Author Topic: Need... more.... power....  (Read 6766 times)

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Offline DME

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Need... more.... power....
« on: August 04, 2006, 12:21:52 AM »
Ok, I´m in dire need of some more power in my café.

Had a small race against a '70 Norton Commando 750 last night and was blown to smithereens :'(

The Commando had Dunstall cams and a ported head.


My engine is completely stock (well, it has been bored to 2:nd overdimension (+.5 mm)) and it pulls well up to 160 kmph (100 mph).

Tops out at around 185-190 kmph.

It has been rebuilt this winter with new bearings, chains, valves and valve guides, as well as rebored.



What would be a good recipe for my engine?

I want to increase power throughout the rev range, not just top end.

Should I go for a big bore (836) with a suitable cam and porting, or is there another, better way?

What would be a suitable camshaft for my purposes?

Carb mods?

Thankful for info!

Cheers
Daniel





Offline nippon

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Re: Need... more.... power....
« Reply #1 on: August 04, 2006, 04:35:18 AM »
oh, what a shame. ;D
I think, porting the head is the most efficient thing to increase power, in relation to the costs, too.
Additional, you can replace your stock camshaft with a mild "hot" camshaft with an adjustable cam sprocket.
Megacycles and Webcam offers a lot of different shaped camshafts for stock cylinders and big bored one,
from the broad power range to top end. I will take a mild, broad power range (street) camshaft for big bore usage.
That's my way to go. The only reason is why i want to use a big bore kit is, that i have to hone my cylinders
and I have to replace my pistons and rings, too (+0.25 ??, don't know, don't like to measure or test compression),
so it's easier for me to rebuild the engine with complete new 836cc stuff.
(I own a second cylinder, so i could go back to the original size, if i would like).
Next and more expensive way would be to use Dyna ignitions/coils and bigger carbs.
But carbs,...not for me, I want to conserve the original look of the K1.

...you own an awesome nice 2 in 1 tank,....gives the bike a really nice and long stream line shape.


nippon
« Last Edit: August 04, 2006, 05:58:31 AM by nippon »

Offline KB02

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Re: Need... more.... power....
« Reply #2 on: August 04, 2006, 05:16:51 AM »
Plus, while I have to admit a certain love affair with the SOHC Hondas, I have to be honest and say that I'm not surprized that Norton beat you up.   ;D ;)

I would have to say try the big bore kit and a Cam. That should give the Commando something to play with.
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Offline mlinder

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Re: Need... more.... power....
« Reply #3 on: August 04, 2006, 06:16:11 AM »
750 commandos weighed about the same, and made the same horsepower, though they reached their peak power a little earlier in the rev range (and lose quite a bit more near redline.)
Shouldnt take much to catch him. The 750's were so close to grenading all the time (the 750 started life as a 400cc or 500cc design, cant remember which, they just kept boring the damned thing out more), that I cant image hes got THAT much more power than a stock.
Shouldn't take much to kick his ass. I'm sure some sohc tuners here can tell you whats best. mreick, etc.
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Offline ofreen

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Re: Need... more.... power....
« Reply #4 on: August 04, 2006, 08:30:38 AM »
What kind of race did you lose, a drag race?  If so, you could change your gearing, might have better luck without spending a lot of money.

Otherwise, if you want to beat the Norton, turn the race into an endurance race.  Should have no trouble beating it then.
Greg
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Offline mlinder

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Re: Need... more.... power....
« Reply #5 on: August 04, 2006, 09:01:44 AM »
What kind of race did you lose, a drag race?  If so, you could change your gearing, might have better luck without spending a lot of money.

Otherwise, if you want to beat the Norton, turn the race into an endurance race.  Should have no trouble beating it then.

Well, that would for sure clinch the contest. #$%*, a 10 mile run at the top 10% of performance on these bikes might kill the norton :P

I would think that in a real 1/4 mile race, your stock cb might win as well. I don't see a norton outpulling you from 50 to 110.
thats the last 7 seconds or so of the race :\
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Offline Jeff

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Re: Need... more.... power....
« Reply #6 on: August 04, 2006, 10:12:49 AM »
TURBO

Offline DME

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Re: Need... more.... power....
« Reply #7 on: August 04, 2006, 10:14:41 AM »
Well, I got wasted by the Norton.

