Gettin ready to rally

comnoz · Jul 4, 2013

Since it has been about 6000 miles since the last service I figured it was time. I hadn't looked at it since before the Lake of the Pines and Barber trip.

Here is why I like synthetic oil. It still looks like oil after a lot of hard use.

Still nice and clean inside.

The cam gear drive has gotten very noisy lately. The gears looked fine but when I took the idler apart I found the ramps and balls that were supposed to preload the side gears had worn to the point of being useless. I will be going back to a chain for now.

Here is what spark plugs are supposed to look like with unleaded fuel.

Now on to the front end. The fork seals are leaking like a sieve. Jim

Cowboy Don · Jul 4, 2013

That is engine internals porn, Jim!

Have you posted details about this stuff before? The gears, the oil pump?

comnoz · Jul 5, 2013

Cowboy Don said:
That is engine internals porn, Jim!

Have you posted details about this stuff before? The gears, the oil pump?

Yeah, it has been a couple years ago but it has been shown before.

I had intended on producing gear drive kits but they have not given good enough longevity to make them worth what they would cost. I wouldn't mind a little gear whine but they clatter so bad people look at me funny when I pull up beside them at a stop sign.

RennieK · Jul 5, 2013

I wonder if 90 wt would help that clatter? Not easy to do but just wondering.

john robert bould · Jul 5, 2013

Jim
Nice engineering! You need to split the centre gear and spring load the halves..honda and scott did this..its an anti back lash gear, the halves are approx 1/2 tooth out,as the cams load and un-load the gear train the gears clatter...the split gear takes up the slack. But you know this!

Time Warp · Jul 5, 2013

The oil pump and gear drive is certainly interesting. 8) (Not the SRM pump ?)
Suzuki TL1000's have scissor gears on both the crankshaft primary drive gear and each camshaft gear,the idler gear being solid and driven by chain.
They can 'tick a little when the springs weaken and clatter when they are removed all together.

http://i30.photobucket.com/albums/c345/ ... issor1.jpg

http://i30.photobucket.com/albums/c345/ ... Custom.jpg

Perhaps the scissor has trouble preloading two gears.
Is that a vernier adjuster on the first driven gear ?

Hobot · Jul 5, 2013

Thanks for taken us into your inner workings Jim. Your nice clean oil is more the results of nice clean combustion so less soot. I've seen this surprise cleaner looking non-syn oil after I Singh grooved my side valve mower engine. Extra very cleaver you can still return cam drive to chain gang. I'd risk almost divorce to afford one of your Star Trek oil pumps. I've put off inventing a belt drive d/t other stuff and question of what type belt that's narrow enough yet tough enough. The prefect plug examples on a wide range of new age gasoline is invaluable to see what to shoot for. Happy to know even a Norton Guru suffers like some of us shade trees with things clinking and clanking if not attended to sooner than later.

JohnTy · Jul 5, 2013

Hi Jim
you have a PM.
JohnTy

comnoz · Jul 5, 2013

john robert bould said:
Jim
Nice engineering! You need to split the centre gear and spring load the halves..honda and scott did this..its an anti back lash gear, the halves are approx 1/2 tooth out,as the cams load and un-load the gear train the gears clatter...the split gear takes up the slack. But you know this!

John,
The idler gear is split into three pieces or two scissor gears, one to take care of the play to the intermediate gear and the other to the cam gear. The intermediate gear and cam gears are offset, each using one scissor section.

Getting spring preload devices into a gear that small was a challenge. There are balls and ramps in between the sections with an adjustable spring preload to load the gears. It worked very well when it was new but it didn't take long before the springs had lost their stuff. I have replaced the springs [wave washers] three times since I built it, every 6000 miles, to keep it relatively quiet.
Now the ramps are worn to the point that replacing the springs is not going to do much. Back to the drawing board. Jim

Holmeslice · Jul 5, 2013

I vote that is the WORLD'S SEXIEST COMMANDO OIL PUMP!

comnoz · Jul 5, 2013

Time Warp said:
The oil pump and gear drive is certainly interesting. 8) (Not the SRM pump ?)
Suzuki TL1000's have scissor gears on both the crankshaft primary drive gear and each camshaft gear,the idler gear being solid and driven by chain.
They can 'tick a little when the springs weaken and clatter when they are removed all together.

http://i30.photobucket.com/albums/c345/ ... issor1.jpg

http://i30.photobucket.com/albums/c345/ ... Custom.jpg

Perhaps the scissor has trouble preloading two gears.
Is that a vernier adjuster on the first driven gear ?

The oil pump is something I whittled out many years ago, after I added an oil line to the end of the cam and my low oil pressure went to no oil pressure.

