Time between engine rebuilds for HP

[lateapex911]

There re better things to spend your money on that will be front runners and help you spend time driving, not wrenching...one is in my garage, LOL.

[Flyinglizard]

I do a compression test every monday morning post race. My new build shows 210# on my gauge. When the test shows 195 or less, I re lap the valves. Total seal rings seem to go all season. Synthetic oil keeps the whirly gigs whirling.
British race car?? They are a hobby and love, not a race car...
Run the airfilters on any high compression race engine. SCCA is just a flush of cash, flushes faster without airfilters.
I just had to do a complete TR 6 Race engine, due to injesting a small stone, smack the head, ruining a rod bearing, ruined the crank, etc.
If you are racing for money, and the airfilter will make you another 2000$ or more, than by all means leave it off. If you run with, and without the filters, without rejetting, then maybe you are off on jetting enough to negate any gains. IMHO. MM