from the pan up - this will be my first.

Thanks for all this information fellas.

Dan

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Daniel, Econo is a relative term when it comes to building Y blocks. I was able to re use my pistons and valves, so I saved some there. Rings, bearings, gaskets, cam, valve springs and machine shop services comprised the bulk of the expenses. Yes you could use good used stock 292 pistons in a bored 272. They would be adequet for your application. My engine had about 45,000 miles but had 1 cracked piston. I bought a used one to complete the set and it worked fine. Ted is correct, total compression distance should be .040. 0 deck plus .040 gasket or .025 gasket and .015 deck. My engine had the piston .018 down the bore. I decked it .010. I ended up with a little more than optimum clearance with a .040 gasket.

The cam is a custom grind from Chris Nielson. Specs are 256 advertised 215@ .050 .325 lift at the lobe 112 degree lobe center.



This is a much more aggressive cam than a traditional Y block grind in the lift vs duration area. The valves open quickly and high allowing good flow without excessive overlap which would kill idle quality. Spending a bit more money on the heads would have gotten another 10-15 hp out of this combination in my opinion. Otherwise, it is a nice street combination

My take on Royce's deck clearance is that's he's at a zero deck now if he's got 0.040" clearance as the composition head gaskets are typically around 0.040" thick.  If using a 0.025" steel shim head gasket, then you'd need to be 0.015" in the hole or below the deck to obtain the same 0.040" 'clearance'.

Lorena, Texas (South of Waco)

RB, do you have the specs on the cam by any chance?

Just curious, but what made you go to .040 on the deck and not "zero" deck like I have read in a lot of other posts and the Y mag. What is your take? ...Obviously you are developing a few horses. I think the 57 two 4's ran around 270bhp. Did you use new pistons? I have been thinking about boring out the 272 to 292 spec and using the pistons from the blocks I have.

"econo" build - what kind of dough are you talking about?

Thanks, Dan

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Daniel, I just did an econo build on a 58 292 this winter. With all stock parts a reground cam with more aggresive ramps, but still streetable, It made 240 dyno hp. Use G heads shaved .020. Select the pistons / headgasket /block decking to obtain ..040 clearance. Use a later recalibrated distributor, a 57 4bbl intake and you should be able to duplicate or improve on my results. I tested an Autolite 4bbl and a Holley 600 on the dyno. The holley made 7 more hp but the Autolite was gving some nice BSFC numbers which would equate to good fuel economy. The next couple of issues of YBM should have articles about this engine