CC 283 Block & Cyl Indentification

[mtuck02]

I purchased a complete CC 283 engine w/paragon trans for my Jersey Speed Skiff project. Everything looks complete and it has been tore down for rebuild. Seller advised motor was late 50's or early 60's and was in a barn for over 30 years (it was I pulled it out)
I have never done an engine rebuild and the first thing I did was look up the ID numbers which has me totally confused. Using MORTEC site the ID tells me the following:
Block ID 3756519 = 283 '58-'62 (OK looks good)
cyl head 3767462 = '62-'67...327 (!)
cyl head 3774684 = '62-64..327 75cc chambers(!)
Block date = april 5 '60 (OK)
Cyl date = April 6 '60 (?)
Cyl date = June 17 '59 (?)
So, I am confused.
Do I have mistakes with my cyl ID's, did CC build (or can you use) 327 heads with 283 block or was it bored out to a 327?
Any thoughts help would be appreciated
mike t

[kenJ]

Small block GM engine of that era. 283 block, different pistons and heads make it a 327. Machine work was cheaper than buying a new block. Lots of DIY performance mods were done, in various configurations. As a general rule, valves jobs were done at about 60K miles, total rebuild at 100K miles or less. Those were the "muscle car" days, gas was cheap. Still a popular engine, should be easy to find the parts you need to rebuild correctly. Take a look at some "Hot Rod" type magizines, should be plenty of parts ads in the back.

[BHOFM]

Chev parts interchange like crazy!

I looks like you have a mis-match on the heads, different
valve size, check the larger valve, one head should have
1.72 and the other 1.94, this is not good!

You may have bought a collection of odds and ends parts!

Load it up and take it to a machine shop for ID'ing
before you spend any more money on this stuff!

[mtuck02]

Gents: thanks for quick reply. Yes I am taking it in for ID'ing. That was the plan all along but still was baffled by the whole thing (especially cyl heads dates dont make sense). Anyway live in Detroit so plenty of places to get the ID'ing and work done.
Just 2 final things:
1. Yes, diff pistons & heads make it a 327 but wouldn't the bore have to be 4.0"? (its not)
2. I guess I may have "bought a collection of odds and ends parts!" but the thing sure as heck looked like it was original (except funky intake manifold)...see the pic...

I guess I will post whatever I find out....thanks again

[2850 Bounty]

Man, it's been years for me with one of these.... I was very much into these in the mid 60's...... but correct me if wrong here:

That 283 would be the small journal crank.
Larger bore (4.00") would not give us 327 ci. (I believe this is how we/they came up with the early 302 ci engine.)

The 327 would have a different stroke..... (larger).

The 75cc heads with a flat top piston will give you the much needed Quench Area necessary for a true and better Marine Engine, IMO here.
(a quench style cylinder configuration is much desired for our marine cruiser type usage... do not reduce compression w/ dished pistons)

You'd have to run the calc's on that to know where your Comp Ratio is due to the shorter stroke..... but you want to stay within a good range for Marine use.
Piston selection is going to be KEY in building this correctly for Marine use.

[PAR]

It's very common for those old Chris Craft GM conversions to "eat" heads. They got hot and warped, cracked, the raw water impeller died and one or both heads melted down, etc. This is a typical occurrence, particularly in a 50 year old engine. It's also possible the internals don't match the build year either. Considering the average life of a small block in a straight shaft arrangement, you're lucky if it has any original parts on it.

This all said, take it to a Chevy guy. All the first generation (small crank journal) blocks are interchangeable as are 95% of the heads, without machine work. This is why you have different heads, one went south on a different occasion then the other.

One tip, those old 283 heads could be "molested". It's very common to have weird porting and "relieving" done on those old heads. Most of the time this ruins the head's ability to flow, but the racers were trying anything and every thing to gain some speed improvements. Every once and a while you'll find virgin heads (I have virgin 1960, 283 marine heads, still on a 1960, 283 in a Chris Craft). The biggest thing I see on these heads is the valves are too big for most marine applications (but great for a drag car) and the intake runners are cut up badly.

You can buy NOS heads for this old girl, rebuilt units or new castings. Go with the 1.94" valves, because unless you're going to toss a 400 HP cam in this thing, the engine can't swallow enough air to make 2.02" worth the extra money, considering it's intake restrictions. These are great, quick responding, reliable engines up to about 300 HP (250 HP is a safer target). After this they like to come apart without a forged steel crank, good rods, studs, stiffer valve train and a host of other mods.

Any real Chevy guy could run down the numbers and let you know precisely what you have. Judging from those numbers, you've posted, it's have a plane Jane 283, probably around 180 HP which has had the intake and the heads replaced at some point in the last 50 years. This shouldn't be a big surprise, especially if the engine has gotten quite hot a few times.

[Jim_Hbar]

Just a few points to clarify - In the car/truck world, Gen 1 Small block Chevys (SBC) were produced from 1955 to 2003, and include both the small journal (55 to 67) and large journal (68 to 2003) blocks... But various versions are still being produced to this day, for the marine, enthusiast and replacement market.

Gen 2 is something a little different, and of very limited production.

In the Gen 1 engines,
A 283 has a 3 7/8" bore with a 3" stroke
A 327 has a 4" bore with a 3 1/4" stroke
A 350 has a 4" bore with a 3.48" stroke.

And there were 262's, 265's, 267's, 302's, 305's and 400's produced by the factory at various times. Chevy did a lot of "parts bin engineering", bolting the various parts together in different ways, to come up with different engines. Check out "Chevrolet small-block" in Wikipedia.

Par offers good advice regarding the heads, and I would recommend checking out the cam when you are in there - early SBCs liked to eat the lobes for the front cylinders, if they were idled for a long period of time.

[David55cobra]

I've seen a few of these Chris modifications of the 283 with newer intake manifolds. The original aluminum manifold had a heating chamber under the carb which would eventually burn through, which would tend to slightly pressurise (sp?) the crankcase and throw oil out the oil fill tube - definetly a BAD thing - probably made a few people think they had a complete rebuild on their plate. This is probably the reason that the intake manifold has been changed. My Cavalier has had both engines altered with cast iron replacements, and work GREAT with newer AFB carbs.