Page 2 of 2

Re: Big end wear, what's your opinion?

Posted: Wed Feb 22, 2012 8:12 am
by ME 109
dougie wrote:Autosol, Simichrome, or Mother's Billet. All good.
'Spose yer right up to date on yer boot laces too! :P

Re: Big end wear, what's your opinion?

Posted: Wed Feb 22, 2012 9:33 am
by dougie
ME 109 wrote:
dougie wrote:Autosol, Simichrome, or Mother's Billet. All good.
'Spose yer right up to date on yer boot laces too! :P
If those companies' marketing people were smart, the would include a proper bootlace with their product. :idea:

Re: Big end wear, what's your opinion?

Posted: Wed Feb 22, 2012 10:36 am
by Deleted User 62
Thanks, now to see if I can find any of those products on this island...

Re: Big end wear, what's your opinion?

Posted: Wed Feb 22, 2012 12:31 pm
by Major Softie
Tim Shepherd wrote:Thanks, now to see if I can find any of those products on this island...
Tim, also check Napa stores for 3M Chrome and Metal Polish. Mother's Billet is not nearly as aggressive as the others we've mentioned, as it's designed for aluminum, but the 3M is the only easy to find product I've found that is really close to Simichrome (easy to find, as it's at Napa stores). Also way cheaper ($18 for a 10 oz. tub). 3M also sells a mag wheel polish, but I suspect it will be less effective on steel, just like the Mother's.

Re: Big end wear, what's your opinion?

Posted: Thu Feb 23, 2012 12:19 am
by Chuey
dougie wrote: If those companies' marketing people were smart, the would include a proper bootlace with their product. :idea:
Especially for Hawaii. No boot laces on flip flops.

Chuey

Re: Big end wear, what's your opinion?

Posted: Thu Feb 23, 2012 1:35 am
by mattcfish
I'd just slap some new bearings in.... the same # as the old. Your shells show normal wear for a bike with miles on it. I've seen way worse, with a crank that looked like new. If the crank isn't scored and is smooth to the finger nail I wouldn't bother going to the trouble of polishing. I'd just call it good, shells are relatively cheap and a new set will last a long time if oil pressure is good. If I were doing a full rebuild I would plastigauge, you shouldn't regrind these cranks
because of the hardening, so if the journals are out of round it's toast.

Re: Big end wear, what's your opinion?

Posted: Thu Feb 23, 2012 11:57 am
by the quinner
mattcfish wrote:I'd just slap some new bearings in.... the same # as the old. Your shells show normal wear for a bike with miles on it. I've seen way worse, with a crank that looked like new. If the crank isn't scored and is smooth to the finger nail I wouldn't bother going to the trouble of polishing. I'd just call it good, shells are relatively cheap and a new set will last a long time if oil pressure is good. If I were doing a full rebuild I would plastigauge, you shouldn't regrind these cranks
because of the hardening, so if the journals are out of round it's toast.
I agree. There is more potential damage to be done by introducing a gritty metal polish than there is benefit. (How are you going to prevent it from entering the oil galleys? Once it enters the galleys, do you think you will be able to flush it out? ...or, further IN? NOT worth risking for little to no gain.)

What I WOULD do is measure the con-rod's big end. They can and do ovalize...and, that's easy for a machinist to repair.

Re: Big end wear, what's your opinion?

Posted: Sat Feb 25, 2012 11:08 am
by John Falconer
Just clean scrupulously, then feel with your fingers around the journal for any metal transfer (which given what I can see I doubt you'll find). I would NOT polish the journal - the last thing you want there is an abrasive.

If there REALLY was rod knock I'd probably use Plastigage to double check that a new set of shells will be all you need but my expectation is that you'll be fine.

John

Re: Big end wear, what's your opinion?

Posted: Sat Feb 25, 2012 6:33 pm
by Motorhead
My Opinion is to use the red lapping tape from any machine shop after a accurate measure for size and roundness if round the tape will help see if the surface has any flake