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Author Topic: update on crank balancing  (Read 12281 times)

xyzer

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Re: update on crank balancing
« Reply #15 on: April 13, 2007, 02:40:00 PM »
Chris,
"Input"....anytime it's cheap...lol. First I don't balance engines for a living... I'm just a tool and die maker...I went through the same things you are except I had a 6/1 and you have a twin internaly balanced...big difference but still in the same arena. I found even the guys that balance engines for a living don't know what the correct % for yours or mine should be, and there lies the problem.  They know the best % for smallblocks, bigblocks, Harleys, and you know a guy that knows continentals, and such. I don't believe your engine will be 62% If I remember right it has aluminum pistons and turns a higher RPM. You need a guy that has delt with any engines with a slight resemblence to yours that has been through it and know the answer to a ballpark %. I was thinking maybe Wayne could hook you up with the guy in Tampa. That would be where I would be headed first. In the mean time as I mentioned I would start to add weight to my bobweight and see if it starts to improve the situation. The factory wasn't perfect but will get you in the ballpark of the correct % and tell you if it needs more on the bob weight. I have a cell phone with tons of rollover minutes I'll never use just e-mail your number and I'll try and really confuse you...lol!
Dave
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cschuerm

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Re: update on crank balancing
« Reply #16 on: April 27, 2007, 02:13:28 AM »
Just a quick update for the curious.  Ran the re-assembled engine for the first time tonight since the "big teardown(tm)".
The balance work on the flywheels and rod/piston assys paid off better than I could have hoped for.  I really hadn't anticipated a great reduction in vibration since I couldn't increase the counterweight mass, but just getting the flywheels well balanced and the rods and pistons matched up made a dramatic difference.  The engine ran very smoothly just sitting on the floor!
Anyway, there's a bit of hope for those without any fancy balancing equipment.  Just get the flywheels balanced and match up your rods and pistons and you *may* find good improvments.

One week to go before the engine show and I still have a lot to do.....

cheers,
Chris

xyzer

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Re: update on crank balancing
« Reply #17 on: April 27, 2007, 05:42:18 AM »
Chris,
Good to hear!
Dave
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okiezeke

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Re: update on crank balancing
« Reply #18 on: April 27, 2007, 08:42:39 PM »
Chris,
Great work.  Glad to hear there's hope for us shadetree-types.
Zeke
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rsnapper

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Re: update on crank balancing
« Reply #19 on: April 28, 2007, 12:49:08 PM »
Glad to hear you got it running smoothly. What did you end up doing to the crankshaft? I've got my 28/2 flywheels in the shop for balancing right now. The pistons and rods are close to being the same weights as assemblies, I haven't disassembled them yet.

Thanks,

Rick

Ulysses

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Re: update on crank balancing
« Reply #20 on: April 30, 2007, 11:40:20 PM »
    That is wonderful news. I also have my crank, rods, pistons and flywheels in a balancing shop right now. I can hardly wait to hear what they have to say about them. They should be getting to them this week.

    My engine is a 24/2 so I am likely to run into the same problems with the counterweights. Thank you for posting this information. I can feed it back to the shop and it sure makes me feel better knowing that I may be able to get by without making new counterweights out of uranium.

                                                                                                                    Bruce
Powerline 24/2 in a million pieces

xyzer

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Re: update on crank balancing
« Reply #21 on: May 01, 2007, 07:19:57 AM »
Bruce,
Let us know what % they used for the bobweights. Chris tried 20% and it wanted to crawl out of the machine. He felt the counterweight was light. But after reassembly it does fine.  It would be nice to know what the real % should be. The flywheel balance are critical for the twins and with no counterweight on them much easier to correct, but that still leaves the crank counterweights you have to deal with. There is a magic balance % that would be nice to know.
Dave
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kltrider

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Re: update on crank balancing
« Reply #22 on: May 01, 2007, 05:49:08 PM »
I still haven't gotten my twin to the point where I need to take it to the shop where it will be balanced. Been focusing on other things. I should have some news soon, and I will post soonest.

evilpsych

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Re: update on crank balancing
« Reply #23 on: May 02, 2007, 05:12:25 PM »
it seems it would have been cheaper to get a custom centramatic-style balancer machined. Oil-filled, and then filled with lead-filled ball bearings somewhere in the half-lb per ball range.

I've got a good vision of the balancer in my mind, such that anyone with a lathe or access to a machine-shop could make one or have a pair made, which would then be simply bolted to the flywheels.

Stan

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Re: update on crank balancing
« Reply #24 on: May 02, 2007, 10:52:47 PM »
There was a whole thread devoted to this topic last year I think...a search would probably turn it up.
Stan

Ulysses

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Re: update on crank balancing
« Reply #25 on: May 05, 2007, 07:19:13 AM »
   Dave,

   Any information that I can develop will be posted. The shop that will be doing the work is a good one and they have worked on Lister engines before. They will be getting to my stuff soon and begin to generate numbers for me relating to runout and clearances. From what I have been able to gather I cannot offer them any guidance on the correct percentage for the bobweights. They will either have their own ideas or they will have to experiment.

   It will be very interesting I am sure.

                                                                                                                  Bruce

   

   
Powerline 24/2 in a million pieces