willy

My Scooby is goin in for a service next week at Robinsons, they use Shell Helix 10w 40 as standard, should I tell them to put Shell Ultra in for a small extra charge?(they give the option)
My car is decatted and will be running a Scubachip when I can get hold of one.
Its not thrashed and is warmed up/down and daily does 25-30 miles.

Can anyone advise?

Cheers
*****

[Edited by ***** - 1/17/2004 2:44:41 PM]

foxygirl

to jgm, im taking my scoobie to api engines £1500 all in.....i can let you know how i get on with them.....i will also be asking them what grade oil they reccommend......i couldnt get hold of midland subaru.....thanks foxygirl...

200mph

99% of the reason that this thread exists at all unfortunately seems to me to be down to design. With such a small crank, (I've seen larger journals on a bike engine!!!)...then you add 300+ bhp any of the many factors will that we all know ...temp, fuelling oil etc.. will result in bigend failure.These limits can be pushed-ignored in many different motors. It's a Scooby thing I s'pose. Use the best of everything!!!!

P.S...My API Motor's goin' fine....

Bob Rawle

If its the design how come some of us are running high power and torque without problems ... confusing isn't it.

bob

APIDavid

iTrader: (4)

200mph, Glad to hear your motor is going fine - it's nice to keep up with customers. Keep changing the oil !!

Good Luck David API

PS foxygirls car is due to arrive am Monday 19th - expect to do our usual thing for her.

200mph

Exactly Rob, How much time, money and expertise has gone into your engines?? Most Scooby owners have the performance of a Porsche, but not the bank balance of a porsche owner.

Bob Rawle

Assume that was for me ... irrelevant in this case, point is that I run with absolutely std main and big end shells, crank is different being nitrided but others are using the stock crank, and thats the same whatever else you do. So, same contact area for the bearings at getting towards twice the torque yet survives ... as I said confusing isn't it. I'd argue that mine and a few others ought to run bigends every month with the load the "expensive" part of the engine applies, yet they don't.

cheers

bob

200mph

You're right...I'm just pissed that mine blew before I got it mapped.
Maybe if you wrote a book entitled "how not to blow up your scooby" and sold it on scoobynet you'd make a mint!!!!

moonraker

Just had mine let go after a motorway duel too.
Oil grade will make a difference, cheap stuff is definitely a No-No, but competition or high performance oils will all do the same thing, lubricate.

I dont think the viscosity of the oil makes much difference at the temperature the engine runs at, look at oil charts and the low visc. will protect and keep its characteristics at lower temps and higher visc. at higher temps, thats all it means, (track days etc are a different story.)

What i fear is happening to our lovely pride and joys is:

On a high speed run for a period of time, the oil pressure is high. There appears to be, from what I have since learnt, a problem with the pressure relief valve on the oil pump. At high speeds, the presure is high so the relief valve dumps some of this excess pressure. It then sticks in this position. When you slow down after passing every other car on the road(!) the pressure drops and the problems then start. Lower oil pressure means your bearings get wiped out in about 5 seconds!! The pump still pumps, but most of the oil comes out of the return straight back to the sump with only a partial amount in the oil galleries, not enough to supply all the bearings.

I would forget about ECU maps etc etc (unless you got a melted hole in a piston) and the first thing on any scooby owners shopping list should be an uprated oil pump.

ECU settings/det whatever will cause more severe damage to the top end mainly, but mine is a 92,so ecu map is tame, no top end damage at all.

As an engineer,this appears the only explanation that has caused the failure with mine anyway! Change you oil pump!!!

Hope this can help to save someone from having to do what I now am, a rebuild!!

Si.

midlife-crisis-scooby

Hi Bob

Missed this thread...sorry !! I'm seeing you for a re-map at the end of Jan and was going to have oil and filter change as a matter of course. SP's use Magnatec here in Carlisle. Just wondered what you would like ??

Midlife.....

Jolly Green Monster

iTrader: (4)

Moonraker,

That is just one of the many many reasons given for an engine letting go.. do a search and you will find pages and pages of suggestions..

Knock being another option.. do you have a knock link or similar fitted??

As to viscousity not having anything to do with it.. I think you should check your ideas on that.

