SLR K-series engine problems

[fast_cat]

Hi,

Recently did a trackday in my 1998 SLR...great day until last session (as always)..Had checked oil twice during day and all looking good (dry sumped). Then into last corner, noticed oil pressure dropped, possible rattle noise from somewhere in engine bay and stalled. Cruised about 100 metres into pits. Temperature was a bit higher than normal.

 

Looked around engine bay, no visible signs of any damage, no oil or broken bits.. Tried to start car..bad rattle/mechanical noise. Water temp was v. hot. (gauge higher than normal).

 

Towed car home and took a look day later.. Thought I'd try and start it..bit concerned as this could do more damage..but thought not too much to lose. Engine started fine, good oil pressure, but I'm paranoid and think the engine might sound a bit clunky/rattly. Not left it running for more than 20 seconds.

 

So..did something like oil pump, water pump, alternator get too hot and seize...only to 'free up' after engine is cooled down or could engine itself sieze only to free up once cooler ? If so what damage may be done ? the fact that car runs means it isn't totally siezed which is what I thought was the case on the track.

 

Any ideas ?...Thought about draining oil to see what state it might be in...any metal etc....

 

worried about running engine too long in case it really is broken..I guess the only way to be safe is to strip it down ?

 

regards

Rob

 

[oilyhands]

If the engine ran low on oil pressure and was rattling, the most likely casualty will be your big end bearings. When the engine is cold and the oil thick they will make less noise, once the engine is hot they will rattle especially when under load.

 

If it is the bearings then further running could easily damage the crank and/or rods so the sooner you have it inspected the better.

 

Try dropping the sump and looking for metal shards etc., you could also rotate the crank by hand and look at the big ends of the rods as they approach the bottom of the engine. Most likely to fail are cylinders one and two.

 

Oily

[SLR No.77]

Rob, very similar description to my experience at Oulton Park last year. The result was numbers 1 & 2 big ends absolutely shot and a knackered crank. I'm suspicious the cause was actually the scavenge pump being tired, which although okay under road conditions just couldn't keep up at the higher sustained revs on track.

In the garage I had full pressure for 10 to 20 seconds, then it dropped off to nothing as the belltank emptied. Leave it standing for a couple of minutes and when started pressure would be back to normal again....... for 10 to 20 seconds!

 

BTW Minister currently have some brand new crankshafts for sale.

 

Stu.

[fast_cat]

thanks guys,

so as I thought really, obviously needs to be stripped and checked. Don't think I've the time to start this myself.. so next question -

 

Car is in North Hampshire, so any recommendations as to who to take it to/call to discuss strip and rebuild ? prefer to be somewhere in south.

 

cheers

Rob

[Racingshoe]

Take it to DVA aka Oilyhands He's in Milton Keynes, so not too far...

[Grubbster]

You can go to DVA where you'll get an excellent service or another you can try that might be a bit closer to home is Tom New (New Techniques) in Bishops Waltham - he has built many race engines including K's (mine included)