SV Project

I hope this forum can be of help even if you are across the Atlantic. I am starting a project that is totally opposite of what is considered normal. I race Micro Sprints which are powered by motorcycle engines. I will attach a photo as soon as possible or you may view photos of our cars at: http://www.maximumdirt.com/gallery/index.php. The majority of the nation allows 619cc engines with the N.E. US and a few of the larger races allowing 637cc, all engines running on methanol. Here are a few specifics of our type of racing:
750 lb. car w/ driver
Tracks range from 1/10th to 1/5th mile in length
Straightaways 220-250ft. in length
Cars are mainly using 600cc R6’s, CBR’s and GSX’s with a few Kaw’s

I am looking at building two SV650’s by reducing their bores to 79mm (613.4cc) and 80mm (629.3cc). I have talked to a couple of engine builders that have parts available readily for this project. I realize that the engines will not produce near the HP of the inline 600’s but the torque should be much better with the SV. I always like trying new and different things that seem out of the norm, lol. The builders are giving me HP ratings of 85 – 100 after having the engine work done. They have suggested Billet crank, stronger rods, larger carbs, light headwork and adjusting the ECU to allow rpm’s of up to 10,500.

I would like everyone’s thoughts on what they think of this project as to its feasibility, etc. Thanks for your thoughts.

I am probably crazy with this project but it won't be the first time someone said that about me. I know the Inline engines do produce way more HP and the torque is fairly close. But on our very short tracks they are not able to utilize both. Their power and torque bands are only hitting thier stride from near the middle to end of the straights. Whereas the SV650 has a wider torque band which should help it come off the corner quicker and be further down the straight before the inlines get into their band. At least, that is what a couple of reputable engine builders of SV's and inlines have stated to me. So am I totally crazy?

[Speedy]

Interesting! And your gonna be running on Alcohol eh!?

I bet it will sound lovely on that! (into Drag-Racing so familiar with exotic fueled vehicles )

Post some pics,let us know how you get on with the fuel and power output!

Speedy

[northwind]

I like your style! If you're retaining the stock ECU and it's a carbed motor you're using, I hear an SV400 ECU gives you an 11,000 rpm redline... You didn't mention cams but I'm presuming you'd be changing those, you can go a fair bit hotter withotu dramatically impacting torque or midrange on an SV.

what's all this about the redline? the rev counter goes up to 11k on an sv anyway...

[northwind]

Rev limiter is lower though. Can't remember where. 10,500? Rev counters usually go past the limiter.

We fuel these cars with methanol which adds approximately 5 HP. Will be changing cams plus lots of lower end work. Wheelspin plays a large part in our racing which I figure will help this engine stay with the inline 600's.