I have never had any sort of catastrophic failue on any bike I've owed or built for a client with 2 exceptions:

1. my little Kawasaki 90 Bushmaster trashing a piston and taking the cylinder and rotary valve with it, due to improper 2-stroke mix with straight 30W crankcase oil, mixing "by eye" at the gas pump.

2. Failure to fully seat the sludge tube in a Triumph crank sludge trap, resulting in blockage of the main oil gallery at the neck; final results were a complete teardown and replacement of rod bearings (no core component damage).

As these rods got severely nicked by the stray washer, they had to be replaced. Since we're warming up the engine with pistons & cams, it's just extra insurance.

Crank & rods all done-

Obvious! Well maybe, just maybe it's all a ghost-story about these inferior D-type rods after all?!

Didn't the story originate from a Norton Villiers technical bulletin? I would take heed. It could be that the run was ok for a while but problems developed during manufacturing, bad alloy or what ever. I couldn't find the original bulletin for review but if the Norton factory acted on it there likely was a real problem of some sort.

nortonspeed wrote:Obvious! Well maybe, just maybe it's all a ghost-story about these inferior D-type rods after all?!

I doubt that all D rods are flawed.
However there does appear to be some evidence to suggest the D rods are likely to fail prematurely, possibly there was a faulty batch, I don't know, but if that is the case, then there appears to be no way to determine which ones will break and which ones won't, therefore I think it would only be prudent to avoid the use of D rods wherever possible, just in case?

http://www.norvilmotorcycle.co.uk/techtalk35.htm

Paul, I recall reading that the Norton racing shop and some of the subsequent Norton gurus, solder the circlip on the early model drain plug with the filter attached, once it is locked into it's slot. Given what you have found inside this engine this seems like a good idea to me as one seldom has to remove the filter anyway and if you do a quick heat up with a small torch should release everything.

daveM, in this case, I was one step ahead of your post!

http://www.norvilmotorcycle.co.uk/techtalk35.htm

Thanks L.A.B. this is just the information I needed to be sure not to reuse my D-rods.

Cylinders ready to bolt on, just need the cam & radiused cam followers from Megacycle...

Great progress. I am curious as to what size cam is going in? And why are you using the Rowe valves and not the Kibblewhite valves?

No big reason to use the black diamonds over the Rowes, this isn't a race bike (althought the spring kit is required by the cam)

the head isn't ported, so it isn't anywhere near critical on the differences in the valves.

Just received the floating rotors, they match up to the Dreer hub perfectly with the bearing caps, perfect center-to-center spacing on the setup.



Also got in the Megacycle cam and radiused cam followers-

Managed to find this very nice remote reservoir shock, I'm patterning the mounting lugs now...

Removing the primary side main bearing was easier than ever. I pre-heated the oven, set the case in there and made myself a sandwich; I'm nearly finished and I hear a "plop" in the oven, there's the old bearing sitting on the bottom of the oven...

New ones dropped straight in from the freezer with zero effort.



Installed the Megacycle cam with thrust washer and red goo they provided-



So that's it, the bottom end is done.

Paul - the superblends in the cases look like one is facing one direction and one is facing the other. Is this correct? The reason I ask is that I have never installed these and I installed mine both with the smooth side up with the inner race facing the crank. This is the way that the races came out of the bearings so I installed them into the cases accordingly.

Do I need to change mine to look exactly like yours?