Direct replacement upgraded oil pump ?

[PatAllen]

Is there a direct replacement oil pump for M10 that delivers more oil volume thant stock ?

Ive seen s14 oil pump talked about but i am not sure.

thanks.

[jgerry2002]

Metric Mechanic used to modify them to run at higher idle oil pressure.

They still sell them I believe.

There are probably other options these days as well.

[john_a]

The standard S14 pump is the same pump body as all the M10 variants, BMW catalog shows they have the same part numbers on the main pump & rotor sections.

Just the pickup bolted on the back is different, giving the pump assemblies unique part numbers.

There is another S14 pump though, that is different than the standard S14 oil pump, and seems to be preferred by the S14 crowd.. I don't have the numbers here now, but searching the S14 sites should dig it up.

But for the regular S14 pump, once you swap your M10 pickup on it you have exactly the same as a stock M10 part, no performance advantage.

[john_a]

Metric Mechanic used to modify them to run at higher idle oil pressure.

They still sell them I believe.

There are probably other options these days as well.

IIRC, what MM did was two things --

Shim the pressure relief spring with a small M4 washer to raise the pressure the valve would start to bypass at (this does nothing to raise pressure when the pump is producing less than the stock 62 psi valve setting, and if you have 62 psi you don't need to fix anything.)

Second thing I remember is they would take an old discraded valve guide (of which they had plenty) and machine it out to make a sleeve for the pump relief piston, the thinking was that this would solve the issue of the piston cocking & galling the softer magnesium it normally rode in.

A 2 cent washer & a scrap valve guide put to good use, I guess if the bronze sleeve don't fall out when the pump body warms up. None of this increases the pump displacement.

Not sure there is a readily available oil pump upgrade for replacing the stock part. The BMW branded part is much safer than the FEBI aftermarket piece, but to improve on stock, you might need a dry sump external pump?

[PatAllen]

ok, so why do they call it a "high volume" then ?

none of modifications you mention increase the presure/volume at idle.

[Retrogroucher]

The s14 pump can be upgraded to sport evo pump, also called Evo 3. Anyhow:

http://store.nexternal.com/shared/StoreFront/default.asp?CS=vacmotors&StoreType=BtoC&Count1=613918483&Count2=531058907&CategoryID=180&Target=products.asp

[PatAllen]

The s14 pump can be upgraded to sport evo pump, also called Evo 3. Anyhow:

http://store.nexternal.com/shared/StoreFront/default.asp?CS=vacmotors&StoreType=BtoC&Count1=613918483&Count2=531058907&CategoryID=180&Target=products.asp

yikes...529$...

the only way i see i can increase preasure at idle is to make the sproket/gear smaller so it will rotate faster at idle...

anyway, i was just thinking...