66 replies to this topic

[siztenboots]

20XE inlet cam with a vernier retarded half a tooth for good spooling

specifically this is what we are on about ,

http://www.vauxhall-...-mod-t1893.html

[LY_Scott]

C20XE

[cheeky_chops]

you would need oil temps north of 130c to see a high performance synth oil breakdown. Perhaps it is oil starvation thru long bends though i havent seen any reports(?)

Good luck with your choice

The oil temp on any modified VXT (stage 2 and above) will easily exceed 130 degrees after half a dozen laps.

Like others have said, fitting an oil temp gauge and oil radiator (ideally on a stat and fan assisted) should be mandatory for any average track use let alone frequent use in highly tuned cars

no way - there is a water cooled oil cooler already fitted (a air cooled one woulf be nice) - and if it was true, loads of people (inc me) would have a dead engine by now.

q1 have you ever measured your maximum oil temps?
q2 have you looked at the size of the oem water-cooled oil rad or even better it's spec vs a 13-row mocal cooler?

No and no.

Back to you - how many people on here (or AOC or ZLET or MIG) have had engine failure? Let alone traced back to oil temp?

[slindborg]

you would need oil temps north of 130c to see a high performance synth oil breakdown. Perhaps it is oil starvation thru long bends though i havent seen any reports(?)

Good luck with your choice

The oil temp on any modified VXT (stage 2 and above) will easily exceed 130 degrees after half a dozen laps.

Like others have said, fitting an oil temp gauge and oil radiator (ideally on a stat and fan assisted) should be mandatory for any average track use let alone frequent use in highly tuned cars

no way - there is a water cooled oil cooler already fitted (a air cooled one woulf be nice) - and if it was true, loads of people (inc me) would have a dead engine by now.

q1 have you ever measured your maximum oil temps?
q2 have you looked at the size of the oem water-cooled oil rad or even better it's spec vs a 13-row mocal cooler?

No and no.

Back to you - how many people on here (or AOC or ZLET or MIG) have had engine failure? Let alone traced back to oil temp?

IME on MIG there has never been an oil temp related failiure with an XE or LET....
We have a few suspect engines at work that keep spinning big end shells when the oil gets hot but we have now managed to work it out that the temps go high AFTER the big ends failed

[siztenboots]

you would need oil temps north of 130c to see a high performance synth oil breakdown. Perhaps it is oil starvation thru long bends though i havent seen any reports(?)

Good luck with your choice

The oil temp on any modified VXT (stage 2 and above) will easily exceed 130 degrees after half a dozen laps.

Like others have said, fitting an oil temp gauge and oil radiator (ideally on a stat and fan assisted) should be mandatory for any average track use let alone frequent use in highly tuned cars

no way - there is a water cooled oil cooler already fitted (a air cooled one woulf be nice) - and if it was true, loads of people (inc me) would have a dead engine by now.

q1 have you ever measured your maximum oil temps?
q2 have you looked at the size of the oem water-cooled oil rad or even better it's spec vs a 13-row mocal cooler?

No and no.

Back to you - how many people on here (or AOC or ZLET or MIG) have had engine failure? Let alone traced back to oil temp?

IME on MIG there has never been an oil temp related failiure with an XE or LET....
We have a few suspect engines at work that keep spinning big end shells when the oil gets hot but we have now managed to work it out that the temps go high AFTER the big ends failed

the only time I recall something oil related engine failure was ineedtheturbo killing his engine whilst on the cannonball in spain ?

[subseamac]

let's just look at facts then 1 do oil temps exceed 130degree under heavy load? answer yes, tested, measured 2 do 99% of oils used by VX drivers begin to shear or lose their lubricating capabilities at or above 130 degrees? answer yes, look at manufacturers spec sheets Many people on here have complained about oil consumption and also finding unusual quantities of oil inside the air inlet tube (sometimes even coating the AMM), indicating the engine breather is spitting out too much oil, again a possible sign of blow-by and shot piston rings. How many people here have run compression tests on such engines to confirm any damaged piston rings etc etc? not aware of many. We'd need to ask our two engine rebuild outfits TMS and CMS All I'm saying is that engine sump oil temps will exceed 130 degrees and oils don't function too happily at those temps. The OEM oil/water cooler is totally inadequate and an inline air/oil cooler preferably fan assisted is needed for any repeated track use.

[siztenboots]

Is a 5w30 fully synth oil suitable then on track , even fast road for stage 2 tuned or above turbos ? I use the Silkolene Pro S 10w50 , its an ester based fully synth , around £50 for 5L , specifically for track use

[subseamac]

It's mainly down to the oil's ability not to shear at high temps. The sylkolene you use is one of the best oils out there with a HTHS of 5.11 and good fluidity even at low temps (which explains its price). I use Motul 300V at HTHS of approx 4.5, recommended by Opie oils as ok to run all day at 130 degrees. I may switch to silkolene next to try it out. Most high performance oils need an HTHS of at least 3.7 to qualify, best to look for as high a HTHS as possible for the VX's as well as good low temp fluidity for winter cold starts There are many people on here much better qualified than I am to talk about oils etc, I'm merely a "user" but I have always been particularly careful with engine cooling.

[siztenboots]

It's mainly down to the oil's ability not to shear at high temps. The sylkolene you use is one of the best oils out there with a HTHS of 5.11 and good fluidity even at low temps (which explains its price). I use Motul 300V at HTHS of approx 4.5, recommended by Opie oils as ok to run all day at 130 degrees. I may switch to silkolene next to try it out.

Most high performance oils need an HTHS of at least 3.7 to qualify, best to look for as high a HTHS as possible for the VX's as well as good low temp fluidity for winter cold starts

There are many people on here much better qualified than I am to talk about oils etc, I'm merely a "user" but I have always been particularly careful with engine cooling.

thanks that was a very informative post , ( off to research high hths products ) , I had always had concerns about the "30" rating of the motul stuff

[cheeky_chops]

Interesting indeed. Googling comes back with a HTHS of >2.8 is considered minimum, not 3.8 as you said. Wear is also not linear so a HTHS +1 will result in approx 80% less wear than the lesser product.

Also HTHS is tested at 150c!!!!!

Some good info here http://www.bobistheo...h...501&fpart=1
Interesting is that changing oil to a better HTHS is not necessarly better - audi experienced excessive foaming and increased wear so had to redesign some parts. Also "shear" relates to the speed of the piston/bearing v temp. Not having a high rev'er like the VTEC's you remove alot of the shear issue eg shear @ 8000rpm is twice what it is at 6000rpm


"HTHS - High temperature High shear A relatively new oil test/specification, the oil is subjected to high temperature 150C and is mechanically sheared at 1 x 10^6 per second. A value of 2.8 or is considered the minumum for normal bearing wear. Here are some HTHS numbers on well known oils, the higher the number the more shear stable the oil; 4's and 5's are excellent numbers and demonstrate basestock quality e.g. Silkolene and Motul. Mobil 1 0W40 HTHS 3.6

Castrol RS 10w-60 HTHS 3.7

Castrol RS 0w-40 HTHS 3.7

Silkolene PRO S 5w-40 HTHS 4.07

Motul 300V 10w-40 HTHS 4.19

Motul 300V 5w-40 HTHS 4.51

Redline 5w40 HTHS 4.6

Redline 10W40 HTHS 4.7

Mobil 1 15w-50 HTHS 5.11

Silkolene PRO S 10w-50 HTHS 5.11

Silkolene PRO R 15w-50 HTHS 5.23

Motul 300V 15w-50 HTHS 5.33

Redline 15W50 HTHS 5.8"

[danger7]

Its just a suggestion - I bought a brand new Z20LEH for Euro 2,600 Complete with ancillaries. PM if you need more information. Cheers Ian PS please disregard the fact that the first Z20LEH I installed had block failure - just unluck

[Guy182]

I use the Silkolene Pro S 10w50

[Stu-7]

Thanks everyone for your advice. For some reason, I've held a(misguided) belief that the technical knowledge on this site was not as advaced as it *could* be - solely as there seems less track-cars out there compared to say, SELOC. It's clear from this post that;s not the case so, I'll belt-up

To be honest firstly I'd find out what has failed and why. Whilst your dianosis maybe correct it is worth finding out what actually has happened. As for your assumption that 280bhp/ZLET on track is a short term combination I have to say I disagree, there is no reason why any high power VXT can't last so I would look to the cause rather than just assuming its your fault.

