Gear ratio

[caseyssugarshack93]

What the gear ratio you guys run on ur surge pumps i have a bb4 and im gunna put a 5 hp honda on it.


Thanks

nate :D

[Bucket Head]

I have no vacuum experience, but I did help out a friend with a vacuum pump that was engine driven. We had to slow the pump and speed up the engine.

I also have no idea on what the reccomended RPM for your pump is. You need to find that out first.

Heres a formula that will get you started. Some experimentation and fine tuning might be required.

Pump speed over (divided by) engine speed = reduction

Pump pulley x reduction = engine pulley

Like I said, you need to know what the pump is supposed to be turning, and you have to have an idea of what RPM you want the small engine to be turning before you start doing any math.

It was a couple of years ago that I did this, so it is no longer "fresh" upstairs. I do not remember what the diameter of the pulley was on his pump. (The pulley on the pump was the original pulley, with the cooling fan blades as "spokes". That had to stay on the pump so we could only change the engine pulley) I do know we shot for 2800 or so on the engine. We did'nt need, nor want full throttle operation. The engine was not turning fast enough prior to the pulley change. It was lugging and fouling plugs. Most small engines are governed at 3600 rpm at full throttle.

Hopefully someone will be able to tell you what they have on their pump. But if not, this will give you something to work with.

Steve

[halfast tapper]

Friend of mine has a delaval pump that has about an eight or nine inch pulley on it and his engine pulley is about a 3 or 4 inch pulley. Runs his engine at about a 1/3 throttle. He also has a 5 horse engine.

[tuckermtn]

Paging parker- paging parker...Parker is the gas motor surge guru...he can probably help you out better than I can..but here goes..

I have a sp-11, which is like an bb3- but I run it on electric..but the sp-11 pump manual lists the following info for the SP-11:

size of motor- 3/4 hp. RPM 475 12" sheave, 3.5" motor pulley

most of the surges I have seen are set up this way- big sheave, little pulley. goal is low RPM's...My pulley size on the motor is closer to the 2" size.

[caseyssugarshack93]

alright thanks for the help ,but ill ask parker what kind of gear ratio for the engine.


thanks guys

[Maple Hill Sugarhouse]

I have sent CSS a PM about what he needs to know.

[nymapleguy607]

I might be off base here but aren't a lot of the surge pumps piston type? If they are the slower you can run them the better I kind of found that out the hard way on my first pump.

[WMF]

Here is a chart showing max rpm's and HP requirements for you piston pump boys.

[Russell Lampron]

WMF do you have anymore tidbits of info on these pumps? That one little chart told me a lot about the SP-22 that I just bought.