Can you build a real Chevy 302?

Larry
I'm a Chevy guy so I'm going to suspect those drivers' abilities in having a big role in that.
My high school pal bought a one year old 68 Z/28, all stock but for headers and Americans.
I actually drove him to buy it. He had just sold his 57 wagon that had a transplanted "real deal" Corvette 283/T-10/4.11's so he had some experience but that first week was a bit of a learning curve in the Z. But when he learned to finness the engine rpm's to combat the traction issues that car was a real animal, the new Hurst shifter really helped too.
Not taking anything away from those 340's as my older neighbor had one in his 70 Dart.
I really loved that car but it was a car my other friends' older brother had that made me respect them, an AAR Cuda, 340/3×2/Torqueflite that was pretty impressive, the guy was not a great driver so I suspect if it had been a four speed car the outcomes would not have been as good.

 

Gonna interject something here,I really don't have a dog in this fight, or a piston in this block.....
But i'm a chevy man from WAAAAAY BACK. Bleed chevy orange. But make no mistake about it, the little 340's mopars were bad mamajammas.

 

I find the time listed for the Z-28 laughable, I had a 63 Impala SS with a 300 HP 327 4 speed that turned those times and my 68 Z-28 was a lot quicker!

 

Here's some fuel for the fire -
stock 340 - 320HP
- add headers - 352HP, more with a 6-pak set up. If they had used the 4-speed spec cam even more HP.

https://www.hotrod.com/articles/bad-mopars-340-beat-ford-chevy-shocking-new-data/

 

I thought the 4-bbl 340 only made 275 ponies.....
And the 6-pak version made 290 hp.....

 

Those are the factory ratings. The 320 & 352 numbers are from the article in the link. I've played with Mopars all my life and those numbers seem credible.

 

Well since you brought it up. Ford won manufacture champion ships in the over 2 liter class, with Shelby first two years 66-67. 1966 GM entered the corvair but had to run in over 2 liter class because motor was to big for the under 2 liter. Chevy had the Camaro z/28 in 67 for the over 2 class. Ford won manufacturer champ in 67. But got to remember , the z/28 was new ,took Penske team awhile sorting it out. But won back to back races at the end of the 67 season. Then it was on .


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Had 68 z/28 302. Put 4.56 gears in it and tri five factory 2x4 intake with 348 WCFBs. Blended intake runners to the heads. Play around with valve lash and timing curve .it was a lot easier to street race. And imho faster. Put factory intake and Holley back on and sold it to one of my brother's buddies. He still has it today. He Street race it a couple of times. Then he put 3.73 gears back in it. Now it sits in his shed. I actually had this setup in a z/28 I own before. The linkage dropped off front carb and jammed against intake runner holding Back carb wide open and I totaled it. That still hurts a little.


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I don't know if this was sorted out in the previous pages but....the 302 v 301 thing is a Factory will round the number up if its over .5'' and to distinguish between a factory v non factory, the latter is rounded down. Its that simple. I have a 301 in my RPU and I love it. I have also built just over 360 SB Chevs of most configurations, the 283, 302 and 327's being my favourites. JW

 

Dropping off some $$ and parts on Monday for this....

 

Might be thru the mufflers...

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More likely that the person driving it didn't know how to go fast, how to shift or leave the line without frying the tires!

 

I have done 4 "tribute" 302" SBC motors using early, small journal 327's with 283 forged cranks.
I can personally attest that they will rev to 9k (or above) with no effort. Had one in a '68 Camaro,
'65 Malibu, '62 Nova and '40 Chevy. Use forged piston and rods, good valve train components and
get it balanced. 2.02 heads and headers. Keep in mind that you have to use a "302" style piston
for correct deck height.

I have my next 302" on the engine stand, waiting for my next project to come along.

Back in the '60's, this is what we did. Used a 283" block bored out to 4 inches and it was known
as a 301".

Lots of fun articles on the web from the 60's telling you step by step how to do it. Hot Rod magazine
did a great article on one.

Bob

 

Can't believe I read all 10 pages of this... I should have went to sleep 2.5 hours ago...
Goodnight fellas!.....

