Crankshaft Run-out?

[dale3dale8]

I'am completely lost here. If the pushrods are out wouldn't all the valves be closed???

[Billy]

I may be wrong and it can be different for different cams but I don't believe anywhere in 720 degrees of crankshaft rotation are all 4 valve lifters completely on the base circle of their respected lobes.

I don't believe they have to be entirely on the base circle to avoid hitting a piston with your valve. You just don't want the valves to be wide open.

No they don't have to be completely on the base circle BUT how do you know how far they are opened??? How do you know for SURE the valves are safe???

You guys can play Russian Roulette all you want but after you fruk up once and have to buy valves and guides, you will have learned the hard way.

[Billy]

I'am completely lost here. If the pushrods are out wouldn't all the valves be closed???

Yes.

[Jeepster]

I have a Tech Tip from Harley on how to check crank runout. It's too large to post. If any one is interested PM me and I'll send it.

[KingofCubes]

I'm about to undertake some winter projects on my 2000 TC88 (bored to 96 with gear drive cams). Before I begin, I want to measure crankshaft runout just to see how things are. Am I safe to assume that in order to get an accurate reading I should remove the cam gears and shorten the pushrods in order to avoid outside interference so the crank will turn freely?
Thanks.

If it were mine I would pull the cam plate clear off, inspect the oil pump, the pinion bushing to shaft fit, and measure the runout both ways. I have seen new cam plates with bushing clearances as much as .0025" which I believe is unacceptable.

[Sonny S.]

I do already have a decent idea; it doesn't sound like anything. If I didn't know I had gear drive, I couldn't tell it from the sound. But before I begin any top end stuff, I wanted to make sure the bottom end was okay. Also, this weather is making me crazy, so I do things I can't explain.

I'm about to undertake some winter projects on my 2000 TC88 (bored to 96 with gear drive cams). Before I begin, I want to measure crankshaft runout just to see how things are. Am I safe to assume that in order to get an accurate reading I should remove the cam gears and shorten the pushrods in order to avoid outside interference so the crank will turn freely?
Thanks.

If it were mine I would pull the cam plate clear off, inspect the oil pump, the pinion bushing to shaft fit, and measure the runout both ways. I have seen new cam plates with bushing clearances as much as .0025" which I believe is unacceptable.

If it were mine I would ...leave it alone ! 
With a gear drive, if you had excess runout or even if the backlash was improperly set.. you'd know it

[Faast Ed]

No they don't have to be completely on the base circle BUT how do you know how far they are opened??? How do you know for SURE the valves are safe???

You guys can play Russian Roulette all you want but after you fruk up once and have to buy valves and guides, you will have learned the hard way.

Being off the lobe gives you a pretty good idea, considering the valve has do be darn near on the peak to break the plane and get near the valve relief in your piston.
Also, I prefer running stock pushrods, or perfect fit (where applicable) rather than adjustables. I would have to pull my rockers to check run-out if I wanted to unload the pushrods.
That would discourage one from even checking runout.

Being well off the peak is a fairly safe bet, in my opinion.

[Jeffd]

If it were mine I would ...leave it alone ! 
With a gear drive, if you had excess runout or even if the backlash was improperly set.. you'd know it
[/quote]

[barny7655]

I will stress this site has some good information , but feel in this topic there is to much miss informed info , i am a motor mechanic, GMH, and will stress that no way will a harley motor turn over several revs to do run out with push rods intact with the pinion or cam sprocket removed with out colliding with open valves,held open by the cam shafts ,tell me if there is a stage where all valves are closed in the cam timming on both clyinders with push rods installed?or that a harley TC is free spinning?the push rods will have to be removed , or releaved so there is no contact with the top of the lobes on both pots,this will insure all valves are shut, please seek your  mechanic on this issue,i would hate to see this causing major mechanical damage to motor, and a disgrunted wife,and a blame to members on this site, cheers Barny

[FXDBI]

 Thanks Jeepster for the Tech-Tip,ex cellant PDF with video. Shows how to to both right and left side crank runouts. They show to do the runout check with the cam plate removed totally,and run the dial on the shaft where it goes thru the cam plate. Left side they remove the compensator and do it off the splines. Very well explained, and the video shows it exactally. Maybe we could get it posted in the tech tips here.....Bob

[Jeepster]

It would be great to put in the Tech Tips Section but how is that done? The file is 8MB

[Faast Ed]

Barney,
I am one of those "misinformed" who has done it at least a 1/2 dozen times with no ill effects.  The valve don't have to be "all the way" closed, to keep from hitting your piston.
I just make sure I am off the peaks of all 4 lobes.

