Chevy BB 302???

[jdub396]

Has anyone built a big block version of a (SB) 302? BIG bore, and short stroke....maybe a 572 block (or bigger) with a 396/427 crank? I was toying with the idea of doing this with some light parts, big cam, instant throttle response, and lots of RPM's. I know everyone is into more and more cubes, but I don't like doing what everyone else does!!

Josh-

[Ricoch3T]

yea man.. check out the nhra pro stocks they do it to get their 500 cubic inch motors. I dont' know the exact specs but they are doing the same thing

[Johnny Blaze]

The pro stocks use the 3.76 stroke, with a 4.5 ( I think) bore.

[Lowend]

There is an old combo floting around for a 36x.xx cid big block that was the short stroke big bore theory... never really caught on.
The 302 was an engine specifically designed to fit withing the rules of a race series, the combo itself is far from the end all be all

[RobM]

a 427 is some what like that. those can spin pretty high

[pdq67]

They are like 4.70" b x 3.6" s = 499.7" of big bore short stroke high winding BB power, imho!!!

Just under the 500" limit back then if I recall right..

And way earlier, guys were reworking 348 and 409 "W" engine cranks so they would fit into the 396 and 427 BB's..

They had 3.25" and 3.50" stroked cranks so would also wind to the MOON!!

4.28" b x 3.50" = 402.8" and

4.28" b x 3.25" s = 374.1" engines............

They'd shift these up at 10,000 rpm back then just like the little 287's, 292's and 302, Z-28 engines.............

The technology is still around to create them, but now why, unless you just want to be different..

pdq67

[RobM]

unless you have a displacment limit for compatition theres not a lot of reason to spin an engine up that high.

for a street car it wouldnt be so fun to be changing valve train components a few times a season. but it would be fun to drive as long as your not using the car for transportation

[Samckitt]

I had thought it would be neet to make an LT1 302 using factory parts. The LT1 is a 350, most everyone knows that, 4.0 bore - 3.48 stroke. The L99 looks like that LT1 but is a 4.3L. I can't remember the bore (same as a V8 305) & the stroke is 3.00. So use the LT1 block & pistons, & the L99 crank & rods. A modern day fuel injected 302 with factory parts.

[RobM]

sweet idea. doesnt the lt1 have hydrollic lifters? youd need to do somthing about that to make that baby sing

[Samckitt]

It has hydraulic rollers. If I was to do that I would probably put some solid rollers in it. It is just a thought to do something different. If it actually came down to it I would probably put a 3.75" stroke in it & make a 383.

[RobM]

i wonder if the fuel injection could keep up with the high rpm, or any of the other stock parts?

[572SS]

The faster it spins, the more you spends!

I agree with what others have said, unless your limited by rules, bigger is better!

Back in the late 70's Honda took bending the rules to the limit on a 750 cc GP bike. It seems they had figured they would need an 8 cylinder 4 stroke to beat the 2 stroke bikes but the rules limited them to 6 cylinders. They built a V-4 with oval pistons! When you looked at the heads, it looked like two four valve combustion chambers with the divider missing. Shift point, 18,500, not sure why but it was a bust!

Maybe because they got the rings from Perfect Circle?

Al

[Samckitt]

Rob, probably not. That may be why when GM did it they put a carb on it.

[pav8427]

Reher-Morrison got around the rules in the early 80's and built a 365 using a modified 348 crank.

[ProdigyCustoms]

It is nice to have a shorter stroke then bore, as mentioned above, 427s, even 540s spin like small blocks. And unlike a 302 which suffers from being to small and to small a storke, the others have plenty of grunt while still turning Rsssss.

I built a lot of 302s in my resotration days. Personally I always thought the best thing you could do to one was slip a 3.48 crank in it and give it some ass!

[Samckitt]

A few years ago I saw an article in some car magazine where they built a big bore 350. I believe it used a 400 block +.030" & the crank from a 327 = 3.25" comes out to 352 cubes. Seems like they used some weird combination of pistons & rods. Seems like the rods were factory for some kind of straigt 6 Ford & were close to 6" in length. This way you have the advantage of a larger bore for bigger valves & a shorter stroke for big Rs. I don't remember the horsepower & torque numbers, I do remember they were pretty good.

[572SS]

Even Ford tried to make a twister out of their old FE style block. For one or two years they (Mercury) put a 383 in their Turnpike Cruiser. It used a Lincoln 430 block with a Ford 332 crank! They beat me to it, I thought I had a great idea and was looking at bore and stroke numbers in a Motors Manual while in HS auto Shop class, ruined my whole day! Back in the day, almost 40 years ago, stroker cranks were not to be had by mere mortals! I never saw one and have no idea how they run, since they only made them a year or so, they must not have been anything to write home about!

Al

[pdq67]

572SS,

Those Ford Corp. 383/410/430/462 MEL engines were like our 348/409/427 "W" engines!

They had almost no combustion chamber in the head so it was basically flat and a slanted 10 degree deck whereas our "W" engine have a slanted 16 degree deck.

I would dearly love to stick a pair of 427 "W" engine Z11 heads on a 454 and use peanut shaped dished pistons w/ a CR. of about 12 to 1 and LONG rods just to see if I could run 87 octane gas!!

AND also flat deck a 409 so it's like a 454 and then furnace weld up it's decks so that I could redrill them and mount a BB -206 headed topend on it!!!

Just for the fun of it..

BUT I'm dreaming as usual...

pdq67