2 strokes a can of worms.

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hawkwind
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2 strokes a can of worms.

Post by hawkwind » Tue Mar 12, 2013 8:54 pm

Many years ago now the "car" racer types saw a problem with the wankle (rotary) engine in as much as it put a similar capacity piston engine at a power disadvantage and so they were penalised to produce a level playing field.
Im sure if cars had 2stroke engines they too would have been similarly penalised. Now this brings me to my point; do two strokes have an advantage over same capacity 4 strokes (yes very much so in my opinion) so is it fair to penalise them so there is a level playing field in the bike classes? ..... this is especially relevent now that two smokers wont smoke with direct injection and 2 power strokes to one = big disadvantage. Even the mighty Honda corp gave up trying to make a 500cc 4 stroke compete with the same capacity smokers.
Its time to look at this disadvantage and see if placing the smokers up 2 capacity classes will level the playing field ..... ie. 500cc goes to 1000cc 250 to 500 etc
comments anyone ?

gary
Vehicle......................A new creation.
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RGV
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Re: 2 strokes a can of worms.

Post by RGV » Tue Mar 12, 2013 9:49 pm

4 valve 4 strokes have an obvious advantage over their 2 valve counterparts. Should they go up a capacity class?
Fuel injected motors v carby fed, liquid cooled v air cooled. 22.000 RPM v 11500 RPM ?

Hang on this all sounds familiar http://www.dlra.org.au/forum/viewtopic. ... 656#p19656

I spose if some one had put as much time developing their 4 stroke as I have into my 2 stroke then it would perform as well maybe. 2 strokes are a black art, you cant go buy a hot cam or high comp piston off the shelf. My bike and a Honda 250 CBR of the same era have similar performance when standard. Should I be penalised for choosing a 2 stroke to develop ?

The yellow bike in front of the Honda in this video is the same model as mine. I cant see any performance advantage in standard form.

http://www.bing.com/videos/search?q=rgv ... ORM=NVPFVR

Thanx Dave
Last edited by 2 on RGV, edited 0 times in total.

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David Leikvold
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Re: 2 strokes a can of worms.

Post by David Leikvold » Tue Mar 12, 2013 10:11 pm

Why not just have separate classes for two strokes and four strokes? It's just another code (2,4,T,F?) on the side of the bike. We already have a kazillion different classes, a few more won't make any difference. Then it is completely fair for everyone because there is no need for someone to have to arbitrarily decide which four stroke classes are fair for the two strokes. That would just start another discussion that can't be resolved to everyone's satisfaction.

And if anybody's thinking "that's not in the SCTA rule book", then this is just another example of why we should never regard their rule book as infallible or even completely appropriate for Australia. Technical commonality is all well and good in theory, but it is of little value to the hundreds of active DLRA members who don't race overseas.

:?
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JonB
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Re: 2 strokes a can of worms.

Post by JonB » Wed Mar 13, 2013 12:07 am

It's not broken, don't fix it.
Everyone has the same rules, we then choose what we want to run in those rules.
Last thing we need is to double the number of classes of bikes.

YOMV
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ben james
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Re: 2 strokes a can of worms.

Post by ben james » Wed Mar 13, 2013 12:10 am

stop picking on 2 strokes you bullies :roll:
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ChrisACT
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Re: 2 strokes a can of worms.

Post by ChrisACT » Wed Mar 13, 2013 12:26 am

Image

Waaaaah, waaaaaah, waaaaaaah. All I hear is WAAAAAAAAAAAAAAAGGGHHHHHH!!!

Why aren't you all racing two strokes if you reckon they're quicker? Huh? :shock:

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internetscooter
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Re: 2 strokes a can of worms.

Post by internetscooter » Wed Mar 13, 2013 6:50 am

Two stroke tech is under developed and the industry is focusing on 4 strokes - one reason is that they are getting more and more power out of 4 strokes and are choosing that direction rather than cleaning up the 2 stroke. Governments also chose to ban two-stroke rather than investing research money into making them cleaner.

I "think" I have the very latest book on 2 stroke tech - that is published in 1999 - I can't even find it as books.sae.org anymore (it was $30) now the only place you can get it charge $200

Two-Stroke Cycle Engine: It's Development, Operation and Design
Heywood/Sher
http://www.amazon.com/Two-Stroke-Cycle- ... 560328312/

Amazon are also charging $1,383.64 for the 1987 Jennings book!

Two strokes are becoming the underdog and the power gap closing quickly.
Paul
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AuotonomousRX
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Re: 2 strokes a can of worms.

Post by AuotonomousRX » Wed Mar 13, 2013 9:15 am

Well I'll be, and I thought this issue was dead in the water.

Like RGV Dave pointed out, I have already raised this in that Motorcycle Class Review Post.

