Ash content corrolations to Pre-Ignition

[vex]

Originally Posted by NoDOHC

tell me if i am wrong, but wasn't that being compared to ATF and found to have half the wear?

If I interpreted the data correctly, 19.6 um/ 2.5 hours with only 1.5 mm allowable wear (8.0 mm stock, 6.5 mm allowed) gives about 200 hours (12,000 miles) before wear becomes a problem on a premixed rotary (which I really don't believe). Granted, this is full-throttle useage, but that number seems out there a little.

I have seen 150,000 mile rotaries with 6.9 mm of apex seal left.

I am not sure that these are 2.5 hour cycles.

I'll have to double check what the cycle times were for the endurance run. But yes, that was comparing ATF to Two Stroke.

[Heeley]

Originally Posted by vex

I'll have to double check what the cycle times were for the endurance run. But yes, that was comparing ATF to Two Stroke.

So if i'm interpreting things correctly, does this mean that using ATF in an oil injection system is better for apex seal lubrication over 2 stroke? Then what would be the comparison to engine oil? and at what point does the ash content come into play? Doesn't it just trade off one problem for another?

[vex]

Originally Posted by Heeley

So if i'm interpreting things correctly, does this mean that using ATF in an oil injection system is better for apex seal lubrication over 2 stroke?

No, Two stroke out performs ATF with slowing Apex seal wear

Then what would be the comparison to engine oil?

See later posts regarding that

and at what point does the ash content come into play?

Pre-Ignition events. The lower the ash content the less likely a pre-ignition event occurs

Doesn't it just trade off one problem for another?

Not really. We're looking for low ash content which is reflective in the base oil being excellently refined. We're also looking for an additive package that still cleans and protects. The protection comes from the oil and additives, not from the ash and impurities.