Polished Kirkham with V12 engine at London

[olddog]

Originally Posted by AZCobra12

. There is not much timing advance as it is detuned to under 1000hp/1000trq already.

Pulling timing lowers Hp, and that's fine to lower the Hp some. If you go too far, in my opinion, that is a poor way to kill power. If you get to the point that you are lighting the fuel so late that a lot of un-burned fuel is going out the exhaust this will make the O2 sensor believe you are lean when you are not. The ECU may compensate and make you burn rich while thinking it is spot on. High over lap cams can do the same thing at idle.

Burning a bunch of fuel after the exhaust valve is open, is a waste of fuel, which might explain your poor fuel mileage. I'm not certain but it might heat the exhaust valve too.

It would be better to tune the engine to run right and just limit the throttle to not open all the way.

[Gaz64]

Originally Posted by olddog

Pulling timing lowers Hp, and that's fine to lower the Hp some. If you go too far, in my opinion, that is a poor way to kill power. If you get to the point that you are lighting the fuel so late that a lot of un-burned fuel is going out the exhaust this will make the O2 sensor believe you are lean when you are not. The ECU may compensate and make you burn rich while thinking it is spot on. High over lap cams can do the same thing at idle.

Burning a bunch of fuel after the exhaust valve is open, is a waste of fuel, which might explain your poor fuel mileage. I'm not certain but it might heat the exhaust valve too.

It would be better to tune the engine to run right and just limit the throttle to not open all the way.

Yes, better to run it like a throttle stop class car than to make it pig rich and retarded timing. Get that first 15% correct, and even if you limit the throttle to 50%, it will still be so much nicer to drive.
Gary

[AZCobra12]

Originally Posted by Gaz64

Yes, better to run it like a throttle stop class car than to make it pig rich and retarded timing. Get that first 15% correct, and even if you limit the throttle to 50%, it will still be so much nicer to drive.
Gary

With all the issues with the current tune I agree with going back to old school power limiting, a light left foot. That has been my approach with my other cars and it does take a little moderation and only me driving it, I have two big issues, 18 and 19 year old sons.... The throttle stop is the most logical way to have a definite limit and the engine would be tuned right in the first place, just plan logical.

[GT Trooper]

When I saw this I couldn't stop looking at it.

[Gaz64]

Originally Posted by GT Trooper

When I saw this I couldn't stop looking at it.

I would have been the same. Lovely car.

[Snake2998]

Thank you to all involved in the project for sharing it - the result is something to be proud off and gives great pleasure to all petrol heads to look at, talk about and I am sure to hear as well - no matter how im?practical it may be.

Truly a Hillary & Everest car - it was done because he could (paraphrased quote/misquote but you get the idea.) Thanks once more - I love it.