Ian928

It seems this patent has incorporated the separator into the oil pump itself, it is a centriugal pump, not like ours, but a neat idea nevertheless.

http://www.freepatentsonline.com/4414006.html

marton

Oh well, just needs one of you guys to knock up a prototype.
At least with our oil pump location, it should be easy to connect an air pipe from the shaft to an oil return pipe.
I guess it would not be more difficult to fabricate & fit the pump in the existing hole

marton

928SS

iirc, there are already a bunch of dry sumped 928's running around w/no oil issues. the bugger is trying to beat a DS, with a magic pan or baffle system. personally, if I were seriously tracking my old gal, it'd be drysumped, no mess/no fuss. biggest problem then is keeping those pesky 911's at bay, dealing w/all the hotties, deciding which sponsors to keep, etc... lol

928SS

http://www.daileyengineering.com/ ck out these roots style DS pumps and pans... super efficient, pull great vacume and less drag than conventional systems... on my xmas list... run about 1500.00US for the custom 928 pan/figure about 3k when done w/the tank/etc... pretty slick

SwayBar

There are three that I know of: Mark Anderson, John Veniger, and a guy in Europe where Cheburator is getting his dry sump pan from.

I planned on dry sumping my motor last winter, but just ran out of time with the new engine, pan not being done, etc. In the meantime, I had told Kevin to build me an I-J dry sump oil scraper system to go along with it. He too was running a little behind so I asked him to build me the wet sump version instead, and am very happy with it.

If I do go ahead and install a dry sump, I will definitely be installing the dry sump version of the I-J oil scraper system too, as it will help the dry sump do it's job better by controlling and directing oil to the scavenger pump pickups, just like an oil traffic cop.

GregBBRD

I agree. Problems always seem so simple when looked at through the small end of a telescope. I guess I just don't have the ability to get so close as to see your expertise as the only/total solution. I tend to step back and look at the total picture. I like to try to see the forest as a complete forest, not just the branches on a single tree as being the forest.

Sorry, I'm going to continue to agree with every crankbuilder in the US that I've talked to, who all say the same thing. The 928 crank is very old fashioned in the design and is RPM limited because of this design. Again, the dry sumped 944 GTRs shed rods like crazy until Porsche Motorsports changed the oiling design of the crankshaft. Chevy, Ford, Chrysler, all found that they needed to feed their large diameter cranks a different way due to this issue. I will agree with you, that this is not an issue, when one is dealing with a crankshaft with small journal diameters.

The windage problem in a 928 engine is significant. The oil return from the cylinder head on the right side is significant. These are indeed areas that need work. I'm so happy that you have helped with a solution to this problem. I too have a system that helps with this issue. However, I'm somewhat different in that I'm not trying to tout my product as the "total solution", which will result in more hot, oily pieces being shed from the inside of 928 engines, in my mind.

I've enjoyed our exchange of ideas. I apologize that my lack of intelligence has frustrated you.

90 S-4

Is there a way to increase the pressure on the factory oil pump (spring change ? )
& would it help in getting the oil to travel a little farther up it's path before it stalls out.

Jim bailey - 928 International

Lower rotating mass ? the gears weigh less than 1 1/4 lbs on a 2.75 inch circle and the outer gear spins much slower and that weight includes the shaft ! The "gain" would be totally insignificant and virtually unmeasurable. Comments like that make one question your other statements...

BC

I am always listening.

GregBBRD

Mr. Johnson:

I went back and looked at your past posts. I didn't realize that you were here to solely promote your own product. I was questioning why you were so thick headed about accepting other thoughts about oiling issues. Now I know why.

Here's an interesting proposition for you. I'm about to start another new race engine, for a customer. I'll buy your windage system and leave the rest of the bottom end stone stock. You underwrite the engine and write the check to replace it when it blows a rod through the side. Sounds like a great opportunity to prove your theories/products. The original version of putting your money where your mouth is.

The great thing about the internet is all of the different people you can meet there. The bad thing is that you never know who you are going to talk to and what they are all about. How many Mensa mechanics have you run into before?

Abby Normal

C'mon guys! This thread is great and is chock full of great info. Please don't let egos train wreck it..

Vilhuer

One local 928 owner is automotive engineer. He studies anything and everything while he is rebuilding engine for his '81 4.5L. One point he checked recently was how much pressure pressure relief valve needed before it opened. Specs say 8bar. In his case it was something like 5.5bar and this was with brand new spring. Simple solution was to add washers to make spring short enough that it will hold little over 8bar pressure.

If I have understood 928 oiling system correctly, pressure relief valves purpose is to limit pressure of oil which is going into bearings by releasing excess back to oil pump intake side when pressure is high enough to compress small coil spring. If specs say 8 and actual value is just 5.5 this can't be good. Both values are still so high that nothing abnormal shows up in dash as needle only goes to 5bar.

There are instructions in WSM how to measure oil pressure on running engine at 4000 rpm. Value to aim for is 5bar (73psi). So pump should be able to create this much by 4k. How much it should be above 6k rpm where problems usually occur? If relief valve is limiting pressure to much below 8bar maybe this is one more contributing factor in bearing deaths? Just one more idea why there can be problems.

SwayBar

I think Kevin has already validated his product with the Dutch Stallion racing team:

Go here, do a 'Ctrl F' to seach for 'Dutch', to pop you to the relevant info:

http://www.crank-scrapers.com/Porsche.html

Rob the team manager also made a post here, but I can't find it.

Because of the results reported by the Dutch 928 team is the reason I went ahead and bought the I-J crankscraper. I've run my new engine with the crankscraper for over 4 hours now at Road America (..2:37's - 2:39's) and have come in from those sessions with a virtually cool Accusump. I think if anyone builds a 32v wet-sump motor for the track, and does not install an I-J crankscraper system is asking for trouble, to work along with a drilled crank and an Accusump.

Greg I know you stated in an earlier thread that you now have your own crankcase oil control system. So instead of installing Kevin's proven unit into this new race motor:
would you be willing to install your own...
as well as...
It should be an excellent experiment at the very least. And if successful, 928 owners would then have another proven scraper/windage option to choose from.

SwayBar

Erkka, how do you measure to check the opening pressure?

How many washers were required? What was the resultant oil pressure? Do you have any pics?

Very interesting hypothesis!

Mike Simard

I know of one, at least a former mechanic. BTW, at a Mensa social meeting you will NOT hear anything like the language used in this thread, there's no need for it.