Cheers

JGM

moonraker

Obviously it will to a point, 90 mph, does it matter if i have 10-40 or 15-50????????

Jolly Green Monster

iTrader: (4)

It's not the speed but the heat the turbo and engine are putting into the oil changing the viscoucity of the oil etc.

The oil pressure valve seems to be open after a number of engine let goes, but is it due to them failing or getting full of rubbish when the engine lets go?

JGM

APIDavid

iTrader: (4)

Moonraker, having seen as many broken engines as we have I feel entitled to an opinion.

My first purchase on a Subaru would be a knocklink not an uprated oil pump. Remember Prodrive use a standard oil pump that is re-engineered to have the pressure relief valve accessible from under the car not inside the covers where it is now - just practical sense on a time precious repair situation. The relief valve is re-engineered to be a better design shape not for any other reason.

An oil pump as it is now delivers more than enough pressure - you would need no more that 60 PSi for the rev range of a Subaru. According to luminaries such as Cosworth etc. Delivery rate is controlled by the gearing of the pump which is fixed to crank speed. Thus it cannot be altered in any mod without major re-engineering. Fitting a spacer under the relief valve spring will up the pressure, sure - but why do you need to do so?

We have only ever fitted 3 or 4 oil pumps in well over 300 rebuilds and that was due to major debris damage to the housing. We clean them thoroughly linish the valve and re-assemble.

Question; If the oil pressure relief valve is a major problem in this engine why don't they have the problem in Japan?

As far as det is concerned it doesn't just act on the piston crown. Det is caused by over-advance [ or poor fuel ratio, which results in det anyway ] which then tries to fire whilst the piston is on the up stroke. Therefore the big end takes the load as it is trying to be forced back down whilst on the way up. Look at any turbo engine that has been mistreated and you'll see that the upper big end shell is loaded and the lower main bearing shell also loaded. Both of which are affected by the over-advanced spark.

David API Engines

moonraker

Ok, I am not here for any arguments, the fact is that is what has caused mine to go, as det will not wear a bearing surface on the cam will it. That is down to no oil supply.

If I could go back and fit an oil pump for 179 quid, rather than having to rebuild now, I would, and if i told one person who did it and it saved their engine then I would be happy.

There are, like many people say, lots of different reasons, I am only posting what has happened to me.


Si.

Jolly Green Monster

iTrader: (4)

No arguing intended at all, hoping we are just discussing opinions..

I'd point the finger at poor oil as to cam bearing damage..

My car is still running the original oil pump and it to my knowledge has not been dismantled or cleaned and the engine has done 142,500miles.. I have been maintaining it myself for the last 42,500miles of those and it was Subaru dealer maintained with the semi synthetic stuff they put in before hand.
I have owned it since 76,000miles so yes it could have had work done on it before that but I cannot find any evidence other than servicing in it's comprehensive receipts and book etc..

I have always warmed the car up and warmed it down..

I have found the engine to be a lot smoother on 15W50 Motul than any other oil I have tried.. the car has also been slowly more and more modified since 100,000miles and now has FMIC, Link ECU etc.. and the standard oil pump is either holding on luckly or is up to the job.. <if it breaks on the way home then I owe you a beer>



When I do the next cambelt I will consider replacing the oil pump due to the miles it has done but will be happy to fit a standard one.

JGM

200mph

JGM, is your car a uk or jap?

tailfin

Subaru insisted magnatec and that all they used
i think it stinks im off to get some mobil1 im not paying for a new engine

APIDavid

iTrader: (4)

Moonraker, I'm not arguing either - you are probably bigger than me LOL.

JGM 142,000 miles ! self maintained ! Keep my number handy !! LOL again.

Keep smiling one and all.

David API

APIDavid

iTrader: (4)

Moonraker, I'm not arguing either - you are probably bigger than me LOL.

JGM 142,000 miles ! self maintained ! Keep my number handy !! LOL again.

Keep smiling one and all.

David API

Flood Control? What flood control - quick find me a boat !!

[Edited by APIDavid - 1/21/2004 9:04:26 PM]

moonraker

I use, and have always used (also in my previous 4 turbocharged cars) ELF Semi synthetic 15w-50 Sport oil. None of those have had any problems, so I think the oil is ok. (unless anyone knows different, if so speak now!!)

