Cracked Slick 50 pistons

Nice thread guys. Really enjoyed reading it. So what generally is considered the turning point CR from cast pistons to forgies?

Gurds

 

Detonation used to nibble the pistons on my old full race mini. On clockwork ignition, it was always a combination of too high CR, ignition advance and fuel knock (octane) rating, and trying to keep full throttle use only in the powerband, from my limited understanding. Forged or not.
Back in the 5 star days.

 

This has got me thinking more. Is anybody running a dash mounted knock detector display thing? I have seen them used on the rollers (audible type). I am a massive fan of the lambda readouts. Just wondered if an affordable knock reader is around yet.

 

11-11.25:1 Gurds.

The slick 50 spec motors are generally around 11.75-12:1, and that's just too much for the long term...highish rpm over long periods for a circuit engine.

 

This would cure the slick 50 engined cars piston issues...



It's my latest piston design for the 1800... it gives bang on 1799cc with a std crank so is totally legal for any engine running within that class capacity limit.

I run 13:1 on these, with both stand alone management & old type distributor engines, and no issues at all, so a slick 50 spec engine on 12:1 would be reliable again.

 

what weight are they Jase? much lighter than stock?

 

I'll did out the specs and have a look.

I plan on doing a light weight short piston with a long rod at some point... maybe for a short stroke 1800.