924Board.org

[daveo]

hi all
as some of u know i got my hands on Dave Dennets old sprint car,
been having lots of truble with her, and on Sat-day she give up the will to live when racing at Brands,
Dave D was at this race meating and was so happy to see her out on track
but twenty mins into the race she blew,
it was going very well and tacking some big scalps (944 turbo, 308 ferrari gt4 & GTB,PONTIAC TRAN-AM6600, XJS 6000 and more)
So its time to recap and think what the hell to do with her, Dave has offerd to rebuild the motor, but cash is tight,
but she will be back,
Daveo

[bass gt]

Hi Dave,

Bad news about the motor!!! What went? head gasket again? Or has the bottom end let go?
If you live around theDagenham aream go see Charlie at CTM. Very good guy!!!

Steve
_________________
Front Wheel Drive is the Devil's work.

[daveo]

Hi Steve
Bottom end let go, banging like a shithouse door.
also lost all water dont know where that whent. i must say she was flying, best handeling 924 i have driven.
Dry sump,,,,, thats going on the shoping list,
I will look out for CTM
THANKS
Dave

[bass gt]

Dave,

be aware that dry sumping her will be VERY spendy, circa £2K.
I would suspect that you exposed the sump pickup, which would have led to starvation. Added that brands is a very "hilly" circuit, you might have aerated your oil to the point of it resmbling a caffe latte, especially as you motor is a "stroker" if i recall correctly. I wouldn't mind betting it was the run over Paddock Hill bend and the run around Macleans back onto the start/finish straight that did you. Thats if you were on the Indy circuit. Otherwise, pretty much every right hander would have chipped in!!
From memory, the oil pickup is on the RHS of the engine, under the exhaust manifold side. So when going around a clockwise circuit, this is the side that the oil will rush away from.
Don't try an overfill the sump, as this just worsens the aeration problem. Your first step might be to modify the sump with some baffles or trap doors, then maybe add an accusump.
Of course the dry sump solution is the ideal solution, and it will free up a suprising amount of power, but is a big job to undertake. But if you do go this route, i wil happily help you with direction as to what you need to do to make it work.
So google CTM and speak to Charlie. He's an ex Burton guy, so know's his stuff, and is not a rip off merchant. He'll source all your parts at very competative prices, and rebuild the motor.
_________________
Front Wheel Drive is the Devil's work.

[Khal]

[daveo]

steve u got it in one,, Macleans was the point she started to nock and paddock she started to bang
in my old white car the sump has a baffle,, but will not fit on this motor as the throw is to long.
Khal haw u doing mate,,, looking at puting the motor from the old race car in to get some races this year,,, will have to look at the dennet motor 2 see what 2 do with her,, i have had a chat with Dave D today and he is up for the re-build.
i will keep u all posted
Dave

[bass gt]

Dave,

Unless you do something about the oil aereating and exposing the pick up, you're going to be rebuilding this motor a lot more than you planned!!
At the very least, you'll need to baffle the sump, and ultimately, dry sump her.
With the longer throw, you are going to be whipping the oil up much more, which is going to increase the problem.
Might be worth looking at a "big wing" type sump, and extending the pickup accordingly.
From memory, did Dave Dennet ever use this car in proper track racing, or just the Porsche Speed Championship?
If just the championship, then the extended duration you are racing for, compared to before, will really be killing the oil. I suspect you were continually exposing the pickup every lap, causing the oil pressure to drop, damaging the bearings. As each lap wore on, and teh oil got more frothy, the damage would have accelerated, and bingo, 20 minutes later, you'vre got no bottom end.
Good luck & keep us posted

Steve
_________________
Front Wheel Drive is the Devil's work.