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Allan
Site Moderator
National
599 Posts |
 Posted - 24 Nov 2002 : 10:22:13 AM
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 may be MA should up date 13.5.3 to read 13.5.3. d ,? cb900 cranks. Plus how many tr3 are tz359g with aircooled barells! This is a modern problem which to my knowloge has not been looked into, how to police it dont know will log books make a difference? have you got yours yet!
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Allan Greening |
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 24 Nov 2002 : 4:37:26 PM
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How do you change the number of transfer ports in a TR3, and bridge the inlet port to make it into an aircooled version of a TZ350G ? You can certainly change the chambers, ignition and carbys, but you can't make the important changes. The reason those TR3's are so fast is that they run methanol. In a two stroke the difference is dramatic compared to petrol. (I think you'll find all TZ's and TR/TD's have the same port timings).
Anyone seriously racing P4 would be silly not to make their TR3 competitive, and it's quite within the rules. That's what racings about.
Using CB900 cranks is still (?) within the rules. I suggest we change the racing to suit the bikes - run both 'Period' and 'Category' racing in the one program, and don't change eligibilty rules at all. We have the bikes and riders who are willing to compete - let's improve the formula and build in what we've got.
I am strongly against eliminating any machine currently racing - it's very counterproductive! |
Is your machine authentic or merely eligible? |
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Former Member
deleted
79 Posts |
Posted - 24 Nov 2002 : 5:07:06 PM
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Any reason for picking on just Hondas? Norton cranks go into Triumphs without too much work, JAP or Jawa cranks have found their way into plenty of singles. A Molnar Manx goes 95mm bore so vitually everthing changes. And thats just the tip of iceberg on what gets done to either get more performance or reliability. It would be next to impossible to find a P4 Honda that was over the class capacity limit (1300cc) I wonder if that could be said for P3 Classics with some of the mods that are done.
Al Kidd |
Al Kidd |
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 25 Nov 2002 : 8:39:34 PM
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The trouble with the Hondas is that when you fit a CB900 crank into a CB750 and run it on alcohol, you have a very fast reliable bike which most other eligible bikes can't compete with. I believe the only bikes which have beaten Rex have been Chris Cutler/Ken Watson 750 (830) Laverda twin which is a lightweight SFC replica, and possibly the Trident from sydney which runs on 14 to 1 comp, has a harris frame and has much modified crankcases and botton end to stop it blowing up. I believe it is impossible to build a Norton twin which would beat Rex, and which would not blow up every second meeting.
The thing to realise is that four cylinder bikes have twice as many valves as twins, and are smoother, so the stresses are less.
The Laverda is a convincing argument, they are a bullet proof motor, and can be made to go very fast. Where do you find one? I almost bought one for $5000, but it was too good to make into a racer.
If you are trying to recreate an era - forget it. No Honda in the 70s was over 830cc, they used to use 450 pistons, we didn't have CB900 cranks. Any 750 Triumph or Norton will demolish a hot 750cc Honda, they just weren't that fast in the old days.
Rex's bikes are a credit to him, they are really good. They are within the eligibility rules, and I don't believe the rules should be changed.
It's simply a matter of organising races where he can also compete against petrol burning P5 machines, as well as in the normal P4 races. Everyone should have a chance at competitive racing. As it is I go to historic races, and I know who will win each race before it is run. Gets a bit monotonous. |
Is your machine authentic or merely eligible? |
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Geoffpgrant
Level 3 Member
South Australia
204 Posts |
Posted - 25 Nov 2002 : 10:36:27 PM
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I'd just like to say that I agree with the comments below. Let the big motors with modern components race but create a category for the 'Period' bikes so that everyone has a chance of winning. I race a P4 sidecar - #30 - and most races the best I can hope for is 3rd or 4th (unless the big Hondas break down or don't show up!) My bike will have a good race with any of the Hondas that are still using the CB750 crank but I cannot catch the monster motors. I am now considering making modifications to try and be competitive with the front runners but I would not do that (and therefore save a lot of money) if I could race with others who are running original equipment.
Let's keep everyone racing but give everyone a chance of taking out a win occasionally!
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john
Forum Moderator
Victoria
3130 Posts |
Posted - 25 Nov 2002 : 11:17:51 PM
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| I have noted that MA Historic commission has approved a 750cc stock class as recommended by WA lads to be run concurrently with the unlimited race. Thisi may extend the number of racers |
John Daley Sidecar #68
' there are those who do, those who dont do and those who undo. We must lampoon the latter." |
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 26 Nov 2002 : 8:39:43 PM
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I don't know what is meant by a 750 'stock' class. I suggest all that is needed is a new capacity class for P3,P4,P5 up to a max of 750cc. Even if the races are run combined with unlimited, it will be better than it is at present. Better still run 750cc machines separately to unlimited, however we probably don't get sufficient entries for this. How about trophys for the winners of the 750cc class in P3,P4, and P5? Also for 750cc Formula (Historic) BEARS, and 750cc Formula (Historic) Japanese?
