I wouldn’t get too carried away with the “theoretical” boost calculations. You’re going to have some losses thru the carb, and more loss thru the intake ports, etc. I know on my blow thru’s there a couple lbs loss between the top hat and the manifold. How much pressure reaches the cylinder I don’t know, but certainly there’s more loss. If you have a static ratio between 8 and 9 to 1, and 5 lbs boost, you should be ok. My OT car with the Eaton on it is a “factory stated 9.4:1 static” ratio. Now it’s a whole different motor, dual oh cams, fuel injection, etc. with a blower sized for its 96 cubic inches. But slowing the Weiand down is a lot easier than rebuilding a engine. Less boost is less horsepower, but as Gaga notes, an inter cooler is a big effect. The heat increase in more boost causes some problem, and an intercooler on your set up is a lot more complicated than his turbo units.

Should be a fun project, and a gas to drive.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Thanks LordMrFord and Miker,

Looks like I’ll just give it a run at 5-7psi boost and see what happens. I will get an ignition retard module too.

I’ll let you know how it goes. It will still be a while off yet until I get a few bits and pieces together.


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

Yes. Intercooler in roots-blower is not that effective because roots-blower only moves air not compressing it.
Turbocharger, centrifugal and screwcharger generatates pressure and therefore heat in charger it self and air is hot already when going in intercooler.
Roots just moves air forward generates heat and pressure in whole intake system from charger to piston and thats why intercooler located in the middle, cools only 50% compared to other charger types.
Water injection cooling might work better with the roots-charger because it can be located closer to piston.


Hyvinkää, FI

Keep the cam mild with not a lot of overlap (fairly wide centers) . If you tell Mummert what you are doing and want he can recommend an effective cam. 

Frank/Rebop

Bristol, In ( by Elkhart) 

LordMrFord- yeah I did read an article the other day saying that intercoolers on roots style blowers (between blower and intake manifold) were pretty much useless. It said that because the air is already compressed once it passed through the rotors that cooling could not make it any more dense, no extra performance gains. it would just cool the air to help with detonation issues. I also read that fuel atomization cools the air by up to 50%. I thought that was pretty interesting.

Peg leg- yeah I was thinking something 112-114 with larger exhaust duration. If John gets back to me I’ll let you know.


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.