My friend bought a blower that was (or had been) on a flathead. He has been looking for one for some time so he jumped on this one. It does not have a pulley so he is looking for info on what size he should use and any other info regarding the spec on this thing. The seller said it was a Weiand unit but there is no info on the unit. Got some pics for reference. While I was there I rotated the unit and was surprised to see some galling on the rotors. When I pointed this out to my friend he said he wasn't terribly concerned. Is this a common issue with these units? Any advise would be greatly appreciated.
Those rotors are not great as the lobes should never touch. For comparison, here are mine from my 6-71 that had about 100K miles on it. My blower guy told me to throw it in the dumpster. Your rotors are not a whole lot better. At the very least, it needs rebuilt and properly clearanced.
Weiand? No, the straight rotors and the angled inlet say it’s a Wade blower, manufactured in England. As said already it looks pretty rough.
yes, did some searching on the net and found a pic of a unit that looks identical That for certain is not a Weiand . Thanks Fordors for the assistance. I will tell him what he has.
As to your question about pulleys, depends on current static compression and performance expectations. A typical street blower application will drive the blower somewhere between 10% under to 10% over engine speed. I'd check around and see what info you can find on that blower on a flathead, but my guess is it will be somewhere between 10% under and 1 to 1.
The "Rodfather" is not one to shy away from things so he has modified an old intake, fabbed up some adapter brackets, built a metal intake box and has the blower mocked up on the bench as of this morning. He is determined to see this run and will be installing it on one of his A coupe projects. I told him he most likely will need a pop off valve mounted in one of the runners ? but I have no idea where he can locate one that would fit in the space available. Any ideas on sourcing one fellas? Pic of where he is at now
If he goes with v-belts he will be OK without a pop off. The most likely time for a backfire will be with a cold engine on startup. Give it a pump or two and use the choke. Cold morning, then two pumps on the pedal for sure.
a little info from a motorcycle page: Wade This was available in twoi sizes. The RO20 is 2000cc displacement per revolution for engines from 2000 to 3000cc for between 5-8.0 psi boost. Two drive ratios were used 0.8:1 and 1:1 depending on the power required. An RO20 supercharger fitted to a 1300cc engine with a drive ratio of 1:1.0 will supply a maximum boost of up to 18 psi. The RO20 weighs 40 lbs. The maximum rotor speed is 6,500 rpm; for continuous use 6,000 rpm. The RO34 is a longer RO20, with displacement per revolution of 3400cc for engines from 3000 to 5000cc at 6,000 and 5,500 rpm. So...you probably need to figure out the size of the blower, and then you can get an idea of what drive ratio you want. A lousy rule of thumb is that you'll get around 7 psi boost if you turn the blower 1:1 and the blower displacement is about the same as the engine displacement. have fun!
Thanks fellas for the input. I suspect that this is a R020 as it does not look as large as the ones pictured. found an older thread from 2015 with some more info. If we are not looking for much boost with a stock flatty how much can you safely under drive a blower? Or should the goal be to have it run as the same rpm's as the engine? Here is the older thread. Good info and input, especially the blower intakes that are being made down under. https://www.jalopyjournal.com/forum/threads/wade-superchargers.973299/
What size is your engine? Unless it's a V8-60, you're not going to make much boost if you dive it 1:1, since it's a 020 blower, not 034.
Here is where he is at currently. Working on several projects all at the same time. He has the blower mocked up on a flatty that is going back into a 31 coupe. That may be a bit down the road as he is finishing his SoCal themed 31 at the moment. Pic follows....
The Jalopy Journal
