66 replies to this topic

[Stu-7]

Well, I knew the time would come.
Big power + standard internals + c30 trackdays in 2 years = engine parts: lifed.
....and here is that time

It started at Silverstone 2 weeks ago on an LoT day.
One and three quarters of a litre of Valvoline's finest 5W 40 was consumed in a trackday.
After a swift oil change @ Guglielmi's, I scooted off to Abbeville this weekend. x3 sessions in the morning (57 track miles) and V22 VXR Z20 LET engine gulped down another litre and-a-half. Hmm....not good. Call it a day methinks.

The engine sounds and *goes* fine. It's become somewhat lethargic at 5k revs onwards in 2nd & 3rd gear, aside from that, no other symptoms.
FYI I am running a Courtenay stage 4, Pro-Aloy Chargecooler, VXR turbo + injectors etc etc.
I am *assuming* it is the bearings or something else in bottom-end (as opposed to cylinder-head or pistons). There is no smoke on start-up or oily-smoke in deceleration. I guess what has happened is that I've let oil temps get too high (I don't have an oil temp guage fitted) on various trackdays and it's started to wear excessively on certain parts. Likely my own fault. Either that or, it's just not good for a std Z20 LET engine to be running 280bhp.....Equally I would add that Spa and Silverstone are the HARDEST tracks on turbo engines. Inlet temps must go through the roof on Hangar and Kemmel straights respectively.......(and I have done x3 Silverstone days this year.....)

So....I face a number of options.
Before I call about, what does the assembled *alumni* think about my options below and, what else am I missing?

Option 1:
Z20LET Engine Rebuild:
Forged pistons, uprated steel rods with ARP rod bolts, under piston cooling (oil spray jets), lightened and balanced internals including crankshaft, flywheel, pistons and rods, the removal of the counter rotating balancer shafts and re-fitting with new oil pump, water pump, cambelt, pullies, tensioner, bearings, stem seals, and gaskets. Price: £3,000 - £4,000+ all-in (dependent on spec).
Benefit of this is i have a highly reliable set of internals to run on trackdays. But....I would need to keep the car for a minimum of 2-3 years to get value back out of it. Downside: You never get your cash-back.

Option 2
Z20LEH Astra VXR Brand new engine transplant: £ 5750 (for a BRAND NEW engine is a fully installed including fluids, labour and VAT)
Can't see why i would do this given Option #1 above.

Option 3
Rebuild to standard spec, set map to standard map. Take off the AP's, Nitrons,Hard top, diffuser, harnesses and chargecooler
rebuild + labour = £ 2,500-£ 3,000?
Sell car on that basis aka: fresh rebuild, standard map, has been tracked (a lot) but all bushes, hub carrier bolts etc have been replaced.
What would i expect.......? £ 16k?
Then add about:
AP's: £ 800
Nitrons: £1,000
Hard top: £ 400
Diffuser: £ 250
Harnesses + harness bar: £ 150
Chargecooler: £ 1,000 (?)
= £ 3,600
TOTAL: £ 19,600 (????)
go and but something else....?

BTW I have taken all my prices from here:
http://www.courtenay...?...oc&docId=22

So...I am totally in-between on what to do. I think I do want to keep the car.....equally I do have a burning desire to go and buy a shed of a 111s and build it into a Class A race-car....but it's probably not the right time in my life to be doing that, what with kids and -all.....so it's likely trackdays for me for the next 2 years or so; which falls back in favour with the VX.

Thoughts?

Edited by Stu-7, 29 October 2008 - 11:00 PM.

[Thorney]

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. Re-building the engine makes a lot of sense but you need to be careful as to the specification of both the internals and the ancillories, we paid the heavy price in this regard in early development in that there are so many things that are both expensive and a waste of time (sometimes both in the same change). For example if oyu looking at a bottom end change then decide on a compression ratio and importantly dynamic comression ratio before you even start to spec, this will lead to what power you want to achieve and importantly how you want to achieve it. We've spent the last year developing a whole load of things on the VXT (brought in part by the kicking we got on vxr36's (forum name) unfinished work) to the extent that we now know that 330-350bhp is actually not that expensive to create and a lot of the development was wasted. At the same time we now know a lot more on the weak points and how to strengthen them. The reason we haven't updated our website for so long is that (this applies to the 2.2 as well) the concept of staged tuning at higher levels doesn't really apply to the car, you need to cherry pick what you need for the purpose you want. I take it the car will remain a track day car? If so then you need to ask yourself what kind of power you want, more of it? More lower down the rev range, up the rev range? Do you want more control over the power delivery? Its perfectly feasable to get 375+ out of the engine but the number of horses is less important that what they are to be used for its also the ancillories, getting moster torque is one thing but a 225 AO48/R888 simply cant cope when you get to higher numbers so you need to look at chassis work to make use of what you want.

Edited by NickH, 30 October 2008 - 08:30 AM.

