CharliePsycho

The P1 Rev limiter is set IRO 8000 rpm :O

I have run reasonably extended periods at high revs and have 17,000 miles racked up over 6 Months without hitch...

Given the higher rev limit have we had cases of prepature expiry of P1 no 3 bearings?

...c

IWatkins

Something else to think about.....

What about the fuel system in general. Many fuel pumps don't fail, they just get weaker and weaker. Seen it many times on Scoobies, GTi-Rs etc. Also, fuel system filters get blocked over time also leading to drops in fuel pressure.

Maybe this isn't seen normally but holding the revs. high leads to the point where the fuel system pressure drops and drops to the point where it cannot sustain the fuelling necessary over time at (almost) max. revs in top.

Maybe someone could take a look with a fuel pressure gauge to look for any drops.

Obviously at high revs. with your foot to the floor, the ECU is open loop, so will be following a set map point for fuelling. If the fuel pressure starts to drop the ECU is going to be none the wiser. A 440cc injector set at 85% duty will only flow the right amount of fuel if the fuel pressure is high enough.

And we wonder why the Jap imports over fuel like anything.....

This is all total speculation by the way, as I have no direct experience, just having a brain dump, so don't shoot me.

Cheers

Ian

bob

Just got of the phone been chatting to a mechanic at my dealers.
The P1 they had with Bigend failure had no other problems. His pistons were perfect and no signs of det. Prodrive did insist on a new air low meter being fitted and any P1 that has engine problems must have a new air flow meter fitted. Why they have to fit new air flow meters they don’t know perhaps we should ask Prodrive. (Reading this Mike)
They have not had to do any other UK cars with bigend problems.
They have had another 5 door WRX Jap spec car with the bigend problems. They had serviced the car and the very next day the chap came back to them with No3 bigend gone. They stripped the car and found No 3 bigend and another had failed. No signs of piston damage or det. They say they always put it 4 ½ lts of oil in on a service and check its just below the full line. They are stumped as to why it should let go like this as they do exactly the same service to all there cars.
The WRX MY95ish was run on 95 Ron.
The P1 had French fuel in unknown what Ron

I believe we are starting to see a trend of engines letting go after runs at high revs.
We also have the trend of cars letting go just after a service.


[This message has been edited by bob (edited 05 July 2001).]

STi wanna Subaru

iTrader: (1)

First off this thread is very interesting and I have been trying to understand a lot of what has been said. My technical knowledge is zero everything I understand is from a common sense approach.

The reason for my post. This is just an idea I had based on what has been said within the thread, I am posting just in case it has any relevance so please don't ridicule me. It has been posted that "The bearings have a very small surface area and oil pressure needs to be
constant to keep the barrier up". It was this point about the "barrier" that needs to be maintained to ensure the bearing able to function correctly that got me thinking. It has been said that a lot of failures occur shortly after an oil change. What happens at the oil change? is a flushing oil used? if so could this contaminate or stop the barrier that a quality engine oil forms. If no flushing oil is used could it be that because the oil has been drained from the engine the barrier is lost until the oil is replaced. If so how long until this barrier is formed again. Does the oil need to heat up to reach a lower viscosity in order to produce the barrier. If so could it be that damage or wear is caused before this point thus leading to an eventual failure.

If this has no relevance then please disregard. I will continue to read with interest.

CraigH

That's one of the things I've mentioned that I'd be interested in - how many that have gone have had the oil flush during the service?

Is oil flush a general motor trade practice? Didn't think it was......

robski

Im sure Ive read somewhere that should be trusted (although cannot say for sure) that its recommended NOT to use flushing oils now a days.

Im sure they go back to the days where oils got highly contaminated, and ended up leaving deposits in the engine, which the flushing oils cleared out (to some extent).

Im sure I was told that modern oils, especially fully synth leave very little behind, do to being harder to break down, and with them having better detergents in them.

