My botttom end has gone on my standard sti v2 I want to know what is the usual cause of this?
I was on a track day when this happened and I don't want it to happen again! The engine was as quite as a mouse and pulled 281bhp the week before this started so I don't think its due to mlg (70,000 mls) so was wondering do they suffer from oil starvation due to oil pumps or the sumps not being very well baffled? also do they suffer from the oil temp getting too high? I'd only done about 4 laps of snetterton.
Thanks Danny

 

on a track chances are temps have become elevated, dont know about oil surge but I suppose it is possible, if you have a low ish oil level then this could also compound high temps / surge.

 

gave mine a pasting over moors other week and the next day first time start slight bottom rattle then fine but 3000 to 3500 rpm light throttle it rattles ..cheaked oil and it was about 2mm in dip stick way too low and not changed for 7 months whitch on mine it should be more like 4 month so its down to neglect on my part that it going on the bottom end flushed oil changed oil to mobil 1 super synthetic (47 blinking quid)or what ever 10/40 i think and put slick 50 in and its not too bad now alot quieter for now. no performace loss............yet.

 

Could be any of a number of thingse.g.

1) Oil level too low
2) Oil pump failure -std ones can get stuck open
3) Oil temps too high
4) Poor fuel - Det.
5) Charge temps too high -Det
6) Fuel pump/reg/injector failure - Det
7) Maf went kaput - You guessed it Det!

Keeping things together on the track is usually about keeping fluids where they're supposed to be and keeping temps down! That's why you'll see a lot of scoobies with FMICs and Oil coolers were you on the std V2 interwarmer? You should also use the finest Ester based synth oils and high octane fuel if you're tracking the car.

Fitting a knocklink or other warning of Det would be a move for the future.

Ns04

 

Most often cause of bearing failure is oil starvation usually caused by the standard OEM Oil pump pressure relief valve sticking. This is because the piston on the oil pump has a 10mm groove in and can become prone to foriegn debris.

One of the best ways to prevent this is to run the modified oil pump from RCMS this has the piston in the pump replaced for a smooth non grooved item.

I had bottom end failure without one an have never had it with one. This is with 4 different scoobies and about 100K miles

 

i wolud also like to know about this because i spun a bearing on a 4000mile old engine
1) Oil level too low ( no)
2) Oil pump failure -std ones can get stuck open (4000mile old uprated one)
3) Oil temps too high (only drove hard for 1 min)
4) Poor fuel - Det. (yes)
5) Charge temps too high -Det (doubt it )
6) Fuel pump/reg/injector failure - Det (not sure)
7) Maf went kaput - You guessed it Det (not sure)

before i noticed the rattle on mine i had just been driving at about 90+ on some long ish corners with it fairly close to the limiter for about 30secs-1min

i think the piston on the oil pump on mine has a groove on it

 

well basically it could be a lot of things driving like a looney could be 1 lol.

 

IMHO - A baffled sump and an external oil cooler would be sensible mods if doing track-days.

Mick

 

Hi, thanks for the replies
The oil level was bang on and the coolant level was bang on. I have a parreral fuel mod with fpr set at 3 bar with vac pipe off and standard intercooler, I had a full tank of shell v power as well.
is there any way of checking the oil pump or is it best just replace because there that common? Is det going to cause just bottom end damage because my pistons seem fine?

 

Det won't cause bearing failure.
I bet this was the oil pressure relief valve sticking. The RCMS is not an uprated pump its modified. To increase pressure you can shim the pump or go for the 12mm AVCS oil pump.

 

Detonation will normally burn the piston crown and ring lands first but the shock wave from the det is also transmitted down the con rod and hammers the big ends also to eventual failure.
The oil pump backing plate screws do tend to come loose,resulting in a lowering of the oil pressure which wont help either - go for a Modified pump as recomended above.

Mick

 

"Det won't cause bearing failure."

i think a fair few on here will disagree and try to prove you wrong mate

 

The problem I had with mine was driving for about 30 secs at 150mph in a Type R, which with the short ratio 'box related to 7500rpm

 

Det will destroy pistons result in noticeable loss of power long before bearings get damaged. I had an engine failure due to severe det. One piston and bore got wrecked. The bearings were not that old and damned expensive (RCMS WRC items) so I reused them on the rebuild. They have been in the engine since and are still going strong.

If bearings are damaged and pistons are OK the cause of bearing failure will NOT be detonation!

 

I'd say the cause of this would be oil starvation. Snetterton has some very long right hand corners and without sump baffling the oil will be moving away from the oil pick up pipe.

Were you on track tyres?

 

Yes, I was on r888's and tein super streets on hardest setting. On your spec it doesn't mention any uprated pump but does mention baffled sump is that true?

 

It will not have been your oil pump and an uprated pump can do nothing if there is no oil around the pickup pipe to draw through.

Mine has the narrow spec c sump which is less prone to surge and the cosworth baffle plate to help further. (I have an uprated/modified pump too)

I would speak to one of the recognised tuners on here to get a baffled sump - Lateral performance do a good one I am told that will protect your engine if you are doing track stuff on R rated rubber.

 

Out of curiosity, what kind of ballpark figure is one looking at for the supply and fitment of a baffled sump?

Ns04

 

Well just to add to the info on here, my bottom end failure was right after a prolonged bout of detonation right at the limiter. To my mind, the det shock transferred down the rod, did the shells in, this then increased clearance at the big end, then a combination of shell and crank material circulated, simultaneously the piston was now rattling because of the huge clearances which destroys the shells even more, oil pump seizes with swarf intake, oil pressure drops even further, engine breaks.

 

They say bottom end failure with Evo IV's is mainly caused by being sat at the lights with the clutch depressed! Not sure if this is a factor with scoobs. Shouldn't be after 4k!

 

You are joking right?