Topic: best cb 750 1/4 mile time

[neil10]

best cb 750 1/4 mile time
keep the exageration believable

[madmtnmotors]

From another forum:

http://forums.dragbike.com/forum_posts.asp?TID=9253&PN=1

Claims 11.28 @ 112mph

[madmtnmotors]

This one might be hard to top:

[madmtnmotors]

I knew I'd seen this somewhere before. The following quote is straight from RC engineering's website:

http://www.rceng.com/history.aspx

"The Revolution in Motorcycle Drag Racing
RC Engineering's reputation for pushing the limits of technology led to the first, successful, blown-injected-on-fuel drag bike. Built in 1971, "The Assassin" weighed a mere 360 pounds and was powered by a 400 horsepower Honda four-cylinder. On The Assassin, Collins set drag race records all over the country. Innovations abounded on that famous bike. It had the first dual- Weber carburetor set-up for a motorcycle and later it was the first motorcycle to use fuel injection and a supercharger together. It was the first Japanese motorcycle to use magneto ignition. It was the first Japanese bike to run on alcohol and nitromethane fuels. By 1973, to beat The Assassin, other racers were forced to use double-engine Nortons, Triumphs and Harley-Davidsons.

Responding to the double-engine "trend", RC Engineering raised the bar another notch. Russ Collins built the "Atchison, Topeka and Santa Fe", a thundering, three-engine, nitromethane-burning, Honda. This frightening machine became the first, seven-second motorcycle in drag racing and the first Top Fuel bike with a Japanese engine to hold a NHRA National Record. The "AT&SF," also, became the first motorcycle to win NHRA's coveted "Best Engineered Car" award at the Springnationals in 1973.

Russ Collins' three-motor monster eventually ran a best of 7.80 sec./179.5 mph but, in the end, proved a death-defying ride. In 1976, it was destroyed in a horrendous crash at Akron, Ohio that nearly killed Russ, put him in the hospital for several weeks and kept him in a wheelchair for several more. You can't keep a wild man down, though. While recuperating from the accident, Collins designed the "Sorcerer", his final Top Fuel bike creation. Built in early-1977 and later billed as the World's Greatest Drag Bike, Sorcerer was powered by a pair of 1000cc. Honda fours. This bike won a second NHRA Best Engineered Award for RC Engineering. Blown, injected and running on 90% nitro, this two-wheeled, twin-engined rocket set a world motorcycle acceleration record for the quarter- mile of 7.30 sec./199.55 mph. THAT MARK STOOD FOR 12 YEARS, a truly astonishing feat in a sport where records are broken monthly.

In 1980, Russ Collins passed the 200mph drag bike torch to younger competitors. Two were his own employees, Terry Vance and Byron Hines, who raced a RC Engineering-built ,Top Fuel Suzuki. In addition to several event wins, their bike won the company's third NHRA Best Engineered Award. Those two racers went on to success with their own motorcycle business, Vance&Hines."

And some more references:

http://forums.sohc4.net/index.php?topic=63940.125

http://forums.sohc4.net/index.php?topic=67576.0
 
http://www.hondahog.com/RCeng_01.htm

[754]

 Nitrohunter on here ran,  between 10.0 & 10.1 on his turbo 736cc. with stock pistons..

[MCRider]

Maybe there's not much data on this, but I'd like to see ETs on stockers. Anyone?

Built motors are fun, but there's no limit to the ET, goes down as $ goes up.

[madmtnmotors]

http://jalopnik.com/5294379/48+cylinder-kawasaki-pushes-boundaries-of-sanity

[srook]

Here are the quarter mile times I had from old magazines.  All the bikes were tested as new bikes and I didn't include anything that was contemporary or long term tests.  These aren't in order becuase I don't have the patience to organize them by year and month.  Let me know if you see something that doesn't look right and I will go back and check the magazine.  If there are 2 bikes listed under 1 magazine it is becuase both bikes were tested in the same magazine (usually comparison tests).