Could all be bollix though. Who was it who was good re oil, wasnt it Jets1n or something?

robski

T-uk

quality thread,the best since finding scoobynet.

a few questions,
if the Scoob runs rich to aid cooling and a decat exhaust leans our cars slightly,surely a decatted car runs cooler,balancing this out?I found on track with a standard MY98 after 5/6 laps the car would not pull as well,as though not boosting properly and missing,performance would return once cooled for next session.for the next track day (same track)we put a decat system on and 10 laps could be done with no noted performance loss throughout the session.
if the problem is oil related,would running with Castrol GTX Magnatec 10w40,with it's sticky molecule things help,or could this oil also cause metal fragments (wear and tear)to stick to the faces?this oil would probably not be up to track days though,just road use.

john

Adam M

John,

regardless of what other may tell you, removing cat will remove restriction, and should cause car to run leaner without adjusting the ecu. running leaner actually makes engine and exhaust run hotter, not colder, as excess unburnt fuel removes energy from the explosion as it is heated.

the reason your car is losing performance on track is because the engine and interccoler are heating up, meaning the charge going into the engine is hotter in the first place.

hotter charge = less power.

This is why we fit front mounted intercoolers for more power.

If an engine runs lean due to a mod, it will heat up the exhaust gases and hence the cylinder more, it also means the mod has released some power. increasing the fuelling brings teh safety margin of cooler running back in.

T-uk

Adam,

I do agree with what you say,but if the restrictions are removed and the hot burnt gasses can flow through easier and not get held up and forced through the cats,will this not balance out with the car running slightly leaner.I am not saying it is safe to lean a car out with a high boost superchip or similar mod,far from it,I just wondered if there is a point at which the SLIGHT leaning of a decat balances out with the quicker expulsion of the hot gasses.
then again it's maybe me thats full of hot wind

john

Bob Rawle

Some good posts today, worth summarising where we may be with this to date I think.

Possible contributers ..

Definately high revs in 4th/5th for a prolonged period.
Cars appear to have a problem after a blast not during it.
There is some link to service procedure and probably oil grade/quality, Craig I would put the flushing oil thought into this category.
Have cheap aftermarket oil filters been used and have owners who change their own oil in between services been doing the same. I also know of a couple of cases where the oil filter seals have failed on the cheap ones and the oil has leaked out (blown out) causing problems.
Fuel lean at high revs has been mentioned, this would cause temperature increase in the oil but not necessarily det. Math calculation to check fuel pump capacity aginst injector flow rates will quickly show what could happen.

Other thoughts ...

Rev limits, soft cut is where the ecu starts to partially cut ignition and fuel (sometimes just ignition) and hard cut is when all ignition or all fuel or both are cut. If an ecu just cuts ignition then there is a possibilty that an engine can partially hydraulic causing oil film breakdown from the shock. If an engine just cuts fuel it will go very lean as its cut possibly causing over heating and det. The safest hard cut is to cut both. Link cuts both and Motec can be set up to do that as well. factory ecu also cuts both (brick wall effect but I am not fully aware wether it soft cuts first and how as I have not run a standard ecu for long enough to find out. (Pete C or anyone ?)

New air flow meters, the only logical reason is that det could occur, if the maf gets a bit contaminated and does not read correctly and sends the wrong voltage (too low) to the ecu then it will make the car run lean, (the oem ecu uses the maf to pick its open loop point, the map sensor mostly just controls boost) overheat and det or cause oil related probs. Exhaust gas temp would increase, this would heat up the turbo, this could overheat the oil and cause a lower quality grade to carberise and break the oil down. carburised oil does not lubricate very well.

After market ecu's tend to run exclusively from the map sensor and relate that to throttle position and rpm to pick the point.

Flushing oil ... used to be an aggressive detergent loaded thin oil designed to scour the carbon from the oil ways to reduce build up. This type of oil is not good for turbo engines and, as has been mentioned, modern synthetics shouldn't need it. What can be a good idea when a turbo is changed is to "flush the system through" with a good quality synthetic then drain and refill with the final product, this ensures that any particles are sent into the filters etc and hopefully drained out before any serious driving is done. Any good oil will coat and penetrate the surface finish of bearings, as long as sensible procedures are followed. (previously mentioned cranking the engine to get the oil pressure up before firing up)

UK and Jap spec Scoobs all run overfueled, Jap spec is not especially different.
The Scoob runs rich to help keep cylinder temps down and allow more advance to be run. As Adam pointed out, changing the exhaust components for a freer flowing item will cause the fixed map to fuel less although the factory ecu will compensate to a degree if the maf is working correctly up to the limit of its settings. Past that it will just go leaner.

Leaner is always hotter, egt (exhaust gas temps) will rise, turbo gets hotter, as air flow is greater turbo spools more, hotter again, more boost = more work = hotter, charge temp gets hotter, and round it goes again. By reducing my fueling by 2% on fast cruise I can increase my egt by 30 degrees instantly.

Leaner can also mean more power though, thats why mapping a car with less fuel and the corresponding ignition timing to stop det releases more power. Some of the strongest cars on the dyno site were also running the leanest. Temperature definately reduces power, on a summer day at 30 deg C you can lose 20-30 bhp compared to winter just from that. Don't say you haven't noticed the car feels comparitively sluggish in this weather.

Final thought for the moment, on high spped runs in 4th and 5th the turbo will get very much hotter than in lower gears, if prolonged it could get close to the limit of temperature. Under these conditions if someone stops the car without allowing it to idle for a sufficient period then the oil could become carburised due to heat soak (the temperature of the housing will rise considerably). There is a mesh filter in the turbo feed but carburised oil in the turbo will go back thro' the system, so when the engine is started again (maybe when its cool) the oil filter relief valve opens due to the thicker oil, the carburised oil gets through to the bearings and sticks to the surfaces all ready to "pick up" under the wrong circumstances.

Something else to add to the list.

I asked about turbo timers previously, anyone who uses one had a problem ?

[This message has been edited by Bob Rawle (edited 05 July 2001).]

MorayMackenzie

msgofaster,

Re: "Piston speed on a short rod is higher at top dead centre than a longer rod..."

This confuses me. At top dead centre (TDC) the piston speed will surely be zero, unless you are considering a slight lag based on elasticity in the rod. Are you actually talking about piston acceleration rather than piston speed?

Moray

msgofaster

Hi now a member

I would like to clear up the differences in piston speed from the two engines (Subaru $ Mitsubishi).

Piston speed on a short rod is higher at top dead centre than a longer rod , even if the stroke is longer and the rod / stroke ratio is closer this will reduce the piston speed ATDC , But piston speed at 90 deg & 270 deg is much faster ,the longer rod will allow the piton to dwell ATDC longer , this has good and bad points , good been you can use less opening deg on cams allowing longer for air to enter the bore and run more advance in ignition timing , less load on bearings /rods , the bad point is the rod is heavier , reducing throttle response and less likely to rev easier .
The piston speed isn't the problem , it is the sudden stop , change in direction has more load on the bearing than the combustion stroke its self will apply .

The Mitsubishi does have a long stroke and a very long rod , the speed ATDC is slower to the EJ20 engine , the max speed of the piston in Mitsubishi is much higher , the speed is much slower mid stroke on the EJ20 engine , but due to the very short rod on a EJ20 speed ATDC is still high .

Now to put this into other theories , the problem with high piston speed on EJ20 is load is already high ATDC , so for it to Det will load it much more , the EJ20 has thin bearings and can't withstand large loads , if this isn't a kick in the butt , the rod bolts are also weak , with high rpm they WILL stretch , the bearing will spin , game over .

The oil is a important thing as far as grade goes , BUT even good oils will break down and with the bearings/ rod set up poor oil will let the bearings down .

All oils will be diluted very fast on engines with ring wear ,high boost or engines that run rich , this will lead to oil again not protecting the bearings .
Even if you wish to run the best oil money can by it still will end up diluted and no longer doing the job , good oil will last longer had it not been diluted but turbo engines , thin bearings , high bearing load ATDC on the EJ20 all add up to a "weak " link .

I have seen engines blow just after rebuilds tuning on dynos running due to "run in oil" thin mineral oils that break down very fast with high oil temps on dynos .

The best thing anyone can do is change the oil often , if you run the car hard on the track , do it EVERY day before you go out , it will be running high boost , rich AR for long periods or time all going straight into the sump diluting the oil .

If you drive hard on the open road for long times at high load I would change oil every 2500km ( 1500mls) .
To say changing oil by Subaru every 12500km is really pushing the limits of any oil in a turbo car , I would be only doing this if granny was driving it round city , Subaru say for heavy driving "we reconmend oil be changed mid service" .


There seems to be a lot of different ideas on the reason for bearing failure , remember this : the only thing between the crank and the bearing is oil , and for some reason it doesn't keep the two apart it will fail , oil in new condition does not compress , so it will stop the two from touching if clearances allow the flow to be sustained , IE bolts have not stretched , crank is not worn out ( crank wears from cold starts every time , so enter good oil ) , bearing aren't getting enough cooling and deforming ( this is due to lack of oil flow either from oil to thick or clearances not enough ) .

