the 71 series blowers you see on race cars have been modified to work for the purpose of being run on a gas engine which is gonna run alot more rpm than the diesel version so it needs to be modified for that purpose. teflon strips just help efficiancy the blower itself will move X amount of air per revolution, so to build boost turn it faster and it will move more air than the engine can take in at a given rpm building boost. The roots design was originally for just moving air and not building boost, and has been around since the late 1800's. A screw type will move more air and build less heat than a roots blower.
The blower I used had the double gears on the snout yet, and that is what needed cut off and car drive installed. I don't remember what way it was geared(slower or faster), as feeding the diesel I don't know what kind of rpm it needed to do that? The gearing wasn't alot but it did alter it slightly from the input shaft. Wish I would have counted the teeth and determined that but it was 9 yrs ago. Detriots turn more rpm then a regular big cubic inch inline 6 diesel. Most I recall were 2800rpm or so, where most I6's were 2100(factory settings).
I'm curious, might have to contact my DD guru buddy and see if he has that information. He's worked on them for 30+ yrs, but not sure if he knows that little tidbit of information?
My understanding, limited it is, is that a 6-71, 8-71 blower directly taken off of a 2 stroke diesel will not make the kind of pressure per-say as a aftermarket gas oriented say B&M "6-71, 8-71" Blower.
due to the fact that the 2-stroke needs more in the cylinder than the piston can draw. It's not pressure that is needed, it's volume of air that is needed to obtain high enough compression pressure to roughly 600 psi to ignite the fuel that is introduced at or near TDC.
__________________ Committee:a group of the unwilling, picked from the unfit, to do the unnecessary.
"Brutus" 1978 F-150 SC 4x4 BB460
" There is a very fine line between "hobby" and "mental illness."
" -Dave Barry, Nationally Syndicated Columnist
They will build boost, you just need to spin them quite fast.
Two stroke diesels need a blower because they don't naturally aspirate. Do to how their cycle works, they can't physically pull in any air by themselves. The piston can't draw in any air on its own at all. The blower literally blows fresh air in, and helps to push the exhaust out.
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- Ian
1987 Ford Ranger XLT 4x4 2.9
Needs a lot of work, including some rot on the body, but shes getting there.
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