JSR29
So, I just saw this on the AHRMA site:
"10.9.2.b.1 – Next Gen Superbike (engine)
Change as follows: “Four-cylinder air- or oil-cooled machines must retain stock stroke. Stock Bore may be increased
up to .080” (2mm) the class limit of 1000cc.” (Chris Onwiler)
Committee: No. Discussion: LL motion to reject; DP seconded.
July Board: 12 For/ 0 Against the motion
October Action: KB motion to reject; FG seconded.
October Board: 11 For/ 1 Recuse (MH) the motion"
I don't know what the practical bore limit of a oil cooled Suzuki 750 is but according to this it could be a 1000cc displacement. I say bullshit. I also say bullshit to 996 stud spaced 888's and 888's with shower injectors, but that's another story.
EDIT: You know, once I read this again I understand the motion was rejected, so......never mind!!
Scott
marvin
I totally agree with the 996 stud spacing. It appears as though AHRMA
a has written the rules so "money talks" Anyone with a limited budget might as well not apply unless you have a really good rider. ( I realize it's 10% bike, 90% rider)
That's why I am selling my prospective Gen II race bike off bit by bit.
Marvin
JSR29
Not just the money, a full bore 955 corse engine isn't cheap to build either, but it existed in the period. 996s did not. Nor did FI beyond dual injector 50mm. I don't blame anyone, cough...CB, for building to the limits of the rules and pocketbook. I blame the rulemakers. I understand why the 4cyl guys would complain. There's no way to build a 150+ hp period 750.
I know the later cases rule was for "reliability and availability" reasons but there are later reliable 916 spaced cases.
Period motors did not make 150+ horsepower. I remember dynoing one of Adamo's 1990ish bikes at 120hp and thinking that was a lot at the time. Certainly more than any other twin we had run till then. My, late lamented, 916/955 made 138rwhp and it was strung pretty tight.
marvin
YES,I too blame the rulemakers. Even though I have a 996 engine that I could use with SPS cams. I don't understand the 996 rule (although a 955 is basically a grenade engine)( but so is a 996 if built up).
I don't blame CB either, but throwing 30K at a bike is way out of my price range!!
Marvin
JSR29
I somehow doubt even you could replicate the CB 888 for only $30K!
Ultimately I figure it's about the lap times, and checking out the AHRMA times at the tracks I know, I think I might be able to hang in there. So I'm going to go ahead with my budget build.
marvin
Go for it!! and more power too you!!
I would love to see someone beat "the money" !!
I just can't afford to compete.
hauge
I´m curently building a 996 engine for ny 748 R for particiaiting in clasic racing in Sweden.
Rules says bikes -98 but 996 is allowed.
SPS engine with pistal HC pistons and bigger throttle bodies. I hope it will give +130 at wheel.
There will be lots of guys with 916 or other bikes with lees HP that will be alot quicker though...
nine16
JSR29 wroteNot just the money, a full bore 955 corse engine isn't cheap to build either, but it existed in the period. 996s did not. Nor did FI beyond dual injector 50mm.
The 996 cases and spacing did not exist, but twins were allowed up to 1000cc at the time (even if nobody took full advantage).
Ducatis would not be all three of "competitive/durable/economical" using the older cases.
Restricting the 851/888 throttle bodies to non-shower type and max size could even the field a bit.
Chris Bush's Muzzy ZXR750R had plenty of motor at Barber.
JSR29
I'd never have a problem racing against a "vintage" bike that's built to the max possible in the period. When somebody brings out an actual factory or factory support bike from the period that's what vintage racing is about. Heck, the fast guys on the fast bikes were fast then and they're fast now.
But. Stuffing a later NASCAR V8 in a 69 TransAm Camaro and calling it vintage because it also has pushrods and a carburetor doesn't work.
stafford
Sounds like the AHRMA are like the CRMC over here, trying to keep to period even though with the right money there are ways around it. The Classic TT suffers the same crazy money route if you can afford an XR69 (with a very modern engine) you can win, you could well see a situation where if you want to compete with a good result the first 10 bikes home will all be the same, where's the fun in that. I use a 996 as the casings are better than the old ones and the rules there allow me to, but they still aren't as quick as some of the 750's (if they are). If you guys did go down the 955 route how long till parts and money dried up?
JSR29
Vintage racing rules are difficult to formulate and regulate so I don't envy the officials their task. Once the cat's out of the bag non period updates wise there is pretty much no way back.
Since it's Vintage RACING and not Vintage parade, competitors can and will push to the limits of the rules and pocketbook to win. If I could afford to buy or build a full bore Corse with the best suspension and brakes and a 98 996RS motor in it I guess I would too!! But since I can't I'm going to complain about them that can😄
There are later S4 and ST4 and late ST2 cases that are stronger than the original 888 and early 916/955 cases. Pistal makes pistons, valves are valves and cams are cams. If you are going for a max performance build a 955 probably costs a bit more than a 996 but not much. You've got to do all the same stuff. No doubt bolting a ST4s motor in can be the most cost effective way to 115hp.
