nigelcurry Posted September 16, 2020 Report Share Posted September 16, 2020 Morning all just wondering what opinions were around as to the absolute need for converting my cp head to unleaded nige Quote Link to post Share on other sites
Nigel Triumph Posted September 16, 2020 Report Share Posted September 16, 2020 If the head is off the engine for refurbishment then get it converted for unleaded with hardened exhaust valve seats. Dont remove the head merely to have it converted, just drive on unleaded and under normal road conditions, it will be fine for tens of thousands of miles. Nigel Quote Link to post Share on other sites
Mike C Posted September 16, 2020 Report Share Posted September 16, 2020 I wouldn't class an unleaded head upgrade as an absolute requirement. 20 years ago the demise of unleaded was the upcoming monster about to be unleashed on the classic community. The threat never eventuated. I've got by by for a few decades adding a dash of lead additive at each fill. Quote Link to post Share on other sites
ed_h Posted September 16, 2020 Report Share Posted September 16, 2020 Judging from anecdotal evidence over the years, some do this, and some don't, both with good results. It seems that it is less common on this (US) side of the Atlantic. Ed Quote Link to post Share on other sites
nigelcurry Posted September 16, 2020 Author Report Share Posted September 16, 2020 As ever very interesting thanks guys nige Quote Link to post Share on other sites
foster461 Posted September 16, 2020 Report Share Posted September 16, 2020 When I rebuilt my TR6 engine, no sign of valve seat recession and I did not fit new valve seats. The TR3 had some serious valve seat recession and I had it machined for new hardened valve seats. Stan Quote Link to post Share on other sites
Yarm 783 Posted September 16, 2020 Report Share Posted September 16, 2020 The TR specialist who looks after my car said no real need, but recommended Shell V Power or similar. Quote Link to post Share on other sites
PodOne Posted September 16, 2020 Report Share Posted September 16, 2020 For all the aggravation removing a head etc while its off along with the relatively small cost I'd have the seats done. Plus I suspect as there is a switch to electric the demand for higher octane petrol/diesel will fall and we will be stuck with the lower octane offerings which these engines won't be as happy using and higher combustion temps and seat recession so it might also be a bit of insurance as well to have them done. Andy Quote Link to post Share on other sites
Mike 5 fan Posted September 16, 2020 Report Share Posted September 16, 2020 I'd agree with the advice but would add that my exhaust seats did need replacing when I removed the head, possibly due to use of unleaded fuel. If your compression is good, seats are probably ok but I would use an additive. Regards Mike. Quote Link to post Share on other sites
nigelcurry Posted September 17, 2020 Author Report Share Posted September 17, 2020 Taking all advice on board thank you,can I ask what you guys would consider good or at least acceptable compression readings,as the last owner had readings done fairly recently.I know I can find them in a book but I would prefer real world advice from the guys in the real world obviously meaning no disrespect to the book writers nige Quote Link to post Share on other sites
elclem1 Posted September 17, 2020 Report Share Posted September 17, 2020 Even pressures across the board is best don’t forget it could be the rings leaking past so a dash of oil in each pot will confirm or deny that. Quote Link to post Share on other sites
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