I am bored and ther is too much snowe to drive the cuda so I am kickin around the idea of building an IR manifold for my stroker motor. My question is where is a good source of info about desighn like how long and fat runners should be, side draft or down draft, what carbs work best? Mabey someone knows of a manifold being produced

Motor will be a 414 stroker, mabey bigger if I can come up with more $$$ for a longer stroke. I have a pair of RHS magnum heads or aluminum mopar magnums 1.7 rockers and a XE268 cam. I mostly want to do it because it's different but I still want it to run good.

I think your going to have A hard time finding carbs big enough. I know guys that run dual 2 barrel 48 webbers on VWs with 120cuin displacement, and they make about 150 to 200 horse power. I dont know how big webbers get, but the VW guys talk about 48s as being the biggest they can get

I figure if I had 250 CFM intake flow X 8cyl I would need about 2000 CFM, mabey a couple 1000cfm dominators set up with identicle primarys and secondaries. Does any one have experiance with dominators on an IR manifold?

You need carbs that were designed for I/R use holleys are not, they will not deal with pulse that an I/R set up creates. If you have ever looked at A webber, notice how tall it is, its 2 or 3 times taller than A holley and that is no accident. its made for managing I/R conditions, your going to spend A lot of money on dominators and time on your manifold to find out it wont work. But if you must have an I/R set up you can start here. http://www.ronsfuel.com/single2.cfm you could use their throttle bodies with EFI. you could also try kinsler or hillborn to name A couple. This way you could get the CFM your looking for.

There was at one time Dominators made to suit IR
Dont know the part No. or if they are still available.

what about motorcycle carbs

I have been looking at some motorcycly carbs but I think they are too small but I don't see flow rateings on them, just MM

The biggest motorcycle carbs TIKO are the S&S Super D, 2-1/4". However, they're side-draft, $$$, have no power circuit, and are intended for a 2 cylinder motor about the size of your cylinders.
You can buy Mikuni with 48mm throats, but over $200. each and IDT that's big enough.

6214 special venturi on the left...

6214 velocity stacks...

A side draft may not be out of the question. I thought about getting some kinda air-gap manifold and cutting everything out except the bottom plate and flange area, then weld in some tubes to cross over and sit the carbs on the oposite side valve cover area.

Are those 2cyl motorcycle carbs 1 throat or 2? Are the cylinders the size of mine individually or combined?

A mototrcycle carb may be fine because they are desighned to feed a smaller engine but at two to three times the RPM.

If a carb is going to feed a 25 cubic inch 1 cyl @ 10,000 rpm it should feed my 50 cubic inch cylinder @ 5000 rpm, is that close to correct?

Just wondering by why would you even want to do this?...

The s&s super carbs you can run em on one cyl or two and they put the on 120in motors that only turn about 6000

A side draft may not be out of the question. I thought about getting some kinda air-gap manifold and cutting everything out except the bottom plate and flange area, then weld in some tubes to cross over and sit the carbs on the oposite side valve cover area.

Are those 2cyl motorcycle carbs 1 throat or 2?
All 1 throat

Are the cylinders the size of mine individually or combined?
Each

If a carb is going to feed a 25 cubic inch 1 cyl @ 10,000 rpm it should feed my 50 cubic inch cylinder @ 5000 rpm, is that close to correct?
Yes, I know that's what the "formula" shows, but it doesn't work. The small cylinder need a small carb or it has poor response, the big cylinder needs a big carb or it has no power.

Cutting off everything but the flange and chunk of the runner and extending them across is exactly what a 1960-61 Chrysler long ram runners look like (except they ended in plenums). There are also Moon Weber manifolds like that - there's no other way to hide the length and put the hood on.

I agree - it's a lot of trouble without much gain - and that's if you get it right. Most people give up after much $$$ and &<?$@~`**!!!!.

why not efi the setup? that way you can still run the IR manifold with individual throttle bodies and youre at least guaranteed a workable solution at the end.