I have been thinking alot about building a 302.. I know you need a 283 crank wtih 4.00in bore block.. Now could I use one of those cranks in a 87-up roller motor? Or would the journals be to small or big?or can I buy a crank from someone? and could i use the Xr270Hr cam that I already have?? Just a thought

 

Took me a while to read that post...big distractions...

I "believe" the answers are:
yes
need pistons and rods to match the small journal crank
yes
yes, I don't think you would have clearance issues

 

Stiffler,
Food for thought: the original 302's used 4.88 gears and high rpm to make up for their lack of displacement to equal 327's and the new 350's of that day. Of course they had all forged internals capable of 7-8k rpm. The 302 was only used in the 67-69 Z-28 Camaro and the reason being was it was the car gm backed in the Trans Am series and rules wouldn't allow anything more than 5.0 Liters of displacement. In 70 the rules changed and they began running 350's (the original LT-1). Chevrolet never used the 302 again in anything. I do think they should have kept it and used it in place of the 305 and 307 engines. But the 327 and 350 are capable of more power (well, mainly torque, which hp is a product of) due to displacement assuming all were built comparably. Preston Smith has an 85 IROC that he uses a 302 in. It's actually 305 ci. and uses a 350 block (overbored .030 IIRC) and a callies or cola 3" crank. With forced induction he designed (he's a mechanical engineer), he runs high 9"s. Imagine what it would do with added displacement?
If you want an idea for a uniqe engine look at an article in Hot Rod or Chevy High Performance from the mid 90's (96 or 97 IIRC) titled "The 350 Chevy Should Have Built".
It is a 400 block bored over .020 or .040 and has a 327 steel crank with spacer bearings. They used 6.125" rods from a ford straight six and je pistons with a raised pin height. They did use afr heads, but with a small cam comparable to stock and a small untuned carb it made a ton of power with a very strong AND FLAT torqe curve. Imagine what it would have done with a big or at least a moderately sized cam and induction that was well tuned. Especially a miniram and a comp xtreme energy cam.
377's are also a great motor. 400 with a 350 crank. A guy around here bought one off of a circle track guy and runs it in a street car and it runs real good.
The larger the bore the more you unshroud the valve's.
The longer the stroke the more torque you generally make.
Alot of people think that 302's and 283's rev faster than other longer stroke motors and that's not necessarily true. That is due to several variables like how the motor is built clearance wise and in parts selection, not stroke. That 377 is probably the fastest revving v8 I have seen.
If you want a 302 go for it, but I just wanted to see if you had considered these other things.
Good Luck!
Draino

 

^ everything he said

 

Great info Drain89.. thanks alot...

 

No problem, but imagine what a 352 or 377 would do with a miniram or maybe a ramjet intake. If only I had a good 400 block.

 

first of I totally agree with drain89, the 302 is way overrated .

Now, if you want to do it with your 87 and up one piece seal block you can use the "baby LT1" crank from the 265ci motors of the early 90's. These motors come with 3.00 strokes, and yes you can use your stock rods.....next is your going to have to find pistons for a 302, not many people make them anymore but I think JE, Ross and Speedpro have good forged pistons still around...not sure about going hypers with Kieth Black.

 

i wouldnt say its way overrated...

my grandpa has a 68 z28 with the dz 302 and m-22 trany
the motor was balanced and blupreinted like the race motors were..

he had it chassis dynoed and it put 406 ponies to the ground

factory redline is like 7,500 or soo and now it screams i mean screams all the way to 8,400....when hes into it he shifts at 8,600

the little motor is a rocket..

like said above...a 352 or a 377 would rev like a mother****er