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Oil Pan Baffle???
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-nick  



Joined: 16 Nov 2002
Posts: 2699
Location: Cambridge, MA

PostPosted: Sun Aug 12, 2007 8:53 am    Post subject: Reply with quote

I can confirm that those "squirters" provide _all_ the oil to the cylinders/oil ring. Knowing this after stupidly putting the con rod bearing without the hole in it on the squirter side so the pistons weren't getting that squirt at all. And the subsequent expensive destruction that ensued...

I would like to know what the difference is between real oil squirters and what we have stock?
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1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet
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Paul  



Joined: 02 Nov 2002
Posts: 9435
Location: Southeast Wisconsin

PostPosted: Sun Aug 12, 2007 9:34 am    Post subject: Reply with quote

I think they squirt any time there is oil pressure present between the rod bearing and the journal.
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Paul  



Joined: 02 Nov 2002
Posts: 9435
Location: Southeast Wisconsin

PostPosted: Sun Aug 12, 2007 9:36 am    Post subject: Reply with quote

A Porsche tech article said that the pistons are oil cooled by these squirters.
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Polar Silver 02 996TT. "Turbo"
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ideola  



Joined: 01 Oct 2004
Posts: 15505
Location: Woodstock IL

PostPosted: Tue Sep 11, 2007 3:54 pm    Post subject: Reply with quote

Paul, can you get a copy of that Porsche tech article? Scan, fax, retype? I'm very interested in this topic right about now...
TIA
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75 Fiat X1/9 | 80 US 928 | 80 US 931 '941' | 78 D-Prod Replica | 78 Poli-Form
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Kevin Johnson  



Joined: 11 Jul 2004
Posts: 8

PostPosted: Mon Sep 17, 2007 2:00 am    Post subject: Reply with quote

Lizard wrote:
I wouldnt bother with the squirters, they cause airation problems,

I also wouldnt bother dry sumping the 924 engine as it doesnt have the rod bearing issues the 944/928 engines have.


I was recently contacted by a 924 racer (2.0) who was loosing engines after switching to tires with more grip. Lap times improved by four seconds but at this cost.
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Kevin Johnson  



Joined: 11 Jul 2004
Posts: 8

PostPosted: Mon Sep 17, 2007 2:07 am    Post subject: For 2.0 engines... Reply with quote

We just added a dual scraper for the 2.0

Some pics (Teflon upstroke scraper shown):





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Min  



Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada

PostPosted: Mon Sep 17, 2007 2:13 am    Post subject: Reply with quote

Oh bleh, I just finished putting my bottom end in the car when new goodies are released ..... typical

Min
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Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11378
Location: PacNW

PostPosted: Mon Sep 17, 2007 2:23 am    Post subject: Reply with quote

Wow, thethxy! Those are going in my next build. . .
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PwrGTOGuy  



Joined: 23 Jun 2007
Posts: 194
Location: Middletown, PA

PostPosted: Mon Sep 17, 2007 3:35 am    Post subject: Reply with quote

Rasta Monsta wrote:
Wow, thethxy! Those are going in my next build. . .


Hmmm, ditto, they are going on my build list.
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ideola  



Joined: 01 Oct 2004
Posts: 15505
Location: Woodstock IL

PostPosted: Mon Sep 17, 2007 4:02 am    Post subject: Reply with quote

Awesome stuff, Kevin! I'll be calling you soon about the custom scraper we discussed. Rods came in earlier this month, and I'm just about thru sorting out what I want to do on the bottom end.
Dan
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Tigger937  



Joined: 11 Apr 2004
Posts: 906

PostPosted: Fri Nov 02, 2007 12:47 pm    Post subject: Reply with quote

Why not just knife-edge the crank?
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924RACR  



Joined: 29 Jul 2001
Posts: 8321
Location: Royal Oak, MI, USA

PostPosted: Fri Nov 02, 2007 10:42 pm    Post subject: Reply with quote

Damn. Might have to upgrade my engine over the winter!!
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924guy  



Joined: 29 Dec 2003
Posts: 2088
Location: Port St. Lucie, FL

PostPosted: Sat Nov 03, 2007 11:21 am    Post subject: Reply with quote

on my list as well, ive been looking into these for quite awhile now, and im convinced that its no longer optional, but a necessity for any 924/931 build with performance driving in mind.
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Sat Nov 03, 2007 8:53 pm    Post subject: Reply with quote

Guy's,

Just my 2 p worth on this, but this is what i have found during this last seasons racing.
The 924 being a slant engine has a tendency to pull oil away from the pickup during long fast right hand turns. This is due to the pickup location, and the fact that it picks up from the side, not the bottom. Another issue is the aeration induced into the oil by the sump design. I have found massive drops in oil pressure even over a short run, only for the pressure to normalise once the air starts to seperate out as the car is stationary. And on left hand turns, the oil will climb the sump wall and be whipped into a froth by the crank. All in all, not the best design. and just adding more oil into the sump just makes matters worse!!
Contrary to what Lizard says, there is an issue with oil starvation to the bearings, leading to damage if the prssure drops to low.
So i believe there are three ways to combat this.
1. Fit an Accusump. works well, but can be a one shot deal as it will take time to re charge.
2. Remake the sump with a boxed bottom section, like wings. Lower the pickup into this area and baffle it to prevennt surge away from the pickup.
3. Dry sump the engine. Technically the best solution, but not without it's own complications. It can be done to a stock sump, but the cost and complexity are not for the faint hearted!! However, theoil control is fantastic, constant pressure and no surge. Areation is removed. add to this the turbo oil drain will become more efficient, as there will be a partial vacuum in the sump. Race cars/high end cars run it for a very good reason!!
Now i will caveat this will reminding you that i am using super sticky slicks, which generate phenomenal cornering forces. This is why i am going down the dry sump route. But for normal road/sport use, i would recommend modifying the sump and pickup to a more surge friendly design.
And concerning the oil sqirters, they squirt once per revolution when the crank is at 90 deg. So as the piston is on it's way down the bore ater the bang, oil is shot at the underside to cool the piston, lubricate the small end and lubricate the bore/oil rings. if you go to aftermarket rods, slots in the big end jounal face will achieve the same result.

Regards,

Steve
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924RACR  



Joined: 29 Jul 2001
Posts: 8321
Location: Royal Oak, MI, USA

PostPosted: Sat Nov 03, 2007 9:59 pm    Post subject: Reply with quote

Good survey of options. I tend to forget #2; I run in a class that forbids such things as dry-sumps, but we can do whatever we want to the oil pan itself. Then again, I've been fine since installing the crank scraper and Accusump. I've even run races pushing 45 minutes without issue.

Note that the design of the crank scraper (even the single one I have) fits up very close against the oil pan on the "low" side. This acts then as a baffle to keep all the oil from climbing up the side of the block on the LH turns...
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