Author Topic: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??  (Read 2227 times)

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Offline toycollector10

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #1 on: March 05, 2007, 03:23:21 AM »
Is this rare and or desirable??

It could be and if nothing else, a interesting piece of high performance nostalgia for the die-hard SOHC collector. Seems that Russ Collins is still around doing fuel injector work and might be willing to shed some light on the details.  http://www.rceng.com/
« Last Edit: March 05, 2007, 03:31:26 AM by USN20 »

Offline 736cc

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #2 on: March 05, 2007, 04:57:36 AM »
It'd be a GREAT start of a cafe project
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Offline Geeto67

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #3 on: March 05, 2007, 05:52:23 AM »
RC was primarily an american company and while he did ship world wide I can't imagine that many of his bikes made it to kiwi-land, espically since they were made to order. If that bike was really built by RC (and that paint seems to suggest so as I have seen others he built painted that way) it would not surprise me if it was the only one down under.
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Offline mwohlenhaus

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #4 on: March 05, 2007, 06:01:44 AM »
outside of ugly (IMHO) the forwards would be worth something as would the body work, but good luck finding a motor that wouldn't break the bank.
With out the motor, it is just another CB 750 (Frame in this case). It has Dunstall bodywork on it.
ditto.
« Last Edit: March 05, 2007, 06:05:48 AM by mwohlenhaus »

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #5 on: March 05, 2007, 09:53:59 AM »
Is this rare and or desirable??

It could be and if nothing else, a interesting piece of high performance nostalgia for the die-hard SOHC collector. Seems that Russ Collins is still around doing fuel injector work and might be willing to shed some light on the details.  http://www.rceng.com/

I recently sent an email to Russ Collins about a big bore kit I'm working on. I was pleasantly surprised when he took the time to respond especially since he's been out of the 750 business for so many years. I believe his personal email is RC@RCEng.com.

If it were me, I'd prefer to have the engine rather than the frame.   
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline chung

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #6 on: March 05, 2007, 10:37:24 AM »
I didn't know he built complete bikes. Very little reading on the web about him. I emailed him several years ago and got the same reply :"That like another lifetime it was so long ago"

I have one of his motors. But no COBRA tag on it although it appears to be the original valve cover as it has the added hold downs for the cam towers. Not sure when they started calling it a Cobra or placing the badge on it?

Mine is a very early K1 @ 70mm bore with stock stroke. That calcs out to 970cc. You can't sleeve one any bigger or the sleeves will touch! Barely an 1/8 inch left in the crankcase.

They tell me that you can bore these sleeves another 1/2mm to 1035 or something close to that.

This one has a RC315C cam and all the goodies except that the rod started life as stock forgings. Countless hours to get them to what they are now but I'm scared to rev it too high. These pistons are huge 8)
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #7 on: March 05, 2007, 10:45:57 AM »
The pistons I'm playing with are 73.75mm. BMFs. Block already bored.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline ttr400

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #8 on: March 05, 2007, 10:48:04 AM »
I think it would be a nice project to have even without the motor, you can build a better motor today with the more modern and new performance parts that are available as apposed to 30+ year old parts.

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Offline jonbuoy

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #9 on: March 05, 2007, 11:08:43 AM »
Ah toy collector we meet again!  I've been looking at that one too, the Frame and rearsets are nice - looks like it might need re-plating.  I can't see anything special about the swingarm though , I have a feeling he is going to want decent money.  I haven't been around to see it yet.

Cheers

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Offline chung

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #10 on: March 05, 2007, 11:49:19 PM »
73.75mm/ you are just trying to show off, huh? I don't have parts handy to measure but it sounds like a hand grenade with the pin pulled and the handle flying in the air ???

