This engine rebuild is getting expensive

1973x75 · Nov 5, 2021

Is it necessary to get new connecting rod bolts and crank shaft hardware or can the old ones be reused?

Richard Tool · Nov 5, 2021

1973x75 said:
Is it necessary to get new connecting rod bolts and crank shaft hardware or can the old ones be reused?

Get new - they are a lot cheaper then the cost if they fail .

oldmikew · Nov 5, 2021

Difficult one ... you MUST fit new nuts beyond that its a toss up.. The existing connecting rod bolts might be less likely to fail than new ones -assuming the threads have not stretched

olympus · Nov 5, 2021

The problem you have is how many previous owners have had it apart and said the same, overtightened the nuts fitted bolts from other engines etc
If you've had the machine from new then I'd re use the bolts and nuts in every other scenario i would replace

concours · Nov 5, 2021

The biggest problem I had answering that was.... parts supply of questionable quality. I've had MANY "new" parts that were not fit for purpose.

1973x75 · Nov 5, 2021

If I were to get new hardware, I would think Andover Norton’s suppliers should have good quality control. Are there any other sources that could be recommended?

Richard Tool · Nov 5, 2021

1973x75 said:
If I were to get new hardware, I would think Andover Norton’s suppliers should have good quality control. Are there any other sources that could be recommended?

Stick with Andover - their claim is everything is made to original spec. They are currently out of con rod nuts however . I am not a wealthy guy but it seems we are talking about two hundred bucks - seem like money well spent for peace of mind.

baz · Nov 5, 2021

1973x75 said:
Is it necessary to get new connecting rod bolts and crank shaft hardware or can the old ones be reused?

If you do replace the con rod bolts be careful on assembly that you don't scrape a shaving of the aluminium con rod under the head of the bolt that will affect the torque setting
I've seen pictures of this somewhere , maybe on the norvil website ?

oldmikew · Nov 5, 2021

olympus said:
The problem you have is how many previous owners have had it apart and said the same, overtightened the nuts fitted bolts from other engines etc
If you've had the machine from new then I'd re use the bolts and nuts in every other scenario i would replace

Even if the latter and the bolts are retained.... replace the nuts

Torontonian · Nov 5, 2021

oldmikew said:
Even if the latter and the bolts are retained.... replace the nuts

The con rod nuts are a one use only. You can see the slots cut into them as special one use only stretch items. So be it.

ashman · Nov 5, 2021

I have never replaced con rod bolts, nuts yes very important to do so, I have rebuilt a few Norton motors my own and mates without replacing the CR bolts and they are all still going, but if you want to its up to you really and really its only a small price compared to a fully rebuilt motor, all motor rebuilds cost money to do right and our Norton motors are cheaper to rebuild compared to other motors, it all depends what you are going to put in the motors that add up the high prices, there are so many goodies these days compared to what was around back in the early 80s when I built my 850 Featherbed and everything was so much cheaper to do, but adding all those good bits and pieces do add to the cost, how deep are your pockets, but you can still rebuild your motor on the cheap and still be reliable without things going bang.

Lineslinger · Nov 6, 2021

1973x75 said:
If I were to get new hardware, I would think Andover Norton’s suppliers should have good quality control. Are there any other sources that could be recommended?

ARP or CNW

850commando · Nov 6, 2021

When I was building the basketcase, there was some discussion about replacement studs and such. I can't remember if someone did some pull tests, but i'd stick with the ones that came out and just replace the nuts see ashman above. if you are concerned then take them to a shop and have them do a NDT on them.

kommando · Nov 6, 2021

I replaced the crank studs and nuts as they showed evidence of plastic deformation, would have used them if they had not been stretched. Kept the con rod bolts but new nuts.

seattle##gs · Nov 6, 2021

I know I'm stepping into a minefield but I like to use red loctite on rod bolts and nuts.

Fast Eddie · Nov 6, 2021

seattle##gs said:
I know I'm stepping into a minefield but I like to use red loctite on rod bolts and nuts.

So did Mick Hemmings IIRC…

ashman · Nov 6, 2021

seattle##gs said:
I know I'm stepping into a minefield but I like to use red loctite on rod bolts and nuts.

I have never had a conrod nut come lose, they are designed to be used once and if done to specs should never have problems be more chances of a blown conrod than anything.

concours · Nov 7, 2021

ashman said:
I have never had a conrod nut come lose, they are designed to be used once and if done to specs should never have problems be more chances of a blown conrod than anything.

And the "blown conrod" failure scenario begins with conrod bearing failure, and the broken conrod comes after the seizure.

ashman · Nov 7, 2021

I have never suffered them problems.

ZFD · Nov 8, 2021

The big end nuts will be back in stock shortly. The current stock is being used to assemble new conrods. But more nuts were already on order.

This engine rebuild is getting expensive

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