Topic: Cycle X Drag Bike - Sneak Peak!

[MRieck]

The crank broke in the middle(where it is thin). All other parts are in perfect shape...Ti rods, head trans etc

I have to clarify this. It pulled teeth off the primary sprockets and appeared to crack the crank...I found this out today.
 This project is not dead by any means....it will rise like the Phoenix.
 Some different tweaks too. Kenny wants to beat Rick Stetson's 9.20 @ 142 mark. I was talking to Rick today and he said somebody should....it's been 30 years.
 BTW...Rick rides his first GS 1100 in push button start class...that does 8.2's in the 160's.....using 36mm RS carbs!

[Old Scrambler]

Good testimony for the primary chains

A friend and I had planned to visit Ken's shop on Monday..................We can wait...........He may be busy

[754]

The days of billet cranks are getting near.. Probably. Less work to make,  than the head was.
 Just not sure how they cut the sprocket teeth back in the day.

[MRieck]

The days of billet cranks are getting near.. Probably. Less work to make,  than the head was.
 Just not sure how they cut the sprocket teeth back in the day.

I'd say they are here Frank for some modern bikes that need stroker cranks. Those Marine pieces are beautiful...buttery smooth counterweights, hollow rod pins ....really nice work. You weld up the old cranks 5 or 6mm and the rod oiling hole literally goes south....billet changes that formula.

[kmb69]

Huh? 

[754]

I know they are around for other bikes, and autos...but it's time for our bikes now....

[MRieck]

Huh? 

My reaction when I see the Texans playing Keith.

[Jerry Rxman Griffin aka MuthaF'er]

Huh? 

My reaction when I see the Texans playing Keith.

Watch yer mail then   

[bear]

We gave up on welded cranks years ago.

Cheers,
Brian

They (large strokers) all eventually break Brian as you obviously know. Billets are nice....I have seen the busa Marine stroker crank.....NICE! (Jay sells them)

We use the DOHC cranks these days and they have proved to be reliable.
Do you think they may be an option for these guys at this stage of development Mike?

Cheers,
Brian

[kmb69]

Brian,
I'm not Mike, but yes, that's what Kenny is looking at.

Few questions:
Where are you guys getting the custom length Hy-Vo chains?
The 1100 crank appears much beefier but also harder to find. Any advantage over the 900/1000?
Any news on the HD transmission parts?
Keith

[jweeks]

The 1100's  had a bigger, heavier cam chain. Nothing gained using it over the 900F cranks. Just my opinion. The 750 cases have more room than the stock Honda +6 mm cranks offer. Jay can stroke these cranks some more if you want more cc's. 

[Bill/BentON Racing]

Brian, what a couple of us was thinking!  HyVo the way to go Kenny!  Bill

[kmb69]

The 1100's  had a bigger, heavier cam chain. Nothing gained using it over the 900F cranks. Just my opinion. The 750 cases have more room than the stock Honda +6 mm cranks offer. Jay can stroke these cranks some more if you want more cc's. 

Weeks is alive???

Got that auto packed up for Valdosta?

[jweeks]

Too much spent going to Virginia. Hope everybody does well at the event. Maybe next year....

[bear]

Brian,
I'm not Mike, but yes, that's what Kenny is looking at.

Few questions:
Where are you guys getting the custom length Hy-Vo chains?
The 1100 crank appears much beefier but also harder to find. Any advantage over the 900/1000?
Any news on the HD transmission parts?
Keith

G'day Keith,

The 900 is the better option, the 1100 has some issues fitting the SOHC cases.

We use a DID cam chain and a Morse primary.
They will need to source a GL primary shaft.

There are other mods to consider as well.
Cam and primary tensioners are a couple that springs to mind.

Jon and I agree on many things but re-welding cranks isn't one of them.

Re the gear sets.
We have a set they've supplied and will fit for Phillip Island in January.
At this stage they are going to cost around 1000AUD, depending on numbers.
But I'm not prepared to put them out there till I've given a set a workout.

Cheers,
Brian

[jweeks]

Brian,
     When you set a record in drag racing the motor runs for about a half a mile. When you road race, you travel the equivalent distance of a season of drag racing in one weekend. They want the quickest n/a cb750. They're not asking for a reliable bracket bike. If the motor breaks another crank in 100 miles, they should already have the record. If they're going bracket racing, the plan is way wrong.. More stroke means more power to get the record. Wonder what Mr. Pena used for his record setting motor?  Bill, do you know?

[bear]

Fair enough Jon.
I know sod all about drag racing.
If I can't get a 100hrs out of my motors it's back to the drawing board for me.
For the life of me I can't get my head around the thought of a crankshaft as a consumable.

Cheers,
Brian

[dragracer]

Fair enough Jon.
I know sod all about drag racing.
If I can't get a 100hrs out of my motors it's back to the drawing board for me.
For the life of me I can't get my head around the thought of a crankshaft as a consumable.

