oil pump upgrade ?

[philippeF]

what could be the best choice to replace my stock 2.7RS engine pump ?
is there something to check to be sure it's working right ?
best regards
Philippe

[Steve@Rennsport]

Hi Phillipe:

The only way to check the oil pump is to open it up and look at the case & gears. It takes experience to assess what you see and if you are not well versed in inspecting these. I'd kindly suggest that you find a 911 specialist (especially a 911 race car shop) that is.

You have several good oil pump options; all of which are better than the 2.7 pump:

1) Carrera pump (requires oil bypass mod on magnesium cases older than '76)

3) Turbo pump (requires same as above and clearancing since its much bigger)

3) GT-3R pump (same as Turbo pump)

Hope this helps,

[philippeF]

thanks,
i'm not sure of what it does (the pump).
I had a low oil pressure when warm before i open the engine.
crank is perfect, bearings are ok, no damage, cams ok....
shall i trust the transmitter ?
i remember it was 1b/1000, 2b/2000 3b/3000 .... when cold,
and the pressure felt at around 1.5b when hot.
this is why i decided to rebuild, (engine is 33years too......)

any idea ?, what about the oil pressure pistons ? how do they really work ?
best regards
Philippe

[Steve@Rennsport]

These oiling systems are called dry sump and that means (in this case) that they employ 2 tandem pumps; one scavenges oil from the engine (hence the "dry sump") and the other pressure lubricates the whole engine.

The different pumps scavenge/supply oil at different pressures and volumes.

You are correct, a healthy engine will have at least 1b per 1000 RPM with proper bearing clearances and tolerances. Thinner oils give less overall pressure and thicker oils have a little more. Oil temps above 210 F (100 C) will reduce operating pressures so that must be accommodated as well.

What RPM did you observe the 1.5b and what oil viscosity were you running?

[philippeF]

hi STEVE

thanks for the reply, oil viscosity was something like 10w40 or near.
1.5 b all the time ....




Philippe

[Steve@Rennsport]

Hi Philippe:

If you are racing or using your car on the track, I would strongly suggest using a 15w-50 oil.

The thinner oils are fine for all the water-cooled cars that do not run as hot.

[Groesbeck Hurricane]

Phillipe,

What about the oil level when you are noticing the drop in oil pressure? Just a shot in the dark, mais...

[philippeF]

what happens when the pistons in the oil circuit don't do their job ?

oil was old when i opened the engine, i'm pretty sure it was not a synthetic modern oil...
as i said bearings look brand new,

Philippe

[philippeF]

david :
oil level was good