Topic: Viper SK250S - eKartingNews

Viper SK250S

Tagged: Justin_evert@ sbcglobal.net

This topic contains 20 replies, has 11 voices, and was last updated by Jim White 4 years, 9 months ago.

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March 10, 2014 at 5:54 pm #23580

Ian Harrison
Participant

Hi Guys
Here’s an image of the Viper Racing UK SK250S installed in an Anderson Maverick 250 National chassis.

Just a few jobs to finish, then we are ready to rock and roll!!

Best Regards

Ian :-)
March 10, 2014 at 10:00 pm #23587

Bobby Butler
Participant

Dang it Ian, you have really outdone yourself! The black power coated head will tick off the gas gas worshippers.

If it performs as good as it appears (no doubt) a game changer as arrived!

Congradulations on the accomplishment!

BB
- March 11, 2014 at 4:58 pm #23641
  
  Ian Harrison
  Participant
  
  Thanks BB
  
  Ian
March 12, 2014 at 7:33 am #23671

Brian Wilhelm
Participant

Ian, it looks very interesting. Can you share any details?
March 12, 2014 at 7:48 am #23672

Dan Davis
Participant

Very nice looking package Ian!
March 12, 2014 at 12:10 pm #23692

Andy Kiker
Participant

Good thing Ian has a picture posted so we all know what Dan was referring to. I think.
March 12, 2014 at 4:28 pm #23703

nigel cooper
Participant

Does it have 6 gears and a counterbalance shaft?
March 12, 2014 at 5:49 pm #23709

Ian Harrison
Participant

Hi Guys

The Viper SK250S is a 250cc single cylinder Superkart engine.
The cylinder is reversed (exhaust out-of-the-back) with a front mounted carburettor feeding into the crankcase via a reed induction system.
The crankshaft is fully shrouded with just a slot through to the top end for the connecting rod.
It has a bore and stroke of 68.0 x 68.8mm and a rod length of 128mm
The crankcases are machined from billet aluminium. It has a gear driven counterbalance shaft with an internal balance weight on the right and an external balance weight on the left.
The cylinder has 3 exhaust ports and 5 transfer ports.
Gearbox, clutch and selector mechanism are taken from the 2002-2007 Honda CR250 and in standard (UK) format it is a 5-speed with alternative gearbox ratios. Our 6-speed gearbox can also be fitted if local regulations allow.
The ignition is Viper Racing’s own digital programmable ignition that runs off the 2002-2007 Honda generator, however, many ignition options are possible.

Best Regards

Ian :-)
March 13, 2014 at 6:58 am #23733

Dan Davis
Participant

Andy!

Very nice description of your…….”engine specs” Ian!
- March 17, 2014 at 9:07 pm #24017
  
  Justin
  Participant
  
  Ian, I am inpressed and so glad I was not the only one who thought this should happen.
  
  I feel that this has so many advantages as oppose to the conventional arrangement,
  
  With the intake being in the front you can get more of a ram air effect, a decent NACA duct on top of the side pods.
  
  A more compact package mean not only better aero, with the muffler tucked behind, but one could in theory put 2 smaller radiators in the side pods (a la F1 or Indy) and eliminate the large rear radiator and thus eliminate the “parachute” effect.
  
  Having existine Honda components is a big plus for ease of acceptability and familiarity, not to mention would be a big plus for the Honda spec peeps.
  
  I know its not polite to ask, but what are you looking at for cost per unit?
  
  I know feel I am one step closer to moving forward with this adventure!
  
  Justin
  
  PS Just curious as to the steering wheel set up, could you show /explain more?
  
  J
March 13, 2014 at 7:52 am #23735

Andy Kiker
Participant

Sorry Dan, That was to easy a setup. I couldn’t pass it up.
March 18, 2014 at 11:12 am #24039

Greg Lindahl
Participant

Very clean design, Ian.

