i have a intercepter marine Y block ford i took apart due to a damaged block (cracked and welded water jacket) when i took the pistons and rods out, it had 312 rods (ecz-6205) on a 292 crank. (EBU main caps so it is a 292 block and no dimple in the flywheel flange making it a 312 crank) the crank is scored really bad and the mains all showed copper. the crank is turned 20/20. mains measured 2.480 and rods 2.278. question is why 312 rods on a 292 crank? . does it have special pistons? the pistons are marked 1791PX L2017 0.40 any y block guru's familiar with this?
I'd ask mctim64 about it...he's a guru. My understanding is that the connecting rods were typical among the 292 and 312's as far as length. Pistons and cranks were different.
The 312 rods are the same length as the C1TE 292 truck rods, used in the HD292 in '61-'64 medium truck engines....the C1TE rods are shorter than a normal 292 rod to accommodate pistons with an extra ring. FWIW. There's no particular reason to use a 312 rod except in a 312, or as a replacement for a C1TE rod (not that those HD truck pistons are available anymore, anyway). The C1TE rods are, or were, used for 312-based builds because they are "considered" to be stronger than a regular Y block rod. A lot of "rebuilders" don't know that those two rods are shorter than a regular Y rod. I'd check the crank stroke just to be sure, if you haven't already done so; not all 312 cranks have the dot on the crank flange. However, the main caps tend to indicate that it's a 292, and the fact that it's an Interceptor. The piston number is also a 292 number. Sounds as if someone just fucked it up. (shrugs)
I think I was wrong. I search over on the y-blocksforever forum, and the 312 rods are .070" shorter than the 292 rods.
Did the pistons reach the top of the deck? As said before the ECZ as well as the C1TE rods are shorter than EBU 272/292 rods but the 312 crank does not always have a dot on the flange. The piston part # looks like a forged piston (truck or industrial). Check the stroke on the crank or post a picture looking strait back from the snout, the #1 counter weight and throw look different on a 312 crank. 292 and 312 pistons do have the same pin hight but a 292 piston on a 312 rod on a 312 crank will hit the counter weights.
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