main and top engine bearing brake

[Albert]

Hello,

This is my first post here, but I’m very glad I have finally found this forum. Form what I read it is a forum that I finally can write at and use my knowledge abut Audi S2 & RS2. Before I have found people talking only on chipping and k26 turbo only.

But getting to the point. We have problem in Poland that struck all of my friends Audis 2.2T. While tuning S2 on kkk k27/29 and pumping 1.9 on stock bottom all of us had a problem with main bearing and top bearing (on crankshaft and connection between rood and piston). While running on the streets on high boost and making rapid turns oil temperature suddenly riches sky high limit 170 Celsius and bearing start to knock and brake. We have examined this with two conclusions … lack of oil pumped in to the motor and temperature of the oil geting to high.

Solutions are bigger oil cooler, bigger sump that will have more oil, that would not run out of reach of oil pump on rapid turns.

Or maby be You will have other solution to this problem ??


Little about our cars
My friend Teadybear has RS2 navy blue, on 18 Cup II alloys, K27/k29 turbo, modified air intake and air manifold, 3” no cats exhaust.

My, S2, 3B, unichip, 3” no cats exhaust, external wasegate, rs2 turbo, big FMIC, 250kpa map sensor, modified air intake, webber fuel regulator, Greddy EGT, Bonalume blow-off, racing clutch.

My webpage is albert.pl/s2/



Hope to exchange information on 20V R5 engine.

[Mihnea]

Albert, sorry for your friend's engine but it is quite well known that the 3B ignition systems aren't up to the task with big turbos pumping lots of air into the engine. Unfortunately, if you had asked before I'd have warned you.... I've tuned quite a few 3Bs myself and I think there's a way to avoid breaking rod bearings but this isn't an easy task and an unichip can't take care of that. If you need more help tuning the car, you can contact me and we could arrange something, either you'd come to Belgium or I could come to Poland to take care of it, BUT the best suggestion I can give you before going any further is to fit the AAN/ABY ignition system and change the wiring harness and ECU accordingly. This will provide you with a much stronger basis and will allow you to get quite close to the 500 HP mark....


Hope this helps,


Mihnea

[Pisobiker]

Hi Albert.

I think that first things you should examine and solve are reasons why oil reaches so high temperatures.
As a matter of fact oil is supposed do create a thin coat between cranckshaft journal and bearing and between bearing and conrod. This coat must prevent metal parts to get in touch each other therefore providing as little friction as possible for performance and wear control purposes.
If you had oil flow problems, I think you should have had signs of this also at lower boost levels.
Given the oil flow is correct, the reasons why this oil coat "breaks" letting metal parts to go in contact each other is:
Too high load (thus pressure, or boost) in respect of oil dragging capability for the given oil temperature.

A cause for oil temps going too high, as Mihnea said, could be a problem with ignition and fuel management sistems. But this is a field in which other people in this forum are better aknowladge than me.


Marco

[Mihnea]

Another issue, apart from not enough fuel (by the way, I've seen you guys use Greddy EGTs, what EGTs are you running and where? before or after the turbine?), the other explanation for such high oil temps (which I've personnally never seen yet, neither in Mark's 400+HP coupe nor in the last RS2 I've tuned to about 380 HP) could be that there isn't enough spark advance so the mixture burns too late, thus increasing combustion temperatures, exhaust gas temperatures and oil temperatures.... the oil has a cooling role on the pistons via the oil squirters, so this could be the reason. Who did the programming on the K27/29 car by the way? Do you guys use custom chips or "off the shelf" for such a setup?


Mihnea

[Albert]

Originally posted by Mihnea
Albert, sorry for your friend's engine but it is quite well known that the 3B ignition systems aren't up to the task with big turbos pumping lots of air into the engine. Unfortunately, if you had asked before I'd have warned you....

First of this has happened in ADU, ABY and 3B engines. Unfortunately i did now about this forum till yesterday ... why there is no link to it at s2central.net ?

Originally posted by Mihnea
I've tuned quite a few 3Bs myself and I think there's a way to avoid breaking rod bearings but this isn't an easy task and an unichip can't take care of that. If you need more help tuning the car, you can contact me and we could arrange something, either you'd come to Belgium or I could come to Poland to take care of it,[/B]

Costs ??? We had the problem on customized programs form Hohenester and MTM. Only my car now has Unichip but i run only 1.5 at max boost. Soon I will switch to autronic, but this is another story.

Originally posted by Mihnea
BUT the best suggestion I can give you before going any further is to fit the AAN/ABY ignition system and change the wiring harness and ECU accordingly. This will provide you with a much stronger basis and will allow you to get quite close to the 500 HP mark....

Hope this helps,
Mihnea [/B]

thanks for the info i will probably rewire my car to ABY ignition system when adopting autornic.

[Albert]

Originally posted by Pisobiker
Hi Albert.

I think that first things you should examine and solve are reasons why oil reaches so high temperatures.

1) It is hot
2) The oil pump on rapid turns is not getting enough oil and it is not pumping oil. But there was just new oil pump put to ADU engine and still ... same problem.