 

In case some of our HAMB yunguns need schooling.
Please forgive if a repeat.




Traco 302 engines are legendary.


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

 

A 302 is like a 427....sooner or later you gotta build one......Bowtie bucket list.

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Just went through all 10 pages and nobody brought this up. I confirmed it this morning on the internet. The General Motors "official" published bore for a 327 when they came out was 4.001", not 4.000". Doing the math, this calculates to be 301.74 cubic inches. That rounds up to 302. A .125" over 283 is a 301. A 327 bore and a 283 stroke is 302.

 

327 blocks are plentiful and cheap. 283 steel cranks are cheap...pistons are where the money is.

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301 was Ford's defination and 302 was Chevy's defination of the same bore and stroke combination of 4"X 3"

 

Like I said many pages ago GM made them 302’s. We built them as 301’s...Too many to count.

 

You mean like the Boss 301?

Ford never advertised a 301, but built millions of 302 engines over nearly thirty years, huge compared to the few thousand Chevrolet built over a three year model run.

 

Being a Ford guy....if you want R's build a 'clone' Boss engine. (5.0 block and crank with 289 rods and special short pistons....the old rod length argument!!) 10+ thousand very doable....don't forget plenty of compression!!

But just for the sake or RPM's in a Shivel-lay why not a 400 block and 350 crank=377 cu.in. That should 'spin-up' pretty good and still have enough cu. in. to be a little more forgiving on the street. Be able to use semi-sensible gear ratio and 9.5/10:1 CR so hi test fuel will work. Cam the snot out of it....decent heads....1.50 /1.75 primary headers.plenty of carburation...single plane intake.....LOTSA $$$ for springs/retainers and such and....zing-it-to-the-moon!!
Post a video when done!
6sally6
It should make some real purtty music

 

The Ford 307 ci (or so) in my new car makes 460 horses and 420 ft lbs of torque.....

 

The reason why there is a 301 and 302 Chevy is very simple and most don't seem to be able to grasp it. When the car manufacturer make a motor and lets say its a 302 and its real displacement is 301. 6 it is rounded up and when back yard man bores out a 283 to 4'' its rounded down. Simply said is factory rounds up, non factory rounds down. I have a 301 that i built in 83 in my RPU. JW

 

Eagle still sells a brand new 302 crankshaft, so if you wanted to start with a readily available, cheap 350, and drop in their 3.00" stroke 302 crank you might save some money. Eagle's 302 crank is also forged, so if you find an old 350 4 bolt main truck motor, you'd have a pretty strong setup you could really wind high.

https://www.summitracing.com/parts/esp-435030005700

 

Here is the step by step article from Car Craft '69. You can enlarge/save the thumbnails.




Magazine write up:

 

First car at 16 years old in 1971 was a 64 Chevelle with a 3 speed 283. Put a 4 barrel intake/carb and 3 speed floor shifter, kept it in tune and after a few street races thought it ran pretty good.
Then made my first visit to a drag strip at Wisconsin International Raceway and watched and heard the 301/302s
shifting & screaming (breaking) and I was hooked.
Now here we go again, you guys got me all fired up to finish this 302 build. Have been accumulating and machining parts for about the last 10 years, this is what I have so far.
Machined to 0 decked, power honed with block plate, 1963 327 passenger car block.
A forged .010 under 283 crank

Thinking I would like to try to build this 302 using Eagle 6"s.j. rods with (cheaper) 350 flat top pistons.
Pistons would need to have .035 machined off the tops to keep them even with the deck.

Any one ever try this?

 

I’ve never built a long rod engine but it sounds good to me, especially if you already plan on aftermarket rods. You get to set the deck clearance exactly where you want it and then there is the best part- cheaper pistons.

 

Back in the early '70's there was a guy in my town with a '67 Z-28 302. He drove it hard and wanted me to rebuild it. He actually went to a Chevy dealer and bought a brand new tufftrided Z28 factory crank. I rebuilt the thing and he let me keep the old (standard) crank. I stuck it in a 327 block and had me a 302. Put it in my '32 with a TH400 and had a respectable runner.

 

Be interesting to see the difference on dyno for 302s with rod length change, keeping all other parameters the same.