SC oil pump improvements

[3literpwr]

I have stumbled across a few posts that the SC oil pump can be modified to flow more oil, but these posts generally don't describe this fix... Upon disassembly of the pump out of my 81 SC it seems that only mod I see is would be to smooth out the entry and exit ports. Can anyone confirm such things? This pump is going in my motor that will be limited to a max of 7500 rpm...

Thanks

[toddu]

Sell it and buy a 964 pump.

[911 tweaks]

toddu...does the stock 964 oil pump flow more oil vs an SC & what about the turbo pumps up to 1989 model yr...??

[0396]

Glenn Yee Motorsport in San Dimas Calif mods the oil pumps to increase flow..look him up for additional details.

[toddu]

I think each model had an increase in flow. I *think* the 993 pump requires modifying the case to fit.

I think the 930 pumps have increases flow over the SC, but not sure how they compare to 964, etc.

Todd

[itsme]

930 pumps are about the same as a 964 on the suction side but are closer to the gt3 pump on the pressure side. I believe the 930 pumps are a better pump then the 964 and are built like tanks. The 964 with its magnesium housings are a bit flimsy and crack and warp. I think the 993 are the same as 964 but are aluminum housings and are a bit thicker in places requiring case web clearancing. Not 100% sure on that though. I am curious to hear what mods can be done to the sc and -89 Carrera pumps to increase flow. Maybe radius the inside inlet and outlet ports? but you are still stuck with the same gears so I am not sure you can make it flow more just make it more efficient.

[3literpwr]

I would guess that you are just increasing the overall efficiency by removing the sharp edges. This is very similar to the mod that I did on my Galant VR4 and Eclipse rally cars.

[Steve@Rennsport]

JMHO, but if you are going to turn your engine up to 7500 RPM, the best pump to use would be a 930 one. Its far more durable than the 3.6 pumps, and has the needed scavenge & pressure to do the job.

GT3 pumps are better yet, but require additional modifications to take advantage of their capabilities.

[Henry Schmidt]

We do a modification the the pump that will yield up to 15% flow increase. 2 day turn-around.

[Walt Fricke]

The 3.2 and earlier cases all require removal/grinding on one of the internal case webs in order to fit a 930 or larger oil pump.

I might be wrong about the 3.0-3.2, but for sure this is the case for the 2.7 and earlier, as well as the early Euro 3.0/turbo 3.0 cases. The big pump came in with the 3.3 Turbo, I believe, so maybe all the cases from that time on - which were all aluminum - had this modification so Porsche didn't have to modify cases for turbos or cast two different cases?

The good part is that you can do this yourself if needed. You lay the larger pump into the case and note where it's rear (toward its sump suction tube) side bumps into the case. Cut this out on both sides and you are there. You can use a cutoff wheel on a die grinder to get the largest part done, and a die grinder to finish up.

[tom1394racing]

I have a 930 pump in my SC case and do not recall having to do any case mods for fit.

[sjf911]

Originally Posted by tom1394racing

I have a 930 pump in my SC case and do not recall having to do any case mods for fit.

Same, no mods needed except a different sump plate.

[brp914]

Originally Posted by sjf911

Same, no mods needed except a different sump plate.

I wanted to ask why one would want to increase the flow of their pumps when I had the mental equivalent of a phonograph needle dragged across a record as I saw the description of your car! I'll bet driving it has a similar effect on one's senses. Quite an accomplishment there.

[sjf911]

Originally Posted by brp914

I wanted to ask why one would want to increase the flow of their pumps when I had the mental equivalent of a phonograph needle dragged across a record as I saw the description of your car! I'll bet driving it has a similar effect on one's senses. Quite an accomplishment there.

Thanks, still very much a work in progress. Always tuning, never happy unless on full boost.

[KTL]

Originally Posted by tom1394racing

I have a 930 pump in my SC case and do not recall having to do any case mods for fit.

Same for me with a 964/993 pump in SC case with a sump plate to accommodate the different pickup screen.

BTW 964/993 pump already has the typical flow modifications that are done to teh SC or Carrera pumps. That's what Aaron at Burnham Performance mentioned to me.

If you put a SC or Carrera pump next to a 930 pump, you can see where the difference lies. MUCH more scavenge length on the pump




The pressure section/port is the hole in the pump you can see in the above pictures. The scavenge exit on the 964 pump is on the intermediate/middle section of the pump seen here



What that means is, everything to the right of the scavenge exit port is the portion of the pump that is dedicated to sucking oil out of the sump and gettting it out of the engine. What that also means is the remaining part of the pump is what's dedicated to taking oil from the tank & pumping it into the engine for making oil pressure. By comparision, you can see the pressure section vs. the scavenge section is quite small.

930 pump is overall dimensionally same as 964 pump (they use the same short driveshaft tube) but the scavenge vs. pressure is different, as the 930 has more pressure capacity. Maybe the diameter of the gerotors is slightly different



The 930 pump is aluminum alloy and cast iron vs. the 964 all magnesium assembly. Mg has been known to crack, plus its not uncommon to find the Mg sort of sludgy. My most recent encounter with a 964 pump found the exterior of the housing to be a bit "dissolved" in that I could rub the pump body in some rough areas and have a lot of Mg residue on the rag. Probably a sign of that engine not seeing a good oil change interval. Internally the pump looked OK but the exterior bothered me.

Porsche put the real deal 930 pump in all the turbo engines, so there had to be a good reason for it. But I think the 964 pump is still a nice upgrade for a SC or Carrera. Scavenging as much oil as possible out of the engine sump and returning it to the tank to be ready on the supply side is a good thing.

BTW general rule of thumb is to mark the orientation/clocking of the pump gerotors to make sure they mesh the same as they came apart. If you look at the tooth count or watch the rotation of the gerotors, the same teeth always engage each other. Not sure how big of a deal it is but the machining is pretty precise so it's not a bad idea to keep it assembled how it's been run-in thus far in its life.

[3literpwr]

Thanks for the info KTL... Any advantage of the newer 930 pump with with attached screen vs the earlier style with separate screen?

[KTL]

Integrated screen has proven to be more durable. But of course the built in screen is also newer.

I had the separate screen on my SC pump come apart. Not real common but still a possibility. Thankfully it didn't cause a problem in terms of screen bits harming the engine.

Upgrade oil pump in 3.0 SC?

[Walt Fricke]

Interestingly, these later (attached) screens are a coarser mesh than the earlier ones.

[ManuFromParis]

I'm thinking adding a front oil cooler on a 3.0 powered 2.7 911 and I wonder what inner size the hose, stat and cooler shall be to hold the flow coming from the scavenge side of the pump without rising the pressure in that part of the network.

I guess the oem hose lines inner diameter shall be a standard for the whole cooling system, but maybe it could be a little smaller.

Any numbers on the original 3.0 SC oil pump flow ?

[m42racer]

Originally Posted by Henry Schmidt

We do a modification the the pump that will yield up to 15% flow increase. 2 day turn-around.

Can you explain how this increases oil flow???

Glenn Yee Motorsport in San Dimas Calif mods the oil pumps to increase flow..look him up for additional details.
02-23-2014 11:25 PM

Another shop that states they can increase flow.

How???