[Thorney]

Caveat to all the above. Sort it and sell it. You've done enough track days now, knowing you I would say you are more than ready and able to go racing and it would open your eyes to how much more fun racing is than track days, LoT series is a great place to start racing, a Class A Elise will not be huge money and having a familly doesn't mean you have to never see them, spend some money on your race set up (a place for them to keep warm/entertained etc can be worth more to a driver than the fastest car) and you'll have both fun and step up to the next level as regards track driving. Still think its worthwhile actually finding out what went wrong though.

[Guy182]

Option 3, get a sorted elise and enter the series

[vocky]

option 1, make a strong engine to endure your track days + fit an oil temp gauge edit: it might simply be the valve stem seals or turbo oil seals

Edited by vocky, 30 October 2008 - 08:03 AM.

[siztenboots]

add to all the above, uprated oil cooler

[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

[burnerblowout]

I would go with Mr T's and other's advice and get the source of the oil consumption traced before big decisions. Ask around re compression tests, borescopes and leak down testing. Might give you more of an indication of engine refresh or upgrade requirements.

[siztenboots]

add to all the above, uprated oil cooler

why just stop at 300, when if you are doing this, nick bits off the x20xe cams, and change the CR and go for megasquirt

Edited by siztenboots, 30 October 2008 - 10:01 AM.

[subseamac]

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

[Pidgeon]

Q1, What's wrong with my engine? That quantity of oil can only go in one of two ways, out the bottom (i.e. a leak) or out the exhaust. Given you would have noticed a leak you must be burning it. A worn bottom end will not burn oil. It is either ring, valve or turbo related, there is no other way oil can be consumed in any quantity. Oil can be burnt without smoke at idle or on start up I don't recall any bottom end failures at 'normal' power levels, therefore most of the expenditure you list is not necessary and furthermore you will be replacing serviceable components. When I have thought through engine changes, only the balancer delete and piston oil sprays will convey any benefit. Further investigations required to pin down the blame. Q2, What next? You are in the happy position of owning one of the few cars whose value is not taking a pounding at the moment, so a conversion to cash is not difficult. I have thought about Elise's many times but something allways stops me. Why not have the best of both worlds, a VX and a BMW? If you need someone to run the car for you, the season costs will be similar (unless you replace the Yoko's every race ), but there is £10K difference between either a car for conversion or race ready Elise and BMW.

[siztenboots]

Why not have the best of both worlds, a VX and a BMW? If you need someone to run the car for you, the season costs will be similar (unless you replace the Yoko's every race ), but there is £10K difference between either a car for conversion or race ready Elise and BMW.

britcar 24hour in the BMW ?

[Thorney]

Valid point I guess, but then most people who race tend not to track day anywhere near as much so the track car becomes more of a white elephant? My best guess would be valves or rings, rings would be rare but depends on how far the ignition timing was getting so perhaps pistons are getting too hot but doesn't sound like it. We've seen a few where valve wear has caused pretty high oil useage but not as high as you are reporting. The VXT race car has an oil temp guage via the stack dash and we never saw more than 130 degrees and that was when it was cooking itself at regular intervals so not sure if that would be the cause, certainly on it own heat itself wont directly cause that much oil useage although it could contribute to the failure which has.

[slindborg]

the concept of staged tuning at higher levels doesn't really apply to the car, you need to cherry pick what you need for the purpose you want.

10million man points!!! Although I would go back and change that to "Stage tuning at any level is a sh*t concept"




Option 1 sounds better imho. Esp if you grow a pair and DIY most of it. All you need to get someone else to do is the rebore (if needed) and thats about it.
Have a look on the vauxsport forum for some very very good/comprehensive LET builds (which will apply to your VXR lump too). 20XE inlet cam with a vernier retarded half a tooth for good spooling

Edited by slindborg, 30 October 2008 - 10:54 AM.

[Thorney]

Esp if you grow a pair

lol, direct as ever

[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.

[siztenboots]

strange nobody ever mentions gearbox oil temperatures

[subseamac]

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?

[Thorney]

I would say an oil cooler is a good idea, its a good idea on most track cars tbh but certainly not heard of extensive failures due to high oil temps. As regards gb temps, well yes, they get hot, everyone fits breathers but again gb failures on track are relatively rare, we killed one on the Britcar due to the cables melting and resulting shifting being a bit agricultural and the 2.2 race cars both broke selector forks due to the drivers not heel and toeing (essential really) in racing. The race VXT never had any gearbox problems save for the cagles melting at Castle Combe, a problem unrelated to the gb itself.

[MAXR]

Stu, Sorry to hear about your engine problems...Your VX has done you proud and given you hours of fun. But, If you think you can get even more out of a another car, you should go for it, I would. You still have several options, I personally would get your engine looked at and repaired if necessary. Then sell if it is not giving you enough thrills. Max.