HMS Commando vs USS Harley Davidson

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crusadersports

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What would you do? I have a mate with an 883 Sportster (don't know how old; mid 90s?) who is annoyingly but definitley quicker uphill than the 'old wheezer', my 850 MKIII. The old wheezer is due a rebore and I'm wondering if I'm wasting my time trying to fly the flag here- in trying to keep up on the Norton. Silly thing is that round the twisties the Norton gets its own back, so we're not that far apart. Must be about 50bhp each. Anyone any experience in making a MKIII 850 fly without getting silly? Can I stick higher comp pistons in the Norton or am I wasting my time? Already have a 34mm single Mikuni and peashooters.

crusdaerports
 
If the motor is aging as you mentions, then probably the camshaft is getting worn down and you're not getting the valve lift and timing it should have. If its an original Mk3 camshaft, they were not adequately hardened.

Mick
 
how much do you weigh? :mrgreen:

rebuild a worn motors and shedding lbs (on bike and body) will no doubt make the bike a bit faster - not to mention other potential bonuses
 
I'd throw a cam and a 920 kit and some head work at it. And start stripping off the useless bits. Just my opinion.
 
ML said:
If the motor is aging as you mentions, then probably the camshaft is getting worn down and you're not getting the valve lift and timing it should have. If its an original Mk3 camshaft, they were not adequately hardened.

Mick
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+1 I've seen commando's and sportsters race....commando's win.
very close hp, sportsters weigh on average 574 pounds...much much more than your commando, so as above there is something wrong with your bike or he has a 1200 conversion
 
A friend of mine got a sportster 1200, early 2000's model. Stock with pipes. My 1975 XS 650 with short dunstall's and pod filters, out ran him. I figure I had a huge weight advantage, and didn't need to shift nearly as soon as he did. He was a little pissed. I heard from a harley friend of mine that there is a huge swing in horsepower from the factory on the sportsters, anywhere from 45-65 HP output.
 
The Harley will make more torque down low, the Commando will eclipse it in the center of its mid range; light to light the Harley will prevail, when the distance opens up the Norton will dominate...

Consider this: Race your Norton; kill your Norton, or be prepared to pull it down frequently, and add bits....

RS
 
Hi
I have own my 74 850 since new and in 91 I brought a new 1200 sportster, I put hi performance exhaust system on it , but after 3 years I went back to riding the Norton, my Norton has a SS cam and head work to match as well balanced crank, my Norton is alot quicker than the 1200, lighter and handles 100% better, but mine you I have put the motor in a Wideline Featherbed frame, so I would just spend the money and rebuild your Norton motor with a few improvements and your mate will be eating your dust...

Ashley
 
pelican said:
ML said:
If the motor is aging as you mentions, then probably the camshaft is getting worn down and you're not getting the valve lift and timing it should have. If its an original Mk3 camshaft, they were not adequately hardened.

Mick
Click to expand...


+1 I've seen commando's and sportsters race....commando's win.
very close hp, sportsters weigh on average 574 pounds...much much more than your commando, so as above there is something wrong with your bike or he has a 1200 conversion
Click to expand...


MK 3s carry a lot more pork than earlier Commandos and also (standard) run a 22 tooth sprocket which lowers the performance as well. If it has the original mufflers they need to get the boot. Also, the single carb will lose out in the standard engine configuration in the top end. If you want the extra punch, start with lower gearing (21 tooth) and check the valve lift to see if your cam has worn over the years as the MK3s were prone to this.
 
How much do you want to spend?

Fullauto Head = 2000 dollars
Dual flat side PWK carbs =435 dollars
While we are at it lets throw in a cam, belt drive primary, maybe even some of those fancy lightweight pistons. Then we can start on the ignition...

Better decide how bad you want it!

Russ
 
You're already the winner. He's riding a sportster and you have a commando. Who cares if it goes up a hill better. Its still a H-D and will never be anything else or anything special. You're bike is a Norton Commando and that is special. I'd rather ride a crappy looking commando than great looking and performing H-D anyday.
 
JimR said:
You're already the winner. He's riding a sportster and you have a commando. Who cares if it goes up a hill better. Its still a H-D and will never be anything else or anything special. You're bike is a Norton Commando and that is special. I'd rather ride a crappy looking commando than great looking and performing H-D anyday.
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+1, and Harley pays my mortgage. My wife works for Harley.
 
swooshdave said:
Just a simple refresh of the motor should have you putting him in his place.
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Despite my attempt at black humor above...I have to agree with Dave here. Time to refresh the old girl and go ride.
However, the Fullauto heads are reporting improved midrange torque...fwiw.
Russ
 
There are well known fairly cheap upgrades and mods for 850, often in old work manual and Duntall Notes. You do not need to go outside of common Norton parts to spank a 883 HD unless its had a few more times the money and effort put into it, usually the first is give it 1/3 more displacement.

850-mk2-engine-mods-t3199.html

CD Manuals http://www.google.com/url?sa=t&source=w ... VQ&cad=rja
The Norton CD is now into its FOURTH EDITION, and covers not just the Commando, ... and the Commando section has been added to with another Parts List, Stage 2 Tuning ... 850 Commando Stage 1 High Performance Modification Notes
 
Why not just put a 19 tooth gearbox sprocket :?: It's still good for over 100 mph, maybe a bit more revs at highway speeds, but you will smoke him on the hills.

Jean
 
You shouldn't need to modify a Commando to embarrass an 883. I have a MK3 that is stock except peashooters and a K&N air filter that I have used for rides with a buddy on his 883. Even after he took it down to the dealer for screaming eagle carb and pipes the MK3 would run away and hide. Jim
 
I bought an 883 new in 1988 . The magazine road tests of the day said it dyno tested at roughly 38 rear wheel HP . IIRC comnoz said on here in another thread that's about what the average stock 850 makes on his dyno , so in stock trim the two are roughly comparable . I also think I remember him saying that on avg you give up a couple of ponies with the single Mikuni vs the stock twin Amals . Even a MK3 should be at least a few lbs lighter than a Sportster . Your MK3 is probably a little tired . It also probably has a soft cam which is robbing you of valve lift and duration which is further reducing your power output . A well done refresh with a few relatively minor tweaks should put you ahead , but Jeandr's and Fullauto's comments regarding gearing are important . 883's are geared low in stock form . After I built my 883 into a 1200 with extensively ported heads and cams , I geared it UP 10 PERCENT to reduce the vibes while cruising , and it was still going only 50 mph at 3,000 rpm .
 
RoadScholar said:
The Harley will make more torque down low, the Commando will eclipse it in the center of its mid range; light to light the Harley will prevail, when the distance opens up the Norton will dominate...RS
Click to expand...

If you can reach the end of 2nd gear before the next light, the Sportster should be in your mirrors.

Consider this: Race your Norton; kill your Norton, or be prepared to pull it down frequently, and add bits....
Click to expand...

I will admit to blowing a head gasket the last time I took on a Sportster... but I spanked him good :D And I had a pillion..
 
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