Author Topic: ARP rod bolts  (Read 2095 times)

Offline coater87

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Re: ARP rod bolts
« Reply #15 on: 04.03. 2017 13:42 »
 OK,

 Called ARP tech support before I modified the nuts. They said the nut will be fine as long as you dont remove so much material that the nut splits. This must be a common problem they hear. There was no way I needed to remove that much.

 Cut these with a carbide insert. the material didnt seem that hard, I think I could have done it with high speed steel but I did not try it.

 I set the compound to 30 degrees and just chanfered the outside of the nut.

 The crank spins just fine now.

 Lee
Central Wisconsin in the U.S.

Online muskrat

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Re: ARP rod bolts
« Reply #16 on: 04.03. 2017 20:11 »
G'day Lee. You need about 6othou (1.5mm) clearance of rod and cases. You'd be surprised how much the crank flexes. I only had this problem once so I just ground off the offending side of the nut.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, .
Australia
Muskys Plunger A7

Offline jjbsa

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Re: ARP rod bolts
« Reply #17 on: 04.03. 2017 20:50 »
Hi John  (Chaterlea) and others,

Thanks for your earlier notification of the suspect centre to centre distance on the R&R rods.  I had occasion to go looking around inside my RGS (suspected low oil pressure which turned out to be caused by a pressure build-up in the body of the glycerine-filled oil pressure gauge, meaning that with 70psi oil pressure, it showed 25 psi!  Rectified by pulling out the little rubber cap holding the glycerine in and then replacing it.....

While I was at it, I measured the A10 R&R rods and they are about 28 thou inch too long.  With 9:1 pistons this made the bike pink a bit around 3,500 rpm.  I put in one of my (Ebor Bikes) 0.7mm compression plates and this seems to have fixed the problem.

Cheers,

Jon

Offline chaterlea25

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Re: ARP rod bolts
« Reply #18 on: 07.03. 2017 23:58 »
Hi JJ
Quote
Rectified by pulling out the little rubber cap holding the glycerine in and then replacing it.

Aha  *ex* rookie mistake  *smile*
In industry the rubber bung is removed permanently on installation
I dont know how the gauge would fare opened on a bike though  *????* *????*

John
1961 Super Rocket
1963 RGS (ongoing)