Cheers,
Brian

I can't wrap my mind about a crank being a throw away item either Brian. Bottom line; once a crank gives way in a high rpm run, there goes the head, cases, block and pistons and sometimes the tranny. All expensive items to replace in the case of the Cycle EX motor. 


It seems to me this bike is not being built to run in any specific class that they've revealed on the forum. So Jon does have a point, I think their goal is not to actively race the bike, only to break an old, but long forgotten record for the SOHC's in normally aspirated trim. A big stroker crank and a big bore/custom pistons with a one off head and special carbs will help to get it done.

Unfortunately, at this juncture in the drag racing game, breaking that record will only have significance to us older SOHC enthusiasts. The reality is, our minuscule SOHC group will have big smiles and be happy for Kenny but the current day racing community as a whole will sigh and say; "so what".

I commend and appreciate Kenny for giving us something new to be excited about in the fading niche of the SOHC drag racing world. He and his crew have worked hard and will succeed one day in achieving their goal.

[Sam Green Racing]

In respect of cranks breaking and wrecking motors, I have to agree but way back in the 60s this happened.
In the I.O.M. TT, Mike Hailwood was leading the 250 race on the six cylinder 250 when he pulled into his pit and complained of being 250rpm down on the top end. He was told to carry on as the mechanics could not see anything that they could do about.
He carried on and won the race.
On later inspection, the crank was found to be in two pieces. The jagged break was the only thing causing the piece without the cam chain on it from continuing to rotate. The fractional difference in the rotation rate of the two parts was enough to upset the valve timing and ignition timing for the drop in revs of 250rpm but there was no damage to the valves or pistons, this sure says something for the standard of Honda engineering.

Sam.

[jweeks]

     The Arana team from NHRA Pro Stock Bikes have broken 5 or 6 billet cranks this season. Not that much different than when the CB750 based Honda's Pro Stock raced in the early days. Lots of parts got broken trying to run quicker.

     I have a Suzukimatic that I'm going to build to beat Vic Force's record for an automatic twin on gas. The same bore sizes in my current Suzdamatic and the Suzukimatic to come. One of the difference is in the various stroke Suzuki twin cranks that are available. I'm building it to get the record. (I want 12's) 4 valve heads from the 4 cylinder bikes also won't hurt. I'm nicknaming it my "Hand Grenade". It will break the crank, it's just a question of when....

[kmb69]

I am with Brian and Frank on crankshafts not being considered consumables, drag racing or not.

Pretty sure Kenny's not planning to have the engine hand grenade in the traps on a record setting run. Not real good for his business IMO.

Jon, is your 750 based automatic a record holder? If yes, what's the time to beat? You need a crank?

[jweeks]

No, I'm no record holder. 10.80's is all the bike has done. There's more potential, but it isn't a priority. I'm running a nearly stock 900f crank with a 73 mm bore. The head is my limiting factor. The rear wheel dyno shows a flat output from about 7500 to 10.500 (loses 1 hp) It was built to bracket race, not set a record. My vague memory is that RC ran in the 10.20-10.30 range. There was one in Texas that ran 10.7's a few years ago. I need a much better head to find many tenths. I've discussed it with Mike R.. I need something like what was on the Cycle X roadracing bike. Probably would have to go with fuel injection to work with those larger ports.

Nobody wants to break parts when racing a bike. Unfortunately, it does happen. My Suzukimatic twin idea came from a west coast roadracer who did the same thing to a clutch Suzuki twin. He broke cranks until he went with a billet one with larger diameter main bearings. He got over a hundred miles racing his before the stock crank broke. I'm hoping that I can have the record before then. It will be parked after the time slip is obtained.

[bear]

I'm running a nearly stock 900f crank with a 73 mm bore. The head is my limiting factor. The rear wheel dyno shows a flat output from about 7500 to 10.500 (loses 1 hp) It was built to bracket race, not set a record. My vague memory is that RC ran in the 10.20-10.20 range. There was one in Texas that ran 10.7's a few years ago. I need a much better head to find many tenths. I've discussed it with Mike R.. I need something like what was on the Cycle X roadracing bike. Probably would have to go with fuel injection to work with those larger ports.

I'm in the same boat Jon.
We seem to run out of puff at around 72mm with the extra 6mm of stroke using the  DOHC cranks.
Our heads flow a little under 80cfm but I think we need a flow of at least 90cfm to run at their potential.

By the by our HY-VO's are hitting their ceiling at around the same rpm.

Cheers,
Brian

[kmb69]

Uuuummmm???

Are we getting our legs pulled about a shucked crank? 

New pictures on the Cycle-X website sure look like a bike ready to go!!! 

Need to get my people talking to Kenny's people. 

[dragracer]

Uuuummmm???

Are we getting our legs pulled about a shucked crank? 

New pictures on the Cycle-X website sure look like a bike ready to go!!! 

Need to get my people talking to Kenny's people. 

Yeah man, get us a top secret update on the project.