[color=maroon][b]Which is the best 250 cc International Engine?[/b]
Commonly referred to as 250 twins, Superkarts are powered by twin cylinder Grand Prix motorcycle engines, or specialist kart racing reed-valve engines.
What I want to know is which one has the best torque, HP, time between rebuilds, easy to tune, value for money etc.
Thanks in advance,
Chris[/color]
Comments16
Re: Which is the best 250 cc International Engine?
They all have their pros & cons, Its personal preference really, The inline "rotary valved" twin cylinders (rotax,fpe,safe,brc,sgm) offer lower centre of gravity more room for seat movement, easier to work on whilst mounted on the kart and a Good top end power / torque due to the tandem firing of the cylinders they will hold they're own against the jap engines.
But the jap engines (honda,yamahas) offer "reed valves" for better tractability, dare i say probably better torque and punch out of corners due to the V configuration..
as for tuning any of the above engines there is plenty of people that know there stuff around the traps you just have to ask around to get an idea of who to speak to just dont deviate too much from whats already been proven.
Parts availabilty & parts costs would decide my route if i was in your position. im sure others on the forum may have conflicting opinions but thats my two cents.
Re: Which is the best 250 cc International Engine?
Like I said just an observation from the outside.
Re: Which is the best 250 cc International Engine?
Go the Jap engine.
Re: Which is the best 250 cc International Engine?
FPE,SAFE,BRC,VM,DEA,PVP,HONDA,YAMAHA!; :D ;) ;) ;) ??? ::)
Re: Which is the best 250 cc International Engine?
Chris,
grab ya self another k9 mate...go dual 125's
Re: Which is the best 250 cc International Engine?
$3,500 we paid for a good TZ V twin and about $1000 for pipes, and it never missed a beat and was as fast as anything in the Vic club at the time, once mounted your home and hosed. To get that speed out of the 256 we need newer electrics and had to pay alot more attention to wear and tear or it just died . Then you had to pay a higher price for spares and chase them down etc. Most drivers I know who went from 256 to Jap never looked back.
Re: Which is the best 250 cc International Engine?
After this Rotax stopped development and production of the 256, (due to higher priorities like making a high volume of engines which = money) eventurly all of the 256 spares dried up around the world and then things became just to hard to continue running this engine against the V twin and the parellel Yamahas.
Now that you can
A) Buy inline parts quite easily unless you are computer brain dead and have your head up your bum,
B) Buy after market cylinders and pipes from the likes of PVP,RCS and FPE to put on a Rotax,
they are able to compete with the V twins of a few years old. However with the V twin, they seem to be harder to fall out of there powerbands from corner entry to corner exit so are more forgiving on chassis set up, driver ability and gear ratio selection. (this is fact and not a dig at anyone)
Have a look at the qualifing times from round 2 of the Nationals last year (Eastern Creek) First qualiy there was only.0675 seconds from 1st to 4th.
Not present here was Gary Pegeraro who got to the lead a few times on the starts and had similar race pace to all of these guys with a FPE engine.
Qualy 1
1 Warren Milveen (NSW) Honda 250I 1:30.3992*
2 Yiani Harpas (SA) BRC 250I 1:30.4235 0:00.0243
3 Sam Zavaglia (NSW) Yamaha 250I 1:30.4336 0:00.0344
4 Darren Hossack (Vic) SAFE 250I 1:30.4667 0:00.0675
Qualy 2
1 Warren Milveen (NSW) Honda 250I 1:30.6184*
2 Sam Zavaglia (NSW) Yamaha 250I 1:30.6344 0:00.0160
3 Darren Hossack (Vic) SAFE 250I 1:30.8217 0:00.2033
4 Yiani Harpas (SA) BRC 250I 1:31.0535 0:00.4351
There were other factors that probably impacted these results.
I think Sam was being conservitive with his package, comprimising a bit of pace for reliability and I believe that if Warren, Darren and Yiani were comfortable with their balance, they would have been approx .4 of a second quicker again.
As you can see, there is bugger all in the choice of engine.
Anyway thats history and do concider that talent has a lot to do with pace. Everything has a potentialy and the challenge is to get the package to that potential.
This year though, I think the BRC will be very strong, reliability has been a large setback for them to date but these seem to have a very wide powerband similar to the Honda's and Yamaha's.
Roll on the Nationals, we are looking forward to competing at the highest level once again against the countries best drivers and equipment.
See ya's and good luck to all regardless of package you run.
Regards Scott
Re: Which is the best 250 cc International Engine?
Even if one of those engines is a few ks quicker or a few hp better doesnt really change the time that much.
Use whatever you find stops the watch the quickest, THATS KART AND ENGINE!
Re: Which is the best 250 cc International Engine?
Re: Which is the best 250 cc International Engine?
Actually, to come to think of it, Sam must know something, as he is selling both of his karts. (Honda and Yamaha) ;)
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Either kart is For Sale, not both. I'd prefer to sell the 2008 Yamaha so there is no excuses for the buyer. 230kph at Phillip Island last time out on nearly a season old pistons/rings and it's also last years championship winning kart.
My Honda still needs more sorting.....so I'm in for that challenge at the moment.
Trialing an inline engine is not yet in my immediate plans. The repair expense is still beyond my limits if I can't keep it reliable. Reliability is the key for any inline, however reliability has come a long way in just the last 2-3 years. I know it doesn't happen here but when I was in Assen I saw some competitors with 2-3 engines each....that's 1 on the kart and 2 on the ground waiting replacement or setup with different power curve....reminded me of when I used to race 100cc clubman.
Re: Which is the best 250 cc International Engine?
There is plenty of good information posted.
Sam, are you selling a Stockman TZ 250? If so, what is it $elling for?[/color]
Re: Which is the best 250 cc International Engine?
http://webmasteraus.com/Forums/index.php?topic=645.0
Re: Which is the best 250 cc International Engine?
Re: Which is the best 250 cc International Engine?
Karts have a much higher drag Coefficient, have smaller wheels and therfore have more rolling resistance and don't have a diff to allow easy aceleration off turns compared to bikes.
Top speed is only around that figure. Some will tell you more but I would have to see their data logger and check their wheel speed sensor measurement to believe it.
Hey Paul, when are we going to see you over here racing?
No Champs this year? Shane remains NZ champ until next year now?
Re: Which is the best 250 cc International Engine?
Whats the weight of a typical 250 kart?
Surely final drives can be sorted with the multitude of gears and primary ratios avail for the Yam.
I went to the island once watchin a national round of the webmasters. The pole sitter was running a Yam. Had a closer look at it between races. The driver told me he pretty much seizes it every time it goes out. This thing was runnin like a bucket and still pulled a ridiculous time and schooled everyone else there.
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Min all up weight (inc driver) is 220kg
When did you go to the Island and see a yamy beating anything? RS250 (Sam) has only had his since the beginning of 2008 and I have never heard it running like a bucket.
Prior to this the only yamy at the island was Jamie toogood's kart and not being awful or anything as he had alot of issues with it and it did run like a bucket but it only did like 1.39's at best is my recollection. (far from the front of the feild).
I could be wrong but I'm going back to 2000 when I arrived on the scene.
Re: Which is the best 250 cc International Engine?