Author Topic: Fastest cb750A ever?  (Read 879 times)

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Offline kmb69

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Fastest cb750A ever?
« on: September 11, 2018, 09:59:36 pm »
What is the quickest and fastest standing start 1/4 mile ever RECORDED/VERIFIED for a CB750A Hondamatic?

This may have been asked and answered previously, but I could not find it if it was.


Offline underdog

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Re: Fastest cb750A ever?
« Reply #1 on: September 12, 2018, 06:42:24 am »
  That's a really good question! Probably have to divide it up between N/A and turbo. I think Bill bought a turbo 750A but not sure how quick it was.

Offline Don R

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Re: Fastest cb750A ever?
« Reply #2 on: September 12, 2018, 07:14:11 pm »
 The old dragbike.com website once had an other bikes section with a lot of cb750 info. It was going to be archived but I'm not sure if it ever was.
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Offline MRieck

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Re: Fastest cb750A ever?
« Reply #3 on: September 12, 2018, 07:28:14 pm »
Probably one they dropped from a plane. ;D
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Offline bwaller

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Re: Fastest cb750A ever?
« Reply #4 on: September 13, 2018, 04:24:36 am »
Probably one they dropped from a plane. ;D

Ahahaha , and by a Suzuki dealer.

Offline TurboD

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Re: Fastest cb750A ever?
« Reply #5 on: September 13, 2018, 05:20:31 am »
I believe RC was said to have built one that went in the 9's.

Offline underdog

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Re: Fastest cb750A ever?
« Reply #6 on: September 13, 2018, 07:32:13 am »
  Jon Weeks said that he had one in the 10's, but I can't recall the details of it.

Offline kmb69

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Re: Fastest cb750A ever?
« Reply #7 on: September 13, 2018, 01:09:55 pm »
I believe RC was said to have built one that went in the 9's.

I've heard that rumor but cannot come up with anything definitive. Did read an old article in a bike mag but it was very vague.

  Jon Weeks said that he had one in the 10's, but I can't recall the details of it.

And he can't/won't provide proof. Was asked to do so, but will not even post pictures of his Auto.  ???  ???  ???

Offline budman

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Re: Fastest cb750A ever?
« Reply #8 on: September 13, 2018, 01:36:47 pm »
Doesn’t matter ‘cause you’re building the record breaker anyway.

Offline kmb69

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Re: Fastest cb750A ever?
« Reply #9 on: September 13, 2018, 02:55:52 pm »
Doesn’t matter ‘cause you’re building the record breaker anyway.

Thank you for the confidence Bud.  ;)
Sure would like to know what the record is though we be breaking!   ???
Hoping to put it deep enough there's no question.  8)

Offline kmb69

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Re: Fastest cb750A ever?
« Reply #10 on: September 13, 2018, 03:42:05 pm »
Probably one they dropped from a plane. ;D

Ah so! You too funny Bro!  :)

Offline MRieck

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Re: Fastest cb750A ever?
« Reply #11 on: September 13, 2018, 05:58:33 pm »
Doesn’t matter ‘cause you’re building the record breaker anyway.

Thank you for the confidence Bud.  ;)
Sure would like to know what the record is though we be breaking!   ???
Hoping to put it deep enough there's no question.  8)
SR-71 top speed??
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Offline budman

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Re: Fastest cb750A ever?
« Reply #12 on: September 13, 2018, 06:10:56 pm »
Doesn’t matter ‘cause you’re building the record breaker anyway.

Thank you for the confidence Bud.  ;)
Sure would like to know what the record is though we be breaking!   ???
Hoping to put it deep enough there's no question.  8)

Wish I had time to help you out.  I’ve made it my goal to finish the house by the end of the year.

Offline gschuld

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Re: Fastest cb750A ever?
« Reply #13 on: September 14, 2018, 04:50:03 am »
A bit of that article.  No times mentioned.

George

Offline gschuld

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Re: Fastest cb750A ever?
« Reply #14 on: September 14, 2018, 04:51:40 am »
I recall seeing a second small write up in a magazine that did offer times.  Pretty sure Benton fwd it to me and I can’t seem to locate it.

