Panhead stuff

[rickthrash99]

Hey guys im back with stupid questions, i just purchased a panhead top end 48 rear and 50 front , ihave a chance to buy 58-62 cases, iwas told it would work, anyone want to chime in on this

[rickthrash99]

Its a 74ci from what i measured its 3.47 bore

[JBinNC]

Yes, you can put the earlier top end on '58 - '62 cases. The top end oil is fed through cylinders in both, so it is a bolt-together deal.

Jim

[Dragstews]

Top-end oil returns on the 48-52 Oem jugs doesn't dump into the bore ..
Will need to drill the returns in those ...

[rickthrash99]

Awesome thanks guys, also ima post some pictures can you guys tell me if the hole has been drilled already? Ima ask more questions as i go thankyou

[Dragstews]

Also, I'm going post some pictures can you guys tell me if the hole has been drilled already?

Easy to tell if indeed your jugs are the 48-52 era ..
No hole in the bore would be the early jugs ..
They drain into a drilled port in the motor case .. Oil is routed to the breather passage never seeing the flywheel cavity ..



53-up has a hole in the bore close to the bottom ..
They drain into the flywheel cavity, oil is then picked up by the flywheels to be deposited into the catch trough leading to the breather gear to be expelled into the cam chest ....

[rickthrash99]

So here is an update guys, i found a right side case looks good it says its a 57, will i have trouble slapping an aftermarket left side? I talked to phil over in cycle works and he does not have any at the moment, and someone told me im crazy for trying to piece together a panhead, am i really?haha thanks for the reply

[Dragstews]

Might be best to wait until Mr. Long has them back in stock ...

He doesn't make any with the 55-68 Timken bearings, his are all 69-up bearings, tis a + in that department ...

[rickthrash99]

With phils 69+ Cases with the different bearing, will i have to update the 57’ right side bearing to match 69’+? Is the fly wheel from the 55’-62’ good to fit those new style bearing?

[JBinNC]

With the bearing set up, will it work for 55-64 flywheel? Im got so many questions guys excuse me for that if i sound dumb, im more inclined in the putting together of a bike than an engine but have done a few top ends thats as deep as ive been

Yes, but DON'T use the '55 sprocket shaft, use the '56 - '64 shaft.

Jim

[Dragstews]

Here's a little history on the 55 sprocket shaft ...
Growing pains for the Mo-Co was in the works back then ..

From first conception to approximately 1954, H-D used a 6 degree taper on the flywheel side.
In 1956, there was a change to 8-1/2 degrees, with a major diameter of about 1.060" at the largest end of taper.
1955 had a special sprocket shaft and flywheel, at 8-1/2 degrees, without a bearing shoulder on the shaft.

The Big Twin was growing in horsepower ..

The 8-1/2 degree x 1.060" taper lasted until 1972.
It retained the 8-1/2 degree taper, but was increased in size to about 1.400" at the biggest part of the taper. This shaft also used a bigger nut, 1-1/8"-16 and the flywheels still used a nut locking plate and screw until early 1981.

In late 81 they became what H-D called the "Communized" taper, which is the old 6 degree, but with a size of about 1.310" at the largest part of taper.
The flywheel side nut has the same thread at 1-1/8"-16, but the flywheels do not have a screw hole for a locking plate ..