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View Full Version : Building my own Chevy 302.....


FlatBlack4Life
01-21-2006, 09:31 PM
Does anyone know what the original Chevy 302's were capable off spinning up to RPM wise?? I've read almost 9000rpm, and other places say 7500. I'm trying to nail down a cam and heads selection and I know I'm probably gonna need a cam with a higher rpm band. And also a good seat of heads that breath well at the top end. Any tips??

GBodyGMachine
01-22-2006, 08:38 AM
I have heard 9000. Mostly due to the shorter stroke motor. The main thing I would be worried about is that all the components match. Intake, Heads, and Valvetrain. You will probably use a single plane intake with a high cfm head and a stiff valvespring. If you figure out what Heads and Intake you are going to run, you can call a cam company and they will help you with your selection. They do it all day long so I would trust them first. Also, look into Aluminum Heads. CNC Heads flow really well and carry big valves.

JEff

XcYZ
01-22-2006, 10:55 AM
How about getting a 3.165" stroke crank for an LS1 and have a LS based 302? :unibrow:

Speedster
01-22-2006, 03:59 PM
FlatBlack -
The question is - how high do you want to spin it ?

I am looking at a 302 article right in front of me and it makes 501 hp at 8000 rpm. The camshaft referenced is a Lunati RRA-675/669 w/282 deg @ .050. But the heads they used suck (old 2.02 slant plug "Turbo" heads) The engine used an Edelbrock Super Victor type intake. The crank used was a factory 302. The rods were factory "service" rods. The only bottom end change was a switch to lighter aftermarket pistons.

Here is another article where a 302 was destroked to a 287 and the car leaves the line at 10,000 rpm - the cam is even more radical with > .700 lift. My guess it the valve springs need to be changed after every couple of runs. This engine used a tunnel ram.

Neither of these examples is really streetable. Kinda comes down to what/how you want to use the engine.

ilovefirstgens
01-22-2006, 08:25 PM
How about getting a 3.165" stroke crank for an LS1 and have a LS based 302? :unibrow:


DOOO IT!!! with 6 bolt mains that thing would really be able to wind up

ProdigyCustoms
01-22-2006, 08:50 PM
FlatBlack -




My guess it the valve springs need to be changed after every couple of runs.

.

Na, We run little 1.55 springs in a small block on the street and the track at .684 lift, and change springs ever couple years. We run Isky Tool Room, ex nascar qualifying springs, $100 a set on e bay.

Now what will be a problem on the street will be the 25HP and 50lbs Tq at 2500RPM. By the time you get that thing to 9000RPMs and making 600HP, the ki8d in the Honda Civic will be waiting for you at the next light!

Kendall Burleson
01-22-2006, 08:57 PM
I had a 302 4" bore and 3" stroke and with pink rods it would turn 9500 in the lite but I had to change the valvetrain to do that with the 461x casting 2.020 intake and 1.6 exhaust with 2" header we had to balance the engine rotating parts it will do it easy :yes:

race-rodz
01-22-2006, 10:37 PM
Now what will be a problem on the street will be the 25HP and 50lbs Tq at 2500RPM. By the time you get that thing to 9000RPMs and making 600HP, the ki8d in the Honda Civic will be waiting for you at the next light!


wow...this sounds like another guy on here building a small inch SB2 :_paranoid

dave96dcm
01-23-2006, 01:29 PM
FYI you can make a LT1 302 with a LT1 block (4" bore) and a L99 crank (3" stroke) and put some LT4 heads on it. I think that CHP or someone did it but I don't know what year. If you wanted to make a gen 3 302 I would use a LQ9 6.0 block (4"bore) and get a 3" stroke crank made. There are tons of heads that flow really good for a gen 3 block.

FlatBlack4Life
01-23-2006, 02:39 PM
I was actually looking to more gen 1 parts in the build. But the LS based 302 sounds like a winner too. I'm just keep doin my homework. I have a 350 block, and I know I can get a forged steel 283 crank. But I was also thinking abot a 350 roller block such as those in GTA's and Corvettes, that way I'll have one pieec rear seal, roller cam, and I thiink larger journals.

race-rodz
01-23-2006, 08:53 PM
well the 283 crank in the 350 block is gonna be an "issue", im sure someplace makes the bearing spacer for small journal(283) to medium journal(350), but i dont recall seeing them. the easier way would be to use a small journal 327 block with the 283 crank, however in a street car i would highly recomend going the rollerized 350 route, after all rpms are cool, but more inches the better.

rocketman
01-23-2006, 09:14 PM
i know a guy here in town with a 302 ls1,its damn bad.

Ummgawa
01-26-2006, 10:36 PM
Isn't a destroked 302 just a 30 over 283? 67-68 302's were 283 cranks in 327 blocks with good rods and pistons, double hump 202/160 valves,etc. and awicked intake,Holley?

MarkM66
01-27-2006, 02:31 PM
Isn't a destroked 302 just a 30 over 283? 67-68 302's were 283 cranks in 327 blocks with good rods and pistons, double hump 202/160 valves,etc. and awicked intake,Holley?

To make a 302 from a 283 block, the 283 would need to be bored 0.125" over, to get the 4.00" bore. Only the early blocks allow this much of a bore.

jeepracer
04-03-2012, 03:23 PM
[I am looking at a 302 article right in front of me and it makes 501 hp at 8000 rpm. The camshaft referenced is a Lunati RRA-675/669 w/282 deg @ .050. But the heads they used suck (old 2.02 slant plug "Turbo" heads) The engine used an Edelbrock Super Victor type intake. The crank used was a factory 302. The rods were factory "service" rods. The only bottom end change was a switch to lighter aftermarket pistons.]
@speedster-

was there anything done to the heads or were they bone stock? is there anyway i can access this article?

osdmike
04-03-2012, 05:59 PM
8500rpm Dyno pull !!!

http://www.youtube.com/watch?v=WYrqGPps1ek&feature=player_embedded

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"Super Chevy" article.

http://www.superchevy.com/technical/engines_drivetrain/completebuilds_testing/sucp_0903_302_small_block_engine_build/index.html

----
Sweet music!!

http://www.youtube.com/watch?v=16FRhHpqxLE&feature=player_embedded

:cool:

jeepracer
04-03-2012, 06:31 PM
what is the best head for the 302? im looking to do one for a dirt racer