used flywheel assembly

[socalrider]

greetings,
im putting together a 1963 flh motor for a chopper i am building. im going to look at a original panhead flywheel assembly that is for sale . rods and pistons are still on the flywheels. what should i look for to determine whether the assembly is worth buying or not? all help is very much appreciated!
gracias,
arnulfo

[Mark]

I'm not a flywheel expert....but I do have a 63FLH with OEM wheels....They should have a "F" and "R" timing marks for the duel points.

[kitabel]

If the condition can't be determined, assume everything needs rebuilding = $$$. You have 2 bare flywheels (should be equally dirty, equal diameter, but 2 different thicknesses, and 2 different part numbers), and a rod core. Left taper is 1-1/4", right is 1".
If it's "recently rebuilt", and especially if "I was told it's rebuilt": ask who rebuilt it, what was done, and how much paid.

No answer: must be cheap or no sale.

[socalrider]

kitabel, mark, thank you very much for the help!
arnulfo

[Bosheff]

If yer gonna buy the wheels with rods assembled, it would be a great time to pull it down for inspection if possible. Check the runout in a truing stand to see where the wheels are at. The owner probably won't let ya break it down before purchase, but it won't hurt to ask. Flywheels could be bruised at tapers or keyways and you'd probably never know till the mill is together and ya got a vibration or worse, the assembly grenades on ya. You can check the crankpin while yer at it. Don't take anybody's word about anything. Purchasing it completely in pieces would be the ideal if possible. Approach with suspicion and caution....bosheff

[kitabel]

More visual ID on assemblies:
All OHV sets 1940-* 8.50" OD
All left sides 2-1/8" wide
All right sides 1-5/8" wide
Sprocket shafts:
1930-54 1" OD, 1" taper, tapered/keyed sprocket drive
1955-71 1-1/4" OD, 1-1/4" taper, splined sprocket drive
1972-* 1-1/4" OD, 1.400" taper, splined sprocket drive
Pinion shafts:
1939-53 1" OD, 1" taper, splined gear drive
1954-57 1" OD, 1" taper, tapered/keyed gear drive
1958-* 1-1/8" OD, 1" taper, tapered/keyed gear drive

[JR JOHNSON]

LOOK at the side play,on the rods,if every thing is correct,as per kitabel,and the seller will stand by it,but the reason I'm say this is that my 59 fly wheels been service to many times,taper of the crank pin to deep,no side play on rods,reason for my failure,took out female rod,lock up engine,just bought the bike a year ago,but some body was in it not so long ago,slow death to my pan..anyway, good luck.......with respect.....JR

[indianut]

It would be foolish to have a Crankshaft Assembly in your hands, that you have not personally disassembled and inspected, or had someone you TRUST Personally disassemble and inspect and assemble it into an engine. If it is all good, the entire process should take less than an hour! If it is not all good then, well it SURE is a Good Thing you looked at it! I have RE-Rebuilt many "FRESH" engines!

[Cotten]

I agree with Indianut,
except it would take me a lot longer if by some chance it actually was a serviceable assembly. If it's trashed, it takes two minutes.

Jr!
Sunken crankpin tapers are easily remedied with an overlength crankpin.

....Cotten

[JR JOHNSON]

cotten,what bothered me the most is that the pin is almost,and about flush on the nut end,in fact the nut is making contact to the taper,never seen one so deep,just for giggles,i put them back together,without thrust washers,different rods,they were tight,the rods that failed where ground down to fit.but only on the sprocket flywheel,and when i took it a part,came apart easily on that side,that's why I'd abandon ship on the flywheels.....................have a good one..........WITH RESPECT.....JR

[indianut]

I agree with Indianut,
except it would take me a lot longer if by some chance it actually was a serviceable assembly. If it's trashed, it takes two minutes.



....Cotten

Yeah, I guess I get 'Keyboard Exaggeration'. I was thinking an hour IF Everything Really Was NEW and CORRECT! What are the chances of that? BUT still MUST be done if the crankshaft is in your hands!

[kitabel]

More visuals:
Any heavy assembly with OD between 8-1/8" and 8-5/16" is probably VL, UL or 1936-39 EL (although some JD is possible?).
All 1932-85 (and some Evo?) 45, K, KH and Sportster are 7-7/8" OD.
Easiest way to tell at a swap meet: since a caliper big enough to work is $$$ and bulky, instead bring a tape measure.
1940-* big twin: 26.7" around the OD
1936-39 EL, all UL: 25.9" to 26.1"
VL (probably): 25.5", also both wheels will say 150-30 (except 1935-36 VLH etc.)
45, K, XL: 24.7"

[JR JOHNSON]

good info.............with respect.......JR

[socalrider]

Thank you all very much for the replys. I decided I'm just going to send the cases to truet and Osborn and just have them install a completely new bottom end. I don't want to take any chances.I'm building this bike as a graduation gift for my son. He is in law school with 1 1/2 years to go.I don't want to take any chances of the bottom end failing prematurely due to my lack of knowledge.you guys provided a wealth of information but I'm still not comfortable enough to buy a used set of flywheels.I've read nothing but good things about T&O on this site. Still undecided on whether to go for the stock set up or the torque monster assembly. Any thoughts on this from anyone?
Gracias,
Arnulfo

[Bosheff]

I would say that all depends on how long ya want it to live. This is probably an old fashioned outlook as I've been told that big inchers stay together much longer now than they did 20 years ago. I'm sure there will be plenty of opinions on this one. Just outta couriosity, what is the bore and stroke on one of these "Torque Monster" setups?....bosheff