Can you build a real Chevy 302?

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All things being equal.....you should be disappointed in the 302 with the hydraulic cam. The thing that makes the 302 work is it's rpm potential. You lose that, you will probably perform just a little better than a good running 283 with a 4bbl, The L-79 and the Z-28 are basically the same motor except for the cam and 25 cu in.

 

Quote:
Originally Posted by Stone
Has anyone used bearing spacers to put a small journal sized crank in a large journal block?

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Bill Jenkins did.
And I've put bearing spacerS in a 400 to run a 350 crank in circle track engines (372) before. Never had any problems with them.
lARRY t

 

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Why would you buy a car with a motor designed for racing and expect it to drive like a stock 283 w/4bbl. That would be like buying a Z-28 and complain about the ride. If you are looking to cruise, buy a car designed for cruising. If you want your performance and still want to cruise, then deal with the pitfalls.

 

Regarding main caps and small/large journal cranks: I talked to Lamar about this, because I had a set of 4-bolt splayed main caps for my build. He said the small journal caps were thick, so cap walk or breaking isn't an issue. He then went on to say that his Pro Stock 331 (327 bored .030) ran 2-bolt caps with studs in his Barry Setzer Vega. It dyno'd at 660hp, he shifted over 9,000rpm, and he won 31 races one season with it, including beating Dyno Don, Grumpy Jenkins and the Sox & Martin Hemi. For him, the small contact area of the small journal crank meant less contact area and less friction, but it was just one of the things that gave him 660hp. The important point for us is that you don't need 4-bolt caps with a small journal 283 or 327.

-Brad

 

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Sorry Larry.....not splitting hairs. Factory installed 327 w/ 4bolt mains never happened.

 

Someone had mentioned if a 327 4-bolt motor could be built... That's an easy one if you have a '68-'72 307 crank laying around and a '70 + 4-bolt block. Back in the days, when ever I needed a 4-bolt block, I'd go to the local junk yard and ask them for a '70-'71 350 4-barrel Chevy or GMC "010" pickup motor. I knew those trucks had them. Some even had the forged steel 350 cranks in them. I believe all the 307 cranks were made from cast iron. I'm not sure if any '68-'69 327 large journal cranks were forged. As for the factory forged 302 pistons, They were all manufactured by TRW back in the day. Finding an original set of new off the shelf 11:1's is almost like hitting the Lotto. The aftermarket ones are around $600 a set if you have that kind cabbage laying around...... It would be cheaper to build a 4-bolt block with a well prepped cast iron large journal 307/327 crank in my book which are great for banging gears at 6500 rpm. That's my .03 cents worth.

 

Just to answer one of your questions they did make large journal forged 327 cranks. I had a couple back in the day when we were racing circle track cars & we used them with 350 4 bolt blocks. They were as rare as hens teeth even back then and I believe they only came in Corvette engines & possibly some heavy duty truck applications. A good source for forged 350 cranks were early 70s GMC school bus engines. That being said, I know alot of guys who prefer the cast cranks because they are a little lighter. We built plenty of 2 bolt main blocks into some fairly high horsepower engines as well. The weak point in a Chevy smallblock is the rods. How many spun main bearings do you see for every blown up smallblock with spun rod bearings or broken rods ? 1 out of 10 maybe.. When you're a poor dirt track racer you learn where to look for good parts cheap.

 

I guess I hit the lotto. I found a rebuilt 283 on CL a while back for $200. While I was there picking it up I noticed a box of forged popups sitting in the floor. I assumed they were 350 slugs and I asked him what he wanted for them. He said 'oh 10 bucks I guess. I picked them up at a garage sale a while back and thats what I gave for them.' So when I got home I ran the trw number and guess what.....Yep.....302. I already have a 283 steel crank and some double hump heads, now I'm looking for a small journal 327 block that will go .030 to complete the package. By the way, its going in my mid engine Corvair.

 

I have a 302 bottom end in my friends shop, the problem with it is that it has 13 to 1 pistons in it. I know it is an easy fix and I want to find a light car to put it in,might put in my 36 ford. A friend of mine had a 67 Camaro and he told me that the 68 com was the best to use when building a 302.

 

The Winters foundry did a lot of low volume aluminum casting for GM, but it was to GM design. You'll see the "snowflake" logo on OEM aluminum manifolds and heads. http://www.camaro-untoldsecrets.com/articles/crossram.htm

Bob

 

After finding this tread i did a little research and found this company http://www.retroperformance.com/ has anyone heard of them? Also crower makes a 3.00 stroke super light crank it weighs 38 pounds. I read the 302 are only good at high rpm? Has anyone had one of these in a model a with a close ration 4 speed and a 3.70 rear gear? tell me what you guys think because thats the combo i want to run.

 

I have the same block in my coupe. But turned in to a stroker.

