Motorcycle "Records" - Really??

[donpearsall]

The Honda CX Turbo bikes must run in the pushrod class (P-PPB). The Kawasaki ZX 750 E1 is an overhead cam engine. So its class is P-PB.
It is still an open class since my bike was disqualified for being worn past stock bore. If anyone wants to cherry pick the class be my guest, but you better measure your bore first.

Good luck
Don

[hotrod]

Can that engine be sleeved to get back in spec?

[SabreTooth]

Stock bore according to the manual is 66 mm but the inspector said his micrometer measured about 67 mm. Disqualified. No record.

Not knowing the BUB rule book (at the moment, I'm focused on SCTA rules, with no rulebook at hand, yeah, I know, get 20 copies and place them everywhere including the throne room ), I'm a little worried by the "about" bit. This is precision stuff, there is no "about" anything when it comes to precision engineering and measuring for records. "About" 1 mm is "about" exactly 39.4 thou on the diameter (bore) or 19.7 thou on the radius or "wear." Also, were measurements taken at multiple points around and along the bore?

Admittedly, 40 thou over is starting to look more like my oil burning, excessive blow-by, Landcruiser "tractor" engine regarding tolerances and wear. What are the BUB limits for overbore for your production class?

Are the inspectors required to use NIST traceable calibrated measuring equipment?

I'm now curious.

Jim

[Stan Back]

I'm not curious after reading Jim L's reliable reply.

[donpearsall]

The AMA rules for production engines are that no over-bore is allowed. The stock bore is required regardless of wear. I have no idea of what the tolerance is for measuring error or rounding.  For engines older than 35 years, the Production Classic does allow +- .050 tolerance . My bike is 29 years old so does not fit there.

Don

[edinlr]

Don, that is funny (as in interesting) about your bike, as the 750 Kawasaki holds the record in the SCTA in 750 P-PB.  I am guessing a previous owner may have put some pistons in your bike, because a pure stock version should have been 66mm or 738cc, at least when it was cool.  The other turbo bikes that run in 750 are the Yamaha and Suzuki, which are labeled as 650s, but are in the 655 to 673 range.  You shouldn't have to sleeve the cylinder to get it legal, I'm sure there are plenty of stock cylinders around, but you might have to buy custom pistons as stockers may be hard to find.  I have one of the Kawasaki 750 turbos too, but I will check the bore before I bring it out there to race.

Too bad about not being able to buy a record, I tried too.

[Beng]

I can't see why any given Class has any performance based relationship to any other Class in Land Speed Racing.
Why does a Gas Record have to be slower than a Fuel Record they are totally separate Classes.

  Most people missed the point of this thread for one reason or another.
 
   SaltPeter, A fuel record does not have to be faster than a gas record, nor does a blown record have to be faster than a normally aspirated record, nor does someone running a four-valve per-cylinder engine have to run faster than a two-valve engine, but you have to admit it looks good if they do doesn't it?
 
    Everyone that races "buys" their trophies and records because racing costs money, but the starter of the thread was not saying anything negative about people spending money to race and have fun. What he was saying is this:
 
     You have the choice to run in an old class that takes a LOT of smarts, skill and experience to set a record in, or you have the choice to run in a class that takes a lot less of those things, and those who do set a record in a very competitive and old class that has had a lot of smart men trying to grab it for many years have a right to crow a LOT louder than someone who sets a record in a class that does not have such a history.
 
       So if two guys are running BSA Goldstars for instance, if the one running ordinary gasoline is an expert tuner who can make it run faster than someone running alcohol or a blower, then YES he has bragging rights.
 
        Likewise if two guys are running Goldstars and the only way the one guy can win the record is to ditch his Goldie engine and to buy a newer design engine with more valves per cylinder, then maybe he will set the record, but he has not really beat the guy that had the faster Goldie engine.
 
         So the thread is simply giving credit to those who set records because of their engine tuning expertise as opposed to those who set records by finding gaps in the rules or record books, and I think those guys do have extra bragging rights don't they?
 
           

[Nortonist 592]

    You have the choice to run in an old class that takes a LOT of smarts, skill and experience to set a record in, or you have the choice to run in a class that takes a lot less of those things,        

You are making the assumption that those who run on an open or soft record are not smart enough or too lazy to bother working hard to break a record.  

I'm putting a blower on the sidecar this year.  The class record is open right now.  Where's the challenge?  First of all you have to make two passes to set the record.  Anything can happen.  Nothing is guaranteed.  Secondly there is the challenge of seeing just how far up you can set that record.  There is no rule that says you have to run slow on an open record.  Nor is there a rule that says if you're smart or skillful or have a lot of experience you are not allowed to run on an open record.

P.S.  Anyone know where I can pick up a Snell 05 or better paper bag so no one will know its me running on an open record?

[Speed Limit 1000]

I know what you are saying. When we first ran our lakester with a 750 Honda we set the J/FL record at 133MPH. A few years later with a Kawasaki 750R we set it at 204MPH. Someone has to set a record in an open class so you can have a goal to go after

[salt27]

Beng,
 What I read in the opening post of this thread (page 1) was Dean giving his opinion on why there were more records set by motorcycles than cars at Speedweek 2013.

At least that was what was said at the top of his post. (It did seem to take a bit of a turn)  

My opinion (for what it's worth) is that the poor salt conditions seems to have affected the lower powered motorcycles less than some of the other vehicles. (traction maybe)

I do hear what Dean was saying about the speeds between the different classes not always being what you would think they should be.
( the record book is full of examples in both the 2 and 4 wheel categories.)

The main issue that I see is not "the extra bragging rights" to some but the belittling of others.

 Don

 Oh and welcome to the Landracing Forum

[mtkawboy]

Id sure think that a 66m bore engine would have a serious smoking and blowby problem when measured at 67mm with an extra .039.4 thousandths clearance. But that's just me.

[grumm441]

I was just looking at the results for the DLRA's speedweek in Australia
Stuart Hooper riding a 1959 Velocette Venom in APS/PBF 650 ran 183.374 mph
I wonder what that cost?
G

[JimL]

From what I have seen on the internet, it looks like it cost a lot of work and dedication, mostly.

Outstanding result.

Pushrod classes are really getting interesting.
JimL

[Vinsky]

Bill Hoddinott recently interviewed Stuart Hooper in BRN. He tells all about the build. His website is:
http://www.worldsfastestvelocette.com/

[Sumner]

Bill Hoddinott recently interviewed Stuart Hooper in BRN. He tells all about the build. His website is:
http://www.worldsfastestvelocette.com/

If I remember it was a 2 part story and a great one.  The modern day Burt Monro.  I can't wait for the movie.

Once again I'd like to stress that anyone that is serious about land speed racing, either car or bike, will cut their learning curve way down by subscribing to Bonneville Racing News and reading those articles by Bill.  If you are starting now buy the reprints of the articles.  The info in them will save you thousands of dollars and years of getting up to speed.

Scottie are you listening  .  For your build some of those articles like the one on Stuart are 'must reads',

Sum