While ever the oil is old , diluted ,thin or broken down the bearings are at risk , then a det problem ,over rev , high sustained rpm , oil surge and the one that has the most load and least protection will fail .

One other thing to think about when tuning ECU , the crank angle sensor is at the front of the engine , all timing is with reference to this , the crank does have a small amount of torsional twist at extremely high engine loads , this will advance timing to the last cylinders , be it only 1-3 deg this must be taking into account when tuning , load on dynos isn't as high on the road this can add to larger loads on the rear bearings .

Hope this helps .

Michael

Hyperex

msgofaster, i very much agree to your post. Especially on the oil change. Oil change frequently is too important. I change mine every 2000 to 3000km (depends on how hard i drive) with full-synthetic oil like Castrol RS 10w/60. This can prevent majority of engine problems. But it is hard for people in european world to buy this theory. Hmmm.... maybe either trust their dealer too much, maybe just want to save some money for pub or too stingy to take money out from their pocket (forgive me if the above comments are offensive, but i have to let it out). Of course some people might not agree to this and maybe will chanllege me that i am not living in the UK where driving long distance on low gear at constant speed is where the milage build up. Ok, fair enough, but if i do live there i will definately do it at no more than 4000km, buy good oil and DIY to save $$$ for bear. Oil change at 12,500km? no no no....... give me a break.
For track day, i will make sure oil change before and oil change after. I said it out loud for the good of all scoobies. So if disagree, please disregard. I have language problem, knows only simple english. Don't know how to beat around the bush, might as well talk straight. So if don't like my wordings, please accept my applogies.

Hyper

WREXY

Moray, My interpretation is that he means the piston stays up at TDC for that split second longer than a piston on a shorter rod. I had longer rods fitted to my Ford and was told this was the case with longer rods. I may be wrong with my understanding though.

WREXY.

Stef

Jan.
Just a thought, but I can't see how the oil temp is so much different in varying ambient conditions. Surely the temp in the engine will be pretty much the same regardless?
Could your temp figures be caused by the fact that the sump apparently offers the lowest oil temps as it is cooled by the air and offers an artificially low figure, one that would probably be affected by ambient temps?
I've heard the best place for an oil temp sender is on no.3. Can someone tell me exactly where, as I need to re-connect mine.

Regarding oils, I've used several different ones on track, Magnatec, Silkolene, etc, and the only one that has maintained oil pressure at speed and idle is Castrol RS 10-60, which I've recently changed to. I found that Silkolene ran as low as 80psi at speed and 20psi at idle after a hard blast at Dono. At The Ring last week Castrol never went below 90psi at speed and 35psi at idle. Does this mean anything?

I'll mail Bob with my engine probs too.

Stef.

msgofaster

Ok
It comes down to rod length and at the angle it goes through , long rod will slow the piston surface speed down towards TDC before it changes direction , so in turn reduces the "sudden" change of direction reducing the load .The short rod will still have a high surface speed right up to the point of "change in direction" this has high load .
The long rod has a low incline angle , a short rod has a steep angle and will increase the load on the piston skirt .With a short rod having a steep incline angle as the piston goes down the bore the rod angle is a steeper angle needed to help apply a greater force upon the crank converting energy in rotational force ,which is needed for large bore small stroke , a long rod has more forces applied to the crank later through the rotation of the crank , but has a longer stroke for a lever upon to turn the crack .

It comes down to the EJ20 designed with performance in mind , not necessarily long life .


regards
Michael South
Michael South Engineering
msgofast@iprimus.com.au

Adam M

Michael, i understand entirely what you are saying buthave drawn up some diagrams, and resolved some forces and one thing doesn't make sense.

you keep referring to the length of teh rod as the deciding factor, but from what I am looking at, it is actually the ratio of the rod length to the stroke which is the important factor.

Would you agree with this?

Bob Rawle

What Michael is talking about is the length of the rod for any given stroke, longer rods on the same crank throw will slow the piston down, a longer stroke (throw) crank with the same length rods as a shorter one will have a faster piston speed.

Its all about leverage and the forces on the big ends will be higher with a shorter con rod and yes the ratio is important if load forces are to be minimised whilst gaining performance.

msgofaster

yes Adam
It is about the lenght of both , the rod / stroke ratio , the engine designer is caught between a rock and a hard place I would hate to be responcable to design and engine layout that did eveything from high HP low torque ,revs to the moon , it is just imposable to get you cake and eat it .