Scissor gears work very well. If I could use a larger diameter idler gear so I could use coil springs like the Suzuki, maybe I could get it to live longer. There is some timing adjustment to the intermediate gear. Jim

bluto · Jul 5, 2013

Very likely something you are already aware of but running 35mm film under the fork seals often fixes them, did the trick on one of my bikes (not a Norton) and completely eliminated bad leaks on both sides caused by mud...worth a try before replacing the seals (I did change the fork oil afterwards as it was due anyway)

bwolfie · Jul 5, 2013

If you are doing fork seals, a little lathe time on the collars and this kit fits.

http://www.mooseracing.com/products/?pr ... tId=114395

works great.

christulin · Jul 5, 2013

Impressive.
I have been trying to prepare my Norton (now named Vivian) for the rally for months. Yesterday a horn stopped working, the primary is dripping oil again and I haven't replaced the front isolastics yet. I'm way less prepared than I hoped. Maybe I'll need to bring a tool box, box of spares, bike lift, etc., etc. It looks like I'll be hauling Vivian in the pickup.

rvich · Jul 5, 2013

As usual, a couple of questions. Would there be any advantage to using a belt for the cam instead of chain? How do you feel about using synthetic oil for break-in?

Russ

lcrken · Jul 5, 2013

Hi Jim,

I've followed your development of the cam gear drive for the last few years with interest, in particular, the difficulty of controlling the noise. I've recently got back to working on my T160 resurrection, and was looking at the way Triumph designed their gear drive system for the cams. They don't seem to have had any noise issues, and no special features to control it. Do you think the difference is in the extra idler gear needed for the Commando, or just that the longer distance between intermediate gear and cam gear means heat expansion is more of a problem for the Norton?

Ken

comnoz · Jul 5, 2013

The scissors gears are set up like this.

I am beginning to like the cushioning that the chain gives to the cam drive. The pinion gear on the crank was very distressed also probably because of the solid connection to the cam. I have a feeling a lot of the noise I had was coming from the pinion to intermediate gear play that had grown substantially.

I cooked this up last night. So far I like it. It uses hydraulic damping and the shoe is allowed .020 float to make up for tight spots in the chain.

It is nice to have my quiet engine back. [once the forged pistons get warm]

I have used synthetic for break-in on my own race engines and have seen no problems. I am not to the point I would recommend it however.

I still use conventional oil [10-30 Rotella] for the first run on the street motors I build. I go to synthetic after the first tank of fuel. Jim

comnoz · Jul 5, 2013

lcrken said:
Hi Jim,

I've followed your development of the cam gear drive for the last few years with interest, in particular, the difficulty of controlling the noise. I've recently got back to working on my T160 resurrection, and was looking at the way Triumph designed their gear drive system for the cams. They don't seem to have had any noise issues, and no special features to control it. Do you think the difference is in the extra idler gear needed for the Commando, or just that the longer distance between intermediate gear and cam gear means heat expansion is more of a problem for the Norton?

Ken

I have looked at the Triumph drive also. I am not sure why they get away with it and I have not. More gears and more distance to the cam plus gear wear that is likely caused by harmonics in the geartrain. If the Norton geartain could be built with larger diameter gears I think it would probably work out fine. I'm not sure the benefits would justify the expense of a complicated and hard to build drive.

I wouldn't say I have given up on the idea completely.....

CanukNortonNut · Jul 5, 2013

comnoz said:
lcrken said:

Hi Jim,

I've followed your development of the cam gear drive for the last few years with interest, in particular, the difficulty of controlling the noise. I've recently got back to working on my T160 resurrection, and was looking at the way Triumph designed their gear drive system for the cams. They don't seem to have had any noise issues, and no special features to control it. Do you think the difference is in the extra idler gear needed for the Commando, or just that the longer distance between intermediate gear and cam gear means heat expansion is more of a problem for the Norton?

Ken

Click to expand...

I have looked at the Triumph drive also. I am not sure why they get away with it and I have not. More gears and more distance to the cam plus gear wear that is likely caused by harmonics in the geartrain. If the Norton geartain could be built with larger diameter gears I think it would probably work out fine. I'm not sure the benefits would justify the expense of a complicated and hard to build drive.

I wouldn't say I have given up on the idea completely.....

Jim
What about a toothed belt drive? The Old 1.6 VW diesels ran for 90k mileage between belt changes. Would something that narrow work without the stretch from the cam lobes loading up and coming off the top? Belt drives seem to help in the pulses for the gearbox gear clusters. Its all R&D to replace the chain but so far I am still sticking with the chain. beware our nortons may start to sound like sewing machines. :mrgreen:
Thomas

CNN

comnoz · Jul 5, 2013

What about a toothed belt drive? The Old 1.6 VW diesels ran for 90k mileage between belt changes. Would something that narrow work without the stretch from the cam lobes loading up and coming off the top? Belt drives seem to help in the pulses for the gearbox gear clusters. Its all R&D to replace the chain but so far I am still sticking with the chain. beware our nortons may start to sound like sewing machines. :mrgreen:
Thomas

CNN[/quote]

I have actually cut out a set of pulleys and bought a little 5mm pitch belt. I will need to make an idler to use it. It seems pretty scary to think it will be running in hot oil and if it breaks the motor is going to be pretty bad.

I talked to the guys at gates and they didn't think it would be a good application either. They wanted much larger sprockets than could be fit under the cover. Jim

Gettin ready to rally

comnoz

Cowboy Don

comnoz

RennieK

john robert bould

Time Warp

.......back to the 70's.

Hobot

JohnTy

comnoz

Holmeslice

comnoz

bluto

bwolfie

christulin

rvich

lcrken

comnoz

comnoz

CanukNortonNut

comnoz

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