drnick

if i read correctly the current crop of dry sump systems re-use the exisiting oil pump and only scavenge from the sump, filling the resivoir that feeds the existing oil pump... around and around! one other spinoff with drysumping would be the ability to lower the car and not worry about knocking off the sump on manholes. true the alternator is still down there but its not as critical

Vilhuer

Nick, you do now want alternator get hit. It will tear piece of block with it. Several 928 engines have sufferent this fate when either AC compressor or alternator was hit.

drnick

erkka i dont like getting hit at the best of times when are you next going to the ring?

heinrich

When the car bottoms out on the ac compressor or alternatior it usually breaks a hole in the block

Vilhuer

Four weeks from now. Will be passanger in S4 which should have Murf level II SC installed by then.

drnick

is that the first weekend in june?? that will be a wild ride no doubt!

Vilhuer

26th to 29th of this month already. Think at least Alex (Cheburator) is going to be there at same time.

drnick

ok will see if i can a) swap out of work and b) get the orange beast back from my mechanic!

evil 944t

Yes, Use the pressure stage of an external dry sump pump and feed it through the oil filter plate. You will have to make an adapter plate and relocate the oil filter.

GlenL

So then the pump is removed and the feed passage is plugged? The sprocket is run by the timing belt and needs to be retained. Sounds like that'd be a problem. Don't want that to seize because it's not oiled.

evil 944t

Thats fine. It will still get oil on it.

SwayBar

Mike Schmidt showed us a video by Louis Ott who had cut a hole in his valve cover (..I think it was the passenger side) and installed a lexan plate with a movie camera peering through it and recording. He took the modded car out onto a track with someone else driving with Louis as the passenger observing the results in realtime as they raced around the track.

Once can clearly see the camshaft spinning and flinging oil as one would expect while on a straight-away. However, all of a sudden, the picture literally frothed up like a ferociously bubbling chocolate milkshake; it happened when the car was negotiating a long left-hander. That would be a good example of the aeration you are referring to.

Unfortunately, shortly thereafter, that engine's 2/6 bearing spun.

Do you possibly have a link?

SwayBar

By the way, I once asked Mark Anderson about dry sumping the 928, and he said that as long as the crank is drilled like a Chevy and an accusump installed, one should not have a problem as Joseph Fan has been racing that combo for nearly 10 years without a bearing failure.

SwayBar

Okay, I found it:

http://www.crank-scrapers.com/928_common_sense.jpg

From this 928 crank thread:

https://rennlist.com/forums/showthre...9&page=4&pp=15

Here's some more relevant items:

http://www.crank-scrapers.com/944_windage_a.jpg

http://www.crank-scrapers.com/944_windage_b.jpg

..from this thread:

https://rennlist.com/forums/showthre...4&page=2&pp=15

slate blue

Dragging up an old thread but I have been doing some research and got a look a Cosworth DFV engines dry sump pan, not really a pan but the pick up points. Guess what we are pretty lucky as a nice system is doable (not saying there is not systems out there already on 928s)

The good thing is having the right hand side available for a pick up point. The other thing they do is never have the pick up holes too big, they always close them down, I suppose that increases the velocity at the pick up point.

To the guys that have dry sump, where have you chosen to place the breather for the system? Some systems have two for excellent scavenging. Also it would be interesting to know what vacuum you guys are pulling? I read an article which compared the dry sumps of Nascar to F1 engines. They use different vacuum levels. Nascar being higher.

Brands of pumps used, for my two valve stroker I have purchased a Barnes with 5 vacuum stages but it is a gear pump not a rotor pump like the top dogs have. If I also build the 4V engine I will get a rotor pump, less friction, more vacuum and longer life and I guessing since the rotors don't touch, they last longer. Auto Verdi is the top pump, so I will have two lots of Swedish parts on my car.
Greg