Author Topic: Sticky Rod  (Read 2226 times)

Offline RichardL

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Sticky Rod
« on: 19.02. 2014 03:36 »
Gents,

Even though I want to believe what you will see in the linked video is not a problem,  I've decided I'd better take some advice before lunging ahead on this belief. What is shown is a bit of stickiness in one rod after assembly on the crank. Somewhat late in the video I've mentioned that this is in a 40 deg. F. garage,  leading to thick assembly lube, but thaat doesn't account for the single-point stickiness and difference between the rods. After shooting this video, I took the rod apart to look for anything unusal and saw nothing. If you've got two minutes to check this out, I'd appreciate any comments.

Richard L.

 http://www.youtube.com/watch?v=G8lJ8zQnXFs

Offline bikerboy

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Re: Sticky Rod
« Reply #1 on: 19.02. 2014 04:00 »
Are you saying you just bolted those rods on the crank?

Offline RichardL

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Re: Sticky Rod
« Reply #2 on: 19.02. 2014 05:04 »
I bolted the rods on after checking journal diameters being within the 30-under spec, a tiny bit of polishing the journals and a dry fit for the plastigage measurement. I think the journal could be 0.0005" out of round. I suppose that if the rod bearings were also 0.0005" out of round there could be some snugging up. I am guessting that what is happening there is not total closing-up of the clearance, or it would seem a lot more like locking up than snugging up.

For those MAP billet rods, the ARP bolts are recommended to be tightened until they stretch 0.005", or, if unable to measure stretch, then 49 ft. lb. I think I did a fair job of measureing stretch and keeping them within the 49 ft. lb. 

Richard L.

Offline muskrat

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Re: Sticky Rod
« Reply #3 on: 19.02. 2014 13:10 »
G'day Richard.
49 ft/lb seems high to me, but I've never had beautiful rods like those (and shame on you for letting them fall onto the vice like that). If the rod and journal had corresponding out of roundness it would be free for a short distance then tight the rest of the way around.
Does the tight spot disappear if the bolts are done up to 40 ft/lb? Have you tried swapping the rods over?
Cheers 
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Offline Briz

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Re: Sticky Rod
« Reply #4 on: 19.02. 2014 14:16 »
That doesn't look too bad, especially given the low temperature. Try warming the rod very slightly and see if it makes a difference.
If it was a steel rod, I'd suggest giving the rod a few light hammer taps to seat the shells a bit. But be careful on ally rods! I too winced when I saw them dropping against something metal. *eek*

Online groily

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Re: Sticky Rod
« Reply #5 on: 19.02. 2014 14:48 »
Doesn't look too bad to my eyes either Richard - the rod seems to drop smoothly when more than a few degrees off vertical - but then I can't feel it like you can. It's not 'notchy' is it? Just an unlikely thought - could it just be there's a very slight impediment caused by almost imperceptible roughness around one of the oil drillings on the journal? (I've had to chamfer them a bit before now, but only usually after regrinds.)
I was always told that a set of perfect rods on perfect journals with perfect shells should just drop gently from off-the-vertical under their own weight with some lube in the shells, but usually I've found even after regrinds that they drop a bit more easily than that (like your other one - ouch again!). Have you given the thing a blast from a hair drier or hot air gun to see if it makes a difference?
The 49 ft lbs does seem high, to Musky's point, but similar brand new rods I fitted to a 650 AMC project motor last year specified 42 ft lbs - near-double the recommended torque for the original-style rods. If yours are like mine on that engine, you literally can't see any join- line between rod and cap when the things are torqued up. They make them to altogether different (higher) standards these days - I hope!
Good luck with the rest of the (re)build!
Bill

Offline RichardL

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Re: Sticky Rod
« Reply #6 on: 19.02. 2014 15:22 »
About hitting the vice, what was really getting hit were the soft jaws made up of a couple of old aluminum pie tins. I figured the pie tins are much softer than the rods, and where the hitting was happening was floppy anyway. Nevertheless, maybe I should have been more careful or, at least, not let you see me being uncareful.

Regarding swapping the rods, "Doh!" That's a good idea and I wish I had done it before assembling the cases. But hey, why should I have thought of that, just because it is just like basic audio troubleshooting, that is, swap the cables.

Richard L.

Offline RichardL

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Re: Sticky Rod
« Reply #7 on: 19.02. 2014 15:47 »
About the torque on ARP rod bolts, please see the attached instructions from MAP Cycle. Let me scream *warn*, 49 FT. LB. IS DEFINITELY TOO MUCH FOR STANDARD ROD BOLTS which we commonly think of as torquing at 22 to 26 ft. lb. depending on who you ask.

Bill, it's not "notchy". About the join line, you're right, it virtually disappears. The landings between cap and rod are serrated to fit together uniquely and with no possible sliding about. So, if it did happen to be due to some slight rise around the oil hole would it matter in longevity. (I hate it when I'm being lazy and don't want to separate the cases again, now that the cam gear, crank hob and worm drive are all mounted. But, hey, maybe a perfect opportunity to fix helicoils. Is it Fall yet?))


Muskie, The snug spot only disappeared on real loosening.
 
