Author Topic: My SRM conrod bolt nuts touch the casing and won't let the crank turn!  (Read 5489 times)

Offline muskrat

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G'day jjbsa,
Didn't make them for the 500. Now it's an A10 and 10.5:1 I still through bolt the thick flange barrels. Once (or trice) bitten.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline MG

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Richard, I'm really disappointed with you.  *sad*
I wrote a serious word of warning about enlarging the cutouts in my engine rebuild thread here:
http://www.a7a10.net/forum/index.php/topic,3195.0.html

Do I have to assume you are not reading my posts with the necessary attention and wholeheartedness???

*Lol*, just kidding. But yes, SRM, and obviously also Thunder rods are a bit wider than the original ones and will indeed hit the spigots (I think Thunder Engineering make them for SRM anyway, but memory might be misleading me now).
So watch out there!!!!!
This is another case for SRM to maybe add a small note on delivery (hint hint nudge nudge).

Best wishes, Markus

P.S. Welcome Cherry Tree!
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Online RichardL

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I, too, am disappointed in me. I will turn in my key to the librarian's water closet and my personal copy of "Guide to the Dewey Decimal Classification System" autographed by Melvil Dewey and handed down through my family for generations.

I have to say, I missed or don't recall your post. If, indeed, I did I see it, I should have given my compliments. Very nice job.

Now, the coincidental and really bad thing is that I have those same rods and knew nothing of widening the notches in the skirts. I got the rods as no-charge replacements for my original rods that the machine shop screwed up by honing out the big-end O.D. without milling down the   landings. Because of this circuitous means of acquisition, I did not get any warning about the skirts (as noted on the mapcycle.com website, I just learned). On the other hand, I haven't heard any banging in the bottom end (restraint boys!), nor has the engine blown up in the 2000 or so miles since the rebuild. It's either luck or trouble on the horizon. I don't think I need to dismantle to find out.

I also appreciated your balancing charts and will use a translator when I have time to evaluate the data. It's possible that I flew over the balancing discussion because the same awkward shop that screwed up the rods was also charged with static balancing my crank and I would have figurered "it's all too late". The fact is, I have no way of knowing if they actually balanced it or forgot about it. Even if they balanced it, it would have been with my old rods, not the billet replacements. The good news is, I'm loving the way my bike is riding right now. Uh oh, jinxed myself, here comes the curse.

Richard L.

   

Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline MG

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 *lol*
Don't be too hard on yourself, it's all forgotten.  *beer*
Thanks for the kind words, the engine is still going strong, so t'was a successful operation.

I've come across a wide variety of these slots, depending on the machinist or his beer consumption the day before probably. Some are bigger, some are smaller, and sometimes they won't even be aligned exactly along the centre line of the spigot.
So you might be lucky to have a set that allows the rods to move freely, machined after closing day of the pubs in Small Heath. If there wasn't any noise when turning the engine over you will probably be okay, fingers crossed.
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria