As someone who checks ebay several times a day for parts, I can attest to bikes being parted out. On any day there are 2 or 3 commandos in pieces being offered, plus parts from numerous others. I myself have had to resort to parting out my 3rd bike because it is not selling as a whole project. I have also parted out a GSXR750 recently, and in most cases bikes are worth more as parts.
Blown Con Rod
- Thread starter ctsbc
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ZFD said:
I suppose in the black helicopter conspiracy theory spirit of things the above statement makes the case for financial motive but if you carefully read Norvil's article on subject rods, they are not telling people to "throw out a perfectly good part"; they are 1.) stating they will not continue a rebuild if the engine is opened and found to contain the "D" rods (presumably to maintain the good name of Norvil) and 2.) conveying their understanding performance of select components ("D" conrods and pirated con rod bolts) based on years of experience as I am reasonably sure they have way more experience than most individuals on this list.
I ask why did Norvil not select the crankshaft or cast iron flywheel as a "need to replace item" as opposed to the "D" connecting rod? It seems like the Norton crankshaft failures are legendary.
I suppose if I were faced with a rebuild and found the "D" rod I would at least call Norvil to gain better insight to the matter and gain some understanding of their experiences and make an informed decision. I cannot just write it off to profit motive on the part of one service and parts supplier with an excellent reputation.
Besides, Norton con rods make neat key fobs.
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stockie2 said:
The alloy rods do fatigue and brake and the aftermarket alloy rods are heavier on the small end (120 grams) and vibrate more than JS bushless Carrillo rods. None of the after market alloy rods are forged and they use cheaper inferior bolts compared to the JS Carrillos. There have been a lot of failures of the aftermarket alloy types. I recently got an email from the "Yelllow Peril team" in France because their aftermarket alloy rods failed and blew threw the cases dumping oil on the rear tire and disaster. I really tried hard to come out with an Alloy rod but the risk is just too high and failure at speed can be life threatening. Doug M can tell you about stock rods failing at Daytona. The JS Carrillos have been subjected to 155HP at Bonnevile by a 920cc on Nitros and there have been no failures. I think they are cheaper than new stock items (OEM type).
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Tintin said:
Tim! My great and worthy opponent. Didn't you know, everyone is entitled to my opinion.
When a vendor that I consider reputable goes on line to state a problem with a type of connecting rod, I take notice. I have never broken a Norton connecting rod and I have never heard of anybody else breaking a Norton connecting rod (other than Steve Maney with the 1,007cc engine or broken rods as collateral damage or broken rod bolts) so what Norvil presents is relatively new information for me and does not seem to fit. It could simply be that the later model rods that Norvil alledges to be faulty have not made it into race bikes and spare parts bins ready for recycle into a race bike.
I have personnaly broken a few Norton crankshafts under race conditions and have personal knowledge of others who have broken Norton crankshafts under race conditions. I literally grenaded a cast iron flywheel at Mid Ohio, I probably contributed to the demise of Cal Lewis's grenaded Norton flywheel at Gingerman raceway, I was on the starting line behind Jim Comstock's hyerpkinetic Norton when he grenaded his Norton flywheel at Grattan raceway, I broke a Norton crankshaft journal at Sears Point California and I broke a Norton crnkashaft main journal on my last race of the season at Talladega. There are numerous others I have heard of. There is a bit of a history there and one needs to look at each particular circumstance. But connecting rods - none, so that is why I am sitting on the fence and listening (reading) and conducting some critical thinking.
Dances with Shrapnel said:
Did you read the explanation?
Honestly, I've seen a lot of b*llsh*t written on the net (and most likely contributed to that fact as well) but the "brakes at the invisible stamping line" stuff is amazing. Micro precision forging, cool. I'd love to see the dies.
Regarding the crankshafts: We don't disagree on grenading cast iron flywheels at all - it is just the counterweight distribution, and I spoke to our calculation dept. lead engineer. Pretty interesting what he said. Basically nothing you'd find using anything else but a FEA due to the complexity. If time permits I'll look into this deeper. Until then I simply resist the urge to become subjugated. :mrgreen:
Tim
When I blew my engine in 02 due to a broken rod bolt with less than 3000 miles on it. I've never found out if this was a genuine part but it did come from a well known midlands supplier in an engine rebuild 'kit'. I don't have a good pic of it for AN to determine if it was a non AN part and it was before present ownership.
In a face to face when I was complaining about the bolt and considering the new AN forgings it was explained to me that the 'D' rod forging was done in two goes because the forging tool was not big enough to handle the whole rod! Apparently the majority of the rod was forged and then the rod moved and hit again to forge the small end. A witness line was therefore left about 3/4" below the small end. I can't even imagine what Norton were doing when the earlier rods were successfully forged in one go. It does seem like a lot of bol***ks but on the other hand there is a surface defect on these rods. What it is who knows.
Keith1069 said:
Basically that is saying there where two dies involved. Costs as a reason for this is ridiculous in its own right. And forging steps in direct neighborhood to each other, yea right, brilliant idea.
An "invisible" witness line? 8)
Exactement. Seems completely weird and could only be explained by a desperate repair measure, something like getting the best of two damaged or worn out dies to save the cost of new ones.
Is it there? From the pic on the Norvil homepage I can't tell. Unfortunately my two 850 sets I have in the dungeon are too old.
I'd love to have the two-dies theory confirmed first-hand.
Tim
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I am quite happy to contact Robert M. Reynolds, Norton's chief buyer for over three decades, about this, but suspect a) the whole story is a fairytale but b) this may have been before his time anyway because he moved into purchasing only around 1971/72. Then again, I admit I don't know when those rods were issued.
In racing, in those 15 seasons, we had two crank failures- first broke right, this year left. No flywheel failures but then we don't rev much over 7 as peak power is at just under 7. Never had a conrod go (standard production conrods re-used both times), no collateral damage at all in fact. Both times it happened to my son Tim who is very attentive and noticed straight away each time something was wrong and stopped the engine. This second time everything went back into the engine bar that l.h. crank piece, including the- often ridiculed as "crap"- GPM pistons that looked like new (higher compression on this engine but same manufacturer as Andover Norton's standard pistons for Commandos). Bike has since done one meeting with two races- your's truly at the helm.
Joe Seifert
In racing, in those 15 seasons, we had two crank failures- first broke right, this year left. No flywheel failures but then we don't rev much over 7 as peak power is at just under 7. Never had a conrod go (standard production conrods re-used both times), no collateral damage at all in fact. Both times it happened to my son Tim who is very attentive and noticed straight away each time something was wrong and stopped the engine. This second time everything went back into the engine bar that l.h. crank piece, including the- often ridiculed as "crap"- GPM pistons that looked like new (higher compression on this engine but same manufacturer as Andover Norton's standard pistons for Commandos). Bike has since done one meeting with two races- your's truly at the helm.
Joe Seifert
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Chris,
We only race locally (the "Grab the Flag" series) and, quite frankly, the only bike I am really good on is my Garden Gate Manx. I think the CRMCC would lap me on the Commando very quickly. In Rijeka this year I was but 2 seconds per lap faster on the Commando, which is riduculous- the Manx, in relation, has no power, no top speed, no brakes and no chassis. Give it to anybody else and he'd easily lap 5-10 seconds faster on the Commando!
Tim is faster than me, but fell off a few times recently which has made him become slower- these youngsters have a brain and use it, something I tend to forget on the track. Brains are bad, take it out at the start line and replace it with aggession. Unfortunately, this only works on the old Manx for me.
We only race locally (the "Grab the Flag" series) and, quite frankly, the only bike I am really good on is my Garden Gate Manx. I think the CRMCC would lap me on the Commando very quickly. In Rijeka this year I was but 2 seconds per lap faster on the Commando, which is riduculous- the Manx, in relation, has no power, no top speed, no brakes and no chassis. Give it to anybody else and he'd easily lap 5-10 seconds faster on the Commando!
Tim is faster than me, but fell off a few times recently which has made him become slower- these youngsters have a brain and use it, something I tend to forget on the track. Brains are bad, take it out at the start line and replace it with aggession. Unfortunately, this only works on the old Manx for me.
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Tintin said:
You ask: "Did you read the explanation?" Without a doubt I read it. You apparently have passion and knowledge but please spare us your drama.
I read but did not delve into Norvil's assessment of the cause of failure, maybe they are wrong about it breaking at some alleged stamping line. What captures my attention is that they claim to see a pattern of breakage. That got my attention. Are you also disputing Norvil's observation of a pattern of breakage? If so, please share as to why.
Norvil made a good case against "pirated" connecting rod bolts that in my opinion, holds water (nobody seems to be disputing their assessment of the bolts) but quite honestly I am not clear on what they are describing on the alleged flaw in manufacture of the "D" rods (the cause). Maybe it is, as you say "b*llsh*t".
As for the crankshaft thread, it is more than the flywheel failure, it includes failures of the rod and main journal. And we can certainly agree to disagree on the distribution of counter weights. The statement "Basically nothing you'd find using anything else but a FEA due to the complexity." is pure myopia. How do airplanes fly and older bridges stand without "FEA" - give us a break here. Unless I have taken that comment out of context, in my opinion, your "calculation department (including lead engineer) need to step away from their work stations, get outside and smell the exhaust fumes a little more often. A proper FEA will gain the users insight and yes possibly point to enhancements.
I had the pleasure of meeting Professor Gordon Blair several years ago. He was gracious enough to assist us in the development of our ultra short stroke 500CC Norton Twin. He was scholarly yet pragmatic. He shared his experience as a young engineer describing work at Harlan and Wolf in developing marine engine cam profiles with log tables and huge wall charts. That is how it was done in the day. There was life and insight and knowledge before FEA. Again I emphasize that FEA and computational models are the cats pajamas when put together and calibrated with insight.
I like your idea of conducting numerical modeling to test your theory on weight distribution. Rather than trying to model a Norton crankshaft I suppose it might be easier and faster to develop a simple Norton crankshaft analog in which you could test your theory of bob wieght distribution. I am open to new insight based on analysis.
Dances with Shrapnel said:
Little drama involved there - actually that was a honest question. To me this explanation sound hilarious and casts a strong shadow of doubt on the rest ....
.... coupled to a further shadow of doubt because it is Norvil / Les E. stating this. After several experiences regarding the quality of the parts sourced from him I won't do it again. And these experiences don't fit the frame of "knowledgable engine buiilder" at all.
And when is a pattern a pattern? Hm.
Sorry, that is the part I don't get at all: Where do they say something about con rod bolts? On the website? Quoted on this forum?
A split stamping for cost reasons and then you don't see the "stamping line"? Come on .... :roll: Doesn't anybody have a D-rod at hand and could do a nice high res picture of the area in question?
PM about that. I still don't see a point in discussing this if that represents your arguing stile.
Tim
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Tintin said:
A little humor goes a long way. It sounds like you have had some bad experiences with Norvil and Les E; accepting that at face value I now understand (not judging) the basis of your opinions on the current subject of blown rods, specifically the "D" rods.
As for con rod bolts, there goes part of my arguement. The source was actually Andover See:
http://www.andover-norton.co.uk/Pirate%20Parts.htm
Apologies for the confusion.
I received your PM notice in my mail but the link led me to the general accessnorton site with no indication on any PM. Any guidance on how to retrieve PM's.
I'll try and tone my style down a bit
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