Can you build a real Chevy 302?

As my machinist told me many years ago, and I've only been using him for 51 years now, that back in the "day", when they were figuring out displacements using "pi" in the formulae, they used pi as 3.14; in later years, when more "precision" was required, pi was figured as 3.14159265359. The final figures come out on either side of ".50". The smaller figure is closer to 301, hence the 301 name, the larger closer to 302 for that name; rpounding up or down to the. Personally, I have't figured them out separately. As far as the 301/302 goes, I've had two complete rotating assemblies, one a small journal, one a large journal, and sold them both to the same HAMBER (he shall remain nameless to protect his good name) at different times. Sold them to him at "thief in the night prices" just to get them out of my way, and last time he got a 4 bolt main 350 block, and a really nice, fresh pair of 461 heads, all the tins, an aftermarket set of I-beam 4340 rods, plus a set of takeout "O" 350 rods. All new stuff. Personally, I prefer an engine with enough torque to pull a slightly overweight, drunk hooker, off a toilet without killing itself in the process. Nice to have power when you want to use it, nicer when it's always there without the worry some parts may wind up on the pavement. Always wondered what kind of warranty work Chevrolet had to do with the 302's? Especially when so many 302's are/were replacement/over the counter engines they replaced into the Z-28 Camaro's; and they did't even think of "numbers matching" back then when doing the work that eventually created various problems to the purists. There's one thing to be said for the 301/302; I don't think there'll ever be a time when there's not an active thread about them here on the HAMB.
I am Butch/56sedandelivery.

 

I have built quite a few of these , numbers matching not numbers matching whatever. Raced em in F stock NHRA . Small journal large journal etc. Little giant killer

 

I still say there is no match for cubes , build a 383 claim a 302 . Only problem is disguising the Mopar distributor in the front oh the W block has distributor in the front doesn’t it !

 

If you are going to try and spin a 383 up to 8000 or 9000 rpm, I would advise standing well back..........

But yeah, cubes = brute power.

 

OK......we got a shot at building a real Trans Am Program engine from left over parts back in about 1990. Those parts are different from the so-called "DZ" engines......GM sponsored program engines: Small mains....to reduce friction, forged pistons with 12+: 1 CR, port matched heads, 2.02/1.50 valves, hardened push rods/guides, threaded rocker studs, high volume oil pump, various cams - we used one that mimics the old ",030-,030" cam......and more.......

It appears they used different combinations of parts.......like any other race program.....so, there is not one "real" 302 engine combo....

 

Deuces, I’ve heard that before too and have always wondered how they would get those numbers.


Sent from my iPhone using The H.A.M.B. mobile app

 

This is how!
Multiple articles in the link below.
If you are willing to blow the text up you'll get a lifetime of small block Chevy knowledge.

http://www.camaros.org/forum/index.php?topic=7774.0

 

We got our parts from a different engine builder, but they used similar techniques on most of their engines (they were "contract" builders for various race teams)......as you can see from the text, these are different animals.......

 

DDDenny, I’ll check it out! I know it’s possible but I’ll be curious how they do it with factory parts and rules.


Sent from my iPhone using The H.A.M.B. mobile app

 

Yeh, you know that teams like Penske didn’t just drive their new Z-28's straight to the track from the dealership. I've read some pretty interesting stuff about some of the "cheat'n" that came from the brain of Mark Donahue.

 

Yeah like changing the brake pads during pit stops...

 

Kudos to the Heritage Gasser Class rules. Remember lbs per cubic inch is real racing. Look up the classes...then calculate the weight you gotta carry to get into these classes. FYI for guys never experienced this type of racing...you want to drop in the top of each class...by weight break... if class is 8.00 to9.99 lbs per cubic inch. You want to be at the 8.00lbs... or its a short day at ye old race track. Hence you can see that many classes will be in 270, 283 cu in range. This is why so many mighty mouses were built. Can you imagine a wt break for 540cuin..be a freaking RV. Many classes only allowed 100lbs +/- factory curb wt... Another note...if you did not win class...you went home. No free lunches back then...pits were full of cars. Forgot to mention, after you win class end if day, you could be pumped down cyl volume checked, dc arc test fuel, torn down with a protest $100. They might be checking ports, cam, valve dia. If you were legal, you keep $100 for gaskets. When we were record holder...we were torn down at every race....many times for spite.

 

Penske owned the dealership lol..

 

If you play by the rules, you lose. lol Lippy

 

And you can build a real 302. If you start with a real 302. Lippy

 

Another tid bit, the camshaft in our 1975 car... there was a lot of work on deflection, front to back based on loading from valve springs. I remember my Dad saying 2 deg of twist, having the lobes ground relative to that for each lobe netting at speed, lobes were all in sync. Whether this worked, not sure, but was one of the nuances in the record holding engine. I believe we ran 3x different heat range plugs as well ... using GM heads. They worked every week looking for another tenth....gallons of late nights, coffee.

 

We’re you guys running the over the counter GM heads or where those factory Z28 castings?


Sent from my iPhone using The H.A.M.B. mobile app

 

I have one set of the 461s, there may have been 492s. I was told the trick heads had exhaust studs off set, machine shop told me exhaust studs were off set. Ran these rockers. 1.7 ratio.

There were flat tappet rules, and head porting rules. Intake was a Scorpion. At the time probably one of the best.

 

Love my little DZ 302's

 

Sweet.
..like the short injection stacks.
Scott....sitting on GM fi base...nice.

 

I have the off road use cam in my 327. Solid lifter cam real rough idle and the power curve is over 3500 rpms


Sent from my iPhone using The H.A.M.B. mobile app

 

I ran the off road cam in my OT 60’s Chevy in my LT1....lots of fun for street racing!


Sent from my iPhone using The H.A.M.B. mobile app

 

Mine was Fathom green metallic also with the white stripes...

 

Many years ago I knew a guy that had a 69 Z in Fathom Green, it had as-cast 15x8" American 200S wheels, it was gorgeous.

 

To answer the original posters question you can replicate a 67 spec small journal 302 shortblock by using the 327 small journal block and a 283 crankshaft.The 68 and 69 spec shortblock can done by using a 68 and later medium journal 327 or 350 block with a medium journal 3" stroke crankshaft.While the 283 crank was made in both forged and cast versions most of the early ones were forged and fairly easy to find,the medium journal 3" forged crank is limited to the 302's,some were also sold over the counter,if any of the later small engines (262,267)used a medium journal 3" crank it was in all probability a cast crank.The Z-28 cam was and probably still is available thru chevy and aftermarket cam vendors,any of the double hump heads with 2.02 and 1.60 valves installed while maybe not "correct" will functionally replicate the performance,the z-28 intake has also always been available thru chevrolet performance.

 

What the hell is a medium journal crank????....
I never heard of one before...

 

I would say its the size of the mains, 400 cid now being large and what has always been known as large is now medium. JW

 

And to think all these years we’ve been calling a large journal a large journal and were wrong. Lol I learn something new every day in the auto world.


Sent from my iPhone using The H.A.M.B. mobile app

 

And another sitting in a guys man cave ....

View attachment 4958117

 

I'm infatuated with these cars as much as any card carrying HAMB'r is allowed and I myself have been known to step over "the HAMB line" so just wanted to say we need to make sure this thread doesn't get closed due to too much OT sheetmetal shots.
If ya know what I mean!