Leak Down Test (Don't Laugh!!)

Just been pottering with the Norton, not a lot of things need doing!

Barrels are with Jim C. so just waiting for him to get back to me on when he will get a chance to work on them!

TBH, when it comes to advice on running in etc. I'll take my lead from Jim C., no disrespect to Mike & others on this forum

I don't think I'd have the neck to run-in rings/bone dry!! I understand the principal & have done some research on the pro & cons but it's not for me!

I'm sure you have all been loosing sleep worrying about how I'm getting on . . . . . .

Got word back from Jim C., 4-6 weeks to get work done, good news is that the 880 pistons are available.

I've a list of small jobs I'd like to do on the Norton so I'll start working through this list, always something to do in the world of Norton's!

We have a 26 page investment in this issue, so yes, still interested. Thanks for the update.

Okay, click, we gave you the 4-6 weeks you needed. Are you still on the path?

Bike still on the bench.

Last email from Jim said he had the pistons but was waiting for the liners, he's a busy guy!

Have no fear, as soon as I get the barrels & pistons back, I'll update you all with plenty of pics

The liners [finally] showed up yesterday.

Th

comnoz said:

The liners [finally] showed up yesterday.

Click to expand...

Thanks for the update Jim, get the big hammer out & start bashing ;-)

I'm sure you guys have been loosing sleep over my Norton woes

Jim has the sleeves installed and bored to piston size, he thought he could just hone the oversize gudgeon pin hole required to fit the 920 gudgeon pins but found he will have to offset the bore to get them right requiring Jim to make a jig to hold the piston!!

All way above my pay grade but I'm happy that one of if not the best Norton engineer on the planet is on the case.

Going to be a winter rebuild at this stage, managed to get 2.5k done touring Scotland and another 3k on trips around Ireland, mostly on more modern bikes but I had the 1970 Triumph T100 out for a fair few spins, so the summer was far from a washout

More anon

Nice to see the Irish flag flying !

Thanks for the update click.

Cheers,

cliffa.

Might be over-thinking this a bit. Run it a bit longer, see if it settles. My re-built 750 was a little ornery at first but spins like a top now. And no smoke.

Stillreel said:

Might be over-thinking this a bit. Run it a bit longer, see if it settles. My re-built 750 was a little ornery at first but spins like a top now. And no smoke.

Click to expand...

I know this thread is VERY long but you really need to look at the pictures of the bore & pistons!! https://www.accessnorton.com/NortonCommando/leak-down-test-dont-laugh.24506/page-11

Your idea of taking it for a hundred mile ride and then reassessing is a good one. Set the oil level (warmed up) to a known point before you ride off and measure after the ride to see if there is significant oil useage. It might achieve nothing other than another enjoyable ride on your Norton but it’s got to be worth the effort.

click said:

I'm sure you guys have been loosing sleep over my Norton woes

Jim has the sleeves installed and bored to piston size, he thought he could just hone the oversize gudgeon pin hole required to fit the 920 gudgeon pins but found he will have to offset the bore to get them right requiring Jim to make a jig to hold the piston!!

All way above my pay grade but I'm happy that one of if not the best Norton engineer on the planet is on the case.

Going to be a winter rebuild at this stage, managed to get 2.5k done touring Scotland and another 3k on trips around Ireland, mostly on more modern bikes but I had the 1970 Triumph T100 out for a fair few spins, so the summer was far from a washout

More anon

Click to expand...

Thanks for the update, click. Not actually losing sleep, but I was thinking about you just yesterday, ya.
Don't quite understand why the 920 is presenting piston pin issues, but yes, you have the right guy on the job, for sure.
Please do keep us posted.

dave M said:

Your idea of taking it for a hundred mile ride and then reassessing is a good one. Set the oil level (warmed up) to a known point before you ride off and measure after the ride to see if there is significant oil useage. It might achieve nothing other than another enjoyable ride on your Norton but it’s got to be worth the effort.

Click to expand...

That ship has sailed!, barrels are off & getting worked on.

Mr. Rick said:

Thanks for the update, click. Not actually losing sleep, but I was thinking about you just yesterday, ya.
Don't quite understand why the 920 is presenting piston pin issues, but yes, you have the right guy on the job, for sure.
Please do keep us posted.

Click to expand...

It's hard to keep up on such a long thread!

The 920 conversion was already done to the Norton just before I purchased it and was from Norvil, they used, I think, a Cosworth piston which has a larger gudgeon pin than the standard piston.

Since my bore & pistons were stuffed I only had 3 options:

1. Get oversize Norvil 920 pistons & get the barrels rebored. I didn't want to go this route for lots of reasons, mainly after talking to the guru in Norvil and asking him a few basic questions and getting fogged off with nonsense answers I decided not to take the risk.

2. Strip the entire engine, split the cases, replace the conrods with standard ones & rebuild as a standard 850. After much head scratching I didn't want to financially sink the type of money I would need to spend on this option. I would have to get an engine builder to take the work on as I know my limits. I got a few quotes and decided this was not an option for me.

3. Along came Jim with an offer to convert the barrels to an 880 and supply 880 pistons with the larger gudgeon pin hole so I can use the existing conrods which means I don't have to split the bottom end.

Time will tell if this will all work out, I thought and still think it's worth a try, whats the worse that can happen

Hi Lads,

Just thought I'd do a minor recap on what's going on!!

Due to 'you lot' keeping poor Jim C. distracted testing the worlds supply of oil types it's taken some time to get the machining work done on the pistons.

Jim has completed this work & the 880 liners have been fitted + the wrist pin holes have been bored to 13/16th and the wrist pins shortened to suit the new 880 pistons!

Hopefully in the next week or so I'll have the parts back & can start the process of rebuilding.

I'll take plenty of photo's to keep everybody happy

Anybody know a good oil I could use for run-in and for normal use + what additive should I use

Head and Shoulders straight for the first fifty, rinse and repeat at 100 then Bel Ray with 5% H+S.


Glen

Castrol GTX
Rotella 15W40 T4
Valvoline VR1 20w50

Don't baby it but do avoid long high speed runs.
Change it to a good synthetic at 100 miles. Jim

PS- the oil tester is still running. I've grown used to the noise in the background.

And by the way. I can not afford to take time out of Norton repairs to do oil tests.
It takes 10 or 15 minutes to start a test.
I have been starting 1 at 8 in the morning and it runs till done. Then I start another at 1:00, after I get back from lunch. And then I start a 3rd at quitting time. I basically got enough donations to cover the oil, the arbor races and building the machine and maybe the electricity. And I appreciate that.
But definitely not enough to pay the bills. That is where the real work comes in. Jim

comnoz said:

Castrol GTX
Rotella 15W40 T4
Valvoline VR1 20w50

Don't baby it but do avoid long high speed runs.
Change it to a good synthetic at 100 miles. Jim

PS- the oil tester is still running. I've grown used to the noise in the background.

And by the way. I can not afford to take time out of Norton repairs to do oil tests.
It takes 10 or 15 minutes to start a test.
I have been starting 1 at 8 in the morning and it runs till done. Then I start another at 1:00, after I get back from lunch. And then I start a 3rd at quitting time. I basically got enough donations to cover the oil, the arbor races and building the machine and maybe the electricity. And I appreciate that.
But definitely not enough to pay the bills. That is where the real work comes in. Jim

Click to expand...

Thanks for the oil recommendation.

Only joking about the oil testing I can only imagine how busy you are in your workshop!

From the video you posted there is some racket from the oil testing rig, look after your hearing!