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Engine basics => Engine set up tips => Topic started by: RknRusty on August 29, 2016, 06:32:51 PM

Title: fp.35 without a thust washer
Post by: RknRusty on August 29, 2016, 06:32:51 PM
Allen's thread reminded me of a question I have.
He called it a space washer, so I don't know which term is correct. I bolted an fp.35 onto my Twister and realized the thrust washer was missing. Probably borrowed for another engine and forgot. I would not use an electric starter without it, and the crank has very little float fore and aft float. Is there any reason it could damage the engine? All I can think of is if maybe the crank floats whenever it burps or shuts off, or when I'm flipping it to crank, causing contact between the drive pin and backplate. I've flown about 18 flights and plan to replace it before the next time, but I'm curious about it.
Thanks,
Rusty
Title: Re: fp.35 without a thust washer
Post by: mike londke on August 29, 2016, 07:09:19 PM
I wouldn't. We had a guy do that with an LA 15 He hit it with an electric starter and galled up the case and bushing pretty bad. Its there for a reason.
Title: Re: fp.35 without a thust washer
Post by: M Spencer on August 29, 2016, 09:22:12 PM
Clankety Clankety Clank , flicking the Iron FP 40 ive fitted to the MC 72 . Surprise Surprise , appears to be no thrust washer .
Though the cranks got say 3/4 or at least 1/2 mm freeplay , fore & aft . Another CHORE ; Find One . Runs ok though .
Title: Re: fp.35 without a thust washer
Post by: RandySmith on August 29, 2016, 10:04:40 PM
Yes it can and will damage it, first you are pushing aluminum to aluminum, that can gall the front od the case and the drive washer
Second it is possible you can contact the backplate with the crank pin / rod

Randy
Title: Re: fp.35 without a thust washer
Post by: RknRusty on August 29, 2016, 11:03:33 PM
Okay then, I'll put one on it before cranking it again.
Thanks,
Rusty
Title: Re: fp.35 without a thust washer
Post by: Steve Helmick on August 30, 2016, 07:31:54 PM
I'd expect one for a .40/.46LA would be fine, if that helps. Early in the LA saga, they said the LA crank was okay to replace the FP crank. That from Leonard Neuman. For ST .35C's, I always replaced the stock thrust washer with a thicker one...after having to remove the (now conical) stock thrust washer after a typical combat match. Maybe you could scout up a Gr.8 washer at the hardware store that you could make work without too much modification. Balance won't be a problem, due to the small revolving radius involved.  H^^ Steve