Bad news from the stars

Like summer is a good time to repaint a 26 years old garage's floor...



... here it is, waiting for some better days...




... didn't have time to open the engin yet. But... got some news from the last shop the bike was in for another almost 2.700$ bill :shock:

After some research and investigation it appears as though this nut would be from the crankshaft. When we performed our services on this motorcycle we did not do any work on the crank or anything in that general region, therefore we do not offer any warranty against our work performed on this engine.
It is very odd that it has come loose and therefore was likely damaged from from the passing rod. It is possible that the bolt may have some side play since the nut is no longer holding it in place and cause further damage to the rod on the other side. It is recommended that this work be done to prevent any further damage.

I have attached a photo of a identical crank to show where we believe the nut to have come from.

Here it comes



Is it really possible to have different nuts around the crank from stock?



And yes, next time I'll have the head and barrels stripped

NKN said:

Is it really possible to have different nuts around the crank from stock?

Click to expand...

If you were wondering why the crank in that photo has different length nuts then they are stock.

Yes it was my question, thanks L.A.B.

Back in the race...

Who already opened an engine after only a very few minutes (seconds?) of running?

My first Norton big job, taking the head off. After playing a little with the pushrods, I decided to heat the head a little and pull out the exhaust rockers and everything went fine. Being helped by Mick's video, would like to see him pulling a head off engine in the frame ^ ^



Next picture explains why only one header was blueing, only one spark was firing.



Gonna have to find out why with a new single ignition coil...

Seeing the inside of barrels shows something nice. Some measurement will confirm.



Camshaft looks good, except a little part of it. Like I am going to split the cases, wondering if I'll put a stock but recent one? What do you think?



For the pistons, except a strange sign on top of one, I believe they would go back in. Does somebody could tell the brand of them?








And, for the follower's thread, all the bolts seem to be in place!!! So the nut that falled when taking the sump nut off remains a mystery...

NKN said:

For the pistons, except a strange sign on top of one, I believe they would go back in. Does somebody could tell the brand of them?

Click to expand...

Are there any markings inside the pistons?

That's it

Looks like the "rebuilder" used a ton of blue silicone sealer on the crankcase halves. Judging by the amount squeezed out in just a couple of the pictures, tearing this motor down now is gonna save it before the Blue goo stops up an oil passage and causes a seizure.

norton73 said:

Looks like the "rebuilder" used a ton of blue silicone sealer on the crankcase halves. Judging by the amount squeezed out in just a couple of the pictures, tearing this motor down now is gonna save it before the Blue goo stops up an oil passage and causes a seizure.

Click to expand...

You're right but there are other reasons to split the cases too, like the camshaft.

Did the loosen nut damaged it like that? If it happened in the engine, how is turning the camshaft? What about its bushes and the play on it? Did the rods get hurted? And perhaps a little crack somewhere in the crankcases?

NKN said:

That's it

Click to expand...

'JCC' is the manufacturer (Jieh Chueng Ind. Co., Taiwan).
They are good quality, also sold as 'Emgo' or Wassell 'Hepolite' pistons.

norton73 said:

Looks like the "rebuilder" used a ton of blue silicone sealer on the crankcase halves. Judging by the amount squeezed out in just a couple of the pictures, tearing this motor down now is gonna save it before the Blue goo stops up an oil passage and causes a seizure.

Click to expand...

Unless the guy was a total moron (hey, anyone could drop a nut in the crankcase, BSA employees used to do it all the time!), that's probably blue Hylomar, not silicone.

I happen to be travelling thru France in the next 10 days. If you are anywhere near my route I'm happy to drop by and have a look or help out or bring tools. My route is calais, Rouen, Poitiers, Toulouse, Pyrenees. Feel free to pm me If interested

Clanger said:

I happen to be travelling thru France in the next 10 days. If you are anywhere near my route I'm happy to drop by and have a look or help out or bring tools. My route is calais, Rouen, Poitiers, Toulouse, Pyrenees. Feel free to pm me If interested

Click to expand...

Waouh that's real nice from you, check your PM.

still thinking the nut is likely not off your bike but maybe got picked up off the road and wedged between motor and frame or someplace then fell off when you found it

but at this point you now have an excellent opportunity to inspect everything and replace questionables

think you can measure the cam lobes to determine if good enough or replace, need an expert here to say how do it?

1up3down said:

think you can measure the cam lobes to determine if good enough or replace, need an expert here to say how do it?

Click to expand...

Don't necessarly need an expert, but my door and fridge are always open to those who, spontaneously, propose to come to help me. With their hands, ideas, know how, special tools, beverages...

Clanger said:

I happen to be travelling thru France in the next 10 days. If you are anywhere near my route I'm happy to drop by and have a look or help out or bring tools. My route is calais, Rouen, Poitiers, Toulouse, Pyrenees. Feel free to pm me If interested

Click to expand...

I got an email from a friend who lives in France. He told me of a friend who was badly injured by "refugees" who throw tree limbs onto the roads leading to the Chunnel in Calais to stop trucks so they can sneak into the UK on them. His friend was badly injured when he hit the limbs on his bike.
And you thought the pot hole in LA were bad!

John in Texas

Hi Guys, looking at the shot with the cam lobe I think that is not damage but is typical of defects on the cast blanks used on the original factory cams. I've seen this before and it's fairly common. Cams from billet are perfect looking but not these. Also lets not forget the followers are 1/2 moon shaped so don't cover the whole area on the ramps either and often don't cover the whole area of the nose and will leave a slight ridge on one side as the nose wears.

Here's the shot and some observations:



Purple arrow - The lobe to the right has a weird diagonal mark across it. The 2 lobes on the drive side look slightly pitted compared to the more mirror finished lobes on the timing side. The stellite pads on the cam followers should be ok but worth checking to see if some debris got caught in there on that exh lobe. Would be nice to get the cam polished.

Yellow arrow - Looks like it took a hit from the bottom at some point but I don't see any damage that would come close to squishing that nut or grinding and blueing it. Check carefully on the flywheel and inside the cases, bottom and sides for scrape marks. The big end caps and their nuts on the back side of the engine are other places a nut could catch that we can't see in these photos.

Green arrow - there is some roughness in the cam tunnel but a nut wouldn't fit in there so that's likely previous scuffing.

Left red arrow looks like a crack and wonder if it goes through. There is 2 studs in the vicinity that hold the case halves together so that may not be so bad but other opinions would be good.

Right red arrow - is a wide scrape that aligns with the lobe casting defect? but the cam follower tunnel on the barrels would cover that area so that has to be previous scuffing as well.

It does look look like someone used the nut with some others to block up the cylinders to get all the base nuts started and then unknowingly lost one inside. It seems to have gone right to the sump plug and stayed there although that doesn't explain the grinding or squished condition of the nut.

RennieK,

Someone needs to hire you for the next 'Sherlock H' TV series!! Well done!

:mrgreen: