Decoke after 10 Months?

[gaxor]

Hi all,

Our SR3 was recently returned to its ancestral home in Peterborough for some repair work, and whilst it was there Powertec advised that Pistons 3 & 4 were down on compression and leaking. Upon investigation it was found that the valves seats were coked, and a re-grind and clean up has restored everything back to normal.

It seems to me that as the car was originally sold to us last October with a refreshed engine a bit soon to be experiencing this level of coking, but to be honest I am not that experienced in race engine dynamics. I do have experience with aero- engines though, and I wouldn't expect any carbon build up until around 1500-2000hrs use, but my Lycoming only revolves at 2500RPM!

Am I being unreasonable in thinking that it seems a bit soon to require a decoke? or could something else we are missing be causing premature build up of carbon in the combustion chamber.

The advice of the forum would be welcome

Thanks


Gary

[BertBert]

What use has it had since the prev refresh? Hours and type of use?
Bert

[gaxor]

Its had about 15-20 hours use - Mainly within the Speeds series, so 90 mins/Race. Plus a couple of track days and testing

Gary

Edited by gaxor on Wednesday 20th October 14:23

[fergus]

gaxor said:

Its had about 15-20 hours use - Mainly within the Speeds series, so 90 mins/Race. Plus a couple of track days and testing

Gary

Edited by gaxor on Wednesday 20th October 14:23

That's almost a new engine in terms of allowing time for carbon deposits to build up. I'd put your question to powertec and see what they say. However, prior to doing that, call TTS @ Silverstone and Mistral race engines and get their opinion. You can then see if Powertec are BSing you.