Can you build a real Chevy 302?

Thanks for that cool info and right there you have answered the original question. COOL. JW

 

around these parts, a bored 283 was called a 301.

 

Mentioned it before, but go back and look at post 296, on page 10. Car Craft in 1969 did an article on using
a 327" with a 283 forged crank to build your own 302". At that time all of the parts you needed
could be purchased over the counter, but you still have lots of options today. You can click on
each image to enlarge it

A couple of small items you may not notice is that on the real 302"'s, GM used the larger, high
performance alternator pulley to slow it down at high rpm's, plus they used two brackets for
the adjustment arms on the alternator. Just a couple of small trivia items...

 

As well as the fact that Chevrolet never offered 302's with an automatic transmission.

 

I think one of the hardest 302 Z28 items to find might be the 1970240 breaker cam. It only came in the ‘67-‘69 Z distributors, or over the counter under that part number. It was ground to give a gentler action to the points.
It’s a must have to build a true Z28 engine.

 

Because back in the day, no one had a calculator.....

 

The simple reason is Factory builds are rounded up and non Factory like boring a 265 or 283 to 4'' is a 301. It just separates the two....kinda like a real steel 32 and a glass one. JW

 

Actually they did
I get (using 3.14) 301.44 ci.
Edit:
But I do think it rounds to 302 if more decimal places are used.
My phone doesn’t have pi on in. Lol

 

Well, the long accepted formula for calculating cubic inch is .7854 x bore x bore x stroke x number of cylinders(8) gives 301.5936!
The constant .7854 is just a simplified breakdown of pi, since most phones don't have that key and most calculators vary in how it calculates pi and may round it differently.

 

A short sidestep: if your calculator doesn't have pi use 355/113 instead. That's accurate to 6 decimal places and that's good enough for 99.9% of calculations.

b-t-w; that's one of the more useful facts I learned in Engineering School over 50 years ago.

 

I know this a little off this topic but could somebody tell me if I could build a 302 out of a 289?

 

Yes, the are both 4'' bore. JW

 

its been my experience that nothing on fords interchange ! a 289 sure wont bolt up to a 400 . 3 351s nothing interchanges , 289 302 . not even close . but ive been wrong before !

 

A 289 Ford has a stroke of 2.87". Making a 302 is a simple matter of replacing the 2.87" crank with a 3.0" crank but if I remember correctly they don't share the same rod length. Not a big issue if you purchase a rotating assembly. With the SBF you have issues with specific balancers for specific engines. I am not the Ford SBF expert, I'm sure there are others here that can help you with specifics. I'm mainly following this thread because I have 2 motors currently going together; a .060" over 283, and a .125" over 283, basically a 301 (based on an 870 casting 283 block),. The 283 will be going into a Project X clone which will be replaced by the 301 at a later date. The 870 casting block 283 is the block you need if you have standard bore 302 (MO or DZ) pistons. It carries the 3.875 bore of the 283 but it's based on the 327 block so it has extra thick cylinder walls. The 870 block could possibly be bored to 4.060" but I wouldn't recommend it. Cylinder rigidity is more important than a few extra cubes. And as for building an engine just to RPM you'll be seeing a lot of what you're seeing in the attached photo.

 

???

 

LOL! That was a typo. It should say 4.060". My machinist friend says they make SBC pistons all the way out to .090" but that doesn't mean it's recommended.

 

Yes, just swap cranks as has been mentioned and you'll need to change connecting rods as well, 289 rods are longer than the standard 302 rods, except Boss 302 rods. The Boss rods are the same length as 289 rods, but have 3/8" rod bolts.

 

Why are Fords being talked about on a specific Chev SB thread?? JW

 

Very popular combo for Jr Fuel dragsters in the mid to late 60's where 310 was the limit, allowed for overbore when you screwed up

 

New question everyone, I need help. Is this a true 1968 Z-28 DZ302 engine?? The heads are 333882. The block casting number and stamping numbers are in pics.... Thank you

 

DZ is a 1969.
MO is a 302 1868 stamp, could be 68 LJ, or 67 SJ. Check crank flange, round with one notch is sj. No difference in basic performance. Casting number is a LJ 302,327,350 block. www.Mortec.com

 

Give us more details, you for sure have a correct block and suffix code but those ‘882 heads are ‘70’s era smog heads. Large 76cc chambers and 1.94 In, 1.50 Ex. valves. The ‘68 302 would have 3917291 castings, chambers about 64 cc (?) and 2.02 In, 1.60 Ex. valves.
Maybe more than the heads has been changed.

 

In 70s... it was common to drop compression for the lower octane field. Easiest with sbc was open chamber heads.

 

Yeah, I get that. The reason for my post was what might have been done with that engine over the last 54 years? Crank, pistons, cam, let alone the externals. No one knows without looking.

 

Ummm...... Ouch!.....
This is why I prefer using a good 327 small journal block for such a swap.....

 

This old zombie is wandering all over the real info. It's been posted. Some wives tales and urban legends too. What gets me is the semantic discussion of 301 vs 302. Theres a difference, well aside from "1" that is. 301="old guy" speak from the ol SBC glory days. 302=marketing for GM. In the 5 liter limit these were all slated for there were 2 302s, a 301, a 304, and if I'm not mistaken also a 303 (MOPAR?). The 302s were available in showrooms, as was the 304 (AMC). The 301 was a Pontiac from over the counter race parts if I recall clearly and the 303 was a 340 MOPAR derivative offered the same way. But, no matter how you get there a 4" bore and 3" stroke is a 302. Use a custom large journal crank (kryptonite?), add the 3 center 4 bolt mains and it should hold up through 7500+ RPM. I'd be more concerned with a stout and light valve train and enough flow volume to make scary butt puckering power.

 

A 283 bored was the same thing. And if you don't have the gear right for the car it's gonna be a pig. Just build a poked 283 and put some compression in it and a cam and go on down the road. I've had some really good running 283's. I've had some really good 327's. Compression and good gas. Good gas makes them run. Like we use to have. I've run 12.5 to one small blocks on the street back when. that's what it takes, good gas and compression. Pay for the fuel if you want to go back in time.

 

Ya know Lip, you're right but $10/gal for street duty isn't viable. However, there's that 85 stuff we aren't supposed to have topics on. Imagine a vintage die grinder SBC built for that. Yes, compression and intake flow volume. Sadly there's no real reason except for class racing to build such a small engine. Fun? Sure but at a price beyond cash. 327 to a 331? Better. 355? As my dear racer friend might say, "Oh fkn HELL yeah!" High revs, bigger power, wears the same tux...

 

The 4 bolt blocks that everyone seems to want arent exactly that much stronger because the outside bolts go into a narrow part of the block. Outside bolts should be canted into the thick part of the block. So a 2 bolt block is the better candidate for the canted bolts by a competent machine shop. I have had some pretty naughty small blocks and were all 2 bolts.