Help with tuning.

Dec 18, 2020 I posted: https://www.accessnorton.com/NortonCommando/hastings-rings.32036/

Any Hastings rings you buy today are old stock. Need to get a consensus on what rings are best since Hastings is no longer making Norton rings.

Surely Goetze , they were dog's bollocks according to few people ..........just I have to fit them nicely with my fingers ! and no I will not file end gap !

Brian4.2,
Glad to hear you've assembled a few engines. Never know what is going on at the other end of a help request. I think you are almost there with the fresh build. I'm rooting for nothing serious at all.

Time Warp said:

There is something not right about the coil expander (imho), the ring tension once they are in place is extremely high due to that expander to the point they are quite hard to fit into the bore (The compression rings were fine)
Time will tell eventually.
I cut the Goetze expander down around a millimetre at a time as a test and only a 'few mm made all the difference (ring in hand with expander and compress / close the end gap.
A check showed it was not the ring groove base but the high circumference pressure they were applying and I mean crazy high.

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I had the same in the 90's on my 850, I was re-ringing it and got Hepolite Apex rings with the 3 piece oil control ring. The only way to get the oil control ring into the barrel was to shorten the corrugated expander ring, the 2 thin rings it supported did not need any adjustment but their ends would not get close to meeting without reducing the length of the expander ring. The rings are still in the engine to this day with no oil consumption between oil changes.

A perfect time to go off topic:

These have been located at the very back of the bottom drawer of the top chest on one of my roller cabinets for 3 decades.



I have no memory of installing the pistons in the Norton though. I did it 3 times, and still can't remember. Last time I did it with some Italian rings. Smoked some initially but doesn't smoke now. Norton heal thyself.

concours said:

Hastings... are the oil rings ONE piece, or THREE piece?

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3 piece with the expander. The shop who bored the barrels checked the ring gaps and adjusted as needed. I dont remember if he trimmed the expander, i bet not as the ends seemed intact. He had a machine that precisely trimmed the rings. I installed them by hand dropping the barrel down onto supported pistons, using light machine oil.

Schwany said:

Glad to hear you've assembled a few engines. Never know what is going on at the other end of a help request. I think you are almost there with the fresh build. I'm rooting for nothing serious at all.

Click to expand...

I still cant explain why it smoked like that and next day with only new plugs has cleared up. I was hoping to find something wrong or an explanation.

gortnipper said:

Right plug fouled badly. On a JC done head, I wouldn't think guides are bad.

Have you checked torque on head?

L plug looks lean. Also looks too hot, but that could be from running lean.

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Thanks, I will torque the head while waiting freeze to be over.

Im not going to worry about the plugs till i get on the street and can do a proper plug chop.

brian4.2 said:

3 piece with the expander. The shop who bored the barrels checked the ring gaps and adjusted as needed. I dont remember if he trimmed the expander, i bet not as the ends seemed intact. He had a machine that precisely trimmed the rings. I installed them by hand dropping the barrel down onto supported pistons, using light machine oil.

I still cant explain why it smoked like that and next day with only new plugs has cleared up. I was hoping to find something wrong or an explanation.

Click to expand...

It was the snow. Snow is magic.

Ted

brian4.2 said:

3 piece with the expander. The shop who bored the barrels checked the ring gaps and adjusted as needed. I dont remember if he trimmed the expander, i bet not as the ends seemed intact. He had a machine that precisely trimmed the rings. I installed them by hand dropping the barrel down onto supported pistons, using light machine oil.

I still cant explain why it smoked like that and next day with only new plugs has cleared up. I was hoping to find something wrong or an explanation.

Click to expand...

New build, not totally unheard of to see some smoke initially. Most new builds don't smoke, but most motors get finalized and run in before sitting around for 2 years with oil in the tank. AMR mod or not the Norton design can still wet sump over an extended time. When they do wet sump they can burn off some oil even if the sump is drained before starting the engine. If you did not drain the sump before starting the motor, what you experienced is not unheard of.

Coincidence section: I've not to date had great success with iridium plugs in my Norton engine once they foul. But I had a lot of odd things going on electrically that I have corrected since switching to double platinum Autolite plugs. Iridium plugs might work in my motor now, but my success with the Autolites is perfect, so why switch. My plug choice runs in the self-cleaning heat range. I carry spares but haven't had to swap out a plug in 2700 miles. The plugs are doing the job they need to do. I only mention the iridium plugs because that is what yours appeared to be initially during the smoking phase.

marinatlas said:

You make me wonder if I could have the same problem , as for the first time I will have to deal with those Goetze rings in a new 750 barrel , I had checked the ring gaps of the two upper rings all is ok , then after your post I had tried to fit the piston with the oil controll one in the barrel and just like you , it was pretty tight , so I stop where i was and will see later , previously I allways use hastings ( dozen of engines )and yes they were tight but when fitted (never file the gap ) no problem .........so , may be I will use a ring compressor that I don't have , as i had all ways use my fingers !!!

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Since 1976 I have only used ring compressors once when the local Honda shop loaned a set when I fit new rings to my 1978 CBX/6, which was a story in itself. (It had turned into a dual piston 1047 cc triple when I fired it up - two piece cam shafts and had installed them with #1 and #6 lobes inline and not opposed)
Oddly enough the mechanic had mentioned that was possible beforehand.

Those Goetze (type ?) rings are still sitting on a shelf somewhere.
Like the replacement Hastings rings, the end gaps were fine out of the boxes, the Hastings three piece oil scraper went into the bore fine by me, the one piece ring due to that coil type expander needed what was more like ironing.
The ring needed to be not only compressed but needed an ironing like movement around the ring circumference toward the end gap and that was on a stock bore cylinder so still had its generous bevel lead in at the bore.