Bike, April 1976
CB750F1
13.82 No Speed indicated

Cycle, April 1977
CB750K
13.33 @ 101.35

CB750F2
12.74 @ 105.14

Cycle, March 1970
CB750K
12.98 @ 102.27

Cycle, May 1975
CB750F
12.939 @ 103.92

Cycle, May 1976
CB750A
15.86 @ 90.72

Cycle, November 1973
CB750K3
13.66 @ 96.87

Cycle Guide, December 1974
CB750K5
13.65 @ 98.6

Cycle Guide, July 1975
CB750F
13.10 @ 101.5

Cycle Guide, June 1976
CB750A
15.59 @ 88.23 (in low)

Cycle Guide, March 1971
CB750K1
13.05 @ 100.00

Cycle Guide, March 1977
CB750F2
13.35 @ 102.5

Cycle Guide, March 1969
CB750 Pre Production Model
12.92 No Speed Indicated

Cycle Rider, June 1973
CB750K3
13.79 @ 97.50

Same Issue
CB750K3 with 16-51 tooth sprockets, 130 Main Jets, Champion RG505 plugs, KH "D" cam, 811 Kit, velocity stacks, & megaphones
11.99 @ 110.90

Cycle World, August 1969
CB750K0
13.38 @ 100.11

Cycle World, June 1977
CB750A
15.62 @ 87.97

CB750F2
12.93 @ 102.73

Cycle World, September 1976
CB750F
13.52 @ 97.61

CB750A
15.90 @ 86.34

Motor Cycle Mechanics, September 1976
CB750F
13.5 @ 90

Motor Cycle World, August 1973
CB750K3
13.80 @ 98.4

Motor Cycle World, March 1970
CB750K0
13.31 @ 100.60

Motorcyclist, August 1972
CB750K2
14.059 @ 95.03

Super Cycle, February 1972
CB750K1
13.07 @ 106.89

Enjoy
Scott

[MCRider]

I was thinking the best numbers were high 12s. Then there were those who massaged the stockers, changed the sprockets, ported the heads, did fineline valve jobs and otherwise "blueprint" the engines, but kept the pipes and airboxes, so it was still a CB750. I'd heard of those getting into the low 12s.

[NitroHunter]

Nitrohunter on here ran,  between 10.0 & 10.1 on his turbo 736cc. with stock pistons..

And after cranking up the boost to 30+ lbs for that 10.00 sec run, all I could think was:
"Sum#$%* STILL won't run in the 9's"!!! 

My XH/S (stock F-2) ran 13.07 @ 101.5 mph.

[HondaMan]

I was thinking the best numbers were high 12s. Then there were those who massaged the stockers, changed the sprockets, ported the heads, did fineline valve jobs and otherwise "blueprint" the engines, but kept the pipes and airboxes, so it was still a CB750. I'd heard of those getting into the low 12s.

I witnessed a 12.4 run in Illinois one night in 1972, 16/54 gearing on 520 chain, modified stock airbox with K&N filter, open TT pipes and his own secret jetting/timing act, 4.25 rear tire, 10:1 pistons (0.25mm overbore), [probably had a port job], stock carbs, and a 90-pound rider, 17 years old. Personally, I never wished to race this guy...I did get to play with his bike a little, noticed it was stripped of every non-essential bracket, tool tray, etc., smaller battery, and a lot of little lightening tricks. Other than that, it was a stock sandcast 1969 bike with points and Honda ignition coils. He was the King of the Town for several years! Nice guy, too. 

[dhall57]

In my neck of the woods in the early 70's the Kawasaki 500 and 750 2 stroke triples were king. Don't get me wrong the CB750's were no slouch in performance either, but the Kaw's were just scary fast. The Honda's were much better all around bikes that did everything well, but if you had a need for speed to go from point A to point B like being shot out of a cannon the Kaw triples were your ticket.

[RRRToolSolutions]

Here is a page from Cycle magazine of 1970 -

Gordon

[gnarlycharlie4u]

2 stroke

this is why.

just before mine #$%* the bed it ran 13.01 basically stock except for 4-1 exhaust and CR carbs.

[MRieck]

9.2 seconds all motor with bars is the best I personally know of.

[paulages]

Here is a page from Cycle magazine of 1970 -

Gordon

I see Norton is king of the pile there.. Nice. 