Bob has got the full swing of things now , it is so hard for me to tell you with out diagrams and pics I hope all this info can help you guys .

cheers

Michael South

Anders

My 22b failed after 600 miles of Power Engineering rechip, it had been serviced a couple of days before by Pete of Scoobysport, using Silkolene.

My car has a turbo timer which I used religously.

The run down to the airfield track day was through a monsoon and so was not at any speed sufficient to excite Police or Magistrates! (As Benny boy ex-Scoobymania is my witness)

Peter Croney is my witness as too a) how cold it was on the way down to Catalunia during our high speed run and b) how slowly I was driving when my car blew as he was in the passenger seat and heard it go!

The £17,000 question for me is whether my 22B would have failed after 600 miles on the standard ECU (with Scoobysport free flow exhaust/filter) as it had not missed a beat or lost any oil, for 29,000 miles before the Power Engineering rechip.

The fact the turbo seals and valve stem seals had been fried with excessive heat makes me wonder and want to blame

One day I will get my 22b back you can all imagine what it must be like to be deprived of your pride and joy since September 99!

Once again thanks to Stef for towing me out of the airfield, so the AA could do its stuff

Davvers

ok just my two pennyworth

we cannot change the fundamental design of the engine - easily

the current design puts a larger load than 'normal' on the bearings

the higher the revs - the more load and the more likelyhood of failure

Question: Are the bearings underspecified?
Or is the oil supply underspecified?

Is it a case of the material itself or are the bearing dimensions themselves too small for the reciprocating loads.

When people have rebuilds do they use the same bearings??

Are there higher spec bearings available?

Bearing material technology has moved on since the engine was first designed, Lead Indium (Vandervell
VP2) bearings are a far superior item, but have only been available this last year - I do not know if anyone manufacturers them in the correct size.

Iain P

Have any of the troubled engines had oil coolers fitted?

Adam M

Davvers,

thanks for summing up, but dont to forget to include that it is also suspected that the standard rod bolts are not up to the job at high speed and load.

I am also very interested in this new bearing material that you mention. Is there any way you could find out the name of the company that makes them? Then perhaps it is possible to get them fabricated to the right size and tolerance.

Admittedly, the japanese are supposed to use standard bearings in their rebuilds, so I dont know if it is really a consideration.

Besides, I am told that it is not wise to upgrade the bearing, as the wear factor is in place to match the material of the block and crank.

Surely up or down grading the wear characteristics will shift the wear somewhere more expensive?

I may have missed something here as ultimately oil is supposed to prevent any metal on metal contact and hence reduce any wear, but it does still happen.

Davvers

You mention that if the bearing doesn't wear it will put strain/wear elsewhere - however if a bearing picks up the engine basically grenades. Surely if we reduced the chances of this happening with either improved oil supply or bearings we would see less dead engines.
I'm just perplexed why if the bearings are going - esp No3 it would appear - it would suggest the bearing is not up to the job - and it would appear this happens at or just after sustained high revs - as you would really expect.

I mention bearings as my 'other' car has a serious design fault regarding this it would appear.
Without mentioning names it has a 1.8 NA 4 and revs extremely high, unfortunately all these engines are going pop - bearings were underspecified - as it would appear is the oil supply, and we are talking sub 1000miles here.
The newer bearings are manufactured 'i think' by QED but for this particular engine only it would appear. However bearings are bearings and I'm sure different sizes can be made.

The problem is I'm guessing its the bearings that are the problem - if its a lubrication problem it doesn't matter what bearings you use no bearing will last if it picks up.

Not really any further I guess :-(

Adam M

ichael, what you say is not difficult to explain at all. Drawing a simple diagram will explain it all.

For the same crank "throw" the opening angle of the con rod is larger (angle between axis of cylinder and rod, when stroke is 90 degrees after top/bottom dead centre and the rod is moving at its highest vertical speed.

If you calculate the vertical velocity of the piston at any point as a function of the anle of the crank, it is written in terms of lots of cosines and the rod length and stroke.

Differenciating wrt time gives the acceleration on the piston.

Good luck to anyone who wants to try this but it isnt tough

The put it blunty, because of the angle of a shorter rod being greater, if effectively brakes later before decelerating to 0 at tdc and bdc. this means that a piston for a given stroke will experience a greater force.

Michaels explanation seems to fit in really well with what everyone is saying about their type of failures.

My hypothesis being that the higher the revs obviously the greater the deceleration on the pistons, but this doesnt cause failure in low gear because the load on the engine is less.

So as michael says, high revs combined with fourth and fifth gear causes piston bolts to stretch and bearings to spin.

This may not prove to be an issue in modded cars, such as rbuilt engines due to arp bolts and the like, hence japanese power ,onsters such as hyperexs' dont suffer from the same type of failure.

And standard jap cars wont eiter due to their speed limiters preventing them combining high load with high rpm.

Once again all pure speculation, but I like it

Bob Rawle

Con rod bolt stretching is not special to Subaru, first mod to a Vauxall 16v turbo engine is to change the big end bolts for Cosworth ones as the same thing will happen to that engine and its an in line four. especially if you are going to run at 2 bar like some people do. (and they use Nitrous on top)

Re-built engines are said not to suffer again but I think it depends on who does the rebuild and what bolts and bearings are used. The better motorsport orientated companies would use uprated bolts as a matter of course and at least one increases the oil flow through the main bearing to help. (Roger Clark Motorsport in fact). As far as I know they have never had a failure again after a rebuild.

N0 3 bearing is not the only one to suffer, raised before but no2 is fed from the same main bearing (centre) and is exactly the same distance away, no 2 also runs leanest on phase 1 cars, not on phase 2. I also know of engines going on both 1 and 4. Four seems almost as common as three.

Improving the bearing material; must help but it could be considerd a band aid in that if whatever happens still happens and the material is better able to withstand than of course thats great but if the problem is still there ?

When this happens a coincidence of conditions must take place, amongst those conditions bearing slip must be more than significant, bolt stretch increases the clearance between bearing and crank, oil pump cannot sustain pressure, contact results, bearing shells spin in con rod and pick up, (oil feed point displaced starving bearing ?). The shells could even "weld" to the con rod, some engines I have seen had completely lost the bearings all together, sump was full of fine swarf which used to be bearing.

Now that scenario I can believe. It still does not explain why several cars have gone shortly after a service though so I suggest there are clues in the earlier discussion of that issue.

Paul_H

Oil filter fitted dry during the service? i.e. not filled up with oil by the mechanic before fitting to the engine? Oil pump has to first fill up the filter before it can supply oil to the crank...

Paul

msgofaster

HI
The bearings are not the problem if the oil is keeping the two apart , nor is oil supply.

It is two main things that need to be controlled :

1 the oil must be the right weight and must always be NEW .

2 you can wait till the engine is worn out or blows up then you must change the rod bolts to ARP bolts , rods must then be resized , the I beam polished and all parts balanced .

The bolts will stretch faster if ;

1 If you bounce off the rpm limiter
2 If you hold it at max rpm for a long time
3 you let it ping to much to long
4 the oil is old or diluted or thin and it doesn't keep the bearings apart from the crank , they will then either wear fast increasing clearance which will no longer allow a sustained flow of oil , the bearing clearance will increase it will knock and will finaly knock to the point the rod will break and snap , while it is knocking it also is stretching the bolts .

In a large CAT engine they have a second motor to start prior to the main , just to run the oil pump to give lube to the crank so as dry starts don't wear the crank .Every time you start your engine you have a split second before you have full oil pressure , this is where most wear from the crank and bearings happens in all engines , this is why we need a good oil to minimise the wear .

The EJ20 engine wasn't designed to to super high rpm in std form , but was designed to rev freely but with a short rod was still to give a reasonable amount of low down torque , trade off is they don't like super high rpm in std form , It would have been much easyer for FHI to make the 22b with stroker crank using the 2.5 crank and just the need to cast new rods , but it would have exceeded there limit on piston speed ,shorter rod , longer stroke.
I am lead to believe the close deck block of the 22b was a speical new casting just for the 22B ?

WREXY

Will this Knocking be heard from cold start, or also when the engine is warm/hot?

WREXY.



[This message has been edited by WREXY (edited 08 July 2001).]

GavinP

Good thread - I have some questions...

Am I right in thinking that oil will have different properties at varying points in the path through the engine, turbo, sump, filter and oil cooler ?

If heat is a factor on bearings, would better coolant reduce this ?