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Author Topic: Thrust washers  (Read 1573 times)

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Thrust washers
« on: May 06, 2015, 06:29:44 pm »
Had some 3120 crankshafts stroked and balanced by Crank Works in Arizona and they added thrust washers to the big end of the crank. In the past I've used bushings on the small end side to center the connecting rod, now I'm wondering if these are adequate for centering The rod?  Wide gap on the Wiseco piston boss...
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Re: Thrust washers
« Reply #1 on: May 06, 2015, 07:23:27 pm »
 You need to make bushings to use the wiseco piston , Wiseco told me to use 6061 T6 grade or better and I never had any trouble , I leave .010 clearance on the bushing to the piston
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Re: Thrust washers
« Reply #2 on: May 06, 2015, 11:55:16 pm »
Sounds good Ed, I'll use the 6061 bushings I've made. Appreciate the heads up...
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Re: Thrust washers
« Reply #3 on: May 07, 2015, 09:58:39 am »
Quote from: aclarke on May 06, 2015, 11:55:16 pm
Sounds good Ed, I'll use the 6061 bushings I've made. Appreciate the heads up...

I don't think you can use them with the trust washers on the bottom end. Almost all automotive pistons are located by the big end.
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Re: Thrust washers
« Reply #4 on: May 07, 2015, 10:50:46 am »
I've always made spacers for the small end when using the Wiseco pistons to keep the rod from riding on one side of the crank. Thrust washers are common on the m/c two stroke kart motors, but haven't seen them on saws?  If the rod is centered with thrust washers on the big end would putting them on the small end be a waste?  About a .180 gap on each side of the Wiseco piston with 084 rod.
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Re: Thrust washers
« Reply #5 on: May 07, 2015, 11:24:21 am »
I would think it would be a waste. Too tight and you might bind the rod, too loose and they'll never do anything.

I'd call the crank shop and see what they recommend.
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Re: Thrust washers
« Reply #6 on: May 07, 2015, 12:47:42 pm »
I'll see what they say. Thk
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Re: Thrust washers
« Reply #7 on: May 07, 2015, 01:00:20 pm »
Talked to Crank Works, they added thrust washers on the big end because the 084 rid is narrower than the 3120 rod. Helps keep the big end bearing from moving side to side. Makes sense, although the crank that Falicon made for me a few years back didn't have the thrust bearings.  Odd...
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Re: Thrust washers
« Reply #8 on: May 07, 2015, 03:57:32 pm »
So it sounds like the washers just restored the normal 084 rod bid end thrust clearance (which should be still decently large)? So you'll would still want to run spacers on the piston pin to locate the rod.
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Re: Thrust washers
« Reply #9 on: May 07, 2015, 04:50:24 pm »
Yo got it, the work order he read to me said : "Make custom thrust washers for narrower rod"  clearance is likely what Husky had on the oem crank I sent to them.  I'm gonna us the spacers I made for the wrist pin.  They still allow some lateral movement. 
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