Norris D+ camshaft wonder

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Just hoping someone might have one kicking around to be rid of
or has experience to share on its function.

I think this Norris D+ -Megacycle 560-D+ is Peel's best chance for me
to kick over and not detonate on moderate throttle on 10:1 CR on 91 octane.
Here's Norris's spec sheet @ 0.020" lift
Norris D+ camshaft wonder


Megacycle spec sheet @0.040" lift. They want $356 to ship one to me.
Norris fuel/drag competition cam. Racing springs and pistons required.
Lift 405", Duration 296*, Lobe centers 105*, Flat tappet clearance .015",
Intake open/close 43 btc/ 73 abc, Exhaust open/close 73 bbc/ 43 atc.

The reasons to try Norris D+ first is based on both engine calculators
and drama by a retired Norton shop owner and drag racer,
Dunchan Campbell. My first few months of Commando possession
in '99 was desparate to find resources to maintain. Found a shop
3 hr ride away so took off to discover piles and trailer loads
of dead Norton remains soon to be sold in bulk. I picked through
for sprockets and do dads, and studied the dragster photo's.
Fuel injected plain and on a boosted beast, with Harley gearboxes as
he said once Norton hit 100 hp zone they puke up AMC's parts onto the track.

He was depressed and slumped old man, dead pan like life fun all used up.
Having cut my motorcycle teeth on P!! dragster, thought to ask
what cam he liked. Bang his eye's lit up, he jumped off stool
in shade out in the sunshine, hollowering like a mad man
while dancing in circles slapping his arthritic knees till could hardly
breath, saying time after time, yEEEHAWW, THOSE NORTONS
SURE LOVE NORRIS D+ CAM, HOT DAM THEY LOVE NORRIS D+,
for like over a minute to calm down and sit again.
Hmm glad I asked.

About a year later called him up on parts, thought to ask him
once more, any cam you liked.... from barely hearing him,
HOT DAM THEM NORTONS SURE LOVE THEM NORRIS D+ CAMS,
on and on and on for almost a minute...
I had to hold phone away from ear, his was up dancing again
and almost dropped the phone waving it to cord limit I guess.
He passed on later that year.

OH man I want some of that for sure.

hobot
 
I had a 69 Commando, back in 1971, that had a Norris R grind. Ran like a scalded cat. IIRC, the top end was great, something that's been lacking with my 72 Combat with a Web 12a cam.
 
JimC said:
I had a 69 Commando, back in 1971, that had a Norris R grind. Ran like a scalded cat. IIRC, the top end was great, something that's been lacking with my 72 Combat with a Web 12a cam.


Jim, Something besides the cam must be holding you back. I have done a lot of racing with a web 12a and have always seen power all the way to 8200. Jim
 
comnoz said:
JimC said:
I had a 69 Commando, back in 1971, that had a Norris R grind. Ran like a scalded cat. IIRC, the top end was great, something that's been lacking with my 72 Combat with a Web 12a cam.


Jim, Something besides the cam must be holding you back. I have done a lot of racing with a web 12a and have always seen power all the way to 8200. Jim

Judging from the specs, I think the 12a grind should perform quite sprightly. I haven't really dug into it very seriously yet. I can't pull anywhere near 8200 rpm in top gear and that's with a 19T sprocket. I recently tore it down (popped a piston top) and found one lobe about completely wiped out. DS cam bushing was wasted as well, looked like the shape of an egg. Thanks for confirming the 12a grind.

BTW Jim, is it you developing the gear drive to replace the cam chain? If so, how soon and how much?
 
Dang I love it when Nortoneers talk over my head, I learn something new.
8200 rpm and 12a cam dang.

Paul from what little I know, I'm thinking a fair condition Norris D+
would not make me feel guilty to alter the profiles some and
have Geoff Collins nitride the whole cam then polish lobes.
I don't need pictures so much as to know if your cam has the
configuration to fit in a factory '72 Combat. Cam is the
next most expensive item to get, shocks are the most left to go.

Nasty cam in one engine configuration can be tamed in another
engine. Bigger engine, small ports and valves, carb and headers
plus over 10 CR and retarding ignition plus advancing cam some.
Adding centrifugal blower to above, that gives a bit of boost at idle
helps it idle smooth but also come on cam in mid range and build
from there.

Theory says long cam with over lap may reduce effective CR
in slower rpm, where lugging detonation is most likely.

Mercedes has produced an example of building a fairly hi CR
aggressive cam engine that can smoke its tires w/o boost
off idle, but as rpms and power needs go up the blower
air curve is kicking in seamlessly for no let up on tire spin
power till ridiculous fast.

Can I assume in 920 Maney engine the .405" or .438" lift listed is
not going to foul valves or pistons or barrel?

hobot
 
JimC said:
comnoz said:
JimC said:
I had a 69 Commando, back in 1971, that had a Norris R grind. Ran like a scalded cat. IIRC, the top end was great, something that's been lacking with my 72 Combat with a Web 12a cam.


Jim, Something besides the cam must be holding you back. I have done a lot of racing with a web 12a and have always seen power all the way to 8200. Jim

Judging from the specs, I think the 12a grind should perform quite sprightly. I haven't really dug into it very seriously yet. I can't pull anywhere near 8200 rpm in top gear and that's with a 19T sprocket. I recently tore it down (popped a piston top) and found one lobe about completely wiped out. DS cam bushing was wasted as well, looked like the shape of an egg. Thanks for confirming the 12a grind.

BTW Jim, is it you developing the gear drive to replace the cam chain? If so, how soon and how much?

Yes the gear drive developement is done and I have a few out gathering miles to make sure before I release them. I just put another 800 miles on my bike last weekend and they are still working well. I am trying to get un-buried right now so I can get a run of them finished but I have a feeling it won't be till August before things slow down a bit. Jim
 
Yes the gear drive developement is done and I have a few out gathering miles to make sure before I release them. I just put another 800 miles on my bike last weekend and they are still working well. Jim

Please let us know when you release them.
 
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