[dmr22]

Originally Posted by bigdog7373

Check out some of the circle track engines on from jegs and build yours similar to one of them. Here are some that i found:
http://www.jegs.com/i/Blueprint+Engi...11CT1/10002/-1
http://www.jegs.com/i/GM+Performance...58602/10002/-1

Thanks for the links, that is a big help!

[dmr22]

Originally Posted by Hippie

I know the early 400 SBC factory 2 bbl. intakes accepted the larger Rochester 2GC's if that helps you any.

Is that the stock high rise intake?

[dmr22]

Originally Posted by techinspector1

Is there a rule limiting the fuel you can use?

The only fuel rule I know of is no alcohol. We are allowed to run race gas, and it doesnt say if there are any limitations to the race gas we run.

[dmr22]

Originally Posted by GMC boogie

Is there a vacuum or lift rule on the camshaft?

It doesnt look like there is a vacuum or lift rule on the camshaft. The cam does have to be a hydraulic/non roller cam with stamped steel rocker arms only, no roller rockers or roller tip rockers

[dmr22]

Originally Posted by oldBodyman

"Rochester’s will be allowed to Run Holley Jets. Venturi Size: 1 3/8” Butterfly Size: 1 11/16” MAXIMUM!"

that's the largest Rochester 2GC, rated 435cfm, minus choke you will not miss the Holley 500cfm. I don't think Ford or Chrysler have them that large. The carb will be the limiting factor.

if there is a flat weight limit, go for a 350
if the limit is lbs/cid go for a 305, 601 heads, 1.84/1.50 valves, bigger just get shrouded

You said best bang for the buck, 305s are virtually free, same stroke as the 350 and the heads will not limit this with a 2bbl.

Have fun with it.

There is just a flat weight limit, 3200 lbs with driver. We are trying to have a good time with it!!

[dmr22]

Originally Posted by sqzbox

using a cross over pipe will net you a few more ponies! Other than that, tire size, rims, and backspacing will help with the traction.

How do I make a cross over pipe?

[dmr22]

Originally Posted by Turdpolisher

I helped a friend go through this exercise several years ago. Here's some suggestions I had for him:
These "tight ruled" classes are ment to keep the motors pretty equal so very little gains can mean big advantages.
Bore it .060 over as the rules allow - bigger cubic inches
Reduce rotating mass by using aluminum pistons - spins faster - quicker.
Use thinnest head gaskets possible (I think there is thin copper available for 350 Chevy) for higher compression.
Use smallest CC heads that have maximum intake/exhaust valve sizes for higher compression.
Use smallest/lightest harmonic balancer possible - lowers rotating mass.
Use smallest alternator possible and cut down or remove fan to cut drag. Use a larger than stock pulley for reduced drag.
Use low flow water pump with oversize pulley for less engine drag.
Install crossover pipe in exhaust to scavenge waste gases from cylinders.
Remember - look for small advantages in reduced drag on the engine - saving 25 to 30 hp rather than trying to make it.

Thanks for the tips!! We are currently leaning to finding a set of 487's or 441's, do you think that would be my best bet on the heads? We will not run an alternator. Where do i install the crossover pipe?

THANKS!!!!!!

[dmr22]

Originally Posted by techinspector1

Good post by Turdpolisher. To expand on his thinking, here is a book I have owned in the past that everyone should own. It has 1001 little tips and tricks that you may never think of on your own.
http://www.amazon.com/1001-More-High...0195256&sr=1-5

Thanks, I have a copy on the way!

[bigdog7373]

For a crossover pipe you can use an x pipe: http://www.jegs.com/i/JEGS/555/30681/10002/-1
or an h pipe: http://www.jegs.com/i/JEGS/555/30651/10002/-1 .
I'm just assuming you're running a 2.5" exhaust.

[dmr22]

Originally Posted by bigdog7373

For a crossover pipe you can use an x pipe: http://www.jegs.com/i/JEGS/555/30681/10002/-1
or an h pipe: http://www.jegs.com/i/JEGS/555/30651/10002/-1 .
I'm just assuming you're running a 2.5" exhaust.

Thanks for the links!

[65smallblock]

You need knowledge!! Forget motor assembly for a while and get some books.. Every little trick in the book is what you need to win with rules like that. There are dozens of "little things" that when combined can add up to a cumulation of significant gains.

A couple of things I see right off the bat are;

1- Exactly what is meant by "extensive milling"? The winning motor will have difinitive knowledge of this and be milled to the maximum allowed. Also use the thinest head gaskets possible. If you are allowed a light decking of the block then do that as well. Those things are good for a few HP.

2- Anyone who can utilize an Autolite carb has an advantage over a Rochester as they (Autolites) use the same type of boosters that are found on virtually ALL performance carburetors. If you can somehow get one of those to work on your sbc and then block of the exhaust heat to your intake, that is worth a few HP.. Even if you are stuck with the Rochester I would still consider blocking the heat risers. But thats just my opinion.

3- The rules say "no lightening of rods, but ballancing is permitted". Ballancing IS lightening!! The whole concept of ballancing rods is to make the other 7 the same weight as the lightest one.. What I would do here is try to scrounge up a large lot of stock rods and hand select the lightest ones. If you do you will probably find some rather large variation. That is where there are gains to be found. Then use the lightest pistons you can find and then have it all ballanced. The quality of the ballancing job is important here. Make sure that whoever does it will match all of the rods and then lighten the crank to match the rest. That will provide an edge and may prevent catostrophic engine failure.

4- The camshaft you select is absoloutly critical, and complicated. Especially considering the limits on heads. There are lots of guys on the board that are WAY more knowledgable than me reguarding cams, but that is the one thing that gives you the most to work with inside of those rules. There are BIG HP numbers to be found there!! The two basic things I would suggest is due to your limits on compression gains I would look to minimize overlap but you want to maximize lift. Less overlap means more cylinder pressure, that will become torque. The stock valvetrain will determine your maximum lift.
That is the simple translation, and it is a good bet that most of your competitors will know that as well. The more complicated aspect is that you will also find that the best cam will depend greatly on your transmission, gears in the rearend and car weight. You want to find a cam that hits peak torque as you come out of the corners, whatever that rpm may be for your particular car. The lighter your car and lower your gears, the more you have to gain from a cam that places you into a higher RPM range. Good luck with this one!!

5- Lifters. Try some speed pro HT-817R's. You should be able to find them at scoogin dickeys. That will give you an extra 200-400 RPMs. Trust me on this one.

6- Forget the 305's. Go for maximum cubes. Go 350 and punch it out .60..