Power Steering pump

[partybarge_pilot]

Speaking of shoveling dirt, every time I pull a drysump belt off the truck it has little rocks punched through it making little blisters on the back side. Scarry! For the PB2 I'm running the DS pump off the cam like a sprint car just remote mounting the electric water pump this time.

[SPONSOR]

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[PBR]

just like dave said it's nice to have a tensioner on the belt at all times... my buddy has this system on his hotrod and it is very sano.
http://www.marchperf.com/

[Dave_G]

Ollie,
Some of their stuff looks pretty good. The only exception is that it looks like a few of their setups don't run a constant tensioner and some do. Another thing to look for is how many degrees of wrap around the crank pulley since it's doing all the driving load. The more degrees of wrap the more power transfer to the accessories and less chance for belt slippage. And that goes for the pulleys on all the accessories too. I typically like to see 180 degees or more of wrap on any accessory pulley.

[hoeker]

[ QUOTE ]
Speaking of shoveling dirt, every time I pull a drysump belt off the truck it has little rocks punched through it making little blisters on the back side. Scarry! For the PB2 I'm running the DS pump off the cam like a sprint car just remote mounting the electric water pump this time.

[/ QUOTE ]

i looked into this for my CORR truck but decided the risks and cost wasn't worth it. i even tested dual electric water pumps to see if they could handle the job, duals could do it, but if the voltage drops below 10 volts they shut down, made the risk not worth the gains. in the last 2 seasons i have had no oil pump drive belt problems so now i have no desire to look at it closer.

back on the PS belt, howe told me nobody makes a universal bracket for thier big pump, the ones in the web links were circle track pump brackets, not even close to what i run so check with lee before you buy john.

[ntsqd]

Driving it off the cam is actually not desirable. Sprinters do it for compactness of lay-out and no belts, not b/c it's ideal. The pump's drive load puts a twist in the cam. Unless the cam lobe timing is sequentially offset to bring the timing back to where it should be, you'll have valve events all over the map. And that will change depending on pumping load. Hey! Variable cam timing.......

This is one of the biggest problems with putting a big wet sump pump on any rear drive cam-in-block V8 (like a 392 Hemi or an SBC). If it is a spur gear pump it will translate chatter back into the drive system which has been demonstrated to affect Ign timing on SBC's. The other reason Sprints can do it is b/c they have no flywheel or flexplate. If you need either you'd better be looking at putting it back at the rear mounted transaxle.

[BAPerf]

I might be off base here, but I had a question about the twisting camshaft post...

If the pump is driven off the front of the cam, and the lobes oare on the back of the cam, (belt or chain drive in the standard location), how would the cam twist from the forces created by the pump?

If the pump were driven off the back of the cam (i.e. Nissan stadium trucks), I could see this as a potential problem, albeit a very small one. In fact there are quite a few OEM aplications that drive a pump directly off the cam.

Sorry for the re-hash,

Brian

[frankh]

I think it runs off the back of the cam. I could see the load thing after using a big drill motor to pre-oil it and see the load when it start pumping is pretty amazing. But unrelated I have had a oil pump on a VW lock up and in turn stop the cam so fast it broke it right after the gear.

[FABRICATOR]

The serpentine belt system is great but can be a science in itself. Everything must be very rigidly mounted and well aligned. Pully belt wrap and facing must be matched to each and every drive. Tensioner type, location, and mounting is critical. If you are slightly modifying a stock system you will probably be OK. If you are designing one from scratch it must be thoroughly engineered with no mistakes.

[ntsqd]

Frank's got it. Not only do Sprinters run the PS pump off the back of the cam, they also run a huge version of a speedo cable from off the back of the PS pump back to the fuel injector pump located in the fuel cell. Usually the dry sump oil pump is direct coupled to the cam and bolted to the timing cover. Then the H2O pump is direct driven off of the crankshaft snout. Ta-Da!! No belts anywhere.

Footnote: Expect to see fewer and fewer accessories that are engine driven on new vehicles. It will come down to a large alternator and nothing else. All power accessories and pumps will be electrically driven.

[BAPerf]

Sorry for the lack of knowledge, but thanks for the update!

I've seen the drysump pumps mounted to the front cover, water pumps mounted to the front cover, and the typical way of mounting the power steering pumps in midgets/ sprintcars (off the back of the dry-sump pump). I guess I'll have to go see some of the SCRA (oops, not SCRA anymore...) cars a little more closely. As for the cable driven Waterman pumps (fuel), I didn't know that they were widely used, I thought that the standard oil pump mount was still more widely used.

Again, thanks for the updates.

Brian