Calculating serpentine belt loading
Calculating serpentine belt loading
(OP)
I have a 1954 Dodge truck I have retrofitted a 400 big block V8 Chrysler into it. I'm planning on twin turbo, and twincharging it. I have two Holset HX35's on it, and plan on fitting EFI. I plan on running compound boost using two Eaton M90's, similar to the WWII bomber aircraft engines. The two holsets will feed into the M90s. The question i have is on belt loading. Ideally, Id like to run a single 8 rib belt of the crank up to a jackshaft, then, drive the first blower off that jackshaft, and the second blower off the first by putting a double pulley on the snout of the first blower. Question I have is this:
Does anyone have any equations to calculate the power transfer ability of serpentine belts?
Each blower will consume about 35HP at full load, so I don't anticipate a single belt will be able to drive both from the crankshaft, but, I want to run the equations to be sure.
Does anyone have any equations to calculate the power transfer ability of serpentine belts?
Each blower will consume about 35HP at full load, so I don't anticipate a single belt will be able to drive both from the crankshaft, but, I want to run the equations to be sure.





RE: Calculating serpentine belt loading
You need a considerable safety margin to cover load from pumping against boost, variations in friction due to rotor clearance changes from temperature changes. You also need to survive a backfire.
Blower belts tension also varies considerably due to engine expansion from heat.
Regards
Pat
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RE: Calculating serpentine belt loading
Its also depends of course on the type weather you get but here, lets say, it varies!
Brian.
RE: Calculating serpentine belt loading
I made the mistake of not cutting my displacement in half to acocult for the 4 stroke engine design. As such,I dont need to run the blowers as fast, only at a 1.5:1 ratio. At a 1.5:1 ratio, they only consume 9-10 hp a piece, for a grand total of 18-20ish, which is much less than a single blower running at a 2.5:1 ratio like I originally had factored. As such, I *Think* I could actually get away with a single belt, so long as I get good wrap of the pulleys.