2721955meteor (3/19/2021)

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...I am interested if the 292 con rods would eventually cause issues.

I prefer the longer rods when I can use them.  There is less piston to cylinder wall wear at the lower ends of the cylinders with the longer rods and in those cases where the compression ratio is marginally on the high side, there’s less propensity for detonation due to an increased residence time at TDC.  Where the stock type pistons have adequate deck surface material and/or a ring land that is not crowding the top of the piston, it’s a simply matter of machining the tops of the pistons to get them back even with the decks.  If zero decking the engines, then it typically does not take very much piston machining to accomplish this when using the longer rod with a 312 crankshaft.

I have run as long as a 6.750” long rod in the Y engines along with a 4.000” stroke and that requires a piston compression height of 1.000”.  That combination makes for a very tight ring package on the piston but is a very strong performer.  I have done several 312 crank, 292 rod combinations with a relocated wrist pin location in 292 blocks and those always end up being very good engines.  As a caveat to this, the longer EBU and C2AE rods are always easier to find than the shorter ECZ and C1TE rods.

Lorena, Texas (South of Waco)

I purchased a y block core from a junk dealer complete engine. on looking why it would not turn 2 revs, removed heads and pan. found this was a 312 , I noticed the pistons came to the top of the block,as well had a rebuilt tag(autherised ford rebuilder). cheked the con rods they where  292 rods(slightly longer than 312.) re info on this great sight. Freed up stuck valves and got engine running, ran well. sold same.  I am interested if the 292 con rods would eventionlly cause issues. the engine had new style thicker gaskets(aprox .040 thicker) than shim typ. coments pls heads where 1956 markings  ecz c that suggests 1956 mercy,

You don't need the valve notches

some 292 pistons can be used on a 312 crank.i used a set of federal mogul pistons years ago.

Valve notches will not line up." Did you mean that the 305/307 pistons will not fit? I ran this by Ted a few months ago. Realizing that I had miscalculated, no, I'm not going to use 283/307/305 pistons.

F means forged, the pin height is good as is, almost all  performance pistons are machined for floating pins, 305 sbc and 307 sbc will fit also, the valve notches will not line up.

Silent Rick.  At an earlier time, like the middle '60s, Thompson Products made PowerForged pistons that were marketed as aftermarket replacement pistons.  I used them in the first y-block I rebuilt in 1966.    Thompson Products merged OR became TRW at some point in time.  You might be able to determine the history on this company change using the Internet.

TRW continued to market replacement PowerForged pistons.  You know more about what became of TRW than I do!

Per an old TRW sheet I have, L-2018 pistons are PowerForged and 3.800 inch diameter.  I don't know what the 'F' suffix you identified means regarding their oversize dimension for the 3.800 basic bore diameter.

Cliff is correct about 292 y-block pistons having a different skirt configuration than 312 y-block pistons.  As Cliff indicated, 312 pistons can be used with a 292 crank, but 292 pistons can not be used with a 312 crank due to an interference issue.

Forum Moderator John 'Hoosier Hurricane' in a posting some years ago explained what modifications he had done to utilize a set of GMC C***Y pistons in a y-block he built.  My recollection is that John indicated that the C***Y pistons he used had press fit piston pins where the y-block used full floating piston pins.  As Cliff indicated, the pistons John used may have been cast rather than forged.  Also, didn't the C***Y pistons have valve notches in their flat tops?  John may be able to recount all that he related previously.  It almost seems like there was a piston pin compression height issue that required John to machine the piston tops, too.

I suspect that the Forum link with Hoosier Hurricane's posting is so old that the software package changes webmaster Jim Culver has installed for the Forum website would make it unreachable in the archive.  John or Ted may be able to answer that accessibility issue. 

Silent Rick, I've got a friend with a stash of old y-block parts and NORS parts.  Last I knew, he had some flat top replacement Thompson Products or TRW forged pistons.  What PowerForged replacement diameter pistons are you seeking?

IF you're going to use a supercharger and are looking to use a static compression ratio of 8.0 or 8.5:1, it seems like you are looking for a set of y-block 5750 / 471 cylinder heads.  Rono is someone you should try to connect with on this Forum.  I recall that he's using a set of 471 heads on his supercharged engine.  I think he's using the same intake manifold you're talking about using as well.

Hope some of this helps!    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Finding the right 283 piston will be almost as hard as finding the right Y-block piston. There's little demand for them.

yep, i have a .050 over 292 block

Yes that's a forged piston, there is a difference between a .050 over 292 piston and a 312 (skirt length) the 312 piston will work in a 292, the 292 piston will not work in a 312 (hits the counter weight), a standard bore 283 piston will work (.075 over 312) you will have to bore the rod (pin) to .927 most forged 283 pistons will be full floating.