OcUK Mini Rolling Road Day 14.5 @ PowerStation (Tewksbury) - Saturday November 24th 2012

Was running too rich and the AFR was out, feels like it is running better across the rev range now.
Although that could just have been dry ish roads :D
 
Bit of an update on the Fiesta ST, the car is back with me and working fine. Mountune said the intake cam had jumped a tooth of the chain, how this happened they really have no idea, as chain tensioner and chain are both fine. Their race engine guys have only ever seen this happen when people take their cars on track days and spin off backwards in gear (at high revs) creating a kink in the chain (as the chain tensioners only work one way). They performed a compression test on all cylinders and everything looks excellent, no bent valves etc.

Just glad to have the car back. :)
 
killer_uk said:
Bit of an update on the Fiesta ST, the car is back with me and working fine. Mountune said the intake cam had jumped a tooth of the chain, how this happened they really have no idea, as chain tensioner and chain are both fine. Their race engine guys have only ever seen this happen when people take their cars on track days and spin off backwards in gear (at high revs) creating a kink in the chain (as the chain tensioners only work one way). They performed a compression test on all cylinders and everything looks excellent, no bent valves etc.

Just glad to have the car back. :)
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Glad it's sorted mate :)
 
Glad to hear the Fiesta is OK!
Have Mountune said how they can ensure that this issue doesn't happen again? It sounds like they have correct the issue but not done anything to prevent reoccurance.
 
killer_uk said:
Bit of an update on the Fiesta ST, the car is back with me and working fine. Mountune said the intake cam had jumped a tooth of the chain, how this happened they really have no idea, as chain tensioner and chain are both fine. Their race engine guys have only ever seen this happen when people take their cars on track days and spin off backwards in gear (at high revs) creating a kink in the chain (as the chain tensioners only work one way). They performed a compression test on all cylinders and everything looks excellent, no bent valves etc.

Just glad to have the car back. :)
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That is good news, unusual problem as they describe it for sure, but pleased to hear no lasting damage! Presumably the car now drives/sounds slightly less like a bag of spanners (only slightly mind, idle is lumpy as anything on these cars with the MR200 kit).

Wonder if hitting the limiter and the drag of the rollers causes a greater load than you'd normally experience, similar to going off backwards in gear at high revs as they describe?
 
killer_uk said:
Bit of an update on the Fiesta ST, the car is back with me and working fine. Mountune said the intake cam had jumped a tooth of the chain, how this happened they really have no idea, as chain tensioner and chain are both fine. Their race engine guys have only ever seen this happen when people take their cars on track days and spin off backwards in gear (at high revs) creating a kink in the chain (as the chain tensioners only work one way). They performed a compression test on all cylinders and everything looks excellent, no bent valves etc.

Just glad to have the car back. :)
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Yippee :)
 
I'd be extremely worried about leaving it as is, having seen the valves in contact with the pistons like that. The compression test may have come out ok but the strength of a valve spring will straighten a slightly bent valve enough for it to seal properly.
Great news until you realise that constant straightening of the bent valve will fatigue the stem, a few month/ years later the head of the valve falls off!!
Hope you have something in writing about further issues cause and effect will be rectified under warranty should something like that occur in The future
 
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