Hey Gary, I went through a similar thing in Drag Racing, writing Rule Proposals for Rotary/4 and 6 cyl/EFI Classes and got shot down, 5 years later they were in LOL. I've never understood why the SCTA did not simply add a Rotary Engine Classes instead of a complicated "Equalisation" factor, much easier.
David Leikvold wrote:Why not just have separate classes for two strokes and four strokes? It's just another code (2,4,T,F?) on the side of the bike. We already have a kazillion different classes, a few more won't make any difference. Then it is completely fair for everyone because there is no need for someone to have to arbitrarily decide which four stroke classes are fair for the two strokes. That would just start another discussion that can't be resolved to everyone's satisfaction.

And if anybody's thinking "that's not in the SCTA rule book", then this is just another example of why we should never regard their rule book as infallible or even completely appropriate for Australia. Technical commonality is all well and good in theory, but it is of little value to the hundreds of active DLRA members who don't race overseas.

:?
I totally agree with Dave L. If this is actually an issue then don't start trying to "Equalise" performance within a Class it never works, it only excludes People.

I have never understood the "too many Classes" argument. This is not about having a Class for a specific Model of MC. It's about a level and inclusive Class structure that Members can set Records in. My thinking was simply based upon the fact that a number of very different engine configurations are now available, but they cannot be "Equalised" in performance through Tuning.

So long as each Class is based upon clearly identifiable engine configurations, Class identification is easy. This already happens in the current DLRA Classes, with Vintage and Pushrod Classes, or do we get rid of these Categories? :wink:

More Classes present nothing more than a possible Administration issue. This could be overcome by creating a separate MC Class position to Administer it.

I don't believe that the MC Classes (I am not talking about Tech Rules here) in the DLRA need to mirror the SCTA. The ECTA has separate Classes for 2 Strokes and 4 Stroke MC's and they appear to be successful and seem to manage it ok.

However if most MC Members are happy with the way it is, that suit's me fine, but don't Penalise me for running a 2 Stroke. :D :D :D

Pete
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Mossy
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Re: 2 strokes a can of worms.

Post by Mossy » Wed Mar 13, 2013 10:42 am

Not that it matters a great deal to me because I'm only ever going to run Pushrod Triumph twins, whether they're competitive or not, anyway.
But I think the idea of trying to equalise different engines through capacity handicaps is stupid. We already have the `Side valves get a 33 1/3 displacement advantage' which is based purely on a rule made by the AMA back in the early 50's, when it was controlled by Harley Davidson, purely to give them a competitive advantage over the Pommie and later the Jap bikes in American racing (not that it worked in the end anyway).
If you really want a change then separate 2 stroke and 4 stroke into different classes.
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AuotonomousRX
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Re: 2 strokes a can of worms.

Post by AuotonomousRX » Wed Mar 13, 2013 1:23 pm

Mossy, that's a good example.

The first question for me is simple, "Do the Majority of DLRA MC Members want to change our existing Classes". That was why I posted http://www.dlra.org.au/forum/viewtopic. ... 656#p19656 to see if it was something worth looking at.

I don't believe that any Rule changes relating to Classes should be introduced without the support of the majority of Members (meaning, MC Members for MC changes or Car Members for Car changes).

From the response to the Motorcycle Class Review Post, I'd say No, Members are happy with the way things are. That's why I did not follow it up.

If, however, it is "Yes", then write your Proposals and send them in.

Like I said I'm happy to leave the Classes as they are, but if change is wanted, I'd support introducing more Classes based on engine type.

Pete. :D
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hawkwind
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Re: 2 strokes a can of worms.

Post by hawkwind » Wed Mar 13, 2013 5:42 pm

Firstly Im not advocating or seeking any rule changes ...just after some lively discussion about 4stroke vs 2 stroke .....reason I started this thread is while looking at the class records where 2 strokes are going head to head with 4 strokes the difference is quite pronounced in speeds..... while i admit there could be many reasons for this; to my mind the largest would have to be the inherent advantage of two power strokes to one ....and as pointed out doubling the rpm of the 4 compared to the 2 in theory would negate this advantage in real life that's mostly not achievable.

some examples the 50cc to the 350cc classes are ruled exclusively by 2 strokes and are many times faster than the 4 strokes ….its not until 500cc are the four strokes starting to match the speeds of the smaller 2 strokes and the lone 2 stroke in the 1000cc class is whooping the arses of the turbo busas. A quick look at the SCTA records just reinforces my point.

I spent a lot of time in Asia over the past several years and got to frequent the mostly illegal drag races, where 200cc was a big block …..well it was a very brave person who would pit there 4 stroke against a 2 stroke ( all drag racing over there involves money and gambling) and let me tell you they have some wonderful single cylinder 4 strokes which rev to the moon but are no match for a well sorted smoker.

Cheers
Gary
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
Rider......................... Tardus Vetus Inflatio

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ChrisACT
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Re: 2 strokes a can of worms.

