Adding all the pertinent numbers from the Mummert tech site, I calculated the deck ht. to be 9.742".  In measuring my parts, I actually came out .007" shorter than that.  The subject block on my BHJ fixture measures 9.772 +-.002 across the deck on one side and 9.668" +-.003" across the deck on the other.  I've checked my BHJ deck mic for accuracy and It's better than .001".  Question... is it common to have to remove that much material from the 292's to get close to "0" deck or am I doing something wrong?  Would appreciate any comments from those of you who do the decks on these engines.  I use a Van Norman 570 broach with a BHJ block thru fixture.  Thanks for any insight.

Warren

The value I use for the stock deck height on a Y is 9.775”.  Blocks being 0.010"-0.015” out of kilter from one side of the block to the other or from end to end is not unuusal on a block that’s never been worked on before.

 

Aftermarket replacement pistons typically have a shorter compression height than the stockers so it’s not uncommon for the pistons to be sitting in the hole slightly more than with the original pistons.

Lorena, Texas (South of Waco)

I use the same number as Ted, 9.775" to figure original block height. The original engine was .020-.025" in the hole, but with .025" steel shim head gasket that was okay.

Most replacement pistons are made with the pin .015" higher than original. That makes the deck .035-.040", which is what is tyically found. The real problem comes when you add .040-.060" head gaskets on top of that. You will now have the piston .075-.100" from the head. This often leads to detonation.

Rule #3. Never try to lower compression with deck height.

Don't ask what rules 1 and 2 are.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

Thanks, guys.  So it seems my measurments were pretty close on a block that has been "rebuilt" but the Mains, deck and bore have never been touched.  Is it acceptable to cut the block to around 9.755 for a good deck?  I also plan to cut about .020" from the "C" heads to help with compression.  Using the Fel Pro gaskets which I believe are .040" compressed.  The guy is buying the Mummert #2 cam (@270/450) and my goal is to get the compression up enough to support this cam in a mild street application.  Thanks,

Warren

I cut most of the blocks to a 9.750” deck height without any issue.  That’s my standard number for the stroker rotating assemblies and a zero deck height.

Lorena, Texas (South of Waco)

Thanks, Ted.  That's the kind of info I was looking for.  I'm cutting the decks this AM.  Thanks again.

Warren

We should also remember that some of these engines are over fifty years old, designed with slide rules, not computers, and made by people, not machines. A friend of mine says that in the fifties your chances of getting a hi-po engine depended on whether the factory worker cut the cam advanced or retarded!

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People should not be afraid of their government, a government should be afraid of the people.

--Alan Moore

I had a B9AE block in the shop to get the pistons zero-decked. The shop has a Rottler F65 machine. Both decks were way out of square. I posted the numbers on this forum earlier this year.



Edit; I found the thread, labeled 'zero deck'. Final height was 9.751". It had ranged from 9.784 to 9.753 on one of the decks.

Best regards,



Paul Menten

Meridian, Idaho

Thanks Paul.  My final came out to 9.753".  The variation across the deck and from side to side wasn't as bad as some I've done but it was way tall for the quench I was trying to get.  I get nervous when doing an older engine I haven't fooled with for a while and the numbers are so far off.  Ford has a history of screwing with the compression ht. of pistons to achieve a certain compression number.  I consider that to be counter productive but before I go whittling on somebody else's block, I try to ask questions of people who are familiar with the engine and problems.  This is a good site for straight forward info.  I'll update the valve thread I started a week ago when I get the seats cut and installed ht. worked out.  From this forum info, I found some 351W valves and springs that seem to be perfect for street performance and are readily available/decent price.  Thanks again.

Warren