0.0045" pinion shaft runout on my 107 - 117 build

[Adam76]

Finally got a dial gauge onto the pinion shaft to check my runout before proceeding any further, and it's a little more than I'd hoped for.

What's considered OK for the M8 motors?  Anything under .005" ?

My build is
114" cyl bored out to 4.125" (117")
11:1 static compression
Star Racing 30-30 cam

I'm expecting around 125TQ / 115HP...

[VernDiesel]

Mine is .004  I'm told that is in the clear so leave it.


Similar set up to you only just doing a cam upgrade.

4.075 bore 114"
11-1
from SE-498 cam & SE tuner 118 HP 122 TQ
to Star F35A cam & PV tuner. Hoping to get +15 ie 133 HP

Did you go S&S 2-1?
I bet with the 30-30 you get 120 HP and a nice torque curve.

Having just seen 141 Jason's El Diablo results with the Chris Riva 544 cam has me second guessing myself wishing I tried that cam.   

[Hossamania]

Mine is .004  I'm told that is in the clear so leave it.


Similar set up to you only just doing a cam upgrade.

4.075 bore 114"
11-1
from SE-498 cam & SE tuner 118 HP 122 TQ
to Star F35A cam & PV tuner. Hoping to get +15 ie 133 HP

Did you go S&S 2-1?
I bet with the 30-30 you get 120 HP and a nice torque curve.

Having just seen 141 Jason's El Diablo results with the Chris Riva 544 cam has me second guessing myself wishing I tried that cam.   

Cam choice is like getting married choice: I do. Wait, I didn't see her!

[Mattls6]

I believe the HD spec is <12 thou which is wild. I'm going to measure mine tomorrow, bracing myself a bit.

11:1, 117", 30/30 sounds like a great/fun combo. I'll bet it cracks 120 if you've got a decent pipe and air cleaner.

[Adam76]

I believe the HD spec is <12 thou which is wild. I'm going to measure mine tomorrow, bracing myself a bit.

11:1, 117", 30/30 sounds like a great/fun combo. I'll bet it cracks 120 if you've got a decent pipe and air cleaner.

Thanks, yes I'll be going with a decent pipe. Either the S&S super street 2-1 or the Supertrapp Fatshot 2-1...

[rigidthumper]

With all the high tech gear why cant HD get it right. Dark horse GMR S&S do

They seem to not have issues with their products. How many flywheels are grenadeing with the stock/SE components?

[JSD]

RT are you saying Screaming Eagle cranks?

[JSD]

Finally got a dial gauge onto the pinion shaft to check my runout before proceeding any further, and it's a little more than I'd hoped for.

What's considered OK for the M8 motors?  Anything under .005" ?

My build is
114" cyl bored out to 4.125" (117")
11:1 static compression
Star Racing 30-30 cam

I'm expecting around 125TQ / 115HP...

Adam is that cam suitable for 11.1 as inlet closes at 20 degree. I think ?

[Adam76]

Finally got a dial gauge onto the pinion shaft to check my runout before proceeding any further, and it's a little more than I'd hoped for.

What's considered OK for the M8 motors?  Anything under .005" ?

My build is
114" cyl bored out to 4.125" (117")
11:1 static compression
Star Racing 30-30 cam

I'm expecting around 125TQ / 115HP...

Adam is that cam suitable for 11.1 as inlet closes at 20 degree. I think ?

Intake closes at 25* and Star Cams (George Bryce) advised me to run a .040" HG for a little breathing space.

[Ohio HD]

Intake closes at 25* and Star Cams (George Bryce) advised me to run a .040" HG for a little breathing space.

It'll have about 10.4:1 corrected compression, making an estimated 225ccp. Should be a very happy M8 motor.

[JSD]

Sorry Adam i miss heard Gorge on tech talk Tuesday im sure he said 20 but you're right 25 it is. 

[Ken R]

From what I've read, that is good, even when an S&S or Fueling oil pump and cam plate is to be used.  I think they're spec is no more than .005".  I've read that  .0095" is ok for stock or S.E. plate and pump.

I'm afraid to see mine before ordering new pump and cam plate; so I'll probably settle with the HD latest pump or maybe the S.E. pump and plate. 

[VernDiesel]

Adam did you ever get this motor put together and tuned?

[bobrk1]

Finally got a dial gauge onto the pinion shaft to check my runout before proceeding any further, and it's a little more than I'd hoped for.

What's considered OK for the M8 motors?  Anything under .005" ?

My build is
114" cyl bored out to 4.125" (117")
11:1 static compression
Star Racing 30-30 cam

I'm expecting around 125TQ / 115HP...

I stopped  by  the  dyno  shop a while  back  and  he  told  me  that  he  has  had  new bikes  with . 008 runout  them.

[JSD]

Shame on HD .

[SP33DY]

Take a look at the actual sizes and clearances involved. The runout H-D says is acceptable doesn't add up. It is excessive.

When you discuss "service limits" keep in mind that anything beyond that is dumpster time. You really don't want to reassemble an engine and send it down the road with parts are already at the limit of their servicable life. 

I have a new set of M-8 flywheels here. I measured the pinion where it goes through the hole in the camplate. It's 0.850"

H-D Factory Service Manual says the maximum service limit of the camplate crankshaft bore is 0.8545", which would be 0.0045" (four and one half thousandths inch) maximum clearance.

Maximum crankshaft roller bearing clearance is 0.005".

Yet it also says maximum runout measured in the case is 0.012" and measured in a stand is 0.005".

So they are trying to sell us on the idea that within clearances of 0.0045" and 0.005" a shaft can be happy running out at 0.012"!

I would say that they are selling naturally produced fertilizer!

[JSD]