Connecting rod side play

[wreck74]

I posted this on another forum, thought i would post it here too.
Ok, i trued my flywheels/pinionshaft/sprocketshaft all within specs. But. i have 0.036 thousands connecting rod end play, the book says 0.005-0.030 My question is, for an old 79 ironhead is that gonna be to much end play ? 6 thousands is not much, but as for the connecting rod is 6 thousands too much ? Has anyone run a connecting rod with that much end play ?

[Lew]

I wouldn't run it like that and would try to tighten it up.

Lew

   

[wreck74]

Thats what i thought, how would i go about tightening it up ? Ream the flywheels ? A different rod pin ? or ?

[Pynzo]

The flywheels have replaceable thrust washers in each side, they come in std and oversized.  You'll need bronze washers for aluminum roller cages and steel washers for steel cages.

[wreck74]

Thanx for all the info.

[Lew]

Depending on the how much you have the wheels torqued, it may be possible to tighten the nuts more to pull things into specs.  You are very close now.  Although the factory says .030 max side clearance, S&S says they've seen no detrimental effects from going as far as .045.   

Lew

[saltcaveminer]

good advise and info given!i prefer to get to at least the mid point in a spec.i want to eliminate as much vibration as possible and keep the pistons centered.Salty

[wreck74]

The only thing that i can do is get the .005 thicker thrust washers, the nuts are torqued to 150 lbs. But will the thicker washers fit in the recess and still have room to ping the edges over. It's pretty close now, maybe they are over .005 allready. This is a budget build, so if i could get away with running it with .036 end play i think i will. The p.o. must have dumped the clutch or something because when i got it it had a broken rear piston, so i took it apart and found the the crankshaft all out of wack. So now i'm just truing it up. I got the srocket shaft and the pinion shaft to just .0015 run-out with .036 end play

[BikeRider]

150 lbs is nowhere near enough anyway
you need to tighten it up
which means you need to do another 20 other things as well
I assume you are actually talking about "sideplay", and not endplay at all

[wreck74]

Yea, side-play, no up and down. 150 lbs. is what they say to torque it to. By they, i meen everywhere i ask or read.

[BikeRider]

You need to understand side play
When there is too much side play, the female rod can move (partially) over the top of the bearing cage of the male rod.
This will result in a light binding sensation when the crank is rolled over by hand, and the race will become chewed out at the point of contact (as the rods have different dynamics as far as speed and direction of travel go, during the various phases of their cycle)
Rod side play has always been correctable by additional flywheel nut tensioning.... UP TO A POINT, OF COURSE.
You are at 150 ft lbs. That is suitable for a childs toy.
Maximium torque specs for flywheels varies with the type of material used.
Forged type S+S wheels can go up to 500 ft lbs(with a recommended minimum of 400).
But if you take a standard set of HD cast wheels, for example(say big twin) then more than 350 could see taper damage.
Unless you have lapped the threads and nut faces, you have no idea as to exactly how much force is actually being applied to the taper anyhow.
You can go 200 - 220 easy, with no fear.... PROIVIDED THAT YOU DO NOT LOSE ADEQUATE SIDE CLEARANCE. Which you will not... not by a long way(unless the flywheels are already damaged in that area).
But, of course, it is up to you.
All the best.

[Lew]

Curious to know where you are getting this information.  The factory torque spec is 150#.  I have a source that states to torque to an additional max of 180# to attempt to bring side clearance to spec.  Even S&S states to torque their wheels to the factory specified torque.
I understand the differing capabilities of different materials used in the manufacture of various brands of flywheels.  No doubt the threads on the crankpin and nut are capable of withstanding much more than the recommended 150# torque.  I realize the ability of torquing beyond recommended specs to squeeze these things together enough to achieve the factory recommended side clearance....through distortion. What I don't understand is why the factory would recommend a certain torque specification if it wasn't required to be adhered to.

[BB]

Jim's had a shorter crank pins years ago for side play problems. Don't know if they still have them . DO NOT over torque cank pin nut , it can damage flywheel .

[Pynzo]

I've been using a Factory Crank Pin Nut Wrench , and it does'nt have any way to indicate a torque reading.
One side is for Pinion and Sprocket Shafts, The other for the Crank Pin Nuts. I just muscle the Nuts as tight as the wrench will allow, and leave it at that.

[Hillside Motorcycle]

With the crankpin at the approx. 5 o'clock postion, and the crankpin clean of oil, check the male rod for ANY up/down movement whatsoever.
Scott

[wreck74]

I ordered the .005 oversize flywheel washers. That should bring it to .026 As you can see in the pics the bushings that spun around, heres the new idler gear shaft with oversize bushings, i still have to get an oversize pinion shaft bushing.



[attachment removed after 60 days by system]