[Straight 8 Racing]

Hi Guys,

Thanks for the input,

When we had the engine up on the bench dyno we / they got things up to an acceptable level for HP & Torque, when trying to stretch the envelope they discovered problems at the top end of the rev range
Initially we thought the spark was unable to cope with the C/R
Then we thought the fuel octane rateing might be the culprit
It transpires that the water pump was not flowing enought volume/pressure consequentially generating steam pockets in the heads and subsequent detonation !

When they dsconnected the engine water pump and attached a swimming pool pump the Power & Torque curve smoothed out and all traces of detonation disappeared ! (The bench dyno has a water large tank that supplies the engine, it is not a closed radiator loop as it will be when installed)

So we beleive the problem lies in the ability of the pump at the extreem end of the rev range which for us is around 7500

I have spoken with John Bennett, he is now working from home on R&D project into diesel powered engines, he has offered to help and I plan to try and get to see him next week( He supplied the water pump assembly for my Cobra which has worked perfectly for the last 7 years, even on the hottest days when we get held on the start grid for extended periods of time we just sit on 85 deg)

Iain