You don't need the valve notches

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,

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)

As No Shortcuts stated, I have an engine with 283 pistons with a 3.750 bore, standard 283 size.  The rod (C2AE/292) small ends had to be honed to .927 for the 283 pins, grooves cut in the piston pin holes for lock rings, the pins shortened to accommodate the lock rings, and the piston tops machined to Y pin-to-top dimension.  The Y rod small ends  were too wide to fit in the pistons, and were narrowed to fit.  I didn't have my Bridgeport mill then, or I would have machined the inside of the piston for clearance. Actually, I went with 0 deck height, so the piston tops were measured during pre-assembly and machined for 0 deck.  The valve pockets were not considered a problem, the machining eliminated much of the pockets.  A plus to this was the top piston ring moved up in the bore.  I was able to do all the machining, except honing the pin bores, myself, otherwise this would have been too expensive had I hired the work done.  Custom pistons would have been a better choice.  I did this because I used an ex stock class block that was already .060 oversize and worn.  The engine is in my F350 car hauler and is still doing fine after several years and thousands of miles. 

John - "The Hoosier Hurricane"

The stock bore of a 283 is 3.875. The stock bore of a 265 is 3.75. A stock bore 292 Y-block would have to be bored .125 for standard-bore 283 pistons. There's also the issue of compression height and rod length.

With 312 rods and a 312 crank (ECZ) you don't have to cut the piston tops, the deck height is about right as is, if you buy aftermarket forged pistons the rods do not need to be narrowed and will be full floating (no need to cut for pin retainers) and yes they still make standard sizes.

Excellent thread. I only wish I would have known all this 7 years ago when I dropped a 312 crank in my 292.   I could have saved .023" of good iron from both decks. After removing that amount from each deck, the pistons were still .009" in the hole.


64F100 57FAIRLANE500

I run 312 blocks with 312 cranks, no problems, I never turn down 312 cranks to fit a 292 block, I worry about overlap (main to rod journal), it's bad enough when I turn down a rod throw to fit a aftermarket rod.

i have a 56-57 292 block that has been bored .050 or 3.80. 

REX HP told me the TRW L2018F has the same profile as a factory 312 piston. so using a EBU or C2AE rod, the piston will sit a bit below deck and with G heads, i'll end up with a static compression ratio of 8.4:1
they said advertised compression is 9.0 but in actuality, it's more like 8.4

the old TRW piece has the stock 312 profile so that it can be used with either crank. i have a forged C1TE truck crank and am looking for a set of C2AE rods also.

a standard 283 piston is 3.875 which would require i go an addition .075 or a total of .125 over the stock 292 3.75 bore. too much.

i need a set of forged L2180F in standard bore size of 3.80