996 Turbo Oil Pump for 1976 930

[356911930]

Hi guys,

My 1976 930 has been parked for 4 years due to a broken head stud or two. After I took it out of a 17 or 18 year hibernation and did a full paint and interior refresh I threw the engine and transmission back in to refresh my memory on what neglected maintenance was needed. In short order I remembered that it had several oil leaks and upon an attempt to re-torque the head studs found one broken and parked it until I could properly rebuild the engine.

While on the slippery slope I was wondering if a 996 Turbo Oil Pump might be a good upgrade to help cool this non-intercooled 930?

What say ye?

Rahl

[Drummer]

Yes, it will.

[baloo]

Is the 996 oil pump an external hose and unit add-on? ... or is this an internal modification (to the engine)?
Electric? belt driven?

[RSstop]

Internal modifications only.
Clearancing of the case to fit the longer pump, shorter pump shaft.
If your 2.7 didn't originally come with the 4 rib pump you will want to consider the internal bypass mod.

[RSstop]

Oops sorry, Ignore the above post. I saw 1976 but missed that it was a 930.
I believe it will bolt right in to a 3.3 930. Not sure about a 3.0 but I think they used a larger pump also.

[TurboKraft]

Any later Turbo pump will be good, and there's a longer drive shaft for it.
At worst you'll be clearancing 2 case webs, but not as much as for a GT3 pump.

[356911930]

Thanks for the replies!

I could buy a later 930 3.3L oil pump, which should also be an improvement, but my understanding is that the 996 Turbo oil pump provides greater volume and pressure, thereby allowing greater cooling for the non-intercooled 3.0L, with only minor clearancing.

Would this be the case or would I just be paying more money for no real gains?

My impression was that the GT3 pump would require considerably more clearancing and best suited for more of a racing application or highly modified engine.

Thanks again,

Rahl

[TurboKraft]

The 1978-89 930 oil pump number supersedes to the 996T oil pump #996-107-008-70.
Early cars also need the dished sump plate #930-101-902-00.

GT3 pumps have marginally longer suction and pressure gears, an additional scavenge port -- unnecessary for a road car.

[356911930]

Wow Chris! Nice details.

Thanks,

Rahl

[dap930]

I had to clearance my 3.0 liter 930 case to fit a 3.3 liter oil pump, plus obtain a shorter drive shaft to connect to the cam drive gear. It is not a lot work to fit the pump.

[356911930]

Thanks Dennis!

Do you recall the part number of the shorter driveshaft or what model it is from?

Does anyone know the difference in volume and pressure with the 996 turbo pump and the original 1976 930 oil pump?

Also, is there a difference in flow rate and oil pressure between the 930 3.3L oil pump and the 996 turbo oil pump or is it just and update of the housing from magnesium to aluminum?

Thanks,

Rahl

[blue911rsr]

Get some steel gears for that 996 pump like 964 otherwise that big pump will eat your aluminum gear and creat some pretty good gear lash ask me how I know

[356911930]

Quote: (Get some steel gears for that 996 pump like 964 otherwise that big pump will eat your aluminum gear and creat some pretty good gear lash ask me how I know)

Is there a consensus on using the steel intermediate shaft gear or is the aluminum gear sufficient if new?


Thanks,

Rahl

[dap930]

Rahl,

Part number for the 930 shaft is 930.107.143.00, is superseded by 930.107.143.03 used on the later 964/993/996 pumps. Found an old post by Bill Verburg that states a 964 pump puts out 65 liters/min and the 930 pump puts out 100 liters/min. But looking at pictures of these two pumps, the pump sections look the same length. So, I don't know if the 100 liters/min is accurate. At any rate the 1976 pump section is almost half the size of the 930 pump. I updated to the 930 pump because I had larger C2 (964) piston squirters installed in the case.

[Ollies930]

It is my understanding that the largest pressure gears are 51mm long and flow 83l/min at 6500rpm. The Indy/935, 3.3 930, 964 Turbo, 993 Turbo, GT3, GT3R and 996 Turbo all use this same pressure section. The differences are in the scavenge section. Difference from 930 3.3 to 996 Turbo is the fact that the scavenge pump housing on the 3.3 is cast iron and the 996 Turbo is aluminum.

[356911930]

Thanks, Ollies930! Good information.

Here is a pretty good thread I found:

https://forums.pelicanparts.com/911-engine-rebuilding-forum/956846-964-oil-pump-911-sc.html

I don't know the diameter (size) of the piston squirters in the 930 3.0L case. Would they need to be replaced with larger to run the 996 turbo oil pump?

The 930 turbo 3.3 L oil pumps have a cast iron housing and 996 turbo oil pumps have an aluminum housing. Are there any wear or flexing issues with the aluminum housing?

Rahl

[TurboKraft]

Originally Posted by 356911930

Thanks, Ollies930! Good information.

Here is a pretty good thread I found:

https://forums.pelicanparts.com/911-engine-rebuilding-forum/956846-964-oil-pump-911-sc.html

I don't know the diameter (size) of the piston squirters in the 930 3.0L case. Would they need to be replaced with larger to run the 996 turbo oil pump?

The 930 turbo 3.3 L oil pumps have a cast iron housing and 996 turbo oil pumps have an aluminum housing. Are there any wear or flexing issues with the aluminum housing?

Rahl

No harm in running the larger piston oil squirters of the 3.6L engine.
The shorter oil pump drive shaft is #930-107-143-03

[356911930]

Thanks guys!

Does the cast iron/aluminum turbo 930 oil pump have any benefits over the all aluminum 996 turbo oil pump?

Chris,

You mentioned that, there is no harm in running the larger piston oil squirters of the 3.6L engine. Did you mean "no harm" as in no real benefit? I wonder if it would be possible to add second oil squirter to each location instead of using the larger 3.6L engine oil squiters?

Thanks,

Rahl
__________________

[TurboKraft]

I would think if the iron pump housing were necessary, Porsche would have re-introduced it on the later Mezger engines i.e. 996/997 Turbo, GT3...

Why 2x squirters per piston? Sounds like a lot of unnecessary planning and machining for an indeterminate amount of benefit. If you're looking for additional piston cooling and/or lubrication, there's better, proven ways to go about this.

[356911930]

OK, so no known problems with the longevity of the all-aluminum oil pumps. Thanks!

What are some of the additional piston cooling and lubrication solutions?

Above, Blue911rsr commented:
"Get some steel gears for that 996 pump like 964 otherwise that big pump will eat your aluminum gear and create some pretty good gear lash ask me how I know"

Has this issue been documented as a know problem when using the later turbo oil pumps with the aluminum intermediate shaft gears?

Thanks again,

Rahl