I hope you guys realise that these are not the valve timing figures that are in the Norton workshop manual.

exactly the reason for the post keith,just to clarify the source of info mike is by far the leading vintage Norton engineer in the uk ,manuals typically give benchmark settings to get a engine running, they are then followed by fine tuning to dial in properly not just cams same applies to carbs ,not saying everyone should strip and reset there cams but if you’re planning a rebuild its well worth a try you may well be surprised by the results

ignition timing + cam timing
you guys probably know all this, but in case another fool like me looks in with problems
try this and the engine runs so sweet and starts 1st kick
CAMS
30 degrees BTDC INLET
25 degrees ATDC EXHAUST VALVE FULLY CLOSE

POINTS START OPENING ON FULL ADVANCE
1/2" BTDC on compression stroke.......... yes 1/2 inch.....not 7/16"

BIKE RUNS COOL AND SMOOTH AND IS FULLY RESPONSIVE TO THE ADVANCE/RETARD LEVER

I do the same exercice and my cam pinions are not marked.

I don't know if my setting is ok or not ? my TDC are not like Heiko.

I send photos of engine:

My TDC look like the manual, Other photos are RFE and AOA:

TDC= PMH
inlet open before top= AOA
exhaust close after top= RFE

Timing 30° in and ex = 8mm

http://imageshack.com/a/img922/9310/jBQUz7.jpg
http://imageshack.com/a/img923/9792/AThVNA.jpg
http://imageshack.com/a/img921/991/dDDvTi.jpg
http://imageshack.com/a/img922/6205/rZ8LA2.jpg
http://imageshack.com/a/img923/8670/EBnN3Y.jpg
http://imageshack.com/a/img924/1636/7wKh44.jpg
http://imageshack.com/a/img921/2964/qtYR6V.jpg

Gents,

I am of the opinion that the picture of Heiko does not show the engine at TDC and therefore might be a little confusing.
When keeping the settings as specified in the original maintenance manual the cams should more or less be in the same positions.
That is how I have done it until now.
I am however game to try the setting John gave.
Modern petrol might require or allow for some change of settings.

The "military" setting always works and the settings on these old bikes are not as critical as on modern cars or motorcycles. There may however be another optimum after 70 odd years.

Cheers,

Rob

Hello,

I have not done any further work on the engine since I took the pictures.

The manual says:
"Inlet open 27° to 30° before top center"

- so is this: Inlet is 100% open (I think so ) or starts to open?

"Exhaust closes 27° to 30° after top center"

- so this is: Exhaust just starts to close ( I think so ) or is it 100% closed?


This might have mislead me, what is now correct?

Thanks,
Heiko

Hello Rob,

Thank you for your reply, please do you think my setting is ok ?

My TDC 1 is like fig. 14 p18 in the manual: In and Ex cams are parallels at 4 o'clock
My TDC 2 (after 360°) photo show exhaust cam begin to close and Inlet cam begin to open.

Any help is much appreciated

This is what happens when you do not follow the instructions in the manual. It all gets very confusing and you end up making mistakes. To time the engine properly read page 18 to 20 of the instruction manual available for download on this site. It even gives instructions for when the marks are missing. (if marks are present do not trust them, people may have altered them over the years).
When you feel confident in knowing what you are doing then by all means experiment with whatever different timing figures you want but it will still be an "experiment".
The figures are Inlet starts to open 27-30 degs (5/16") BTDC
Exhaust fully closed 27-30 degs (5/16") ATDC

Obviously this refers to TDC on the exhaust stroke not the compression stroke.

The figures from Mike Pemberton only puts the exhaust 2 degs out of spec ie 25 instead of 27-30 so could be worth a try.