This is a good point. I am wondering whether I have jumped to conclusions. I guess as I haven't seen any oil smoke coming out of the exaust on cold start-up or acceleration, I've assumed it's NOT knackered rings or a turbo on the way out, but it could be. I spoke with Mark @ Courtenay earlier today who has given me some basic checks to assess whether it's top-end or turbo-related, which I'll carry out over the weekend.

Re Oil temps, this is something I've been aware of for some time. My previous trackday mule was a highly modified Evo VII. I had all sorts of worry-guages installed, including a Oil temp and pressure guage and come to think of it, i really don't know why i haven't had one installed on the VX.
I've been *aware* of the need to install one on the VX but I haven't got round to it. Whenever I've gently enquired about it, I've been told that the standard one is "adequate" so have never felt the need beyond that. If I decide to keep the car and continue to track it, I will definitely be installing a secondary oil cooler - probably one of the smaller MoCal units - on the return side of the std OEM unit as well as an oil temp and pressure guage.
FWIW I use either Valvoline 5w-40 (with an API Classification of SM) or Motul (with same API classification) and have the oil changed every x2 trackdays.

I'm interested by John's point re: reliability.
I would tend to agree.
I've always felt - and have been told by various assembled *illumi*- that the Z20 LET engine is good for a reliable 350bhp. That's why i'm very surprised about the present situation (let's actually wait and see what the problem is, appreciably) and i'm still hoping-against-hope that it's not bottom-end or even top-end related (and could be a turbo on the way out). That said, the VXR turbo was BRAND new in October last year......

Anyway, I digress. Is this perception misheld? (I am not saying I have been misinformed BTW).
However..... I'm not aware of *many* other VXT trackdayers/racers out there who have subjected their engine and associated ancilliaries to as much abuse as I have in the last 2 years. I'm not trying to be arrogant when I say this but, the BIG tracks: Spa, Silverstone GP and the Nordschliefe place a unique challenge on the VXT's inlet temps (and subsequent oil temps) that no other circuit does. So as a result, is the right information getting back to the tuners AKA Courtenay and TMS...?

I know for example, Mr M, MaxR well and see them at most UK tracks. Adrian I have seen at Spa, but not too many others (I don't think) regularly take their car to these tracks?

For those of you that know the 'ring - the run up Kesselchen for example (after Bergwerk, just after half-way point) is where you CLIMB over 500 feet in altitude; in the VX I am flat from Bergwerk, all the way to Mutkurve (confidence lift) then flat again up to Steilstrecke:
http://www.billzilla...ordschleife.jpg
...you are flat in 4th gear and into 5th for well over 30 seconds, then for another 20 seconds; all uphill.

Kemmel straight at Spa is the same (as per my first post) as is Hangar straight at Silverstone. It really rockets the inlet temps. Even on a cold day at Silverstone earlier in october, my ECu was backing off the boost after only about 3 laps down hangar straight (Mind you this could be related to whatever problem I have in the engine).

Does this place too much of a strain on the VXT's inlet (read oil) temps?
I know for example that at Silverstone 4 weeks back, that Mark (Mr M) - who is running an identical setup to me - was seeing 135 degrees oil temp. So by default, so was i. Is this too much? Maybe it is without an additional oil cooler.....Just a thought anyway.

Thanks for your advice everyone; I'll keep you updated.