The cyl walls have to be literally paper thin. or the crank case openen up to a huge oval hole with the web totally removed/

i'm so corn-fused ???
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1972 YDS7, 250
1972 YR5, 350
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1981 XS650 Special II

Offline Terry in Australia

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #11 on: March 06, 2007, 12:25:11 AM »
I've seen a few RC Cobra CB750's (one of the SOHC4 members here had one) and I doubt that RC built that bike, yeah, I know it's got an engraved tag that says "RC Engineering" etc, but RC were engine builders, and all the other RC's I saw were all about the engine, and I can't ever remember seeing one with Dunstall bodywork.

More likely someone bought an RC Cobra-engined bike, and added some Dunstall bodywork. The whole thing looks a little "dated" to me though, isn't it funny how when we were young, we all though that the Dunstall bodywork was really cool, but nowadays, the original bike actually looks better?

Geez, I hope that's not maturity sneaking up on me, next thing I know I'll be sitting out in front of my local Safeway store, telling stories about the "good ol' days", ha ha! Cheers, Terry. ;D
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Offline Big Jay

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #12 on: March 06, 2007, 12:38:21 AM »
Thee Cobra part was the motor, which this bike doesn't have. Don't remember there ever being Cobra bikes.

Jay

Offline toycollector10

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #13 on: March 09, 2007, 02:01:17 PM »
"when we were young, we all though that the Dunstall bodywork was really cool, but nowadays, the original bike actually looks better?"

You got that right Terry........I think it's amazing how the Honda design team nailed it first time. A design classic for sure.
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Offline Terry in Australia

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #14 on: March 09, 2007, 02:07:49 PM »
"when we were young, we all though that the Dunstall bodywork was really cool, but nowadays, the original bike actually looks better?"

You got that right Terry........I think it's amazing how the Honda design team nailed it first time. A design classic for sure.

Thanks mate, are the donations flooding in for the "Buy Terry a Sandcast for his birthday" fund?  ???  ;D
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Offline toycollector10

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #15 on: March 09, 2007, 06:56:28 PM »
It's looking good Terry, in about a week I should have enough for a pack of those litte washer thingiies that fit the tabs on your $350 set of NOS tank emblems so they stick to the tank.

http://cgi.ebay.com/ebaymotors/Honda-NOS-Gas-Tank-Emblem-Screws-CBX-CB400-CB750_W0QQitemZ280088379414QQcategoryZ35593QQrdZ1QQcmdZViewItem?hash=item280088379414

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1973  Z1 Kawasaki

Offline JohnG

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #16 on: March 09, 2007, 07:37:44 PM »
In the late '70s I used to get his catalogues regularly as I bought alot of part from him for various projects. Even rode out to his shop one time while going across country in '78.

The catalogues were completely motor oriented. Except for drilling disk rotors, I don't recall a thing for chasis, and certainly not complete bikes.

He had two "business cards" in those days: a triple engine , 750 Honda based drag bike "The Atcheson,Topeka and Sante Fe"  and a late dual motor bike.  He crashed on the triple and almost died. I think he had one of the motors made into a coffee table. He was located in Gardena, CA then.

The Cobra motor was top of the line in the catalogue with almost everything either replaced or beefed up: forged rods, heavier cylinder studs, his own cylinder block (this would be a give-away for ID purposes), ported head, big Manley valves, cam....).  Cooling would of course be a MAJOR issue and one would want the best oil cooler available (or live in places like Alaska). ;)

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Offline jevfro

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Re: Russ Collins RC Cobra CB750 bored to 1000cc. Who knows anything...??
« Reply #17 on: March 13, 2007, 04:37:09 PM »
Quote
"when we were young, we all though that the Dunstall bodywork was really cool, but nowadays, the original bike actually looks better?"

You got that right Terry........I think it's amazing how the Honda design team nailed it first time. A design classic for sure.

I must say I really like the looks of the dunstall body work... If any of you have a dunstall tank I'll gladly trade you my stocker for it anyday!

I must still be "young"  :)

Seriously though has anyone seen any dunstall tanks lying around?  Got one in your attic you don't want anymore? I'm dieing for one

 

;
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