Ok, I'm new to the forum, and have the most basic of questions. The numbers on my block are ECZ 6015 C. I have been checking John Mummert's web site and he ID's this as a 312 or 292 with EBU main caps. How do I know the difference, and what are EBU main caps? I have also been checking the heads and find no ID on them in the usual places. This engine came out of a 56 F100 (not the truck I have) and it is not known if it is original.

Thanks much.

Wally

The main caps will be marked as either EBU or ECZ. EBU is a 272/292. There is also a part of Mummert's site for crank identification. If the engine is out it's easy to check the marks on the flywheel end of the crank. Unfortunately its impossible to really tell with the engine in the car. Thus an awful lot of non Y-Block folks will advertise ANY Y-Block as a 312. Chuck in NH.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Thanks Chuck, guess I'll have to pull that trans now.

Wally. Welcome to the site.

If you can see the rear flange of the crankshaft while the engine is in the car, then the possibility exists that you can identify it as a 312. Any inspection or flywheel covers in that area will need to be removed to facilitate looking up at the rear crankshaft flange. With the harmonic damper placed so that the TDC mark is in the 6:30 o’clock position when looking from the front, then the cast in recess on the crankshaft flange will be pointing straight down or in the 6 o’clock position. The 312’s will have a 5/16” round protrusion or dot sticking up in this recessed area while the 272 or 292 engines will have a ¼” or smaller or no dot. The only nuance to this is some 312’s came through with no dot on the crankshaft flange as did many of the 292’s so if you’ve got the 5/16” dot, you do have the 312 but if you have no dot, then odds says it’s a 292 although could still be a 312. At that point, you’ll need to dig deeper into the engine and check for the ‘ECZ’ main caps or pull a head and check the stroke. If the bore is smaller than 3.800”, then it’s obviously also not a 312 but anything at 3.800” or larger can potentially be a bored out 292 and not necessarily a 312.

Here’s a link to another thread discussing crankshaft identification.

http://forums.y-blocksforever.com/FindPost8676.aspx

Lorena, Texas (South of Waco)

Thank you Ted, gives me something to do this weekend.

At the risk of being thought of as a dumba**, can someone explain to me why my 292 has ECZ main caps??? The block is ECZ 6015 A and all the main caps are ECZ and it has a EC crankshaft. Everything was marked std. when I took it down for the rebuild. Tom

last week i couldn't spell mukanik, now i are one

P.S. Was refering to myself as the dumba**. Tom

last week i couldn't spell mukanik, now i are one

As with anything, there are exceptions to the rule and this is possibly one of them.  But are you sure this isn’t a 312?  Measuring the the main bore hole size or the main journal size of the crankshaft will help to validate what you actually have.

Another identifier for the crankshafts are the lightening holes in the crankshaft rod journals; the 312’s use a ¾” hole while the 292’s will use a 15/16” hole.

Lorena, Texas (South of Waco)