Engine Puzzle ??

[Full_Blown]

Hi Folks,

I'm a newbie here but I just got my first vette and I'm looking forward to my new hobbie car and making some new friends here in the process.

I got me a 1979 coupe from a kid who through a rod in the motor. The vehicle is in solid shape. It's had some major work done to it, ie. gas tank, front end, exhaust, brakes etc. Looks like possibly a replacement motor in it now. The motor's got a Holley 1850 carb on an Edelbrok Performer intake along with some Moroso dressings.

I'm trying to sort of a couple of motor issues and wondered if some folks can assist me before I having to strip things a part.

I picked up a rebuild for a good $$. The guy told me, he was told it was out of a 74 vette. I check some of the casting numbers and it looks like parts are from a 75 L82 vette from the best I can tell.
Here's what I've got:
Block: #3970010; 4 bolt - ID V1003CKC - ser#(?) 165407472
- Cast crank (from best I can tell).
-Inside piston from bottom end view #TQW
-Intake: 346249

Question: Is this an L82? What Cam would yould expect it to have based on the numbers?, What type of pistons would it have? (I was told forged)

The head #s are: 333882 - 1.94/1.50, 76cc, but there are P3965543 finned aluminium valve covers with it.

Question: The second (rod damaged motor) is #14016379 with #462624 heads. According to specs, these could be 2.02 valve heads. Is there anyway to check for sure (withut removing them).

Question: Out of all the bits annd pieces I've got here, I'd really like to know what I've got and what the best combination of parts might be for a good snappy motor.

Any input is greatly appreciated.

Full_Blown,

P.S. Sorry for being so long winded.

 

[Vettehead Mikey]

Hi and welcome to the CAC from a fellow canajun.

First off, there were no L-88s made in 1975 (last being in 1969), and all L-88s were big block engines anyway. Your engine guy has been smoking all little too much wacky tobaccy.

From the CKC code and the block casting number, looks like this is a '76 L-82 engine from an automatic transmission car. Maybe your engine guy meant to say L-82 and not L-88. This is a 210 Hp engine.

Your intake manifold and head casting numbers are also the right numbers for a '76 Corvette, either L-48 or L-82.

 

[Full_Blown]

Oooops, my bad I meant L82.

So my fellow Canadienne , If understand you right, all parts are a match for a 1976 L82? So I can assume I've got a high performance cam? What a bout the forgered pistons. From my info, stock forged pistons don't match with the casting # of the head.

FB

 

[Tom73]

FB,
Lets check out the numbers. The 3970010 block is a very common block. Was used from 69 till 80 in Vettes and all other kinds of Chevy and GM products. The V1003CKC translates a V=flint engine plant, 1003=Oct 3rd engine assembly date, and the CKC is the engine usage code. CKC was used three times, twice in the Vette. First was in 1973 as a 350ci/145hp manual trans in the A and X bodies. Second was in 1975 as a 350ci/205hp automatic (L82) in the Vette. Third was in 1976 as a 350ci/210hp automatic (L82) in the Vette. Check the block casting date to determin which you have.

The head #, 333882, was used in the Vette from 74 through 77 as both big valve and small valve configurations. The other heads, 462624 , were used in the Vette from 78 until they changed over to alumn heads in mid 86 production. They were both small and large valve config. By the way, the only way to tell the valve size is to pull the head.

Also, the VIN stamped on the block, 165407472, looks almost correct for a 76 Vette. It should look something like, 1Z6S407472 (1=Chevy, Z=Vette, 6=1976, S=St Louis, 407472=last six of the VIN or the 7,472nd Vette in the '76 production.

The production L82 used Alum. impact extruded pistons, a forged crankshaft, and a 4-bolt block. Much stronger then the base L48. The L82 cam is a good Hydraulic cam, same as was used in the 69 350ci/350hp engine or the 68 327ci/350hp engine. Its specs are .450/.460 lifts, 222/222 duration, and 114 lsa .

Hope this helps somewhat.

tom...

 

[Full_Blown]

Good post Tom,

There was a lot of good helpful info in it. Enough that I can safely assume I've got a good rebuilt 1976 L82 engine. Me and my buddy are going to strip it down next week and redo the torques and guage everything (just to make sure) before it goes into the car. So I'll have a better idea next week.

Steve

 

[Full_Blown]

Any one know where the casting date is stamped? I see the clock casting but no date.

Steve

 

[Vettehead Mikey]

Casting date ( if it's a Flint block as suspected) will be at the rear just forward of the bell housing bolting flange and just to the right of the distributor.

 

[Full_Blown]

I'm getting some mixed information from some of the tech sheets, can anyone tell me what the factory intake valve sizes were for a 75, 76 and 79 L82?

Thanks,

Steve

 

[mike weyman]

the 882 castings came with either 2.02/1.65 or 195/160 valves. these are the best of chevy's "junk heads" they are no fuelly heads or camel humps, but they flow really well when ported, polished and gasket matched.I have the same engine in my 75 and with a little port and polish, a decent carb and intake, with some headers, this baby can put out 300 h.p. without attacking the short block, also at the same time keeping the 8.5-1 compression if you want higher compression have the heads planed down .020 and use a g.m..026 metal shim head gasket. this will bring it up to about 9 to 1 compression.
what cfm is that carb, mine is a holley 680 with vaccum secondaries, this is even maybe a bit high, 600 cfm gives great power while being not too bad on fuel.
the 010 block has a serial # on the block near the firewall on the driver side. if the 4th or 5th digit is a "j" you have the L82 engine 195/160. if it has a (I think" k")or other letter it is the L88 wich is the 202/165 valves.with either one that motor is sweet. mike

 

[mike weyman]

oh yeah the j or k thing only works if the heads are original to the block, but it sounds like a matched set since mine is a matching #s car and it has the same block and head #s as yours.

 

[Full_Blown]

Wooohooo!!,

I pulled her apart this afternoon and I've got 2.02 heads along with all the other L82 goodies. I'm sending the heads out Monday for porting and polishing. Mike, I've got an Edlebrock Performer and a Holley 600 to put on her too.

Someone I know recommended putting in longer pushrods. Any comments?

BTW, I've got flat top pistons with knotch outs for the valves. Any ideas wht I have here.

Thanks for all your input guys, I really appreciated it!

Steve

 

[cruzer99]

You might consider a set of roller rockers if you have it that far apart. You get a lot of performance for the $$ spent.
Good luck...

 

[Full_Blown]

Thanks Cuzer82, I was considering it. Thanks for the support!