Homemade Blower Intakes And Stuff

I want to build a blower intake for my 8-71's to fit my olds 455 motors. Has anyone around here ever built an intake from scratch? Anyone know the math for runner length or plenum size? Any suggestions, pics, or horror stories?



Another question. Has anyone used chain drive or made their own drives, multiple v-belts, or idlers.

Thanks,
Richard

 

I saw this on e-bay. Would this work ????

 

I believe those are V6-71's not 8-71's you do realize they have to be reworked for gas application?

 

They are Detroit Diesel 8V-71's. The one farthest away has been rebuilt and converted.

 

The easiest way for you would be to take an existing Olds intake & simply bolt a flat plate to the carb flange (s), machined to fit & drilled/tapped where appropriate. The Offy Olds Port-O-Sonic & the 360 are what I've seen commonly used; also, the 360 dual-quad low rise, modified. Both Dyer's & BDS used to do it that way; still might, for all I know. The dual quad would be my personal choice.

I think the Torker would be a tad high to do this, & the Victor Olds, but possible.

So far as runner length & plenum size, most of the time common sense prevails, but you can figure out the displacement for each full revolution of the blower, the required airflow of the engine, & go from there.

 

One vote NO.

 

When using a common intake to make a blower manifold you have to machine the carb surface parallel to the crank centerline before you mount a plate to it. This to keep the belt running true.

Frank

 

Yup - 5-8° tilt is common on carb mounting flanges, and this mounts the blower shaft at an angle to the crank.

More: http://victorylibrary.com/mopar/blower-GMC.htm

 

Thanks for the link !! That answers alot of questions. And thanks to homespun for tipping me on the 2x4 intake. I am laying my hands on a used one tommorrow.

Does anybody know anyone using chains or multiple belts as an alternative to the gilmore belt? My Wife took a couple blurry pics at the York US30 show last year and caught a sidewinder using what appears to be motorcycle chains.







This year I will take the pics.

 

Why not? It's a rear bearing cover. It just holds oil and a breather, right? I saw that guys pics and figured it would be a cheap way to cover the back bearings, Instead of paying a couple hundred for a cast aluminum plate. I just wasn't sure if the diamond plate would leak when it heated up.

 

Hence my words "machined to fit". The flange itself is usually machined mostly off, depending on some factors, & you generally wouldn't use the carb studs, either the locations or the diameter.

The low-rise dual quads generally have the flanges machined as noted, and often material is added on both sides between the two flanges, with the middle being machined out, so you have a fairly long plenum. Hope this clarifies a bit. I believe that I actually have a picture somewhere of the Olds Offy dual intake modified for a 6-71, but I'd have to think where it is.

Depending on a number of things, a radius on the bottom of the plenum may be a good idea...it may not. Fuel shear can be an issue, and some of the Offy manifolds aren't particularly efficient by today's standards. You are, to an extent, on your own and will need to experiment.

The chain drives I have seen were all custom, or homebuilt if you like, deals. I believe I have some pics of those also.

 

1/4" thick Aluminum Diamond Plate isn't going to leak,
but the proper part is thicker because it supports the bearings.





The rotors are around the same length as the main housing,
the bearings are in the end plates.

 

Chains were used before Gilmer belts,the only other option
at the time was multiple v-belts.

Chains are heavier,messy,and can do more damage if they ever break.

 

Here's a thread with some pics of what I whittled. Works well.

http://www.jalopyjournal.com/forum/s...t=blower+drive

 

Chain and other drives: http://victorylibrary.com/mopar/blower-drive4.htm