I'm goind to try some heat again, now that the garage is not freezing.

Richard L.


Online groily

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Re: Sticky Rod
« Reply #8 on: 19.02. 2014 17:51 »
If it were me .  . . and I know you're not me Richard, you're far more sensible  . . . I'd go with it as it is having got to where you are. I really don't think any harm will come of it.
Thanks for the 'cc' of the instructions that came with the rods - scary stuff about what happens if you don't do it like they say, but heck  . . . you did!
I went and bought some torque-measuring protractor device to go on a socket spanner (sorry, wrench) one time, to let me know when I'd hit x ft lbs (or metric unchristian equivalent) plus y degrees of tool-twist on top. Did all that - modern car engine iirc - and everything was fine. But it probably would have been just as fine if I hadn't bothered and hadn't bought this gizmo that I'll probably never ever use again.
I'd be very surprised if you had a problem with what you've done. A bit of care for the first few miles and I bet it will settle down beautifully. Not famous last words from a person about to be eviscerated by wiser souls, I hope!
Bill

Offline RichardL

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Re: Sticky Rod
« Reply #9 on: 19.02. 2014 18:46 »
Wellll, I didn't do it exactly as ARP recommends. I used my 2"-3" micrometer instead of this here device that they want you to use:

http://www.summitracing.com/parts/arp-100-9942?seid=srese1&gclid=COKOvLPp2LwCFStgMgodPxEASw

As for trying to get accurate torque, my torque wrench is the cheap type with a pointer. To calibrate it I measured from the center of the drive to the center of the handle. Using this measurement I  calculated (basic arithmetic) the weight that I would need to hang off the handle to generate 49 ft. Lb. Then, I filled a five-gallon bucket with the water weight I needed and hung that off the handle while the drive was clamped in the vise and recorded the reading off the graticule.

Sorry, it turned into more story than it's worth.

I'm looking forward to getting home and seeing where I stand with the warmer garage.

Richard L.

Offline chaterlea25

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Re: Sticky Rod
« Reply #10 on: 19.02. 2014 19:34 »
Hi Richard and All,
Like the other posts I believe that your rods will be fine, assuming that you followed MAP istructions and that the shell tangs were not causing an issue
WHen the offending rod is at the tight spot have you tried pulling it side to side (rocking)?
That may cure it ???
Also check  that theres the required side clearance on the journals

I have a MAP kit to go into the RGS project whenever time permits me to get at it, I had read the instructions, but seem to remember discussion on this "high" torque value before on the forum ????

Re torqing 5 times on NEW rod bolts seems weird to my way of thinking  *conf*
Most automotive head bolts torqued as Groily described are one use items

Now a 64,000 dollar question  *help*
I have another A10 engine on the to do list which has original BSA rods and a set of new ARP bolts
What proceedure and value do I use to torque these  *????* *????*

When I was a young teen I spent a lot of time working at the local car garage,
I can well remember reground cranks being fitted and having to lever the crank round to fit the rod caps
When rebuilt these cars often had  to be towed to get the engines to turn over and start *eek* *eek*
After a while running they would loosen up and be OK
At the time I thought this was "normal"  *eek*

Regards
John
1961 Super Rocket
1963 RGS (ongoing)

Offline bsa-bill

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Re: Sticky Rod
« Reply #11 on: 19.02. 2014 19:52 »
Quote
Re torquing 5 times on NEW rod bolts seems weird to my way of thinking

The last bolts I bought were a special batch made for a certain Mr Cheyne who some of you may know.(may even be here)
They had a higher torque figure than normal (sorry can't recall at the mo) and required to be torqued up to the same figure three times, also supplied with stretch measurement which I checked after torquing and found to be spot on
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Briz

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Re: Sticky Rod
« Reply #12 on: 19.02. 2014 20:25 »
The torquing method they recommend is normal for ARP fasteners. It says the same on the ARP site.
These, and most other billet rods use 3/8unf bolts. The stock ones are 5/16" cycle thread. Hence the different torque requirements.
If you can measure bolt-stretch, thats the best way. A mic is fine, you dont need the expensive dial tool.

Online Brian

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Re: Sticky Rod
« Reply #13 on: 19.02. 2014 20:40 »
John, ARP recommend 28 ft lbs for their bolts in standard BSA rods.

I tightened mine twice as per their recommendation and then the final time to the 28. The multiple tightening thing seems odd to me, I have never run across it before.

I had a few e-mails back and forth from ARP's tech department before they recommended the 28 lbs, the bolts came with a slip of paper recommending a much higher figure, cant remember exactly what it said but it was obviously way to high for std rods.

I did use loctite, against their recommendation.

Offline chaterlea25

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Re: Sticky Rod
« Reply #14 on: 19.02. 2014 21:20 »
Hi Briz, Brian
Thanks for the quick replies  *smiley4*
28 ft lbs it is then, I can cross check bolt stretch as well

Its taking a while longer than I thought to get back onto the workshop after my op on New Years eve
I can manage an hour or two per day this week but its still painful
The work load has backed up a lot  *sad2* but bugger all I can do about it

Cheers
John
1961 Super Rocket
1963 RGS (ongoing)