oil leaking 850 race engine

gitcar · Post by **gitcar** » 19 May 2008, 09:43

Hello

I am new here, my freind got a problem whit his 2.5 liter 850
When it is in dynoTest(or on rollers) it works more than okB but when it is going racing on the tracks it spurts out all the oil from the fillerhole!!

Both turbo and compressor mounted 1.7 bar pressure

I am from denmark, The engine bottom made in sweden by speciallist

Any sugusitions? Sorry for my bad english c;)

You can see the engine on http://www.hq-racing.dk

Best regards Gitcar

bockreiter · Post by **bockreiter** » 19 May 2008, 11:05

Try the balloon trick on the Dipstick tube. If the balloon does not inflate, you're friend may need just a new gasket on the Oil-filler cap. I've seen several reports of the gasket going bad. If the balloon does inflate, the PCV line may be clogged. I have a hunch though that the race track engine just simply overwhelms the filler cap gasket with oil spray on the inside which works it way through. Hope this helps!

gitcar · Post by **gitcar** » 19 May 2008, 11:39

Hello

Thanks for the reply, I dont belive the ballon trick wil give us the clue we are looking fore.
The cleerence on this engine (piston, cylinder ) Is a little bigger than an stock engine. A seperate tank i mounted for absorbing the oil coming out of the breather.

The gasket is brand new on the fillercap So!!

It simply emptyes the engine for oil in secons (not heltty for engine)
Result is conecting rod bearing defekt
this has happened 2 times now, but not when it is tested in dynotest

we have just returned from a race and got no clue at all

Gitcar Denmark

chuckcintron · Post by **chuckcintron** » 19 May 2008, 14:05

So, you are saying that almost all of the engine oil is being poured out of the oil filler, with the cap on tight and a good gasket? I can't picture a situation that would create that kind of pressure/leak out of the filler.

You sure you don't have a cracked block that isn't showing itself until at the track?

-Chuck

bockreiter · Post by **bockreiter** » 19 May 2008, 16:32

Is the oil pump stock? What you're describing sounds like a great amount of oil is pumped into the head at a much greater rate than on a stock engine. What happens when the engine is idling or reving at relatively low rpm and you remove the filler cap? Any oil coming out then?
The main difference between the dyno test and driving on the track are vibrations. Is my guess correct that you run the engine at the same rpm on the dyno as on the track?
Do you have sufficient clearance between engine and hood to mount an extension on top of the head to increase the distance between valve cover and filler cap? If you can create enough room to place a baffle under the filler cap you might have a workable solution.

Free2drive! · Post by **Free2drive!** » 20 May 2008, 10:40

Hi

This is not much use but I looked at you link and it seems the motor is fitted for a rear wheel drive car. What have you made?

Matt

gitcar · Post by **gitcar** » 20 May 2008, 11:03

Hello

Thx for answers

We belive we have found a problem whit the radiator, it was modified but not quit right

The data loccer had a temp loocked at 1o5 celsius. So the piston rings might be dameged. Explaines why it empties the block

But we are not sure.

The oilreservoir is modified whit some plate welded vertikal, so the oilpump might have a problem getting oil fast enough

That explaines the dameged conecting rod berings

maybe

Bockreiter: good idea whit the raised fillercap, wil be in the back of our minds,and same rpm in dyno and on track

Chuck:We have a oilfume tank( is that spelled right?) mounted on the side
and our suspision is pointing at it now. (If you picture a coffeepot whit a hole in the side, and you blow in it. you can get it to spurt quit high)
Thats the best way i can describe what we think

Wil be back whit more info later

regards gitcar

chuckcintron · Post by **chuckcintron** » 20 May 2008, 11:52

Understood.

It's hard for me to tell from the photos, but do I see a belt-driven oil pump? (in other words, is this a dry-sump configuration?) If so you may also need to play with the drive ratio, but I'm sure you know that already.

If it's not a dry sump, then you may want to move in that direction

Much easier to maintain negative crankcase pressure...

-Chuck

gitcar · Post by **gitcar** » 12 Oct 2008, 00:34

Hello

A Late Update

Now the engine is working as it should! Pistonring clearense and a little overheateing was the problem. It does 498Hp 700+nm. Tested last sunday(In heavy rain) But and it workwd

http://www.hq-racing.dk

Best Regards Gitcar

Post by **MadeInJapan** » 12 Oct 2008, 06:42

I saw your 3 video's...the most impressive one is here:

So, you put the 850 engine in sideways and made a RWD 850, is this right?