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Twin Cam / Re: Torque Plates/Head TQ/Distortion ?
« Last post by FXDBI on Today at 03:52:03 PM »

Bob, my assertive friend.

Torque is a measure of rotational force, not bolt preload or bolt stretch.

The error in accuracy Iím referring to is not torque wrench accuracy, itís the accuracy of bolt preload. The torque method of preloading is inherently less accurate than the torque-turn method. For instance, picture a rusty nut and stud connection and then apply say 50 ft-lbs of torque to this connection.  The rotation and thus the bolt preload or stretch will be far less than when torqueing a clean and oiled connection to the same 50 ft-lbs.

Put another way, rotating a rusty connection 90 degrees may equate to 50 ft-lbs of torque, whereas this same 90 degrees of rotation may equate to only 20 ft-lbs of torque for a clean and oiled connection. Hence, the torque-turn method is a more accurate method of pre-loading or stretching the bolt than torque alone. 

The error percentages I quoted in a previous post were not made up.  Instead they were quoted directly from the 26th Edition of Machineryís Handbook on page 1,480.  Have a look for yourself.

Best,

Jason

Jason I fully understand bolt stretch and torque. The reason the engineering dept give a specific torque value to work with is so the applied force will provide adequate bolt stretch to reach the required clamping force for the application. This is done with clean fasteners not rusty old junk.  The OP was talking about torqueing heads on a Harley not working with rusty things.  Turbine studs are always heated turned so many degrees cooled and measured. Repeat until studs meet required measure stretch. They always told you to start at x number of foot pound torque and measure. Then someone did the math and gave the degrees to mark out before the heating began. Forty years ago it was a long time consuming job. Now 2 guys a side with a 1/2 million dollar induction heater for each pair and they do it in a shift.  Bob
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Twin Cam / Re: Torque Plates/Head TQ/Distortion ?
« Last post by Norton Commando on Today at 03:43:22 PM »
I always wondered about the torque plate deal too. I have checked cylinders with a .0001" bore gauge and they were a couple tenths of a thousand within round. If they were round without the plate, where do they end up with torque plates? :idunno:

Yes me too.

What the bore measures after it has been clamped between the head and block is the important measurement.  Within reason it doesn't matter what the cylinder measures in the non-loaded condition because it's not run/used in that condition.

Best,

Jason
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Thanks Steve, it came off to easy IMO to be powder, it had no smell like laquer.
I'll ask around. Thanks for pointing me in the right direction.
Pete.
If you find out anything let me know, I tried to re-coat a set some years ago, stripped them then polished them up, then cleaned them with acetone sprayed them and the paint did not stick. I don't remember if I used an acrylic lacquer or urethane it's been maybe fifteen years or more. In all honesty gave up and now just keep them polished, and getting tired of that so going chrome in the near future :doh:
I think clear powder would be interesting to see how clear or now they have a chrome powder.
You might look into that.
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EVO 1340 / Re: Cylinder Studs
« Last post by JW113 on Today at 03:09:42 PM »
Done it many times before. Just need to be careful to block the hole on the inside, and use a shop vac  hose at the hole when removing metal. That's the easy part. The sucky part is having to run (and ruin) a 3/8-16 die or two on the case end of the studs to recut the "locking" threads to regular threads so they will spin into the Time-Sert. The die gets so hot doing this that you literally can't touch it. Those studs are made of some pretty damn hard steel.

-JW
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Twin Cam / Re: Torque Plates/Head TQ/Distortion ?
« Last post by PoorUB on Today at 02:35:07 PM »
I always wondered about the torque plate deal too. I have checked cylinders with a .00001" bore gauge and they were a couple tenths of a thousand within round. If they were round without the plate, where do they end up with torque plates? :idunno:

While I agree that they typically one shift 1/4 to 1/2 thou when plated, where did you get that bore gauge? Best I've seen is 0.0001.

Sorry, fat fingers and a smart phone. One too many zeros! Fixed it.
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General / Re: Compensator shims
« Last post by Maddo Snr on Today at 02:23:41 PM »
Ron's spot-on. No point pre-loading a sacked out spring and no amount of pre-loading will fix scoured-out ramps. SE new ones are $275US if you look around.
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Shovel Head / Re: Looking for a Voltage Regulator
« Last post by billbuilds on Today at 02:22:23 PM »
     Are you using the stock regulator bracket? Are there star washers between it and the frame like the factory did? Are the frame bosses fairly clean where the mounting bolts thread in or are they covered with paint or powder coating? It's imperative that you have the voltage regulator grounded well. If you can wait a few more days go on line to Battery Mart and order a Big Crank for about $110 delivered to your door. Bill
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EVO 1340 / Re: Cylinder Studs
« Last post by turboprop on Today at 02:21:01 PM »
File this one under "as if I didn't expect this to happen".

I took my '92 for a spin up to Sacramento (130 miles each way) this weekend to get some CV jet needles. Other than having to split lanes for about 70 miles, was mostly uneventful. Coming home though I decided to take I-5 through the Central Valley. Was kinda hot, maybe 88deg, but the wind was horrendous. I was doing 75mph most of the way, and pretty hard into the throttle to hold speed. When I got closer to home and going up and over Altamont Pass, I had to drop to 4th and even 3rd a couple times, as the uphill and even heavier wind through the pass was a killer.

I had earplugs in, and I had hear what I thought was pinging under heavy throttle. So I took it a little easier until I got home. I went to fire it up this morning, and then realized that it was not pinging. I heard that very distinctive 'chirp-whistle' every time the rear cylinder would fire. Yep, chirpin' out past the head gasket, and a dollar to a dog turd says it pulled a cylinder stud.

One of the more charming things about those early 90's Evos, they seem to hold up find until you pull the heads off the first time. Which I did to this bike last year. A smart guy would pull all the studs out and Timesert the case. Being both stupid and lazy, I didn't, but knowing the whole time that someday I'd regret it. Guess that day is today.

So time to pull it all down and 'sert the case. Damn. One little thing that bothers me about this motor is a very noticeable vibration right at 2600rpm. Now the big question, since I'm gonna be in it that deep, pull the case apart and have it balanced? Which means the thing will be down for a month at best.
 :emsad:

-JW

Hmm, you would install a Time-Cert in the case without splitting it?
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General / Re: What coating is on Harley front fork?
« Last post by Maddo Snr on Today at 02:20:35 PM »
Thanks Steve, it came off to easy IMO to be powder, it had no smell like laquer.
I'll ask around. Thanks for pointing me in the right direction.
Pete.
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General / Re: Noise on pump power on...
« Last post by fbn ent on Today at 02:02:43 PM »
Just to finish this off.......Put some Marvel Mystery Oil in it like Ron suggested....Hasn't made any more than it's normal a little too loud sound since. Annnnnnd today the replacement highflow arrived  :doh:. I have a spare now  :teeth:
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