Stu

[slindborg]

basically, 110deg in the sump = 130deg at the big ends........ so 130-135 in the sump = FOOOOOOKKKKKK at the bearings lol. BUT if its not knocking/stuck a leg out of bed then the big ends/mains should be fine (but will ideally want inspecting to be 100% happy) Rings dying would be something else causing it rather than oil temps imho. EG if your inlet temps are too high then you could have some mega hot (but not detting) gas frying the life out of the lube on the walls/actually killing the ringlands of the piston etc. Needs more diagnosis first though. Given the VX is a hot bastid on engines, and what I've had to do at work rencetly with instrumenting the life out of a 400CC air cooled engine. I'd be inclined to fit Thermocouples at the air box, the turbo entrance, the exit and both ends of the cooling mechanism (CC or IC, or both lol). And of course fit TC's to the sump, head oilway, cooler exit and somehow in the oil feed to the mains. And log it all.... OK that does sound like a fcuk load of effort/cost but if it means you can develop your engine into a nice bombproof setup then it will save you cash in the long run.

[Duncan VXR]

Spa especially puts a lot of strain on cars Ring is also a big track and the temps over there are a lot more than here. I have had oil temp problems in the past at Spa but work on my charge temps and coolant temps etc also made a big difference before finally doing some more work on oil cooling side of things. If your inlet temps are hot it all has a knock on effect to coolant and oil in my experiance. I am measuring the oil temp at the oil filter section of the system and never seen above 110deg on track. I do have a mocal oil cooler in the system also though. Since playing with ducting for the oil cooler and channeling the air out I have not seen over 105deg on track

[mandarinvx]

LEH engine for sale over here

[Lou1s Cyphre]

LEH engine for sale over here

Engine & Gearbox sold

[mandarinvx]

Engine & Gearbox sold

Doh

Prob should have checked the thread again

[Stu-7]

OK all.
Many thanks to those of you who have PM'd me.

The Good news is that after a lot of tests earlier this week, we think it is at WORST case, a turbo on it's way out (turbo bearings more specifically).
Off to get it looked at in more detail. It's a Astra VXR turbo and is only 10 months old so, should be covered under warranty.

Will let you know......

Stu

[Stu-7]

Hi everyone,
Just a quick note on progress.
I am hoping that there is light - a small chink of light - at the end of the tunnel

This morning, I had the engine Compression tested.

Some of you reading this post may not know what this is (I didn’t!)…… it’s a relatively straight-forward test, to see if there is any pressure escaping past the piston or piston ring.
If any of the cylinders are significantly lower on compression than the others (when the engine is running) it can indicate a knackered ring or piston.
Subsequently, a leak-down test will then diagnose the exact extent of the issue.

You can imagine there was some sense of relief on my part – surprised relief – when all x4 of the cylinders returned readings well within the range expected for a peachy engine; 161-167 PSI. This is great news – no cause for concern Equally; if it was something piston/piston-ring related, not only would the compression test pick it up, but there would also be tell-tale signs on the plugs – which are as clean as a whistle - as well as oil smoke coming out of the oil filler cap hole or oil dipstick hole – which is definitely NOT happening.

Next step after that this morning was to do a leak-down test on each cylinder, and again, there was ZERO leakage. So – great news

So….we are getting closer to diagnosing the problem. The general feeling now is that it must be something in the turbo – either seals or bearings.
So, later on we are stripping thr turbo front pipe off and checking that, as well as the impeller and inlet pipe into the chargecooler.

So – I’ll take it all back - I must confess at being a little hasty in assuming that oil consumption = “engine rebuild”
This type of thing hasn’t happened to a car I’ve owned before and, given the fact I’ve spent over £ 14k on modifying this thing in the last 2 years, it was natural to assume the worst. This only goes to prove I am a complete nincompoop when it comes to all things teknikalogikul

That said – I doff my cap to Courtenay who felt right away that it was *most likely* a turbo issue, given that they’ve been tuning these engines for a significant amount of time and not seen this before – a sentiment also reflected by Thorney in his earlier post.
So….here’s hoping it IS. I’ll post up later / at the weekend on what happens next….

Stu