Return to Website

Rob's WD16H and Big4 Forum

Dutch army, Johan Herman Fuhler, somewhere between 1945 and 1950

Forum: Rob's WD16H and Big4 Forum
Start a New Topic 
   Board|Threaded
Author
Comment
cam timing 16h

hi again just replaced the 3 crankshaft bearings ,and a little puzzled on the cam timing theres no visable timing marks on either cam gear or on the 3 slotted pinion gear ,help please
thanks john mitford

Email  
Re: cam timing 16h

That's a common problem. If they're not marked, you must mark them before disassembly. If you have the manual, look at page 18, there are instructions on how to proceed. If you don't have the manual, it's available on this site for download.

Re: cam timing 16h

Samuel Cormier thanks for the link ,my manual does not not have that info

Email  
Re: cam timing 16h

Even if the cams are marked they cannot be relied upon to be reliable. Check everything yourself as per the manual.

Re: cam timing 16h

spoke to mike pemberton at pushrod ,great guy who gave me some pointers ,got inlet @ 30 BTDC and exhaust fully closed @ 28 decrees ATDC using a degree wheel

mike also told me on the pre 1947 16h with only the exhaust cam driven by the pinion, the best setting are 30 inlet and 25 exhaust ,i just could not quite achieve that but i got close

also used the 3 slot pinion ,one slot = 1/3 of tooth to get as near as i can ,i will drop the engine back today and see if i am correct

if anybody else experiences the same problem please ask and i will post how i did it ,the hard part i found was getting me head around it ,the actual timing part isn't as hard as it seems
thanks again

Email  
Re: cam timing 16h

Hello John,



I did the same exercise lately.


I also struggeled and did not find it easy to match the degrees.

The matching points were also gone but fortunately I marled the drive pinion so there was not a 3rd wheel to be aligned.


A pity that the I5 and E5 marks were not used as matching marks.

After some trail and error it finally looks when on TDC like this:



 photo DSC_2205.jpg



Hopefully I did not oversee anything.


Heiko

Email  
Re: cam timing 16h

Quote: john mitford
spoke to mike pemberton at pushrod ,great guy who gave me some pointers ,got inlet @ 30 BTDC and exhaust fully closed @ 28 decrees ATDC using a degree wheel

mike also told me on the pre 1947 16h with only the exhaust cam driven by the pinion, the best setting are 30 inlet and 25 exhaust ,i just could not quite achieve that but i got close

also used the 3 slot pinion ,one slot = 1/3 of tooth to get as near as i can ,i will drop the engine back today and see if i am correct

if anybody else experiences the same problem please ask and i will post how i did it ,the hard part i found was getting me head around it ,the actual timing part isn't as hard as it seems
thanks again


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

Re: cam timing 16h

Quote: Keith H
Quote: john mitford
spoke to mike pemberton at pushrod ,great guy who gave me some pointers ,got inlet @ 30 BTDC and exhaust fully closed @ 28 decrees ATDC using a degree wheel

mike also told me on the pre 1947 16h with only the exhaust cam driven by the pinion, the best setting are 30 inlet and 25 exhaust ,i just could not quite achieve that but i got close

also used the 3 slot pinion ,one slot = 1/3 of tooth to get as near as i can ,i will drop the engine back today and see if i am correct

if anybody else experiences the same problem please ask and i will post how i did it ,the hard part i found was getting me head around it ,the actual timing part isn't as hard as it seems
thanks again


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

Email  
Re: cam timing 16h

Quote: john mitford
hi again just replaced the 3 crankshaft bearings ,and a little puzzled on the cam timing theres no visable timing marks on either cam gear or on the 3 slotted pinion gear ,help please
thanks john mitford


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

Email  
Re: cam timing 16h

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

Email  
Re: cam timing 16h

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

Email  
Re: cam timing 16h

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

Email  
Re: cam timing 16h

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.

Re: cam timing 16h

Quote: Heiko

Hello John,



I did the same exercise lately.


I also struggeled and did not find it easy to match the degrees.

The matching points were also gone but fortunately I marled the drive pinion so there was not a 3rd wheel to be aligned.


A pity that the I5 and E5 marks were not used as matching marks.

After some trail and error it finally looks when on TDC like this:



 photo DSC_2205.jpg



Hopefully I did not oversee anything.


Heiko



This doesn't look right to me Heiko, the inlet valve shouldn't be open like that at TDC. At TDC the inlet and exhaust valves should be open about the same amount (Not on compression stroke) one just closing the other just opening as already mentioned. If you turn the crank back and forwards on TDC you will see them see-saw up and down about the same amount. I have never seen any Norton cams with timing marks, even on my 1940's Model 18 and ES2. If it has got marks, they weren't done at the factory. When setting the valve timing, both cams will be at 4 o'clock position, when the engine is turned to the other TDC position both cams will be at 10 o'clock position, so this is a good starting point.

 photo 16HValvetimingdiagram.jpg

 photo IMAG2014.jpg

Email  
Re: cam timing 16h

try not to over complicate things ,start by downloading a timing wheel off google print it cut it out and paste it to some card ,make a hole and put it behind the large crank nut ,put engine at TDC doesnt matter what stroke your on because at this stage there's no cams fitted ,firstly fit exhaust cam and pinion in a position that the valve as just fully closed @ 25 degrees ATDC ,using the timing wheel and independent marker for reference ,the pinion only drives the exhaust cam ,by doing that you have told the engine its on exhaust stroke ,next mesh inlet cam @30 degrees BTDC again using your timing wheel as reference ,if you can not quite get it to your required settings move the pinion to a different slot and try again ,as you know theres 3 slots each moves the time by 1/3 of a tooth


how do i post pictures please

Email  
Re: cam timing 16h
Re: cam timing 16h
Re: cam timing 16h

Hello John
I am building a 16h engine, from my reading Norton did not put marks on the gears and if I am correct, these gears are driven from exhaust cam. I am trying to get my head around the timing, I feel once you get it it is quite straight forward. Do you have any pictures of you setting the timing if so they would help a lot?
Thanks
Steve

Email  
Get your own FREE Forum today! 
Report Content ·  · Web Calendars   Counters & Site Stats   Email Forms   Free Guestbooks 
Powered by Bravenet