I'm posting one more of these now that I've got a bit more info, I'm new and have no idea if multiple threads are annoying. If they are, tell me. Firstly, I don't expect to revolutionize the supercharged racing industry and make the next blower for a death class dragster, however cool that may be. I doubt many people would even want one, but I personally think if I could build an old hold hunk of iron spinning at 7000rpm and making 20 psi. That it would be possibly the coolest thing ever. Sorry for rambling. Based off the advice from other people in here, I've been guided towards more vintage boat, truck, aircraft and industrial blowers/superchargers. And I was just wondering if anyone had any experience modifying these standardly not used blowers to work for more standard racing purposes/racing engines.
Back many decades, the roots blower was commonly found on trucks delivering sawdust/chips to the neighbors basement to run their furnace....we haven't created anything new, just improved for our use. No doubt someone has a picture of such a truck.
If it can be done, it has been. If you are not seeing it done, there is probably a reason. There is sound reason why the blowers from Detroit Diesel/GMC are the default for people like us.
More often than not, from my experience, the primary motivation behind trying to find an alternative blower is the perception of cost savings. From experience, I can guarantee that there is not one. The blower is not the thing that costs the most. I got this 4-71 for free. Getting it to this was, very emphatically, not free. Just getting it here was even farther from inexpensive. And it ain't done yet!
Yeah I get that it's a dumb idea, and if it was easy and good everyone would be doing it. It's just something I want to try, and hell if I do it and make it badass I'll give the world a heads up. Also badass 4-71
It is not dumb, at-all. It is just not cost-effective. That 4-71 I showed is not cost-effective. Hot rodding is not cost-effective. If your idea were a dumb one, hot rodding would not exist. You are on the right track. If you want to do it, that's awesome! Make it happen. Do a good job, and take lots of pictures. I am just making sure that you, and everyone else, is aware that it won't be cheap. Putting a blower on anything is not cheap, as I have mentioned, even if you get the blower for free.
Right now I'm looking at industrial pneumatic blower, god knows how much I'm gonna have to do to it to get it to a running state
Also air mover blowers may have problems with having a carb on top of it. But if carb is above it makes it what is called a wet blower because fuel is going passed the rotors which help cool them. Dry would be say fuel injection below the rotors, then the thing becomes a heat pump! Engines don't like that. I say go for it, but figure out how its all going to work and how many customs parts have to be made to do it.
An important thing to consider is that all blowers use some of the engine's power to run. Your setup, unless it is for the sound and show, would need to make enough power to offset what is required to run the blower. Not all combinations of parts will do this. The 4-71 that I built, shown above, is configured for net-zero power. It makes just enough boost to offset what it takes to run it, and little to no more. The customer wants the look, and the sound, but the car is already overpowered for what it is.
Im probably gonna go with a bbc dart block or something. I know it obviously won't compete with actual race blowers, but I still plan to make some power or try to.
If I remember it right, screw type blowers have far better efficiency and handle more boost than the common roots blowers do. If dragracing rules in general allowed them you'd probably se way more off them, but racing rules are often not intended to make it easier to get more power, quite the opposite in many cases since safety has become an important factor.
I think I get what you're trying to do. I'm wondering if these industrial blowers have iron rotors? Knowing the intended original application, I'd think they weren't concerned with instant acceleration, just steady state use. So maybe they used iron to cut costs. Might be hard to accelerate if used as a supercharger. On another thought, I had the opportunity to buy a Whipple R980 at a very good price years ago, when I was building the hemi for my Studebaker. Screws have much better pumping efficiency, and the thing looks bananas, which I think is part of what you want. Ultimately, I knew it would require a lot more support stuff than I could afford, and to justify it and make it work, the car would be totally unstreetable, so no dice. I went with an old 14-71 Littlefield, and made crazy power, while pretty street friendly. I still think about it though. Chasing power is very addictive...
I have way too many projects and way too little money to be focusing on this alone, it's just something I think would be really cool if it worked out. It would be nice if I could find a twin screw industrial one, fewer out there though. I try to keep my eye open for about any good deals under the sun though, so I'll keep watch.
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