Motor dyno test; assembly lube question

[Clem Z.]

Re: Motor dyno test; assembly lube question

Can you be more specific? What are the materials?

Thanks,
Jim

i do not have the material list here but i will try and dig it up.

[Duke W.]

Re: Motor dyno test; assembly lube question

Most oil additives - detergents/dispersants, anti-wear, etc. leave ash, which can form deposits that can increase the incidence of detonation due to loss of combustion chamber volume and/or "hot spots".

That's why back in the seventies GM recommended "ashless" aircraft oil - basically non-detergent oil in racing engines, but it lacks critical additives such as ZDDP. Aircraft engine valvetrains are very lightly loaded, so they need little or none.

IMO you should use a well fortified oil like CJ-4 or CI-4. If the engine has proper oil and fuel control, deposits won't be a problem.

Oil spec sheets like what Chevron has online for Delo list percent ash and CJ-4 is less than CI-4.

Duke

[Jim L.]

Re: Motor dyno test; assembly lube question

Most oil additives - detergents/dispersants, anti-wear, etc. leave ash, which can form deposits that can increase the incidence of detonation due to loss of combustion chamber volume and/or "hot spots".

This much I already knew.

Are you saying that EOS contains these additives, possibly in abundance?

Jim

[Duke W.]

Re: Motor dyno test; assembly lube question

I believe it contains a high concentration of ZDDP - not sure about the others.

Duke

[Clem Z.]

Re: Motor dyno test; assembly lube question

GM used to include a can in every crate with a new short block and the can had something printed on it about not to be used with regular oil changes