How soon any displacement DesmoQuattro blows up seems more related to how it's built and how high it's rev'ed more than anything else. Speaking as someone who's had a few let go in various ways.
nine16
Like I said, the 996cc cases and displacement allow for durability and availability--an 888 wouldn't be a competitive option for most riders otherwise. So much of the motor is interchangeable with the 851/888 parts--it's really a subtle evolution of the motors that actually were eligible and used in the period, nothing like using a testastretta. There are other ways to limit an admitted advantage--mainly throttle bodies or valve sizes.
And as noted, there are other vintage classes that are FAR more biased--the reproduction Manx and XR69s are probably the most obvious.
griff851
Our Vintage racing has some beauties. The premise for most of the rules is silhouette and the latest major component dictates the class. Then there are year groupings that span 10 years and CC's just thrown in to help things along. Basically it's all about trying to get numbers on the track currently. There's guys hiding injectors in delorrto's on 900ss's and using P8 ecu's, and Pantahs up against TZ's. it gets a bit stupid when it comes to the 851's, because I can run my 851/888 against anything between 1980 and 1990. So if I put Brett in the saddle we'd be guarenteed a podium, with maybe 1 other bike to actually race against. Not much point really. The only competition would be from that 888 that went to the TT, its actually a 92, but nobody cares really.
In the pits it basically turns into your own times that's the only thing that counts. Trophy's are just something that somebody is going to get, nobody really cares that much. Most of the guys are just racing for the sake of racing and seeing what they get out of their machines. There are the occasional twisted individuals that get all funny about playing by the rules , but mainly it's about fun. Can't actually remember hearing anybody actually actually lodging a protest here in Qld, but may happen down south.
However once you move into bears and post 91 it's not classed as Historic and things change.
Yamatr3
nine16 wroteThe 996 cases and spacing did not exist, but twins were allowed up to 1000cc at the time (even if nobody took full advantage).
Ducatis would not be all three of "competitive/durable/economical" using the older cases.
Restricting the 851/888 throttle bodies to non-shower type and max size could even the field a bit.
Chris Bush's Muzzy ZXR750R had plenty of motor at Barber.
Chris Bush's Muzzy Kawasaki is Aaron Slight's 1993 World Superbike. It is also a 1993 and should not be allowed to race in the class. The rule book specifically states Kawasaki's from 1988-1992. His bike is allowed because supposedly it was made in 1992. Other classes have a date cut off of Dec 31, thus allowing it for now (Note, the rulebook currently does not have a date cutoff in this particular section, thus allowing some grey area to make it legal, nor does it include the wording "model year" adding to the grey area, but it is clearly against the original intent of the rules). They also did nothing to clear this up for next year.
nine16
Yeah, it's a cool old bike. M model, as you mentioned, but built in late '92.
I get that it's "racing", and I'd even like to do a couple rounds per year, myself. I just don't get all the hyper competitiveness and people getting bent out of shape. I'd WANT to see as much variety of the cool old stuff as possible.
Yamatr3
nine16 wroteYeah, it's a cool old bike. M model, as you mentioned, but built in late '92.
I get that it's "racing", and I'd even like to do a couple rounds per year, myself. I just don't get all the hyper competitiveness and people getting bent out of shape. I'd WANT to see as much variety of the cool old stuff as possible.
People get bent out of shape because in their mind they are following the rules when they build their own bikes. Then someone comes in with a bike that is clearly not in line with the original intent and allowed to race. He has a 91-92 bike that is legal for the class but wants to race this bike as it is much faster than the 91-92's and can actually compete with the Ducati's.
I personally don't care what they do, but they need to make it clear cut for the future and either allow the 93-95's in or add the "model year" reference to the rule book thus making the 1992 the last Kawasaki 750 eligible.
JSR29
"Like I said, the 996cc cases and displacement allow for durability and availability--an 888 wouldn't be a competitive option for most riders otherwise. So much of the motor is interchangeable with the 851/888 parts--it's really a subtle evolution of the motors that actually were eligible and used in the period, nothing like using a testastretta. There are other ways to limit an admitted advantage--mainly throttle bodies or valve sizes."
First off, the rules are what they are so this is all bench racing masturbation anyway. Hey racing seasons over so what else is there to do?
I just take issue when the "Like Kind" rule results in "later kind, non-period kind"
While there are number of interchangeable parts between a 851/888/926/955 and a 996 the cases, cylinders and heads aren't. Isn't that basically not interchangeable?
While 1000cc was the twins class limit, there weren't any in the period. At least not in WSBK and AMA since it wasn't easily possible with the homologated crank. Although there were guys running 984 with long stroke cranks in local races.
Adam, I agree it's less expensive and more reliable to start with a 996, and if, like you suggest, tuned to period as regard to valve sizes and fuel injection it does become a distinction without very much of a difference.
I don't know from Kawasaki, but if someone brings out a full bore period factory Superbike from the period I certainly expect it to be fast! More power to them. Like I said before, writing the rules is hard.
I would assume the 92 rule for Kawasaki was meant to exclude M-series models. Too bad they weren't more specific. Or maybe not since its a Russel Championship year bike and that's pretty cool.
I guess part of my problem is I haven't yet quite adapted my mind to "vintage racing" and i keep thinking about where I'm going to finish .