George
« Last Edit: September 14, 2018, 04:53:26 am by gschuld »

Offline MRieck

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Re: Fastest cb750A ever?
« Reply #15 on: September 14, 2018, 05:29:44 am »
Not surprised he had trouble holding the bike with that front brake. J Weeks was right about needing a 300 or 320mm rear rotor with at least a 4 piston caliper. I'd use a 6.
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Offline Don R

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Re: Fastest cb750A ever?
« Reply #16 on: September 14, 2018, 09:06:50 am »
 I'm thinking I read that coan rebuilt some torque converters for the CB autos for a higher stall speed. That would ease up on the huge rear brake needs. I think they mostly just clearance them, didn't get into fin angles and such. And is it true the early car converter and some other trans parts also fit the 750A? 
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Offline Medyo Bastos

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Re: Fastest cb750A ever?
« Reply #17 on: September 14, 2018, 09:21:22 am »
The cvcc torque converter Don


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Offline underdog

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Re: Fastest cb750A ever?
« Reply #18 on: September 14, 2018, 09:53:11 am »
  Jon helped me get my stator machined. I'm pretty sure that Neal Chance did the work. Just machining though, no changing angles or anything fancy.

Offline MRieck

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Re: Fastest cb750A ever?
« Reply #19 on: September 14, 2018, 12:09:49 pm »
We have been through this. I have an auto engine here for Bill that is 72mm and it has a lot of bells and whistles. I promise to have it completed by Thanksgiving. Bill needs to get a real rear brake and get rid of the struts/ancient RC swingarm. It should pull about 5,000 stall and with a brake that holds it will screw.
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Offline dragracer

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Re: Fastest cb750A ever?
« Reply #20 on: September 14, 2018, 01:53:49 pm »
  Jon helped me get my stator machined. I'm pretty sure that Neal Chance did the work. Just machining though, no changing angles or anything fancy.

Jim French had Sam auto's converter done by a place in Houston. The name escapes me now.

Offline kmb69

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Re: Fastest cb750A ever?
« Reply #21 on: September 14, 2018, 02:47:13 pm »
.....
Jim French had Sam auto's converter done by a place in Houston. The name escapes me now.

That was Brittain Parts Services. They have an assembled one pictured on their website.
That particular one is rumored to look like it was "machined" with a hammer and chisel.
I hate to put out bad PR on anybody not being a personal witness. Maybe the owner or his mechanic will chime in.
Just guessing you can probably get a more professional job done by Chance if he will do them.

Brittain Parts Services, please accept my apology.
I have been advised that the converter from Brittain was reasonably OK only requiring minor cleanup.
The "abomination converter" was the first one Jon provided for SamAuto, the origin of which is in question.
« Last Edit: September 14, 2018, 07:34:39 pm by kmb69 »

Offline scottly

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Re: Fastest cb750A ever?
« Reply #22 on: September 14, 2018, 09:58:11 pm »
Forgive me if this has been answered before, but would it be possible to fit a "trans brake" to the Auto? As I understand it, the brake operates two gears at the same time, effectively locking the trans, without relying on the rear wheel brake to prevent the vehicle from rolling through the beams..
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Offline underdog

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Re: Fastest cb750A ever?
« Reply #23 on: September 14, 2018, 10:57:31 pm »
All transbrakes that I know of block the trans into first and reverse. Could there be another way? Not that I can think of,  but there are certainly smarter minds than me out there. 

Offline Bill/BentON Racing

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Re: Fastest cb750A ever?
« Reply #24 on: September 15, 2018, 04:00:47 am »
We have been through this. I have an auto engine here for Bill that is 72mm and it has a lot of bells and whistles. I promise to have it completed by Thanksgiving. Bill needs to get a real rear brake and get rid of the struts/ancient RC swingarm. It should pull about 5,000 stall and with a brake that holds it will screw.
Bill has chassis 90%. Rear brake correct, 6 piston or at least 4. Have a 4 now. When Samauto goes to the track again.....it will have a button brake line lock only thing on left handlebar to push/release. Bike will run and look good! Mike, thanks and good luck finishing up the Triple.
Keith will own the record one day! Bill
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