Pan Knuckle
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Stage II
Joined: Oct 2020
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From: mass
Pan Knuckle
I am starting a new build and I had planned to go with a new SS Panhead, but i recently was offered a motor that is a Knucklehead Bottom with a Panhead top. All legit with a title for the motor. I know this was done back in the day so I was hoping to get some old school guys to comment on this combination. Anyone have one and like it? Have one and dont? Any positive or negative comments on this combination?
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From: la la land jerzey
no they did not for the reasons below - but you have what does not work if you have that
1 knucklehead engines feed main oil pressure oil out of the cam cover to the rocker boxes via a split line to the rocker boxes - that oil has NO drain holes in the head or the jugs as well as the engine block ( say it again NO oil drains at all -- so how the oil is returned is vacuum - the oil is sprayed from the rocker shafts into the valve spring pockets on all 4 valves - that oil is picked up by metal lines at the bottom of the spring pocket holders - then those lines go into the top rocker boxes ( its all up hill last time i looked oil does not drain UP hill ) - they in turn spill that oil under suction into the pushrod tubes and that same oil is drained into the lifter blocks - and they are connected to a special port in the front of the breather valve < this is the spot the suction comes from - it then gets sprayed into the cam cover and returns to the oil pump - dont understand - look up knuckle oiling system diagrams read as you look
now if i say if the pan heads are 1963 to 1965 they will be external oiling heads - but need drains for the oil you feed to the heads has a way of getting back to the oil pump - earlier pan heads are internal oiling they had drilled passages to the heads and drains coming back to the flywheels all pans and shovels use drains in the jugs - heads and block - - shovels work a little different but it needs a feed and a drain as well and knuckle blocks are as described above have NO drains drilled
if it actually works would be interested in seeing what they did -- but like all engine mods done by questionable people i would have to see it work and what they did > my guess it does not work as expected
1 knucklehead engines feed main oil pressure oil out of the cam cover to the rocker boxes via a split line to the rocker boxes - that oil has NO drain holes in the head or the jugs as well as the engine block ( say it again NO oil drains at all -- so how the oil is returned is vacuum - the oil is sprayed from the rocker shafts into the valve spring pockets on all 4 valves - that oil is picked up by metal lines at the bottom of the spring pocket holders - then those lines go into the top rocker boxes ( its all up hill last time i looked oil does not drain UP hill ) - they in turn spill that oil under suction into the pushrod tubes and that same oil is drained into the lifter blocks - and they are connected to a special port in the front of the breather valve < this is the spot the suction comes from - it then gets sprayed into the cam cover and returns to the oil pump - dont understand - look up knuckle oiling system diagrams read as you look
now if i say if the pan heads are 1963 to 1965 they will be external oiling heads - but need drains for the oil you feed to the heads has a way of getting back to the oil pump - earlier pan heads are internal oiling they had drilled passages to the heads and drains coming back to the flywheels all pans and shovels use drains in the jugs - heads and block - - shovels work a little different but it needs a feed and a drain as well and knuckle blocks are as described above have NO drains drilled
if it actually works would be interested in seeing what they did -- but like all engine mods done by questionable people i would have to see it work and what they did > my guess it does not work as expected
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Stage II
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From: mass
Thank you to Johnjzjz for the specific input. Based on his comments I decided to reach out to the original builder and I got some more details. For those who might be interested this motor was first built in 1984 with an original knucklehead Bottom and Pan top. Scot said he used Panehead tops and cylinders with external oiling so that answers the first issue. He also said it is a Stroker motor. He said the oil returns on the top section continue all the way down into the lower end after they modified (drilled) the lower to allow the drain ports to continue ( forgive me if I am slightly off on the details as I could only take in so much as he was speaking). He said back in the early 80s there was a company that made a drilling jig the allowed you to measure the exact placement and depth of the hole etc. It was very interesting and locked me into that motor as I doubt I will find another like it.
For the record he is not a questionable builder. He has been in business for 30 years, has built 100s of bikes, had cover bikes, won national and international shows and has a great reputation. He loves the old school stuff as he sees it as a dying knowledge set. If anyone wants to speak to him about this specific modification, or any other old school stuff, let me know and I will pass on his info. He is located in Framingham Massachusetts and the shop is American Motorcycle Service.
Thanks for the replies
For the record he is not a questionable builder. He has been in business for 30 years, has built 100s of bikes, had cover bikes, won national and international shows and has a great reputation. He loves the old school stuff as he sees it as a dying knowledge set. If anyone wants to speak to him about this specific modification, or any other old school stuff, let me know and I will pass on his info. He is located in Framingham Massachusetts and the shop is American Motorcycle Service.
Thanks for the replies
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Joined: Sep 2022
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From: Florida
I know this is an old thread but it pulled up when I googled it..
I was at the Leesburg Bikefest yesterday and at the Full Throttle Ike Show there was a hodgepodge pan head that really caught my attention..
It looked like a 50s hardtail frame THE CASES WERE 47 it was a panhead. The sign just said 1947 panhead. Sadly nobody around understood why that didnt jive. I scratched my head a bunch looking at it. It was a running bike.
Im hoping its there again today. I want a better look at it. The jugs were pan too. I had never heard of anyone putting a pan top on Knuckle cases I want to see the oil pump and any lines. It was cool and sad. There are probably knuckle heads somewhere that need cases there is probably some original pan cases that need heads.
I was at the Leesburg Bikefest yesterday and at the Full Throttle Ike Show there was a hodgepodge pan head that really caught my attention..
It looked like a 50s hardtail frame THE CASES WERE 47 it was a panhead. The sign just said 1947 panhead. Sadly nobody around understood why that didnt jive. I scratched my head a bunch looking at it. It was a running bike.
Im hoping its there again today. I want a better look at it. The jugs were pan too. I had never heard of anyone putting a pan top on Knuckle cases I want to see the oil pump and any lines. It was cool and sad. There are probably knuckle heads somewhere that need cases there is probably some original pan cases that need heads.
Last edited by Rains2much; Apr 26, 2025 at 10:25 AM.
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From: la la land jerzey
Every once in a while we see a paper on another engine that was re stamped its what the guy had and no real money to correct is it a thing no but at some events it will be impounded and you will get a summons tp appear not a good thing will happen
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