anybody know if 292 and 312 have the same pin height? i got a 292 bored to std 312 size running std 312 pistons but they kind of look too low in the bore. they're flat tops with no valve reliefs. could they had been low compression supercharger slugs. i'm new to the y block world.
The 292 is no doubt going to have a different wrist pin placement as the stroke is different. They had the same length rods. here is something to keep in mind, perhaps useless info but something to keep in mind. Blower pistons have a dish in them. The quench is measured from the top of the piston to the head and if you leave your piston farther down the hole to lower compression you increase your quench. There are many theories on quench but most builders agree that you want to keep your quench around .040 and moving the piston farther down the whole would not be an option. So blower pistons use a dish to lower compression not an adjust pin location.
Find a 312 crankshaft and have the mains ground to 292 size. Cheaper that custom pistons I bet and you pick up a few inches. "If some are good, more are better".
Wouldn't the 312 bore be the same as .050 over 292? Pistons that size might be as hard to find as a 312 crank.
Could be. I am not going to look it up and don't know offhand. If so .050 or .060 pistons should be pretty common.
John Mummert list the 292 rod as being 6.324" long and the 312 rod at 6.252" long. Then there is the 292 HD truck rod at 6.252" long. Which rods do you have on these pistons? -Dave
Compression height is 1.76 on both. A 292-312 is like a 289-302 Ford changed the rod to make up for the stroke difference.
Try here. http://www.ford-y-block.com/technical.htm Also check the head section, different castings had different volumes. Depending on the chamber size, my Y blocks run from flush to .010 down, with flat tops. These are stoker motors, 292 block, 312 crank, custom rods and pistons. Mummert also has stoker kits.
so which is it? different pin heights or different rods? i'm guessing different pin heights. i'm leaning towards going another .010 and getting .060 over slugs and starting over. there might be be other oddities to find, especially if the builder thought he could get away with using 312 pistons in a 292. thanks everyone
272 & 292 used EC 3.30" crankshaft CRANKSHAFT IDENTIFICATION 312 used ECZ 3.44" crankshaft Rod journal diameter: all 2.1880-2.1888" standard Main journal diameter 239-256-272-292: 2.4980-2.4988" standard Main journal diameter 312: 2.6240-2.6248" standard
From NAPA's catalog 292 compression height 1.76 car ,some truck 1.85 with 312 rod, 312 car 1.76. Yes Ford changed the rod length compression height is the same. Just like a 350 and 400 Chevy rods changed. The advantage will let you bore a 292 .110 over using common over size 312 pistons.
Go to the site ford-y-block. Near the bottom of the page you will find the "Information Center". You can trust any and everything John Mummert has to say about the Ford Y-block. -Dave
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