Octane booster

[jimj]

My newly rebuilt engine is pinking a bit on 97 octane fuel plus Castrol Valvemaster Plus which is meant to boost the octane rating. The timing is set at 10 degrees rather than 13. Do I need to retard it some more? How much? or is there a better additive?
Jim

[billwill]

When unleaded fuel became the norm, I found that Redex Lead Substitute, significantly cured any pinking and increased power output and the cost of the Redex substitute plus unleaded fuel was less than the 4-star you could still get then.

But Govmint taxes have since removed the cost diferrence, not that you can get any leaded fuel any more in the UK can you?

[elanman999]

Jim,
IMHO a fresh engine running super unleaded set at 10 deg should not pink unless the comp ratio is far too high or the dizzy is advancing up early.
If the dizzy is old I would check this first.
Best of luck
John

[jimj]

The head has been skimmed and the block slightly decked so the comp. ratio will be a little high.
Jim

[hatman]

The head has been skimmed and the block slightly decked so the comp. ratio will be a little high.
Jim

Mine too (had it done last year) - I use 'Tetra Boost' lead additive (not lead substitute) which enables you to raise the octane rating to 100 (and above if required) and I've never even had a suspicion of pinking.