Black363IROCZ

not the 5.d'oh block, but the destroked 327 of first gen fame!. I was wondering if any companies made a 4340 or 5140 forged crank, and rod kit with hypereutectic domed pistons for a 302 motor. If I am correct, the 302 is just a 327 with a 283 crank? correct me if I'm wrong. Do they use bearing spacers like a 377 does? I can get a 327 block for dirt cheap and I think it'd be a lot of fun to make a high winding 302 and put it in a manual 3rd gen.

bigals87z28

this comes up everyonce in a while... I think that there is a problem with the journal for the 283 going into the 327. Im just throwin out what i heard. it would be a cool motor to have.. i wish GM never got rid of it.. thats gunna be a hi rev'er, good luck

Black363IROCZ

there was a small journal 302 and a large journal 302, the large journals were 68-69,. the small journal was 67 I believe. I guess if I were to pick up a 68-69 327 block I could use a large journal 283 crank.

ede

if you have a SJ 327 block any 283 crank will fit and work just fine since all 283s were SJ. i doubt you find any hyper pistons, or cast for that matter. callies, ohio crankshaft ,lunati among others could provide you with a crank.

Black363IROCZ

all would need are 327 pistons though, the bore is 4.000" for a 327 and a 302. I could also find a 283 block and bore it to 4", be the same thing lol! thanks for info on the cranks. what is the length of the rods for the 302? 5.7"?

ede

all SBC except the 400 use 5.7 rods. can't take a 283 to 4", even if a lot of people have. thing to do if you had a 283 would be to install sleeves. don't think 327 pistons would work, i'd guess differant wrist pin locations, you'd need 302 pistons, or 4" 283 pistons (maybe).

Black363IROCZ

Who makes 302 pistons? Are you sure a 327 won't work, I've heard all you need for a 302 is a 327 motor with 283 crank

ede

most anyone that makes pistons will make a 302 piston. got to figure the wrist pin is in a set location and if you shorten the stroke by a 1/4" the piston is going to be in the hole that much more. it sure ain't going to stay in the same place with less stroke.

Cronic3rd

Just do the math

crank throw (1/2 stroke) + rod length + piston CH = Block deck height.

the deck height of a SBC is 9.025" or less if your block is decked/

so

1.5 + 5.7 + X = 9.000 (assuming a decked block)

7.2+x= 9

x= 9-7.2

x= 1.8

1.8 is a high compression height. A 350 has a CH of 1.56.

assume a 6 inch rod in the above equasion and you get 1.5. Assuming your block isn't decked that would make the pistons .035 out of the hole. Which should be acceptable. sooooo go buy some 6 inch rods and standard 350 pistons.

Black363IROCZ

cronic, thanks for that equation! you have any idea what a set of forged 6" rods for a small journal crank would run?

Air_Adam

Actually, some 283ci motors CAN actually be bored out 1/8" to be a real 302. This is only for the '57 blocks though i think.

jms

iTrader: (1)

You can bore most any 283, up thru mid-model year 1962, out to 4" bore. From mid-'62 thru 1967 model year you are taking a chance but some will do it.

I've done about a half dozen this way. They used to be called 301s before Chevy decided to say 302.

By the way, if you have one, don't use a '57 block. They don't have side mounts on the block (you can't easily bolt it in a third-gen). Plus the restorers will give good money for an original '57 283 block.

The 1967 and earlier 327 blocks with the steel 283 crank makes an easy 302 combo. And 302 pistons are not hard to find. Not too cheap, though.

jms

Black363IROCZ

I was thinking about going with a 327 SJ block from a '67 chevelle. Friend has one, excellent condition, but ultimately replaced with a firebreathing 454 . I've looked high and low through summit and jegs catalogs and I've only been able to find FORD 302 pistons , if what cronic is saying is true, that'd make my search must easier. I'd rather use the 327 block instead of the 283 block cause there is no $$$ to spend on boring the block. If you can link me to 302 pistons I would appreciate cause I've looked high and low I'd prefer strengthed hypereutectics with small dome, for about 10-11.5:1 compression with 64cc heads. And then I need to find a 5140 or 4340 283 crank, also no luck

jms

iTrader: (1)

In less than five minutes searching, I found about 10 different versions available for a Chevy 302.

http://www.jepistons.com/pdf/2002-srp-chevy.pdf

Look about halfway down on the above page.

Also I saw a couple sets on www.flatlanderracing.com

They are out there.

Summit and Jegs are just the tip of the iceberg when it comes to small-block Chevy performance parts.

Just look for 'em.

jms

Black363IROCZ

jms, thanks man! still haven't found anything for a 283 forged crank!

jms

iTrader: (1)

Find a good 283 crank. They're all steel (although I have "heard" a few late in the '67 model year were cast---I cannot verify this).

Many, I mean many, 283s have left the staring line at the drag strips at 8,000 to 10,000 rpms.

The old Jr. Stocks and Super Stock classes used to be covered up in 283s.

They will turn the rpms if you build a valvetrain that can stand that kind of torture. BUT, it won't be cheap.

jms

DartByU

Another way to build a 302 is to take a late model 350 block and get the crank and 5.94" rods from a '94-'96 Gen.II, 4.3 liter V-8 "L99" engine, you can use standard 350 pistons and you can use the modern roller cams too. I just don't know how much HP and RPM the stock crank will hold up too.

Black363IROCZ

I'm planning on solid roller cam 2500-7000 rpm powerband, I think some hypereutectic pistons and forged rods and crank should be perfect for that. Solid roller valve train should be ideal for those rpms.

bigals87z28

maybe i didnt read the whole thread, but what form of fuel delivery will you be running? carb or efi?

Black363IROCZ

carb. this is a low tech project, I put fuel injection on my 363 and it cost me way more than I ever want to spend again.

bigals87z28

ahh hehe ok.. i was gunna say, if you were, i would NOT go with TPI... TPI's not a big fan of above the 5k mark...

Black363IROCZ

lol, I've known that for years, stock TPI isn't a big fan past 4500 rpm. I have a mini-ram for vortec heads on my 363 *fast burn* , expensive, but oh so worth it. just not the kinda money I've got available for the 302 LOL

PhilM

I just put my small journal 302 in the camaro last weekend. PM me and I will give you details.