Engine failure questions (pics)

[matt dunn]

Ok,


The valve cut out in the pistons are there too give more clearance for normal operation, not to clear if the cambelt fails.

A standard 20v Blacktop Pistons still has the cut outs,
but if the belts breaks, the valves still hit the pistons,


so just because the cut out dont suit the head, does not mean anything at all.

[NZ_AE86]

if your gunna build something that temprimental you prolly want it non interferance anyways? or just buy some proper aftermarket pistons seems people shy out on the most important part of there powerhouse

Have you ever seen the DX 'TIMID'?
This has the same setup and because it was built and tuned well it was, at the time, the most powerful 4agte around!
I you build a serious N/A motor you will always end up with clearance trouble if something goes wrong.


So as Matt said - just because the cut outs dont suit the head, does not mean anything at all.

[flygt4]

as said its common as hell for engines to be interference.
timid was pushing ~330kw atw with that setup , my own car runs 218kw atw with the exact same setup. matt dunns car was running around the same power when he had ST head and was 1600cc.

its a tried and proven formula for some decent power.

[sergei]

Most car manufacturers make interference engines these days.
Nissan - as far as I am aware all are interference
Mitsi - as far as I am aware all are interference
Honda - some are interference (VTEC when it is on)
Toyota - most petrols are not interference (although trend changes with new cars)
not even talking about euro/american rubbish - most of them are stuck in stone age.