Author Topic: CB 550 hillclimber  (Read 2370 times)

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Offline Big Bob

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CB 550 hillclimber
« on: December 21, 2009, 03:53:05 PM »
I figure somebody around here will get a big kick out of these.  My dirt bike club puts on a few hillclimbs every year.  On July 19 2009 a dude shows up with a CB 550 engine jammed into a dirt bike frame.

His first run didn't go exactly as planned....

http://www.youtube.com/user/RobertoGrande#p/u/12/6N2YRZZ_ReI



Later in the day he puts it over the top in 4.375 seconds:

http://www.youtube.com/user/RobertoGrande#p/u/38/s6zzE5NMSAI




Minnesota Nick had some problems on his Harley too.  May have been Budweiser related:

http://www.youtube.com/user/RobertoGrande#p/u/23/0JRBXXEQKyM





Offline 1080

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Re: CB 550 hillclimber
« Reply #1 on: December 21, 2009, 05:00:59 PM »
 No dead man switches required?

Looks like fun.

Offline Big Bob

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Re: CB 550 hillclimber
« Reply #2 on: December 25, 2009, 07:38:40 AM »
No dead man switches required?

Looks like fun.

Look at his left wrist at the end of the video where he rides it back down.  He's got a tether for a kill switch.

The engines noise you're hearing was from bikes in the staging area.  It was just to my right as I was shooting.

Some of the bikes that come out - unbelievably loud.  It's nute how much noise you can get out of some of them.  The four strokes aren't too bad for the most part.  But the two strokes?  Eeek!  Especially when you take a two stroke triple and stick it in a dirt bike frame:


http://www.youtube.com/profile?user=RobertoGrande#p/u/52/H7jV_OiGmoE

http://www.youtube.com/profile?user=RobertoGrande#p/u/34/td0Fz3ULWls



This guy takes a while to go but puts on a nice finish.

http://www.youtube.com/profile?user=RobertoGrande#p/u/57/IvPEbQ7J1go

Offline OldSchool_IsCool

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Re: CB 550 hillclimber
« Reply #3 on: December 25, 2009, 12:33:14 PM »
Search the site for "big bang cams"  You'd be surprised how effective our sohc engines can be as hill climbers.
Can I have a motorcycle when I get old enough?
If you take care of it.
What do you have to do?
Lot’s of things. You’ve been watching me.
Will you show me all of them?
Sure.
Is it hard?
Not if you have the right attitudes. It’s having the right attitudes that’s hard.

Offline 1080

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Re: CB 550 hillclimber
« Reply #4 on: December 25, 2009, 02:18:32 PM »
Sorry, I see it on the 500 rider now.  The background engines did make it sound like it was still running. I can not make it out on the HD rider but it did go dead after dumping the rider.

Merry Christmas 1080.

Offline paulages

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Re: CB 550 hillclimber
« Reply #5 on: December 25, 2009, 05:10:43 PM »
i've always wanted to find a flipped cam to turn a four into a twin-druple.  ;D i wonder if megacycle still has any of these on file or could at least cut and re-weld a stock cam 180 degrees out. that would make a fun hillclimber.
paul
SOHC4 member #1050

1974 CB550 (735cc)
1976 CB550 (590cc) road racer
1973 CB750K3
1972 NORTON Commando Combat
1996 KLX650 R

Offline OldSchool_IsCool

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Re: CB 550 hillclimber
« Reply #6 on: December 25, 2009, 05:57:07 PM »
i've always wanted to find a flipped cam to turn a four into a twin-druple.  ;D i wonder if megacycle still has any of these on file or could at least cut and re-weld a stock cam 180 degrees out. that would make a fun hillclimber.

I'd like to have a big bang cam too, just to have it in case the right engine and titleless frame comes along.
Can I have a motorcycle when I get old enough?
If you take care of it.
What do you have to do?
Lot’s of things. You’ve been watching me.
Will you show me all of them?
Sure.
Is it hard?
Not if you have the right attitudes. It’s having the right attitudes that’s hard.

Offline MRieck

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Re: CB 550 hillclimber
« Reply #7 on: December 25, 2009, 07:26:44 PM »
i've always wanted to find a flipped cam to turn a four into a twin-druple.  ;D i wonder if megacycle still has any of these on file or could at least cut and re-weld a stock cam 180 degrees out. that would make a fun hillclimber.
They should have the records for 750 and GS1100 Paul
Owner of the "Million Dollar CB"

Offline paulages

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Re: CB 550 hillclimber
« Reply #8 on: December 26, 2009, 12:45:08 AM »
i've always wanted to find a flipped cam to turn a four into a twin-druple.  ;D i wonder if megacycle still has any of these on file or could at least cut and re-weld a stock cam 180 degrees out. that would make a fun hillclimber.
They should have the records for 750 and GS1100 Paul

i'll keep that in mind for my next 750 engine.  ;) ;D
paul
SOHC4 member #1050

1974 CB550 (735cc)
1976 CB550 (590cc) road racer
1973 CB750K3
1972 NORTON Commando Combat
1996 KLX650 R

Offline Retro Rocket

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Re: CB 550 hillclimber
« Reply #9 on: December 26, 2009, 01:36:18 AM »
Hmmmm, tell me more about these "big bang" engines...... ;)

Mick
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750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline OldSchool_IsCool

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Re: CB 550 hillclimber
« Reply #10 on: December 26, 2009, 08:59:32 AM »
Hmmmm, tell me more about these "big bang" engines...... ;)

Mick

The theory on a "big bang" is to change the firing order of the engine so that #1 fires at the same time as #4.  Similarly, #2 and #3 fire in unison too.  This is done by changing the cam grind so that #3 and #4 lobes are 180 degrees from their stock positions.  In other words, they MATCH the lobes of their partner cylinder.  No need to change ignition timing due to the "wasted spark" design of the SOHC engine.

Instead of your engine firing with a nice, smooth bang-bang-bang-bang, you get BANG!-BANG!-rest-rest.  Massive low-end torque with a built in re-grip cycle (kinda like modern anti-lock brakes).  You give up the high-end power band and smoothness. 
Can I have a motorcycle when I get old enough?
If you take care of it.
What do you have to do?
Lot’s of things. You’ve been watching me.
Will you show me all of them?
Sure.
Is it hard?
Not if you have the right attitudes. It’s having the right attitudes that’s hard.

Offline Big Bob

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Re: CB 550 hillclimber
« Reply #11 on: December 30, 2009, 04:21:12 AM »
I'd love to see someone bring out a CB 750 to our hillclimbs.  Somebody has to give my buddy Dan a run for his money:



And the BSA guys:



And then of course the dang Sportster, there's got to be a SOHC4 that can beat this guy: