Reply to "What RPM are most of you turning with the modded engines"

Jason,

That's a lot of bhp, congrats!

But there are a couple of considerations to look at before asking that motor to make that kind of bhp regularly or to spin it any higher than 6500 rpm. As far as bearings are concerned, your motor needs a good, tough set of tri-metal bearings like the Clevite variety.

The oil system and the production iron block are the Clevo's weak links at high rpm and elevated power output.

The oil system need the lifter bores bushed, restricted, and set for tight clearances with the lifters, a good oil pan and a high pressure oil pump relief spring work in conjunction with the lifter bore mod to insure a constant supply of oil where its needed. The rod bearings is where the lack of oil shows up first.

To prevent the block from cracking, the engine needs a good blue print - indexing & align honing the block, and dynamically balancing the reciprocating assembly. A half fill with block grout wouldn't be a bad idea (because the thin cylinder walls have a propensity for cracking). And finally, run the best harmonic balancer you can purchase. Knowledgeable Cleveland racers will be your source there. A good balancer goes a long way towards preventing the webbing above the main bearing saddles from cracking. This issue is what separates the bull from reality in regards to dampeners. The guys who know are the racers who have cracked blocks in the past and through trial and error, or the advice of other racers, have found a balancer that works.

cowboy from hell