Congratulations
March 19, 2014 at 9:37 am #24106

nigel cooper
Participant

brilliant product! Using/reusing existing Honda parts from your engine makes the most sense to me and it can save you about 1/3 of the cost.Why re-engineer and manufacture new components that are proven,already and easily accessible.Just change only what needs to be changed from the CR250 engine.

Does it have an external water pump and how much does the engine and exhaust weight?

Could anyone in north america purchasing one, post your opinions on it after trying it out? Vibration levels,smoothness,power and torque ect.
March 22, 2014 at 7:19 pm #24336

Ian Harrison
Participant

Hi Guys

First ever track outing for the Viper SK250S at Silverstone test day, with driver Mark Stansfield.

Next outing Oulton Park, Cheshire, UK March 27/28th MSA British Superkart Championship

Best Regards

Ian :)
March 26, 2014 at 3:32 am #24520

Chris Reinhardt
Participant

Very nice Ian, good luck with it…

CR

Chris Reinhardt

CR2 Motorsports

http://www.cr2motorsports.webs.com/

XV Racing Products

http://www.xvengineering.com/
March 26, 2014 at 6:57 am #24538

Larry Dobbs
Participant

It looks the business Ian! Have a great run at Oulton Park:)
April 6, 2014 at 7:13 am #25131

Justin
Participant

Ian,

Any more news from the second round of tests at Oulton Park?

One thing I forgot to ask, would this be available as an conversion to an existing CR250 engine or is there too much internal modification required for this engine?

Regards,

Justin
April 6, 2014 at 5:55 pm #25167

Chris Reinhardt
Participant

Justin, download Ian’s PDF files, it’s priced both way it seems, but if I understand the pricing, looks cheaper if Ian builds for you with all new pieces…

Results: http://www.superkart.org.uk/

Looks like a solid 3rd, not bad for a brand new motor…

Chris Reinhardt

CR2 Motorsports

http://www.cr2motorsports.webs.com/

XV Racing Products

http://www.xvengineering.com/
April 7, 2014 at 4:03 pm #25229

Ian Harrison
Participant

Hi Justin

We are actually expecting to get it on the dyno for the first time this week. That sounds absolutely crazy that we’ve been on track twice without it going on the dyno, but we were hit with availability on a specific part and then with some mods that we made. On both occasions finished the kart on the morning of the tests without time to dyno. Hopefully now, we have the time (6 weeks) to optimise and release the figures everyone is waiting for. However, we have learned an awful lot about the engine and the name of the game has been meeting peoples expectations regarding it’s appearing on track.

Chris’ summary is pretty spot on and anyone is welcome to either buy the kit to build their Honda into, or to have us build it for them using their Honda parts or for us to supply a brand new fully ready to go package.

Best Regards

Ian :-)
April 7, 2014 at 4:09 pm #25230

Jim White
Participant

Hi Ian, check your pm’s please
March 18, 2014 at 6:12 pm #24062

Ian Harrison
Participant

Hi Guys

Thanks for the favourable comments.

As you might imagine we are now in the middle of the development programme to optimise carb/ignition/pipe design, etc.

As a special introductory price, the complete engine package of engine/carb/pipe and ignition is £5,995.00 UK pounds fully assembled, dyno-tested and ready to go.

The steering wheel is a Sparco car steering wheel and at present the buttons don’t do anything!! Just the wheel is the drivers personal choice . . . . nothing too exciting.

I believe that the ram-airbox will end up under the right-hand pod, with probably a snorkel duct on top of the pod.

Here’s a price list link for the full motor:
https://www.dropbox.com/s/m52csesljxlwqs9/SK250S_Price-List_09.01.14.pdf
and a list for any potential self-builders with their own Honda crankcase induction Parts to use:
https://www.dropbox.com/s/8aokmzwhp8q4kl5/SK250S_Self-Assembly_Pricing_09.01.14.pdf

Best Regards

Ian
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