[barny7655]

Faast Ed your been lucky in knowing what your doing, in general terms you may be running mild motors ect,pistons have a bearing on the piston the valve clearance ,also as to the lift of the cams, you know what you have been doing to not cause this problem in your motor, not as a general rule to all others ,there are alot of short cuts in the motor industry ,but to share some of them on here i would not unless the motor was completely standard,which not two HDs are the same,the speed at which the motor would turn from the rear wheel being turned even slowly can cause a bent valve at the angle the piston hits the open valve,no offence to you Faast Ed,its the others i worry about as a general  rule to protect, our most pride and joy , our HD , cheers Barny

[Faast Ed]

You have a very good point Barney. It's true that mine is a mild build with flat tops and the same might not apply in other circumstances.

Cheers to you for protecting others from getting into a bind.  I learned from this string as well!

(bTW:  No offense taken)

[Faast Ed]

I think a very important thing that a newbie can miss, is getting all four lifters off the peak of the lobes. This can be a bit tricky and it's hard to see all the lobes without putting good effort into it.  There is another member of this board that we did the same method while checking his runout, maybe he'll chime in.

Either way, I see Barney's point and he means well.  Historically, he's not been one to bust our chops just to embarrass us.
Besides, there are likely motor combo's out there that could get tricky using our method.

This is not a war of ego's.  We all have our methods that we feel safest with.

[WVULTRA]

Since the original post is upgrading to GD Cams, I'm wondering why one would want to check the crank run-out with the valve train intact.  Is there any load placed on the crankshaft gear while driving the rear cam sprocket to actually increase the crank's runout?

If not, then IMO removing/cutting the pushrods would be much more efficient than attempting to line up the cams to prevent interaction before pulling the CS gear.

For my own curiosity, I'll be cutting the pushrods then checking the r-o with the cam plate installed then with it/cams removed.  I'm thinking any difference will be evident during inspection of the cam plate bushing and oil pump.

Just some thoughts; and please correct me if I'm way off base.

[Faast Ed]

Strictly speaking of my own situation, I avoid adjustable pushrods when possible, so checking the runout would become a much bigger project having to remove the rockers (fuel tank and all) simply to check my runout. If I am good to go with the cam plate on, I don't see a need to go any further. However, if I am swapping cams anyway, then I'd do a second check with the plate off.

Not that this answers your GD related question. I hope someone jumps in on that.

[longshooter]

Barny .....      

Fasted... Valve reliefs are not meant to provide clearance at or near the highest lobe lift. They are there to provide clearance with the piston at or near TDC and you have a valve chasing the piston or the piston chasing a valve. Most TDC lift measurements of these cams is quite small compared
to total lift. It's a dangerous game not to pull or shorten pushrods with the valvetrain disconnected and rolling the engine over.

It is undoubtedly much more work with stock or perfect fit pushrods and that is the main reason I use adjustables in my builds.

Not looking for a pissing contest here,just would hate to see damage done that could have been prevented.

longshooter

[Ratfade]

Okay; I asked the original question, and I really didn't expect the thread to run this long; but I must say I've learned quite a bit from it. Just for the record, I already have gear drive cams, and I just wanted to check the run out to see how things are given that I have over 80,000 miles on the bike. I expect to find very little run out (<.003) since the bike's an early model TC. Also, since the pushrods are adjustable, it's easy enough to go ahead and remove them, so that's what I've decided to do.
I'll probably do this later in the week or on the weekend, and I'll report the results just to bring this thread to a happy conclusion.

[barny7655]

Ratfade, your thread has been a good one in teaching us  about a topic that alot of us will do in the future ,let us know how it works out and post the runout specs and the time it took you from start to finish , that will give us all a guide as to time,and how you did it from scratch ,as some of us might print the page as a reference,some simple posts can lead to good factual information that will be past on to others, cheers Barny

[Faast Ed]

All please excuse my ignorance

I'll excuse you, if you excuse me,.....    LOL

[Bakon]

Anyone got a map because I got lost.

[Billy]

^