Max speed for Pace oil pumps

[reflexdb]

From information I received from Pace, they don't advise running their compact C pumps at speeds higher than 6500 rpm. Pump will be used on an F4i motor. I was planning on driving the pump with the crank shaft (where the stock water pump is), as it seems many teams do. Have any teams had problems running their Pace pumps at higher speeds than 6500 rpm? Or, are you gearing it down to run at a lower speed? If it's geared down, it doesn't seem like it will have a high enough flow rate capacity.

[Maverik]

The stock water pump is not driven by the crankshaft (at least the RR, I'd assume the same on F4i), it is from a chain connected to a smaller gear on the backside of the clutch basket which also drives the stock oil pump (stock oil pump and water pump spin are connected with a shaft). So the long winded explanation is, in the RR, we have not had any issues with pump life or getting the pressures we've wanted with the pace pump... very good pumps. Out of curiosity are you using just a scavenge or fullout three stage pump?

[reflexdb]

Maverik, looks like your right about the pump's drive shaft. Just checked. So, it is geared down from the crank. I'm planning on using a three stage (2 scavenge, 1 pressure). My thought being that we could make the oil pan covering as low profile as possible, for the lowest mounting of the engine. However, I'm rethinking that now.

[Maverik]

There are definite tradeoffs with using a dry sump , but in my experience the benefits far outweigh the negatives. Some benefits:
- Accurate control over oil pressure
- Chop the pan, so much lower engine and much lower CG (this alone can make it worth it)
- Ability to plumb in oil cooler very easy

Negatives:
- Added complexity
- Weight of additional components
- Added draw from electric water pump
- Packaging (though you can make it look good if its well thought out)
- Cost

So why reconsidering?

[jack]

i think the most you could get from a CG drop is a 1/4 inch or so, 3/8 tops. sure seems like a lot of weight and complexity to me. best thing to do would be to ask the lapsim....

[kwancho]

For the record, the other day I was listening to a tape of the 04 Detroit design review overviewing the top 5 teams in design, and I think the 2 or 3 teams that ran a dry sump all did it for the lowering of the CG, which the judges said was the proper reason for a dry sump.

[Beatle]

Lowering the CG is an added benefit but I would argue with any judge who said that is the reason you should do it. You should do it because the oiling system on these engines are not designed for lateral loads. Reliability should be a much larger priority than lowering your CG.
One of the nicest things about the dry sump is that it opens up a lot of possibilities for packaging. Many more components can be remotely located so you can adjust your design around other "more constrained" systems.

[kwancho]

I'm no expert here, but at least in conversations with my engine guy, I think with the proper baffling and pickup modification, we can get 90-100% of the reliability of a dry sump. The packaging is definitely a plus, but not 30lbs worth.
For what it's worth, we're going wet sump this year, but only due to time and money constraints. We'll probably go dry next year.

[Brian Evans]

I wouldn't run a pump like that over 5000 rpm if I could get away with it. When we use those types of pumps, we run a 50% reduction belt drive, and our engines (not motorcycle based) are under 8000 rpm red line.

The traditional reasons for running a dry sump are engine reliability and ground clearance, which of course translates to CoG.

[reflexdb]

Maverik - I'm not reconsidering doing the dry sump. Seems to me that the added reliability and lowering CG are reasons enough alone to add a little complexity and weight. We're dropping enough weight everywhere else anyways. I was reconsidering using the 3 stage pump. May now go with a two stage, and use the internal pressure pump. Only problem may be with the stock oil cooler / filter location on the F4i (interference with exhaust manifold). Looking into it though.