Oil Pump Changes when Installing Electric Tach?

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Conrad Carter
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Oil Pump Changes when Installing Electric Tach?

#1 Post by Conrad Carter »

I am removing my mechanical tach and installing electric tach. When I remove tach drive cable from engine oil pump, how do I seal up that opening?
Conrad

Dick Weiss
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Re: Oil Pump Changes when Installing Electric Tach?

#2 Post by Dick Weiss »

Conrad,

You can make a closed end-cap ring, or Ab Tiedemann Afterwerhe can supply one.
However, the trouble to exchange the pump's gears will be a little difficult in getting a "feeling" of the shafts not binding when turned
w/o removing the 3rd piece which requires a few things to be removed for access.

Dick

Dick Weiss
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Re: Oil Pump Changes when Installing Electric Tach?

#3 Post by Dick Weiss »

OOPS; I didn't mean to exchange the whole thing--unless you want to do so; Just add the closed cap.

Larry Brooks
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Re: Oil Pump Changes when Installing Electric Tach?

#4 Post by Larry Brooks »

Or just stick a 912 gear and cover on it if it's a large oil pump type(1960 or newer). The gear you need to change and the 912 cover are readily available.

Brad Ripley
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Re: Oil Pump Changes when Installing Electric Tach?

#5 Post by Brad Ripley »

For new pump cover from Porsche it's 616-107-108-01, for about $270; but there are plenty of used ones on Ebay for less than $100. Just be sure the bearing holes are within tolerance; there's a reason they're for sale!

Complete new gear is 616-107-017-00, about $400. However, there is a bare shaft, NLA-107-017-01, for about $120, which may be the cost effective way to go assuming your gear is still OK. Often only the bearing end is worn and a new shaft is needed. I believe http://www.competitioneng.com/OilSystem.htm can do a rebuild including the shaft.
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Dave Wildrick
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Re: Oil Pump Changes when Installing Electric Tach?

#6 Post by Dave Wildrick »

Conrad Carter wrote:I am removing my mechanical tach and installing electric tach. When I remove tach drive cable from engine oil pump, how do I seal up that opening?
Conrad
On my 64C, I used a Watts A263 brass flare cap (1/2 inch) from Home Depot. Works fine.
WattsA263photo.JPG
FlareCapWatts-A263.jpg
FlareCapWatts-A263.jpg (45.23 KiB) Viewed 872 times
brassFlarecapInstalled.JPG
Dave Wildrick
Houston, TX
#10230
64C coupe
65C coupe

Conrad Carter
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Re: Oil Pump Changes when Installing Electric Tach?

#7 Post by Conrad Carter »

I want to thank all of you for your advice. Great info.
Conrad

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Albert Tiedemann
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Re: Oil Pump Changes when Installing Electric Tach?

#8 Post by Albert Tiedemann »

Dave Wildrick wrote:
Conrad Carter wrote:I am removing my mechanical tach and installing electric tach. When I remove tach drive cable from engine oil pump, how do I seal up that opening?
Conrad
On my 64C, I used a Watts A263 brass flare cap (1/2 inch) from Home Depot. Works fine.
WattsA263photo.JPG
FlareCapWatts-A263.jpg
brassFlarecapInstalled.JPG
Dave, are you telling the whole story? That cap looks way too short to use without removing the tachometer drive shaft, and how well do the threads match the 18 mm x 1.5 mm ones that exist?

BTW, that safety wire on the nut does not look very effective.

I did a little searching and found that the thread size for that 1/2" fitting is 11/16" x 20. That is not even close to M18 x1.5.. I am surprised that you were able to get it on that far with such an interference on the pitch. But the hex is at the ready. You certainly have a good seal at the threads.
Albert Tiedemann, C356C
"The Hermit"

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Dave Wildrick
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Re: Oil Pump Changes when Installing Electric Tach?

#9 Post by Dave Wildrick »

Albert Tiedemann wrote:
Dave Wildrick wrote:
Conrad Carter wrote:I am removing my mechanical tach and installing electric tach. When I remove tach drive cable from engine oil pump, how do I seal up that opening?
Conrad
On my 64C, I used a Watts A263 brass flare cap (1/2 inch) from Home Depot. Works fine.
WattsA263photo.JPG
FlareCapWatts-A263.jpg
brassFlarecapInstalled.JPG
Dave, are you telling the whole story? That cap looks way too short to use without removing the tachometer drive shaft, and how well do the threads match the 18 mm x 1.5 mm ones that exist?

BTW, that safety wire on the nut does not look very effective.

I did a little searching and found that the thread size for that 1/2" fitting is 11/16" x 20. That is not even close to M18 x1.5.. I am surprised that you were able to get it on that far with such an interference on the pitch. But the hex is at the ready. You certainly have a good seal at the threads.
Ab,
You are correct. I forgot that you do have to remove the tach drive, but this just pushes out with your finger or a screwdriver after you remove the large nut (and safety wire on the nut) that keeps it in its tube/passageway.

Add the brass cap, using Teflon pipe dope (tape) to prevent leaks, and put the large nut back on the other end of the tube/passageway, and that’s it. Despite the threads not being really close to M18 x 1.5, it still worked for me.
Dave Wildrick
Houston, TX
#10230
64C coupe
65C coupe

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