I need more power, not lower gearing....

My Honda pulls up to the redline in topgear with stock gearing.

Lower gearing = faster acceleration / LOWER top speed :(

Don´t want that.

Faster acceleration with the same gearing = more power :)

Yes please!

Somebody come up with some hands on tips on what camshaft to get, what porting to do, compression ratios to run.....

....and hurry, cause soon the Honda goes back in the shed for another 10 years while I´ll pop some wheelies on a snortin' Norton 8)

I know the knowledge is here to give the Honda performance to match it´s looks!

Cheers
Daniel

Offline DME

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Re: Need... more.... power....
« Reply #8 on: August 04, 2006, 10:16:30 AM »
TURBO

Lots of power, yes, but wouldn´t look right.... too modern... would consider supercharging, though...

Cheers
Daniel

Offline mlinder

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Re: Need... more.... power....
« Reply #9 on: August 04, 2006, 10:28:06 AM »
Well, I got wasted by the Norton.

I need more power, not lower gearing....

My Honda pulls up to the redline in topgear with stock gearing.

Lower gearing = faster acceleration / LOWER top speed :(

Don´t want that.

Faster acceleration with the same gearing = more power :)

Yes please!

Somebody come up with some hands on tips on what camshaft to get, what porting to do, compression ratios to run.....

....and hurry, cause soon the Honda goes back in the shed for another 10 years while I´ll pop some wheelies on a snortin' Norton 8)

I know the knowledge is here to give the Honda performance to match it´s looks!

Cheers
Daniel
In what kind of race were you? just form a stop to like, 80? Or in the twisties, or what?
message MReick. He does headwork, and can recommend cams and such. You'll need to do carb work too, of course.
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Offline DME

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Re: Need... more.... power....
« Reply #10 on: August 04, 2006, 10:31:51 AM »
Drag race.

Offline mlinder

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Re: Need... more.... power....
« Reply #11 on: August 04, 2006, 10:32:45 AM »
Drag race.
To what speed?
In any case, PM MReick.
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Offline Hondell

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Re: Need... more.... power....
« Reply #12 on: August 04, 2006, 10:38:58 AM »
Turbo Turbo. Will destroy that oil leaker.
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Offline DME

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Re: Need... more.... power....
« Reply #13 on: August 04, 2006, 10:41:18 AM »
TURBO

Lots of power, yes, but wouldn´t look right.... too modern... would consider supercharging, though...

Cheers
Daniel

Offline mlinder

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Re: Need... more.... power....
« Reply #14 on: August 04, 2006, 10:48:00 AM »
Stock norton 73 commando. 1/4 mile time by EXTREMELY skilled rider : 12.6
Stock 69 cb750. 1/4 mile time by skilled rider : 12.8 -13
Your bike is lighter than stock, I'd imagine.

Shouldn't take much to get you to beat the crap outa that norton.
10 CRANK horsepower should take at least half a second off your 1/4 mile time if you weigh about 170.
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Offline nickjtc

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Re: Need... more.... power....
« Reply #15 on: August 04, 2006, 10:55:19 AM »
Turbo Turbo. Will destroy that oil leaker.

Hey!!! Be kind, not all Nortons are oil leakers! Mine has an oil-tight motor but pisses swingarm lube oil (yes, you use heavy weight oil, not grease in there), just to make sure there is some mess under the bike when you park it.

Seriously though, and at risk again of sounding like an old fart, why increase power when it may affect the chassis' ability to handle it............or am I opening a can of worms that shouldn't be opened here??
Nick J. Member #3247

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Offline mlinder

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Re: Need... more.... power....
« Reply #16 on: August 04, 2006, 10:57:50 AM »
By modern standards, the chassis can't handle the power it already has. Flexi-Flyers, indeed.
Nothing those of us who have ridden these old bikes at some speed before can't handle, I dont think.
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Offline DME

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Re: Need... more.... power....
« Reply #17 on: August 04, 2006, 11:02:17 AM »
Stock norton 73 commando. 1/4 mile time by EXTREMELY skilled rider : 12.6
Stock 69 cb750. 1/4 mile time by skilled rider : 12.8 -13
Your bike is lighter than stock, I'd imagine.

Shouldn't take much to get you to beat the crap outa that norton.
10 CRANK horsepower should take at least half a second off your 1/4 mile time if you weigh about 170.

Yes, I know.

I just want to know what would be the best mods, what works best together....

in essence:

 - what camshaft grind to look for?

 - what porting to do?

 - what compression ratio to run?

 - what carb-mods to to?

 - should I run electronic ignition?

 - big bore? (got an extra cylinderbank bored to 67 mm, 895 cc but no pistons)

 - what exhaust to use (keep the 4-2, 4-2-1 or 4-1?)
 

Want an engine with more power overall, and with maintained driveability.

Don´t want to start buying parts randomly.

Cheers
Daniel

Offline DME

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Re: Need... more.... power....
« Reply #18 on: August 04, 2006, 11:04:48 AM »

Seriously though, and at risk again of sounding like an old fart, why increase power when it may affect the chassis' ability to handle it............or am I opening a can of worms that shouldn't be opened here??

Chassis is fine. Anyway it´s beside the point.

Offline mlinder

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Re: Need... more.... power....
« Reply #19 on: August 04, 2006, 11:19:22 AM »
Click this:
http://www.sohc4.us/forums/index.php?action=profile;u=49

PM him.

If you get different cam/exhaust/whatever, I think you could probably talk to this guy about carbs..
http://www.cyclexchange.net/index.html

I'm buying carbs from him. He likes to talk to people about their bikes before he sells them carb setups.
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Offline dusterdude

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Re: Need... more.... power....
« Reply #20 on: August 04, 2006, 11:21:11 AM »
Click this:
http://www.sohc4.us/forums/index.php?action=profile;u=49

PM him.

If you get different cam/exhaust/whatever, I think you could probably talk to this guy about carbs..
http://www.cyclexchange.net/index.html

I'm buying carbs from him. He likes to talk to people about their bikes before he sells them carb setups.
which carbs are you buying?
mark
1972 k1 750
1949 fl panhead
1 1/2 gl1100 goldwings
1998 cbr600 f3

Offline mlinder

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Re: Need... more.... power....
« Reply #21 on: August 04, 2006, 11:26:01 AM »
Click this:
http://www.sohc4.us/forums/index.php?action=profile;u=49

PM him.

If you get different cam/exhaust/whatever, I think you could probably talk to this guy about carbs..
http://www.cyclexchange.net/index.html

I'm buying carbs from him. He likes to talk to people about their bikes before he sells them carb setups.
which carbs are you buying?
http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm
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Offline DME

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Offline dusterdude

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Re: Need... more.... power....
« Reply #23 on: August 04, 2006, 12:04:57 PM »
Click this:
http://www.sohc4.us/forums/index.php?action=profile;u=49

PM him.

If you get different cam/exhaust/whatever, I think you could probably talk to this guy about carbs..
http://www.cyclexchange.net/index.html

I'm buying carbs from him. He likes to talk to people about their bikes before he sells them carb setups.
which carbs are you buying?
http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm
cool,ive been waiting for someone here to be the guinea pig with them,please let us know how they work out for you.
mark
1972 k1 750
1949 fl panhead
1 1/2 gl1100 goldwings
1998 cbr600 f3

Offline mlinder

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Re: Need... more.... power....
« Reply #24 on: August 04, 2006, 12:09:31 PM »
Click this:
http://www.sohc4.us/forums/index.php?action=profile;u=49

PM him.

If you get different cam/exhaust/whatever, I think you could probably talk to this guy about carbs..
http://www.cyclexchange.net/index.html

I'm buying carbs from him. He likes to talk to people about their bikes before he sells them carb setups.
which carbs are you buying?
http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm
cool,ive been waiting for someone here to be the guinea pig with them,please let us know how they work out for you.

You can bet your ass I will.
500 bucks for:
(2) VM34 mm Mikuni carbs (prejetted)                             
Special cast alloy  manifolds.                                                 
Motion Pro turbo throttle (7/8 bars)                                     
Motion Pro throttle cable.                                                   
Velocity stacks ( screen and foam type)                               
Carb rubbers and stainless clamps.                                       
Instruction sheet
Extra jets

If it works, it's a #$%*in steal.
only 2 carbs to adjust and synch!                         
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