Panhead Knucklehead oil pump

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Paysonpan
Posts: 22
Joined: Wed Apr 24, 2013 2:30 am
Bikes: 63 FLH
55 FL
honda 90

Panhead Knucklehead oil pump

#1

Post by Paysonpan » Thu Nov 16, 2017 12:35 am

My 55 Fl mutt Pan is starting and running very well after all of the help from this forum.Motor has been rebuilt to factory specs. How ever it not only sumps it dumps oil. When running, oil flows freely from the breather and upon shut down it leaks most of the oil out of the tank. I replaced both check balls and did my best to look at the seat without removing pump by shining a flash light and viewing with a magnifier . Seat looked shiny so I did not remove to lap. After start up still same leaking. Consulted Palmer book to find out as much info as I could about the pump to see if perhaps I have either one or both springs wrong.In my reading I find that i have a very early 36 to 39 oil pump. I say this as the 2 oil fittings are cast in the pump cover and not threaded in which Palmer notes as being early pump. Only markings I see are a faint 12 stamped on cover. Measured springs and compared to Palmer and was still confused.Also looked on this site at Knuckle Service manual and see that my spring for check valve is same type as by pass valve spring. Called Old Dude to hopefully purchase right springs. After discussion Dude figures i have wrong springs and is sure the springs I have ordered will correct issue. Springs are on the way. I see that the adjustment for by pass valve is "end of adjusting screw 3/8" from outer from edge of valve chamber". So I will adjust accordingly after assembly.
All this being said, if leak is fixed, will my motor be happy and get enough oil with the Knuckle pump? Or should I track down the correct pump of my year Panhead? Or should I purchase a new shovel style S&S pump suitable for my year Panhead? Don't really want the S&S look but if it is the proper solution I am game. Fellow who built the motor urges me to buy S&S. This is by no means a correct machine but 90% of the parts are OEM and the S&S pump would stand out
Much thanks to all of you for your knowledge



RUBONE
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Re: Panhead Knucklehead oil pump

#2

Post by RUBONE » Thu Nov 16, 2017 12:55 am

Post a picture of your pump. Knucklehead pumps will not supply enough volume of oil to keep hydraulic lifters pumped up if you are using them. They have much thinner gears than a Panhead pump, so consequently they will not return as much oil either. There are also more issues involved than just check balls. If the pump is worn or the gear clearnce is too great it can be an issue. So can pinion bushing fit. But the pump needs to at least meet the needs of the engine and an early pump is not adequate for a Panhead. Panhead pumps are around though. I have a few bodies and pieces extra. A '68 up Shovelhead pump works fine also (where S&S got their design), but depending on the pump a bit of drilling may be necessary. Not so with a stock Panhead pump. Your pump if not damaged is as valuable as a correct Panhead one so a trade is a good possibility.
Robbie

Paysonpan
Posts: 22
Joined: Wed Apr 24, 2013 2:30 am
Bikes: 63 FLH
55 FL
honda 90

Re: Panhead Knucklehead oil pump

#3

Post by Paysonpan » Thu Nov 16, 2017 2:11 am

Rubone
Thanks for the prompt reply. My motor has solid lifters.I will have a friend here this week end who is MAC computer savvy and will be able to help me post photos to this site as I have tried and failed.
I have read many of your posts and always appreciate your incite and knowledge. Would you have interest in a possible trade for my pump?
I can take photos and measurements and email to you if so.
If not Robbie perhaps another member might be interested in a trade as I would much rather deal with some one on the forum than try to find a pump that is not junk on Ebay

Paysonpan
Posts: 22
Joined: Wed Apr 24, 2013 2:30 am
Bikes: 63 FLH
55 FL
honda 90

Re: Panhead Knucklehead oil pump

#4

Post by Paysonpan » Wed Dec 06, 2017 7:24 pm

I was able to trade my early knuckle pump for 2 later pumps for my project. Also got a handful of gears in the deal along with an oem oil pressure sending bit and 2 shafts. Both do have noticeably larger gears. One pump is complete with check balls and springs. The one with springs has an 1/8" diameter tube about 1 inch long coming out of body close to adjusting screw for oiler of primary. I assume this is for a rear chain oiler. In place of the needle screw for adjusting oiler is a small screw. This pump has a number 4 cast above the oil pressure sending hole.
The other pump has number 3 in same location. The shaft size on lower right of pump is smaller in diameter than the pump with number 4.
# 4 is much better condition than #3 so I hope to use it.
I have searched the knowledge base and consulted Palmer as well as looking through my factory service manual attempting to make sure this pump will work for my 55FL. Cant get an absolute answer so I would like members advice prior to ordering new gears, needle valve, clips and keys for shaft. I will order parts from Old Dude unless someone has a better suggestion.
Also,
Do I need to remove pushrods and lifters prior to removal of gear case cover? Knowledge base says yes and not necessary both.
For operation of the rear chain oiler do i run a copper line to the rear chain guard?
I have attempted to attach pics for the first time and I see them under the add files area below save draft preview submit. But when I click preview they do not show. If you guys can not get photos I will email them to any one wishing to help me out

panhead
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Re: Panhead Knucklehead oil pump

#5

Post by panhead » Wed Dec 06, 2017 7:34 pm

Email the pics: panheadforum@gmail.com

Paysonpan
Posts: 22
Joined: Wed Apr 24, 2013 2:30 am
Bikes: 63 FLH
55 FL
honda 90

Re: Panhead Knucklehead oil pump

#6

Post by Paysonpan » Wed Dec 06, 2017 7:43 pm

Panhead
Pics sent via email
Thank you very much for your help
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IMG_0002.jpg (89.03 KiB) Viewed 151 times
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IMG_0003.jpg (88.67 KiB) Viewed 151 times

Doc37W
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Re: Panhead Knucklehead oil pump

#7

Post by Doc37W » Thu Dec 07, 2017 6:07 pm

To make it easier to remove the gears within the cam chest, it is best to remove the pushrods. However, you can pull up the two tappets ( the hydraulic lifters in them) in each tappet block, and wrap a rubber band around the two to hold them from falling down onto the cam. No need to remove the tappet blocks. It makes pulling the cam, timer, and pinion gears easier. As to running a line to the rear chain, that tube had just a small rubber hose run around the rear of the transmission to drip on the inside top of the lower chain running back to the rear sprocket, so it would sling oil down on the chain and any extra away from the bike. Other oil pumps had fittings attached to the return line, as it left the oil pump, for a steel line to do the same thing. I believe the oil pump is for a '65 Pan-'66-'67 shovels with the cast inner & outer primarys. Probably the best oil pump for your pan. Run it, unless you going for a 100 point restoration. Doc

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