oil pump recognition by the # of fins??

Tim Boyer · Tim Boyer's Garage

HI,
I read somewhere that you can determine the year (s) of an oil pump by the number of fins that are found on its side. I am pretty sure that one with four fins is considered to be the desirable one. Can anyone confirm this or have a picture of a desirable oil pump for me to see so that I can confirm taht the oil pump that I have is the "better" one??
Thanks,
Tim

KTL · 02-13-2011, 04:51 PM

That's correct. The later pumps with 4 fins are the ones typically desired. Here's some nice pics of the later hi-po pumps people like to use for hotrodded engines.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/548297-when-use-gt3-vs-930-pump.html

Wayne's engine rebuild book has a complete section on the oil pump's progression throughout the air cooled engine's lifespan. The early pumps are typically replaced with the later 4 rib or greater pumps

Tim Boyer · Tim Boyer's Garage

HI,
Thanks for information. Maybe it was Wayne's book where I first saw this. I will have to check that out tonight.
Tim

tom1394racing · 02-16-2011, 01:21 AM

Tim

Here's some pics of the various oil pumps

From the top:

1. Early AL pump used up through '68
2. 3 rib Mg pump used from around '69 through '75
3. 4 rib Mg pump incorporated in '76 with the oil bypass mod in the case
4. SC 4 rib Al pump used on the 78-83.5 SC's same as the Mg 4 rib pump but more resistant to wear
5. 3.2 Carrera pump which is the same as the SC pump but with a built in strainer designed to work with the no sump crankcase used from late '83-'89
6. 964 pump which is longer and requires the short layshaft connector

Grady Clay · 02-16-2011, 04:00 AM

Tom,

Great discription.

Can you repeat this image with a plain background?
This is a classic. Thanks.

Here is a GT3CUP pump.

Best,
Grady

tom1394racing · 02-16-2011, 07:15 AM

Grady...I wish I could but I snapped this a while back for my own reference and do not currently have all these pumps in stock.

I am not that great with PhotoShop but anyone who wants to attempt a plain background is welcome to contact me for the original pic.

arrivederci · 02-16-2011, 11:26 AM

I assume that #3 and #4 in the list are actually #3 in the picture (ie, look the same?). 6 listed, 5 pictured...

bavaria911 · bavaria911's Garage

I sure hope I have the right oil pump in my new 2.4S motor:

tom1394racing · 02-19-2011, 03:37 AM

Scott

Looks like 4 rib Al SC type pump...That's a good one for your case assuming you had the oil by-pass mod done.

Tim Boyer · Tim Boyer's Garage

Thanks to all for their input, especially Tom. As always, he is one of the go to guys when it comes to information about Porsche's.

Tim

tom1394racing · 02-23-2011, 05:20 AM

Here is a more complete description of the various oil pumps with pics

KTL · 02-23-2011, 06:08 AM

Great image & thanks for sharing Tom. Note that the 83.5-89 930 pump part no. is incorrect. It should be 930-107-008-04. The part number shown is actually a 996 Turbo pump part no.

tom1394racing · 02-23-2011, 09:53 AM

Kevin

I think you are correct. The Turbo pump is NLA and the original P/N you mentioned has been superseded to the 996 P/N.

I'll make the correction to my chart.

Thanks
Tom Butler

KTL · 02-23-2011, 10:57 AM

I figured it was superseded (was going by parts diagrams), since you know your parts, and you are correct- plug in the original 930 pump P/N to Pelican catalog search and it supersedes to the 996TT pump. Good to know there's a newer replacement for worn out original 930 pumps.

Thanks,
Kevin

Tim Boyer · Tim Boyer's Garage

Tom,
Thanks for an even greater explaination of the various oil pumps, however, I have a question. Are these interchangable? If I wanted to use a 4 rib pump in a earlier 70's motor, could I do it? If so, are they all interchangable or only certain ones?
Thanks,
Tim

Flieger · Flieger's Garage

Longer ones need shorter drive shafts. Larger ones need to have a bit of case webbing machined for clearance.

tom1394racing · 02-23-2011, 05:27 PM

Quote:

Originally Posted by Tim Boyer

Tom,
Thanks for an even greater explaination of the various oil pumps, however, I have a question. Are these interchangable? If I wanted to use a 4 rib pump in a earlier 70's motor, could I do it? If so, are they all interchangable or only certain ones?
Thanks,
Tim

Tim

The 4 rib pumps work best when the oil bypass mod has been done on the case. The Carrera, 964 and Turbo pumps require that you use a dished sump plate on an early case to clear the strainer.

The 964 and Turbo pumps use a shorter connector shaft.