I just think some good advice for anyone who is going to do the cambelt to change the oil pump too. One of the local importers of scoobs near me started doing an oil pump and cam belt change on every car he sold after having a few blow, and he has not had any problems since.

Like several people have said, there are many different reasons for the same type of failure, (if I ran out of oil, I could hardly blame the pump, could I!!)If it was ecu mapping and I got det, surely I wouldn't have 2,3 and 4 big ends all in good condition would I?? (I.e not a single mark or any changes at the centre point of the shell)

Like I said before, to help one person avoid the problem would make me happy. If I got another scoob, one of the things I would do fairly quickly would be to change the pump. Along with other mods too, dont get me wrong!!

There is obviously no hard and fast rule that every one is going to cause a problem, but you never know until its too late, as I found out!!!!!!!

I also change the oil about every 3000miles or every 6 months depending on how much i use it, usually being the 6 months.


Si

Bob Rawle

The problem with the oil pump relates to the pressure relief plunger, there are some sharp edges that can dig in and thats what causes stiction, a modified pump, as part of its upgrade, will have the plunger modified to prevent this, higher oil pressure is not the result (or shouldn't be) as the pump generates a minumum 6 bar in any case, if an oil pressure guage is fitted then you would see that, with the thinner oils, full pressure is reached at about 3000 rpm, with those suggested above full pressure is reached at 1800 rpm, big difference. My own STi5 idles at 3.8/4 bar and is at full pressure at 1500 rpm, but thats not down to the pump rather the oil and engine build quality.

Even with three big ends gone a pump will still provide 3 bar pressure and even more at higher revs.

However if a car has done a "few" miles then the pump is clearly not likely to have a problem, and a new std item is probably more likely to cause a problem than an old "good" one, btw one of the causes of stiction is oil carburisation ... magnetec anyone ? (I'll get my coat)

And no BRD do not supply oil pumps so no axe to grind.

As a word of advice, the std oil warning pressure switch is set at 0.15 bar, not too much use i think we would agree, so don't rely on that at all.

cheers

bob

ALX

I often call the oil pressure light the "engine is dead light"

There are a number of factors why these engines die, it's just not as simple as saying it's the wrong oil, or this that and the other. There are a number of flaws that the engine is susceptable to, and the component that always suffers mostly from this is the big ends.

The normal trend, well at the momement anyway is fueling/ignition related failures. That being damage or premature wear on the big end bearings through detonation (caused a by a number of things, but a failing MAF sensor is a common cause). Damage is cumlative and thus shortens overall bearing life, so a fault could be fixed and the car can run on for many miles, even change owners. Then one day it decides to expire.

Not all engine fail from the same cause, be it poor oil flow/supply from pressure relief valves, neglect, abuse, faulty sensors (eg. MAF, O2, knock), bad modifications, incorrect fuel, incorrect fueling/ignition mapping.

If the cause was a single definite fault then it could be easily addressed. But that's not how it happens

Jolly Green Monster

iTrader: (4)

Uk

lol.. biggest job so far was changing the clutch...

I am considering a strip down inspection and perhaps a rebore..

Interesting thoughts Bob.. might fit an uprated one or stick with this one then when I change the cambelt.. thanks

Simon

200mph

Anyone used Bartol 20/50 Fully synth???
I got 10 gals of the stuff from a TT rider sponsored by them who stayed a couple of years back--and is 2yr old oil ok?--don't see any "best by" date!!!! Bartol is US/Italian

Jolly Green Monster

iTrader: (4)

If it is bike oil then it will be no good in a car.

Car oil has extra lubricate properties that bikes cannot have due to the clutch being soaked in it..

you would kill a car engine by running it imho..

JGM

moonraker

Hi all,

Just had a close inspection of the oil pump, guess what, as you say too bob, the valve is stuck open.

Si.

Hmmm, time to get modding now me thinks....!!!!!!!!!!

moonraker

APIDavid, its at times like this when I go to the boat and cry!!!

Was that a guess or did you know??

Si.

APIDavid

iTrader: (4)

Moonraker, Sorry it's Monday and i'm a bit slow. Know about what?

David

Jolly Green Monster

iTrader: (4)

David,

Hoping it was nothing to do with this

Although originally directed at me..

JGM