We will still have the problem that anyone racing a sixties Triumph or Norton 500 or 750 will have to compete with Japanese two strokes, I think we will have to live with this. |
Is your machine authentic or merely eligible? |
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steve
Level 2 Member
Queensland
86 Posts |
Posted - 27 Nov 2002 : 11:58:21 PM
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Hi All
Here in Queensland we have been trying a new class which I think the Yanks are into also. "750 Pushrod Class" it's working well with entries getting bigger every meeting, people dusting off leathers & bringing the Old Nortons/Triumphs BMWs etc etc back.They hung up their leathers years ago when the Big Honda's were pushing the limits in the unlimited class (yes we have all heard the rumours "1450cc").
Trying to get twins up to the HP & the bikes wouldn't last long at all, not to mention the money side of things!! At Bathurst I think a certain Honda lost his placings for the weekend, because of a late model "frame" let alone the engine CC size. The Pushrod Class here has exciting racers & from a spectators point make it more interesting to watch,I raced at some of the Aussi Champs & there have been 26 Honda 4s & maybe 6 other bikes, & the spectators go & get lunch. I think a cut off of 750cc & the unlimited can race in the period 5 to get the numbers up both with entries & spectators,I think you will see more people who use to race attending meetings again with the old twins in period 4 750PR, but of late, numbers are down both in riders & spectators. Lots of the old timers saying the Hondas were never that fast in the Period but back then a good Truimph/Norton could match most bikes across the paddock all week-end with out to much work & money!! I know if they checked a few engine sizes I think a couple of fellows would be sent just home like Bathurst I allways throught reading the rule book that it was 5% over the size of the the bikes standard bore/ccs. Thats my line of thinking & I'm sure there's a few more who think the same way. P.S one time at the Aussi Champs a fellow rider asked how come your Honda goes so much faster than his & this fellow dragging another engine from the trailer said if you haven't spent $10,000 on bike for the meeting your not in the race (they had 6 spare engines 2 had broken) the fellow packed up his truck & drove 4000klms home & never raced again Steve
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 28 Nov 2002 : 9:08:01 PM
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A 750 class in P4 solo racing would end a lot of the problem of the big motors. Rex has only been beaten a few times by people like the guy with the super expensive Trident from NSW and Chris Cutler's Laverda twin. Of all the P4 bikes raced back then, only Vic Vassella on the Jime Eade SFC beat Hone and Decker on the Z900s. Frank Mussetts Triumph trident with Peter Allen or John Collins aboard was actually slower than the Bonneville.
In reality to beat a true 750 Triumph or Norton with a true CB750, you would have to build a Daytona replica (Bill Patterson Honda), and you'd have something which would give you a really hard time. |
Is your machine authentic or merely eligible? |
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john
Forum Moderator
Victoria
3130 Posts |
Posted - 28 Nov 2002 : 9:34:15 PM
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| Why focus on Rex, he has worked within the rules and provides excellent machinery. The Focus could perhaps be directed towards support classes to build on Rex's involvement. The 750cc stock class involves from memory, 4 stokes with no more than 5% rebore allowance, so the problem of big bores is not an issue, lets work with details. Surely there are machines out there that fit the bill, BSA, Triumphs, Nortons, and the Italian stuff, remember we are trying to get more variety of bikes out there racing and having fun, not desiging or determining which bike will win and talk everybody out of even trying the event out. Just Do it! Otherwise why did WA push for the class. They reckon the opportunity is there so lets work towards its fruition. Still I would prefer more sidecars. |
John Daley Sidecar #68
' there are those who do, those who dont do and those who undo. We must lampoon the latter." |
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steve
Level 2 Member
Queensland
86 Posts |
Posted - 29 Nov 2002 : 12:32:41 AM
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HI John
I think I missed something you said the WA guys had pushed something about the 750 class?? to MA??? & also is a new rule coming in soon about the 5% over whats on your crank cases??? when is it coming or is this what I was dreaming??? I feel the racing bikes of the era should look like race bikes of the era, I see a few bikes around looking like I'm riding to the shop to get milk look, sit up in the wind, This was brought to my attention when a spectator asked if those guys are the marshalls or officals?? they don't look like the race bikes he ridden back in the good old days!! I just feel it would be good for the sport if we had more different bikes then the 80% of the field on the same bikes (I'm getting milk look today) bikes, If we can get some of the different bikes back & more closer exciting racing I'm sure the spectators would return with there money & sponsorship as I know of a few sponsors who haven't backed certain classes as for the reasons above.
Steve |
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john
Forum Moderator
Victoria
3130 Posts |
Posted - 30 Nov 2002 : 12:51:04 PM
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| The proposed rule is "750cc class for solos in P4 and P5 to be run concurrently with the unlimited class. All rulkes in current GCR's to apply excepting the rule regarding capacity which will be restricted to 526cc - 750cc. In addition a similiar class will be offerred to P3 machines with a capaciry limited to 526cc to 700cc. the rationale being to encourage an increased variety of machines in the unlimited fields. |
John Daley Sidecar #68
' there are those who do, those who dont do and those who undo. We must lampoon the latter." |
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