[MCRider]

I really wanted that Norton back in those days. But the British industry was falling apart, the local Norton dealer couldn't guarantee me delivery, or service if I got delivery. So I "ended up" with the CB750. so glad.

[Retro Rocket]

This is the original bike i bought for my restoration, 776cc Venolia pistons 14.5 to 1 compression running on methanol, ported head, back cut gears, barnett clutch, big cam, all RC internals and a set of the sandcast CR31's, it was good for 10 second passes. I have all the data in a box with piles of spare parts, when i start the rebuild i will post some more detailed info here..



Mick

[paulages]

I really wanted that Norton back in those days. But the British industry was falling apart, the local Norton dealer couldn't guarantee me delivery, or service if I got delivery. So I "ended up" with the CB750. so glad.

The Combat model (which I have) was pretty much built to rule the drag strip in stock class. Sure, the cranks would snap because they were designed for a 500cc bike 20 years earlier... but they'd go fast in a straight line!

Did you notice that the Kawa Mach III shares the 12.80 time with the 750 Norton? 

[MCRider]

I really wanted that Norton back in those days. But the British industry was falling apart, the local Norton dealer couldn't guarantee me delivery, or service if I got delivery. So I "ended up" with the CB750. so glad.

The Combat model (which I have) was pretty much built to rule the drag strip in stock class. Sure, the cranks would snap because they were designed for a 500cc bike 20 years earlier... but they'd go fast in a straight line!

Did you notice that the Kawa Mach III shares the 12.80 time with the 750 Norton? 

Yeah the M3 was really fast, and of course the 750 even faster.

I remember there was some guy(s) building 3 cylinder Kaw dragsters that would just clean the clocks of all the 4 cylinder mega complicated DOHC hardware even up till recent times. I think only the rules could put them down. It always made the pursuit of 4 stroke speed seem sort of rediculous.

But they're only toys anyway, and 4 strokes sound better than 2 strokes.

[RRRToolSolutions]

Guys, this is one of my favorite "old videos" - no trick photography and a 100% stock 1971 H1/Mach III.

The burnout at the end says it all.

I've got a restored 1970 and it impresses me each time I've pinned the throttle in the first 2 gears.

Enjoy, Gordon

[MRieck]

Guys, this is one of my favorite "old videos" - no trick photography and a 100% stock 1971 H1/Mach III.

The burnout at the end says it all.

I've got a restored 1970 and it impresses me each time I've pinned the throttle in the first 2 gears.

Enjoy, Gordon

Pretty cool Gordon. A friends brother had 69 H1 that he sold in 71 when he went to Viet Nam. God we used to just stand there and look at that thing. My buddy with the 73 Z1 also has a 75 750H2
 I have worked on both and feel the H2 was the quicker of the 2 but talk about riding a chainsaw attached to 3 weedwhackers with 2 paint shakers bolted on for fun. .........

[HondaMan]

Here is a page from Cycle magazine of 1970 -

Gordon

I remember that road test: if you have the next month's issue, you will see all sorts of complaints from the non-Norton riders because the Norton guys were allowed to lower the gearing substantially on the Commando during their drag tests, while the other bikes ran stock ratios. I don't know if that was a "fault" of the testers, or just that the other tuners didn't think of it, but it certainly used to improve the Honda's times in those days.

Those were fun days, watching the latest new "superbike" news every 2 months or so, all trying to catch or compare to the CB750. 

[dave500]

In my neck of the woods in the early 70's the Kawasaki 500 and 750 2 stroke triples were king. Don't get me wrong the CB750's were no slouch in performance either, but the Kaw's were just scary fast. The Honda's were much better all around bikes that did everything well, but if you had a need for speed to go from point A to point B like being shot out of a cannon the Kaw triples were your ticket.

when we were all of license age a mate of a mate bought a 500 triple kawasaki,we were at his house one day when his mum said he tries to keep up with the cars on it,we all looked at each other,we had respect in the old days not to say something smart to older people.

[Sam Green Racing]

I asked the same question a few months back on Dragbike.com, seems there were a few single motor bikes that got into the low 7s.  http://forums.dragbike.com/forum_posts.asp?TID=14706&PN=1
Had you posted in the race forum you might have found this.

Sam.