Rennlist - Porsche Discussion Forums

Rennlist - Porsche Discussion Forums (https://rennlist.com/forums/)
-   928 Forum (https://rennlist.com/forums/928-forum-69/)
-   -   Dry Sump Status (https://rennlist.com/forums/928-forum/316661-dry-sump-status.html)

BC 12-08-2006 05:24 PM

I wonder if I could design that in Solidworks. Or even Emachine shop. Making ten or more of them should be cheaper then 1500.

danglerb 12-08-2006 05:48 PM

I don't think you are allowed to use the word cheap in the same sentence as dry sump.

BC 12-08-2006 05:56 PM

I could have used "more inexpensive"

SharkSkin 12-08-2006 08:23 PM

OK, thanks for your input guys... a have received more info now from a source that I trust, and I see now that I was mistaken. Advances in cutter geometries & coatings, combined with other advances in CNC controls, spindle rgidity, etc. etc. have changed things. Aside from the ridiculous "molecular level" comment, you guys were right and I was wrong. Learn something new every day! :cheers:

Oh, and yes the 0.002" was very tight for such a large, thin plate. Fortunately the spec also called for holes for 6 countersunk screws on either side so the plate could be mounted either side up on the robot where it was to be used; these were used to hold the workpiece during machining.

JEC_31 12-09-2006 09:52 AM


Originally Posted by SharkSkin
.... Aside from the ridiculous "molecular level" comment,....

:biggulp: :biggulp: :biggulp: :biggulp: Ok I have come to my senses. I got a bit sideways there, these things happen on Friday. :typing:

I love this forum for sharing interesting technical stuff.

Can't wait for the acid test of the Devek dry-sump system!

lorenolson888 12-09-2006 03:34 PM

Pretty!
 
Precision of the sealing surface will be determined by how heavy the final cuts are...

If you cut 20 or 30 thou then deflection will be sever... but it your last cuts are only taking 1 or 2 thou then it should be great...

I imagine that Marc is making the prototypes as perfect as possible as the extra time to get to the final tolerances is negligable with CNC...

The time required in precision machining is all about setup... 90% of the billet can be blasted away in the first 20% of the cuttng process...

The cheapest approach for a final product will be to cast a rough blank that has some handling poimts (reference datum) and then machine all of the prceision features onto it... I think that cast aluminum is nothing like cast iron when it comes to machinabililty... hehe

Looks Great Marc. Maybe someday I will have to get one!

Loren

H2 12-09-2006 09:28 PM

This is a great project! Thanks!

Harvey

Tom Cloutier 12-09-2006 09:35 PM

Pan update
 
1 Attachment(s)
I just came from the shop where the dry sump pans are being machined. I watched the final machining being done to the rough outside shown in the pic Marc posted. The cutter stepped horizontally 0.01" to start each new pass as it ran up and down ramps and rounded corners, producing a very nice finish. We have discussed the possibility that the gasket flange may not end up as flat as we'd like, and if that's the case, we'll make certain it is flat before it leaves the shop!

The pan is just the beginning of the $$$$ outlay! You'll need a scavenge pump (at least 3-stage), a remote tank, some hoses and AN fittings, mounts for the pump and tank as well as drive sprockets and belt. I must have forgotten a thing or two!

In anticipation of building a dry sump system, I bought a 10 qt. tank on eBay a few years ago. This is a large tank--probably 10" in dia by 16" tall. Too large. The only reasonable place for it is in the rear seat area. That makes for overly long hoses and I will probably look for something smaller that will fit somewhere up front.

This first pan will probably appear on my car in about 3 mos. I wish it would just appear!

Cheers,

Tom Cloutier

Tom Cloutier 01-02-2007 02:27 PM

What I got for Christmas
 
1 Attachment(s)
I picked up the first finished pan on Sat. and it is simply BEAUTIFUL! Much too nice to hide away under an engine where it will be subjected to the insults of sandblasting, oil, grime, etc. I couldn't talk my normally cooperative wife into displaying it as sculpture in the living room, so I guess I have little choice but to mount it on an engine!

The new pan weighs about 12lbs as compared to 19 for the stock unit, but scavenge pump, tank, etc will make for a slight weight increase. Marc T. has said that as much as 7hp per liter can be reclaimed with a good dry sump lubrication system, not to mention the near total elimination of oil pick up problems during spirited driving. I'd say these advantages far outweigh a little additional weight.

Also the new pan is much stiffer than the original as the sealing flange is wider and about 1/4" thicker and it's made from billet 6061 aluminum rather than cast material. Early concerns about the machining process leading to warping at the sealing surface did not materialize; the flange is very flat.

What's next? Testing, testing, testing. Yahoo! I've been a dry sump fan since the purchase in 1970 of a brand spanking new Norton Commando 750. It's due for some rehab work and may sprout fuel injectors, but I digress and that project is a long way off.

Happy New Year!

Tom Cloutier

John Veninger 01-02-2007 02:50 PM

Looks nice. Good luck with the testing.

SharkSkin 01-02-2007 03:22 PM

Looks incredible, Tom! Good luck, and keep us posted! :cheers:

daveo90s4 01-02-2007 03:30 PM

Tom Cloutier said "In anticipation of building a dry sump system, I bought a 10 qt. tank on eBay a few years ago. This is a large tank--probably 10" in dia by 16" tall. Too large. The only reasonable place for it is in the rear seat area. That makes for overly long hoses and I will probably look for something smaller that will fit somewhere up front."

Tom, a while ago now I had the fortune of doing some laps at Nurburgring (as a passenger) in a genuine 924 Carrrera. It had dry sump oil reservoir mounted in the rear in the spare wheel well. If that's worked well for a factory 924 Carrera that has done 30,000 quick kms around Nurburgring, wouldn't a similar location also work in a 928? Locating the oil reservoir atop the battery box (in which case it'd have to be removable to access the battery when required) would seem to provide for enough vertical height for such an oil reservoir. Another option might be to relocate the battery into the spare wheel space proper, and use the additional depth of the battery box to provide for the oil reservoir. (though the battery location may be critical to overcoming central shaft harmonic problems, so more investigation about that aspect might well be warranted). Just my comments, for whab they're worth. Good luck with this.

Dave O
Dubai

PorKen 01-02-2007 03:52 PM

Beautiful!

Are there enough threads for the fittings?

Peter F 01-02-2007 03:57 PM

When will mass production of a dry sump kit for the racer start?
Looks great :thumbup:

/Peter

Rick Carter 01-02-2007 04:41 PM

:thumbup:


All times are GMT -3. The time now is 03:37 PM.


© 2024 MH Sub I, LLC dba Internet Brands