Let us know what you find. In the early stages the wear will be very slow as the outer surface of the cam is hardened. Mines gone through that layer now and is running away at a vast rate of knots.
One thing I’m looking into is oil. The Toyota dealers use a semi synthetic 10W40 which is Toyota branded. I dont know what Lotus dealers are putting in… It oculd be that certain oils have much better film strength and or lubricant additives which work better in boundary lubrication conditions. 10W 40 is certainly “thicker” than many syntheics.
Cheers Mike, it certainly isn’t a problem which appears to be limited to a certain batch of engines.
I’ve just been out and stuck it back together, there’s no way the spray jets being slightly skewed would cause a problem, the jets fire right onto the centre line of the big lobes.
After seeing how much oil p1sses out of the rail earlier and then just squirting a few ml of oil over the cams before I re assembled the cover it looks very likely that the oilway in the head is blocked. There was absolutely nothing on the cams when I took the lid off.
I have had the dealer back on today to give me an update and the area engineer is off on hol till monday, so i expect to get some more feedback on monday,
in the meantime he has asked that i take the car off the road till we get some feedback from the engineer,
i fully expect to be taking the car through to them next week.
For info also i have be advised against the Stage 2 Piper cam from someone who has had one fitted.
What were the reasons Phil? Just, having driven a car with them fitted I think they are a massive improvement and if you can live with a lumpy idle there aren’t really disadvantages.
For info also i have be advised against the Stage 2 Piper cam from someone who has had one fitted.
I know someone who blew an engine valve after having piper cams fitted with new manifold, cat & silencer. Guys reckoned the ECU needs tweaking to cope with the increased bhp and torque?
Hi Bob,
Took my cam cover off earlier today and am relieved to say there is no abnormal wear on my cams. They are in beautiful condition and there appears to be plenty of oil being delivered to lubricate the camshafts.
My first thought was that the ‘o’ ring fitted to the oil connection pipe between the cylinder head and cam cover was missing or damaged, but it is clearly visible in your photo showing the water jets.
As you say there could be a partial blockage in an oilway somewhere or defective hardening of your camshafts. Might be an idea to get some hardness checks carried out at various points around the good and worn cam lobes.
I am sure that Lotus will resolve the matter for you free of charge even though the warranty ran out a month ago as it is obviously not normal wear and tear.
Cheers David, I’m keeping fingers and toes crossed…otherwise I may own the first Audi S2 Exige…
I was having a look at the oil control valve earlier, its quite easy to see the cast in passage from the valve to the head so I’m going to strip it down and investigate in the next few days.
I just removed the oil control valve housing for the VVTL. There is a direct passage from the main gallery feed to the spray bar feed and I’ve blown through the passage to confirm it isn’t blocked.
There is a small gauze filter where the gallery feeds the housing and there was no sign of any blockage either.
So in conclusion I cant see any signs of blockage in the oil system so the failure is most likely due to poor case hardening of the camshaft, this is backed up by the fact that Phils has failed on a different lobe to mine.
The rear clam will be coming off for replacement in the next few weeks so it shouldn’t be too expensive to get the cam/rockers replaced at the same time (whoever ends up paying!)
I hope your right Bob, i will be alot happier knowing it was just a camshaft issue, Even so i will be keeping an eye on the cams in future, prob removing the cover every couple of thousand miles.
Also i will be intrested to see the price of the cams from lotus as oposed to toyota sourced items
How about I draw a nice detailed schematic and post that up for you??
that could help, thanks.
I asked about the photos because I still think the VVTL valve is the key to understand the problem…
the valve closes a “dump” passage to give pressure to the mechanism and I’d like to see evidence the drain isn’t actually the spray bar
Anyway, if the oil feed to the head is clogged, the 2nd cam will never became operational.
it does!
I still miss the point of the “small metering port”, as the main oil feed to the rocker shaft should always be open and flowing oil…
If I got it right the “spool valve” just closes the relief port to leave all flow (and pressure) to the rocker shaft rail. The “spool valve” should also work as a relief valve, once the high pressure needed to activate the 2nd cam has been reached.
![http://i90.photobucket.com/albums/k252/Bob_Corbishley/oil1.jpg[/image]](http://i90.photobucket.com/albums/k252/Bob_Corbishley/oil1.jpg%5B/image%5D){kind=link}
![http://i90.photobucket.com/albums/k252/Bob_Corbishley/oil2.jpg[/image]](http://i90.photobucket.com/albums/k252/Bob_Corbishley/oil2.jpg%5B/image%5D){kind=link}