924Board.org

[924RACR]

We pulled off the oil pan yesterday on the racecar to assess the wear of the first season and a half on the race-built motor, and see if our choices of oil, etc., were working - and put in new rod bearings while we were at it.

To recap, we've been running Valvoline dino VR1 SAE40W race oil with an 8x11" oil cooler, changing the oil and filter every weekend. Oil and water temps were great all summer, in spite of abnormally high temps (normally about 95 deg in the shade, much hotter than normal around here). However this engine was built rather loose, with 3 thou bearing clearances in the rods and mains, and would only reach about 3-4bar oil pressure at around 6000rpm - so we weren't sure how it'd last.

As always, #3 is the worst, but it looks like maybe 50kmi worth of (street-equivalent) wear on it. Not bad at all, and we could probably get away with another season on it if we had to. Of course, for longevity, we do fully intend to replace them - might as well.

Sealing the oil pan with the Elring Dirko has been a wonder of sealing - no leaks any more. VW places tend to sell this, like The Bus Depot, if you can't get it locally. But I can't find their page, so here's Performance Products' page:
http://www.performanceproducts.com/productpage.aspx?pid=101773&name=Curil+Sealants

Oil pan just doesn't leak any more.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Paul]

I assume you still used the 4 piece gasket set.

Did you use the sealer on both sides of the "paper" gaskets or just on the surfaces of the oil pan?
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[924RACR]

Correct, the 4-piece gasket set. I used sealer on both sides of the gasket material, contacting the block and the pan.

Further update on the bearing wear, after replacing them all - definitely more wear on the top half of the bearing (contacting the rod side, towards the piston). Makes sense, since that's the side that's under pressure when power is being made on that cylinder. So after going through and looking at the rest - 3 was still the most worked, followed by I think 2, 1, and 4 in order. But enough wear to justify replacing, looking at the top halves.

Also - bores and pistons look great from below (haven't pulled the head, not going to at this point - it's sealed, don't mess with it!)...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Paul]

Found this, is this a good price for 100 ml?

http://cgi.ebay.com/Elfing-Dirko-Crankcase-Sealer-100g-Tube-0783-830-2120_W0QQitemZ7755761006QQcategoryZ85915QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[924RACR]

Seems like it... I've actually been using the Dirko HT... not sure that the HT is necessary, though...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Paul]

I've been using the same quart bottle of Aviation Cement (looks like black shellac) for the last 20 years. Nothing has leaked yet!

It's almost empty and that stuff makes taking the old gasket off a PITA so it's time for a change!
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.