Skip to main content
000000 000003 000006 000009 000012 000015 000018 000021 000024 000027 000030 000033 000036 000039 000042 000045 000048 000051 000054 000057 000060 000063 000066 000069 000072 000075 000078 000081 000084 000087 000090 000093 000096 000099 000102 000105 000108 000111 000114 000117 000120 000123 000126 000129 000132 000135 000138 000141 000144 000147 000150 000153 000156 000159 000162 000165 000168 000171 000174 000177 000180 000183 000186 000189 000192 000195 000198 000201 000204 000207 000210 000213 000216 000219 000222 000225 000228 000231 000234 000237 000240 000243 000246 000249 000252 000255 000258 000261 000264 000267 000270 000273 000276 000279 000282 000285 000288 000291 000294 000297 000300 000303 000306 000309 000312 000318 000321 000324 000327 000330 000333 000336 000339 000342 000345 000348 000351 000354 000357 000360 000363 000366 000369 000372 000375 000378 000381 000384 000387 000390 000393 000396 000399 000402 000405 000408 000411 000414 000417 000420 000423 000426 000429 000432 000435 000438 000441 000444 000447 000450 000453 000456 000459 000462 000465 000468 000471 000474 000477 000480 000483 000486 000489 000492 000495 000498 000501 000504 000507 000510 000513 000516 000519 000522 000525 000528 000531 000534 000537 000540 000543 000546 000549 000552 000555 000558 000561 000564 000567 000570 000573 000576 000579 000582 000585 000588 000591 000594 000597 000600 000603 000606 000609 000612 000615 000618 000621 000624 000627 000630 000633 000636 000639 000642 000645 000648 000651 000654 000657 000660 000663 000666 000669 000672 000675 000678 000681 000684 000687 000690 000693 000696 000699 000702 000705 000708 000711 000714 000717 000720 000723 000726 000729 000732 000735 000738 000741 000744 000747 000750 000753 000756 000759 000762 000765 000768 000771 000774 000777 000780 000783 000786 000789 000792 000795 000798 000801 000804 000807 000810 000813 000816 000819 000822 000825 000828 000831 000834 000837 000840 000843 000846 000849 000852 000855 000858 000861 000864 000867 000870 000873 000876 000879 000882
English French German Italian Spanish

Cam shaft identification.

Forums

Could someone help please?

Tim Gostling in the records forum was kind enough to identify my "hybrid" Dominator 99's engine by size and date of manufacture. Since it was made in October 1957 as a bog-standard 99 it has acquired a couple of SS stamps on the crank casing. 

It is possible that there is nothing but misrepresentation (fraud!) about this but could the 1973 rebuild have included a sports cam? I have the cylinder block off the engine at the moment and, without taking the crankcase apart, the only real measurement I can make is the "rise" of the cams from the cam shaft itself.  It is consistantly 8.5mm on one side of the cam and 8.9mm on the other across all four cams. (The shaft has different diameters; the cam surfaces are square!)

Attached diagram shows what I measured.

Is it possible to tell from this measurement if I have the standard cam shaft or is it something different?

Many thanks,

Derek

Attachments
Permalink

Are there any identifying stamps on the camshaft that you can see?  I do mean stamps, not casting numbers although that might help too.

"X1" or "X2" indicates an "SS" cam and "QR" (Quietening Ramps) is a Daytona cam fitted to 99s from about 1959 or maybe earlier, I haven't checked.  It's probably listed on this site but I've started, so i'll finish this posting!

Permalink

At 8.5mm as per your diagram it is very close to the special cam of the day that went on to become the standard cam we know today as the 06.1084. A cam so nice that it was re-introduced for the later Commando's as the standard cam. 

Permalink

NHT cams are either on twin chain (cam/magneto) core or later commando single cam drive chain version.While they have some dimensional similarities, they are not interchangeable.

22729 is the "SS", (on a twin chain core 1949-1970)

06-1084 is the "1S",  (on a single chain core 1971-1975)

The grind profile is the same but will not interchange for mechanical differences between engine series. 

http://atlanticgreen.com/camsurvey.htm

Would like to borrow a "daytona" cam (pre QR) for profiling. TIA

Permalink

Thank you for your replies. They have been most helpful and I now know that I have an early SS cam.

Casting number T2219@3 and stamped X2.

What a great resource this site is. I am much obliged.

Best wishes,

Derek

Below is chapter and verse from last January.

 

Submitted by philip_hannam on Wed, 30/01/2019

The following info is taken from the unreleased Dominator Service Notes...........

There were four main camshafts produced by the Norton Factory for their standard Dominator engined bikes. All have the casting number of T2219. Those for the Model 7 engine are best avoided if the plan is to rebuild a post 1956 engine and expect a decent road performance from it. The first camshaft was right for the early ‘Iron headed’ engine, in that it helped to produce enough power without the top half over-cooking.

The later ‘Aluminium cylinder heads were able to cope with more power; especially those with the extended finning. So when the 99 engine arrived, with the ‘Daytona’ camshaft in 1956, this had extended times for valve openings, increasing the power, but also the valve train noise. The addition of a 0.010' ramp to its lobes, around 1959, to help quieten down the engine rattles. Hence the title of Q.R. camshaft. These identification letters generally being stamped onto its sidewall.

 The fourth variation of the camshaft arrived with the Downdraft SS cylinder heads. (But was also fitted to the non-downdraft head used on the 99SS).

Basically it was the QR camshaft but slightly altered in profile and renamed as the SS. Most have a casting number of T2219@3. From 1960, this camshaft was a standard fitting for all the Dominator SS engines, including Atlas and Mercury. It even survived, in a modified form, to become a standard Commando part until ousted, for a while, by the arrival of the Combat 2S disaster.

The earliest SS camshafts were stamped with X1 (Bracebridge) or X2 (mostly from Woolwich). The X2 camshafts were supposed to have deeper hardening to cope with the 650 engines power but the late John Hudson claimed that the X1 version was produced with greater accuracy. Later Mercury camshafts often just have the casting number.

The SS camshaft will fit into any of the pre-1960 engines and run quite happily as long as excessive revs are avoided. Otherwise valve float can occur, especially above 6000rpm. But who (track day lads excepted) hammers an engine that much nowadays?

The attachment shows the four Dominator camshafts used in production bikes from 1949 up to 1969. The camshaft on the far right came from a very early Dunstall tuned 99. His later versions having the option of a fitted needle-roller bearing and positive oil feed.

Attachments
Permalink

It even survived, in a modified form, to become a standard Commando part until ousted, for a while, by the arrival of the Combat 2S disaster.

lobe grind was identical but the drive end was reengineered for a single drive chain and inboard tach drive gear was added.

"Basically it was the QR camshaft but slightly altered in profile and renamed as the SS"

This above statement needs to be corrected....

the Daytona was modified to become the(88/99) QR,  the SS/22729 was entirely new see below

Also the SS cam in earlier (non SS) engines will need additional work, the 88SS had modified barrels to accomodate the valve train...99SS ?? I have no experience here...

 

M7-QR-SS(22729)

 

Norton Owners Club Website by White-Hot Design

Privacy Policy