<TABLE border=0 width="100%"><TBODY><TR><TD>1969</TD><TD>3956618</TD><TD>302</TD><TD>290</TD><TD>290</TD><TD>4</TD><TD>Z28</TD></TR><TR><TD>1969</TD><TD>3956618</TD><TD>327</TD><TD>235</TD><TD>235</TD><TD>2</TD><TD>fullsize</TD></TR><TR><TD>1969</TD><TD>3956618</TD><TD>350</TD><TD>250</TD><TD>350</TD><TD>2/4</TD><TD>cars</TD></TR></TBODY></TABLE>

 

302... yawn...

How about a 383 that you can dump the clutch on at 7500...

It'll put out 100 more horsepower RIGHT OFF THE BAT that an equally prepped 302 will... and rev faster and harder through all the gears.

302's were meant to meet a displacement requirement in Trans Am racing... not built to make power.

Sam

 

Uhh, yeah...

Racing engines are rarely built to make power....

 

i dont know,,, smokey built one that made 500hp with all gm parts....

 

Not only did Smokey build 500 hp from the Chevy 302, so did Bud Moore. In a interview he (Bud Moore) did for a TV show, he was talking about how they (the Ford teams) were getting beat by the Camaro in Trans Am racing. He said that they purchased the parts at their local Chevy dealer, assembled the engine and ran it on his own dyno and pull 500hp. When the Ford guy says that he got 500 hp from the Chevy engine, I'm willing to believe him.

 

I see the old apples and oranges debate is still alive and well. How about this one. Compare the horsepower per cubic inch of the best 302 ever built and the hp/ci of the best 383. Both engines equipped with similar components,ie solid rollers,iron heads, single or dual quads. I'm betting the 302 will come out on top. If you really want to feel humbled try comparing the HP/CI of a motorcycle engine with an automotive engine.
With horsepower being a function of RPM a high winder will have a built in advantage.

Frank

 

Smokey also said, torque wins races, horsepower sells cars.

 

How do you seperate them when one is a function of the other?

HP= Torque X RPM / 5252
Torque= HP X 5252 / RPM

A dyno figures horsepower by measuring torque & rpms. The formula also is the reason that Torque and HP are alway the same on a dyno printout at 5252.
Larry T

 

Hi Crew..

Hi Sam we have to get together someday soon.. Wild is rocking! Hoping all is well with you and yours!
Now back to this..

A 69 T.A.302 with Block # DZ is not the same as all 350s There a High nickel alloy added to the block for added strength....68 is a #MO block.. My 383 is a My Old DZ block... The 383 will smoke street tires in all the 4 gears just by wot... Has a cam peak HP at 7200 RPMs So did my stock DZ 302.. The 302 would never smoke the tires with out dumpng the clutch in 3rd up...

BUT.. above 5800 rpms. The DZ 302 would rev to 7800 before you could think.. You had to shift fast.
My 383 has tork up the you know... But I know when I am in the 7000 rpms range. In the DZ 302 I would always be in the 7000 rpm range...

I have a Lightened High Dollar Crank in the 383 I would love for it to scream like My 302..I had built it to be my secret mountain house motor that pulls like a unleashed L88 and revs like my old 302. Pulls yes, rev like no..
the 383 just does not rev faster above 6000 rpms than My 302.

Now on the other hand.. The 302 was the biggest slug under 5000 RPMs.. My DZ 383 revs so much quicker under 5800 rpms.. Everything is a trade off.....
I love the power of the 383.. But sure miss the Sweet pulling super fast High revving 302.
This is not scientific with all the variables.. But it is the same car with the same gears....

 

Back in the 70's when I worked for M&M Speed in Sacramento I had a '63 Nova I always wanted a 302 so I built one using a 327 block and 283 crank at that time Badger made 11 to1 cast pistons in Std, .030 and .040 oversize sold for $89.95 a set back in the day!

 

i have all the stuff to build a 302 if u are interested

 

Do you have the GM Z/28-LT-1 intake manifold???.......

 

Bet it don't wind out to 8500 rpm like a real one does.

 

>>>>>,Actaylly ,,,the 302 ain't really a 302 ,,,if you go back in history ,,when the 327 first came out ,,us hot rodders were stuffing 283 cranks in em right off the bat ,,to make a 301.4 Cubic Inches ,,i ran a Hilborn Injected 301 in a '55 Chevy D/Gasser / Muncie 4 Speed in the middle '60's ,,spin it to 9,000 rpm every shift ,,when GM decided to build that Can-Am motor for the Camaros & Firbirds ,,they didn't want to recognize what the hot rodders had already done ,,so they rounded off the Cubes to 302 ,,if you do the math ,,those 302's are just a hair above 301 cubes ,,
so,,,go build your own 302 ,,

 

Be careful. That 3" stroke makes for one sluggish Mutt at anything below a bazillion RPM

 

TRUE. Chevy called their version 302, so as to let people think it was "their" baby.

 

Deuces,
There are a ton of 3.48/3.50 stroke engines that will turn 8500 rpms. Just gotta build them right. I think the valve train is probably more critical than the piston speed here.
Larry T

 

I come up with 301.59 C.I... Sooo... Why not round it off too 302 ci???

 

Your right Larry! My goof.