[Skeletor]

we've heard of some pretty mean 377 sb combos around here, any thoughts on the potential of a big bore short stroke big block? like a 502 block with a 427 crank.

[Novaguy73]

The 488. If i was to build a big block this would be in high concideration for me. Especially if i was to build it race only. My thinking is that with a big block and 488 inches, youll have more than ample supply of torque no matter what you do, so if one was to loose a some tq on the bottom for alot more in the mid range and upper RPM it would be much easier to get to hook and be easier on parts. Just my train of thought....but remember im the guy that built a 350 to run 11's instead of a 383.

[Skeletor]

ok, lets here some theories on this motor, what cam would you use? gears? heads..... oval or rectangle? c'mon guys lets get some opinions.

[greg moreira]

There is a very knowledgeable guy on one of the other boards running a short stroke big block and pulling down serious times. Its based on a .060 over 454 but with a 3.76 crank(440 incher). Nothing too fancy at all...the fact that its a stroker is the most exotic thing of the whole deal. Its got replacement L88 heads with a little port work and still running the 2.19 valves with a solid flat tappet crane camshaft. Anyways, motor alone is low 10's and on the bottle it runs high 8's. Here is a link to his webpage so you can see more complete info about his combo.

http://www.homestead.com/schmidtracing/TheBirdPage.html

If it were me, Id have done it slightly different. If we want to stick with the short stroker theme(the only good reason I see is to allow for more rpm with slower piston speed......euqalling more bottom end safety), I probably would be using a bored 502 block with a 396/427 3.76 inch crank. That will get you around 480 inches depending on the overbore. Rectangle heads are better for higher rpm's, but still, a good oval port head(afr, brodix) is capable of holidng this thing to 7000 plus rpm. If you want a lot more, might as well jump right at some aftermarket rectangle ports. At least a solid flat tappet cam, if not solid roller cam is necessary. Probably a 4.56 gear or more with at least a 4500 converter. On motor, this should be faster than low 10's if done correctly. It would be fairly radical and not a street motor by any means, but in comparison to his motor, youve got a few more cubes and more modern tech heads to help it go a tick faster without running as hard.

[Novaguy73]

Ok what purpose would it have? If it were a 15:1 alcohol burner id say big rectangles, if it were a 10:1 mid range motor id say ovals.

[69Project]

This months Hot Rod had an article on this I believe. They took two SBC's I think(maybe they were BBC, can't remember, been a long day) and built them to the same size, but one had a big bore short stroke and the other had long stroke small bore. Anyways, the bottom line was there wasn't much difference and you wouldn't notice a difference unless you were a serious racer and needed that extra tenth. I don't know if a BBC would be any different. To the average street guy, I don't think it would really matter.

[pdq67]

Here is the link to the long thread on this that I started over at Team Chevelle if you want to read up on it??

Title: Freiburger's Bore vs Stroke article!!
http://www.chevelles.com/forums/showthread.php?t=89298

pdq67

[67RS502]

477s are pretty common combos for racers, especially nitrous motors.
There is no reason why you couldnt take a 502 block / 3.76 crank and
make a nice street motor out of it. With a small cleaned up rect. head
that flows around 375cfm, and a cam around 250dur, you could make
650+hp easy on pump gas, and could be shifted around 6500rpm. If the car
was set up right it should run high 9s easy, with a 4000+/- stall and 410s,
so it would still be streetable. I think you could compromise a bit, like I do,
and stick 373s and a tight converter in it and still run high 9s with such a
combo. If built more radical, killer 400+cfm heads, cam 260-270dur. solid roller,
5000stall, and 430 gears, you could make an honest 700-725hp (on pump gas)
and rev it to 7500rpm and run mid 9s, although it wouldnt be as streetable
as the 1st combo I mentioned. I'd personally just go for the cubic inches, and
not de-stroke a motor (no replacement for cubes), but a 477 would be plenty
big to go 9s and still stay streetable, because with the amount of
good aftermarket cylinder heads available today you wouldnt have to build
it very radical to make the 650hp needed to go high 9s.
Hope that gives you some ideas...

[MY10secSS]

I currently run a 440" BBC (4.310x3.76) that I built about 5 years ago similiar to Schmidt's except I used 049 ovals and a small Lunati roller. I have run 6.70@103mph at 3250#. I was motivated by an article I read about a cheater 396 that used a Bowtie block (4.500) and a L-88 crank (3.76). The 502 block has a one piece rear main and will not work with the early crank but the Bowtie will as will blocks from World products. The only advantages I see with this is 1. A cheap forged crank and internal balance 2. Using longer rods and lighter pistons 3. Telling everyone that it really is a 396 (honest). I am one of the few that believe you either build a race motor or a street motor but you can't have both. With SBC's surpassing 450" a short stroke big bore BBC is hoohumm nowadays but the nitrous guys swear by them and I am happy with mine. The bottom line is, I built it because I got the parts cheap and I wanted durability with low maintenance.

[pdq67]

For sh-ts and grins, I figure 4.625"b x 3.76"s = 505" BB motor should run about like a little Z-28 motor if set up right with parts that can withstand 8,000 rpm blasts!!

He, He!! And you shouldn't have to worry too much about low end torque b/c it IS a 500"+ motor!!

Step up to a 4.375" stroked crank and still be over-square and create a 588" jobber!!

pdq67