With that ring in hand when I removed the top end and the expander in place three fingers per hand could not compress it.
With the expander cut a little at a time it could be compressed with what I guesstimated was reasonable cylinder wall pressure but elected to replace them with the Hastings type.

Time will tell how that goes smoke or smokeless wise. (if I stop modifying things)
On an iron bore I like to not dilly dally around at run in but not let the engine get to hot with plenty of high vacuum (throttle closed deceleration)
You pretty much get one chance at that or risk partial glazing and who knows what shape the bore is (roundish) on a new engine when hot or over hot.

brian4.2 said:

3 piece with the expander. The shop who bored the barrels checked the ring gaps and adjusted as needed. I dont remember if he trimmed the expander, i bet not as the ends seemed intact. He had a machine that precisely trimmed the rings. I installed them by hand dropping the barrel down onto supported pistons, using light machine oil.

I still cant explain why it smoked like that and next day with only new plugs has cleared up. I was hoping to find something wrong or an explanation.

Click to expand...

Duff spark plug, not burning all the effluent.
Take the win.

If pump gas fuel was left in the bowls, two years is a long time, and the fuel will more than likely have evaporated and left a chalky residue that is a pain in the butt to clean out.

Or turns into glue . gum . gook .

A HOT plug melts your pistons .

A COLD plug , it wont start . So YOU get HOT from kicking it over .

NGK & Chumpion numbers are reversed .

On the track , road plugs can cook in a minute & you get no usefull spark .

Suppose HARD Plugs & SOFT Plugs is far more rational definition .

Describes the correct proceedure as " Engine Warm , go full speed , pull choke .
If it slows , its rich .
if it speeds up , its lean .

Course the main jet hight was adjustable directly , by hand . Dual Carbs Even !

Of course the shop at the top of the ' Test Strip ' now , uses a dyno on their race injuns .
These aparently dont compensate for not having a car & a few other things involved .
So ARNT RICH .

Might explain while they melt RS 3100 pistons , while they live at the top of ' Our ' Test Strip .

Modern Fuels some say DONT give good readings . Though no doubt, still ,
if the center electrode ( and side ) edges are rounding, Your To HOT . lean or advanced .
You want a loose open face helmet so you ccan HEAR the ignition range action .

Pinking lumping chuntering . whatever .
Intermitent miss ( stall in combustion ) LEAN .
rich throbby beat . RICH .

Normally full tourque low revs gets a pinking period aroud 2 or 3 tho. rpm . Just .
Inteligent riders compensate . japanese factories fit C V Carbs to eliminate this .

As we dont have vacume advance .

Its blinking obvious , warm , ripping along , throttling about . By The RESPONSE

as to wether its right . If you can hear the bleedy thing .

And this australian beers so appalling its not worth drinking .

p.s. It First Says " Remove the Aircleaner " , I would think this is so as you can here it twice as well , sans silencing . intake .

On the subject of tight oil control rings... one thing I learned 'the hard way' is Pre-'71 pistons have a shallower oil ring groove.
I also discovered this on some original AE Powermax pistons, and I think the High Comp Dunstall (GPM) pistons may be the same, but I can't lay my hands on them right now.
I just checked the Service Bulletins and bikes prior to 146584 were affected. After this the Factory went to spring expander type oil rings with a deeper groove in the piston.
I think they persevered with the slotted pistons up to '72, so another reason for ditching the early pistons!

brian4.2 said:

Thanks, I will torque the head while waiting freeze to be over.

Im not going to worry about the plugs till i get on the street and can do a proper plug chop.

Click to expand...

Hey Brian,
Have you been able to take it on the street and verify no smoke and tune for idle?

Ted

I have run it around the block a few times (about a mile) There is no smoke but it is still running roughly.

I have about a half mile slight uphill to the house to do the plug chop (picture added)


Im going to go through the Amal "How to Tune Up" Guide. Im not ready to run at full throttle to check the mains yet so I will start with the throttle adjust screws and Pilot Air screw. I will do this by pulling one of the plug wires.

I have marked a scale on the twist grip to clearly see the throttle opening phases.

I have found the problem, I think. I'm going to do a leak down to confirm later today. Yes I am slow! I moved out of state and was busy with other bikes.

The Norton might have had the wrong specs. 81 lbs pressure both sides dry. So I did a wet test with 2 tablespoons of oil. Shot up to 110 lbs both sides. Should be around 130 I know. Looks like new pistons and another rebore. Bad spec I guess.

The fact that the pressures are exactly the same left and righ, dry or with oil, is revealing, any thoughts?

Was confusing me cause it was causing oil problems on the right side only. The bike might have 50 miles on it since the rebuild.



The pistons are .040 over. The barrels not sure till i break it down. Looking for 060 over pistons, once i measure how big the bore is now. Where can I get the barrels machined in OR?

Brian

FAG is a good shop. His machine work is not your problem. What pistons/rings?

brian4.2 said:

I have found the problem. I'm going to do a leak down to confirm later today. Yes I am slow! I moved out of state and was busy with other bikes.

Machinist who did my barrels on the Norton screwed up. 81 lbs pressure both sides dry. So I did a wet test with 2 tablespoons of oil. Shot up to 110 lbs both sides. Should be around 130 I know. Looks like new pistons and another rebore. Bad spec I guess. The fact that they are exactly the same left and right points to a machining error.

Was confusing me cause it was causing oil problems on the right side only. The bike might have 50 miles on it since the rebuild.



The pistons are .040 over. The barrels not sure till i break it down. Looking for 060 over pistons, once i measure how big the bore is now. Where can I get the barrels machined in OR?

Brian

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What were the ring end gap measurements when you assembled the engine?

I dont remember, its been a couple years. I can measure once its apart. What am i looking for?

What else could it be?