[Shad Laws]

Hello-

You guys mention that the windage effect of the crank and piston back side is drawing power. Doesn't the factory 914 ' windage tray' eliminates that effect largely?

It helps, but not as much as a dry sump.

Nowadays, just about _every_ production engine has *some* sort of windage tray, whether integrated into the block (for an aircooled example, look at a Corvair) or in the oil pan.

A good dry sump system helps quite a bit more, though.


Also, neutralizing the windage effect by the windage tray, I thought that the a multi stage dry sump pump costs more power to drive it than it freed, thus resulting in a less power situation with a dry sump system?

No. The higher you go up in racing, the more stages they use...

They also use vacuum pumps to drop the air pressure in the crankcase, further reducing windage.


Poor quality dry sump pumps leak and lose pressure losses because of different materials expanding differently (iron/aluminium)

Iron gears in an iron-bodied pump will give the highest pressure. Simply seal the iron body to the aluminum case on the outside and you're golden. Yes, I know this is contrary to "common knowledge," but think about it...


and bearing issues of the pump gears. Therefore good dry sump pumps are very expensive ($ 500,-- - $ 700,-- or more).

The closer and closer you want to get to *perfect*, the more it costs.

For a situation where competition isn't that heavy, i.e. a street car or amateur race car, a simple 2-stage pump is *often* the best bang-for-buck.


Also, most all reputable tuners in Germany use a stock 24 mm pump in their own (!) engines and make regular drag starts with it, even in 226 DIN hp (tested) 2733 cc cars that do 0-62 in 4,5 sec.

The stock pump isn't that bad...

My guess therefore was that although the system in itsself is very good, we obviously don't need it in a street car application.

Of course you don't *need* it. But it's a nice thing to add :-).

But if anybody did any testing and found they gained hp, I would definitely reconsider...

All well-built dry sump systems save power.

I thought parts of the crank were splash lubricated?

A dry sump system lubes the main, rod, and cam bearings, and the lifter bores (and therefore pushrods, rocker arms, and upper valvetrain) the _same_ way as the wet sump system. It's pressurized from the oil galleys, after the last pump stage (which, for a wet sump system, is also the only stage :-).

The lifter faces, cam lobes, wrist pins, and cylinder walls are splash-lubed from the oil spray coming off the main rotating assembly. Of course, other modifications can change this a little one way or the other.

In the engine gallery you will find a picture of a dry sump pump that Eddy Remmele made. It is 30/26 I believe but from the setup identical to the Schadek (CB) pump. He told me that he will not make them anymore. It was not cheap. If there is enough interest maybe be would get him to do them again.

There's a 914 racer somewhere on the East coast that custom-makes them, too. But, like Remmele, I think he's kinda lost interest in making more due to tiny quantity. If curious, ask Chris Foley for more details - I'm just repeating what he told me.

Chigger, The large quantities of oil do not help cool the engine, it just prolongs the warm up time until all the oil is up to a useable temp.

_Absolutely_ correct.

If you use a dry sump, you _really_ need to use a real, temperature-based thermostat, not the pressure-based stock one.

Take care,