Originally posted by Pisobiker
As a matter of fact oil is supposed do create a thin coat between cranckshaft journal and bearing and between bearing and conrod. This coat must prevent metal parts to get in touch each other therefore providing as little friction as possible for performance and wear control purposes.
If you had oil flow problems, I think you should have had signs of this also at lower boost levels.
[/B]

Exactly ... thin coat ... that's what we are missing ... but why ?? we use Castrol RS ... now we will switch to Motul. On normal operation the oil flow is correct and temperature also.

Originally posted by Pisobiker
Given the oil flow is correct, the reasons why this oil coat "breaks" letting metal parts to go in contact each other is:
Too high load (thus pressure, or boost) in respect of oil dragging capability for the given oil temperature.
[/B]

So what we should do to avoid that ? Bigger oil intercooler ... anything else ?

Originally posted by Pisobiker
A cause for oil temps going too high, as Mihnea said, could be a problem with ignition and fuel management sistems. But this is a field in which other people in this forum are better aknowladge than me.


Marco [/B]

Thanks for help

[Albert]

Originally posted by Mihnea
Another issue, apart from not enough fuel (by the way, I've seen you guys use Greddy EGTs, what EGTs are you running and where? before or after the turbine?),

EGT Greddy 16000822 centrally mounted before turbine. http://www.greddy.com/products/electronics.htm#6EWG

Originally posted by Mihnea
the other explanation for such high oil temps (which I've personnally never seen yet, neither in Mark's 400+HP coupe nor in the last RS2 I've tuned to about 380 HP) could be that there isn't enough spark advance so the mixture burns too late, thus increasing combustion temperatures, exhaust gas temperatures and oil temperatures.... the oil has a cooling role on the pistons via the oil squirters, so this could be the reason. Who did the programming on the K27/29 car by the way? Do you guys use custom chips or "off the shelf" for such a setup?


Mihnea

custom chips on this setup form Hohenester

some times the boost is 2.0 maybe that’s it … but this is ok as long we go on straight

[Pisobiker]

Albert, I think actually many Companyes produce quality motoroil suitable for high output engines, from who you may try to find a higher degree multigrade oil (if you're not using any at the moment), such as Mobil1 5w50.
The 50 degree viscosity when hot, will help keeping oil thick enaugh for higher load applications, but...... at 160°C .... this seems to me way too high for resonable working temperatures on even a highly tuned engine.

About the oil "drafting" problems in high speed cornering, you may want to slightly modify the sump adding some transverse "bulkheads" just to avoid too fast mooving of oil avay from oil pickup.


Marco

[Pisobiker]

Uh... sorry Albert,
I see right now you are using Castrol RS that should be 10w60 which is very good. So, since you say oil pump is OK, your overheating problem I really think should be sourced over other topics.


Marco

[Albert]

Originally posted by Pisobiker
About the oil "drafting" problems in high speed cornering, you may want to slightly modify the sump adding some transverse "bulkheads" just to avoid too fast mooving of oil avay from oil pickup.

Marco

that's the way we will go ... but could enybody just make some coments on this ? and what shoud be done in the sump ?

[Pisobiker]

Albert, I've never had the occasion to take the sump off yet, so I don't exactly know where the oil pump pickup is actually located. Since oil filter is just underneath the turbo in the area where turbo oil return line goes back to the sump I would guess pickup to be left side, in the middle (looking engine from front). Any position of the pickup, anyway, you should create some "compartements" in the sump such as, for example, using a "bulkhead" in the center of the sump going assially with the crankshaft (this one will actually hold oil when cornering) as tall as you can without interfearing with the crankshaft itself, and then at least two trasveral ones that divide sump in three compartments. The latter ones will prevent too fast moving of oil farward and backward when hard braking and accelerating.
I believe you may experience an oil pickup problem as the sum of hard cornering and contemporaneus hard accelerating or braking forces.


Marco


P.S. Of course oil must flow through all compartements in the sump via some resonably big holes in the bottom of the bulkheads.

[Greg_S]

the OE sump has 2 or 3 fins down the North South length of the sump and an extra section bolted onto the side to increas the oil capacity.

If your having alot of problems with the oil surge it may be worth looking at a dry sump system such as.

Dahlback Dry Sump

[Martynf]

Well my technical knowledge compared to the guys posting here is nothing!! I bow my head in admiration to the level of knowledge some of the guys on this forum have.

Talk to me about parts, and yes... 20+ years of Audi parts experience, I know a thing or two.

So here's my parts related input:

In the sump, the oil pick up pipe has a gauze 'pre-filter'. I've seen a lot of these in my time working with Audi and some of the ones I've seen were amazing! they can clog up with general debris and 'gunk' over the years no matter how clean you keep your oil this could lead to oil starvation simply because oil cannot get past the crap in the gauze pre-filter.

Also, on our oil pick ups, there is what Audi call an 'intake manifold' this is like a circular extension that fits onto the gauze pick up pipe, that can also clog, I've also seen these come off the pick up pipe and then float about in the sump!

Not saying this is the cause... but all and any info may help...

Martyn

[Albert]

Thanks Guys. We will be taking apart ADU engine tomorow. Maby i will post some pictuers here. I will try to investigate furder and write what we have came with.