What engine is this? 3959512 block [Archive] - Team Camaro Tech

: What engine is this? 3959512 block


3959512
Aug 23rd, 09, 11:30 AM
I just bought a SBC motor and tore it down I need help decoding it ive never seen any SBC that looked quite like this. I was gonna put it in my 69 c-10 but when i searched the casting number in google this board was all that came up. it was supposed to be a 350 from the guy i bought it from Block casting 3959512 It has no vin on the place where the vin goes The code is CE8A23482 where the code taht tells what the motor is. I tore it down and the crank was this crank 3815822 it was 2" on the rods and 2.3" on the mains, i used my digital caliper so at this point i was pissed i thought i got screwed into a 283 but the the pistons have a huge *** dome and they appear to say L2210 30 on them i measured and they are 4.03 inch bore and the pin is 1.8" from the deck ive never seen those measurements on a SBC piston before, at first i thought it was a 283 with an insane overbore but it could be some kind of early 327??? the heads were just regular 882 heads dated 1978, i think im going to scrap these and go to either camelbacks or to vortex heads depending on the deals i can find i already have a 383 kit my question is can i put it in this block? if not what is this block worth? also it looks to me like it is a serious *** motor for race gas only so can I sell the 383 kit and use this engine instead except set up for pump gas?

Barefoot Dave
Aug 23rd, 09, 12:23 PM
The block is an early 327. Used from 62 to about 67 I think. The crank is a good small journal steel crank and the pistons are TRW 302 pistons I think. I'm sure about the crank and block...not so sure on the pistons but definitely NOT a 350.

69duskblueX33
Aug 23rd, 09, 12:29 PM
You have what looks to be a 302ci service replacement engine for a 67 z28. There is no way to know if that is what it started life as, especially now that it is .030 over and rebuilt, but it is by no definition a bad engine. Those pistons were used to give 12.5:1 compression with 64cc heads, and I suspect that your engine has had the 882 heads swapped on to lower compression for pump gas. With those pistons, a zero deck, and .040" head gaskets, you should have right at 10:1 compression.

That block is a 4" bore casting, and according to some sources it has thicker than normal cylinder walls. I have one dated for 62, and my machine shop did mention that it's walls were thicker than most late model 350's that they'd sonic checked. All of the sites list it as a small journal 327, but that casting pops up on ebay as a CE 350 from time to time, and i think there are even a few cases of CE 302's using that block.

As for doing a 383 kit, you can buy another crank for a small journal 383 build, or you can open that block up to large journal main saddles (GM did this on some service engines). I wouldn't do either of those though, getting another 350 block would probably cheaper than either of those approaches. If you really want to stroke that engine, you can use a small journal 327 crank and build a 331 cubic inch engine. I'd use flat tops, vortec heads, and a small solid lifter cam for a street build that would run on pump gas, provide the grunt that your truck needs down low, and allow you to run it up high the way early 327's did. That probably wouldn't work as well as 383 in that c-10, but you would definately have something to talk about as opposed to the dime-a-dozen cheap 383 builds that are in the older pickups.

You can also leave it as a 306, but you'll have to think long and hard about the cam choice to get it to work well in a truck. It will certainly breathe better than a truck motor 305, so that's not to say that it can't work in a truck, but that engine is definately out of it's element between the fenders of a fullsize.

What I'd do with it is just freshen it up with new rings and bearings, possibly a hone job, put a set of fresh double humps back on, and stick one of these cams in it:
https://secure.pawengineparts.com/shoppingcart/ShowItem.cfm?itemid=71657&catid= (-140 grind)
https://www.horsepowerparts.com/index.php?content_id=175&product_id=210980 (-140 grind)
http://www.summitracing.com/parts/MEL-22450/ (-754 grind)
(those are the new copies of both of the GM racing grinds, -140 is easier on the valvetrain than -754 is)

Put it on ebay or craigslist as a hopped up CE 302 and it will sell, then you can use that cash toward your 383 build.

67 Plum
Aug 23rd, 09, 12:36 PM
Yep it's a 302.Not sure if it started life as one but it is now.Unless you bought your 383 kit to fit 1967 back small journal blocks it won't work.

RPOZ11
Aug 23rd, 09, 04:17 PM
Block casting 3959512 It has no vin on the place where the vin goes The code is CE8A23482 where the code that tells what the motor is.

My Corvette friend had several of these over the years and he was pretty sure that that 512 block on a SBC is a Warranty use Block.

The internals may represent whatever the Factory determined it to be the warranty for.

Whether it was had 302 or 350 internally, that 512 Block was used for replacement use.

zdld17
Aug 23rd, 09, 05:19 PM
My Corvette friend had several of these over the years and he was pretty sure that that 512 block on a SBC is a Warranty use Block.

The internals may represent whatever the Factory determined it to be the warranty for.

Whether it was had 302 or 350 internally, that 512 Block was used for replacement use.

:yes: Looks like a warranty replacement made in 68? Those stamping numbers are in the 20000 range, Flint engine ? This makes me think of what CRG mentions.
http://www.camaros.org/engine.shtml#service

Jerry@CHP
Aug 23rd, 09, 07:02 PM
That casting was a warrantee replacement for the '67 Z28. I have a couple 512's in the '67 Z28 registry that were replaced under warrantee. It's also a higher nickle content block too as many of the NHRA racers who run Stock Eliminator llike this engine block for racing purposes. Legendary sportsman racer, Ben Wenzel is one of them who uses the 512 block.

Jerry

Kurt S
Aug 23rd, 09, 11:18 PM
That block was made for years. I've seen it used in the 70's. It was a generic block that covered most applications.
http://www.camaros.org/drivetrain.shtml#BlockCast
"The 3959512 casting was mainly used for warranty / service blocks, though it did have very limited production usage in 69 engines. It is a 4" bore block, thus could have 302, 327, or 350 applications. "