Post by ChrisACT » Wed Mar 13, 2013 6:14 pm

Air cooled engines, whether 2 stroke or 4 stroke, cannot produce the same amount of sustained power as their water cooled counterparts. Especially the way we run them (wide open for sustained periods).

So, by the logic of previous posts, we should create separate classes for air cooled v water cooled.

As for 2 strokes, do we create separate classes for reed valve vs piston port vs rotary valve? There's currently a separate class for pushrods vs overhead cams isn't there?

Where does it all end?

We're running the risk of disappearing up our own orifice here.

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internetscooter
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Re: 2 strokes a can of worms.

Post by internetscooter » Wed Mar 13, 2013 6:38 pm

Gary the simple solution is to talk to Greg about allowing enthusiasts to maintain sublists on the dlra.org.au website. The class record will still be the record, but there can be other lists where someone keeps a track of engine type (if they are that way inclined) or anything i.e. unofficial lists.

I was racing MPS/G 250 but the list I was aiming to be the top of is http://www.100mphscooter.com/100_mph_speeds.html - and even there I am initially aiming to only regain the title of world's fastest Vespa - not the overall top speed (yet). The VW's have a similar thing going.

I think something like that would encourage more racing because people can go for PB's of what ever someone else cares enough to maintain a list about :)

edit: Actually it could be an official list - the way the 100mphscooter list works is people submit official race tickets - so it would be easy to verify the record was real and the list owner only has to deal with people that want to submit their speed to a list.
Paul
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ben james
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Re: 2 strokes a can of worms.

Post by ben james » Wed Mar 13, 2013 9:02 pm

hawkwind wrote:Firstly Im not advocating or seeking any rule changes ...just after some lively discussion about 4stroke vs 2 stroke .....reason I started this thread is while looking at the class records where 2 strokes are going head to head with 4 strokes the difference is quite pronounced in speeds..... while i admit there could be many reasons for this; to my mind the largest would have to be the inherent advantage of two power strokes to one ....and as pointed out doubling the rpm of the 4 compared to the 2 in theory would negate this advantage in real life that's mostly not achievable.

some examples the 50cc to the 350cc classes are ruled exclusively by 2 strokes and are many times faster than the 4 strokes ….its not until 500cc are the four strokes starting to match the speeds of the smaller 2 strokes and the lone 2 stroke in the 1000cc class is whooping the arses of the turbo busas. A quick look at the SCTA records just reinforces my point.

I spent a lot of time in Asia over the past several years and got to frequent the mostly illegal drag races, where 200cc was a big block …..well it was a very brave person who would pit there 4 stroke against a 2 stroke ( all drag racing over there involves money and gambling) and let me tell you they have some wonderful single cylinder 4 strokes which rev to the moon but are no match for a well sorted smoker.

Cheers
Gary
the lone 2 stroke in the 1000cc class probably has around 200 horsepower doing 240 mph ,
the turboed busa's have more than 400,
don't see that much of an advantage there.
ben james dlra#389
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RGV
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Re: 2 strokes a can of worms.

Post by RGV » Wed Mar 13, 2013 9:46 pm

hawkwind wrote: some examples the 50cc to the 350cc classes are ruled exclusively by 2 strokes and are many times faster than the 4 strokes ….its not until 500cc are the four strokes starting to match the speeds of the smaller 2 strokes and the lone 2 stroke in the 1000cc class is whooping the arses of the turbo busas. A quick look at the SCTA records just reinforces my point.

Cheers
Gary
Dont confuse time spent with $$$ spent on development. I for one cant afford 16 titanium valves and spring retainers, 4 high comp pistons, 2 Yoshi cams, fancy EFI and ECU. I can afford to do a lot of reading and tinkering in my shed. As for 2 strokes ruling exclusively, most of the 2 strokes have aero changes whereas the 4 strokes dont? Is the speed accomplished by HP and $$$ or carefully designed fairings? A loud exhaust on a stock bike isnt going to get you a record, it will probably slow you down. That seems to be what a lot of the 4 stroke bikes seem to do.

There is nothing stopping people building a bike like Bretts and putting a turbo bussa motor in it. Again not a lot of $$$ but a lot of shed time invested in his bike.

Ive started work on my new motor for next year. A METHANOL breathing version of this years.FASTER and LOUDER. But no dearer to build. 2 second hand carbys from Evilbay. 2 new rods from a different model and some redesigned ports, heads and pipes.

Dave

Last Minute Racing "its a 2-stroke ya twit - Its supposed to smoke"
DLRA #928
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2010 MPS/G 250 118 MPH:)
2011 Washed Out:(
2012 Washed Out:(
2013 MPS/G 250 131 MPH (RECORD):)
2014 MPS/G 250 140 MPH (RECORD):)
2015 MPS/F 250 DNF:(

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