All sold!

Last chance price, $37 each shipped or both for $75

I always run both pumps. Run the pulse on the bottom plate to a fitting on the intake, just as you would for the remote pump. You can also cap the bottom plate fitting or use a sealed bottom plate, and then you would use the hole on the carb flange (shutter side) and angle drill the intake flange to where it goes down into the intake port. The factory gaskets and some racing intakes already come pre-drilled for this. And some snowmobile carbs dont have the hole in the carb flange drilled all the way through so you may have to drill it. For general tuning, set the fulcrum arm and pop off pressure for the fuel you are using and engine needs. If using alky, E85, or a highly oxygenated race fuel, you may have to do numerous other mods. When done correctly, they work great with little issue.

The Noram Star clutch would be the best choice. It works great and is easy to change engagement rpm. Don't worry about the factory HP rating on it. It will handle far more without issue.

http://www.bmikarts.com/Noram-Star-Clutch-_p_735.html

Stock bore for 25/27hp command v-twin 3.270"

Kohler all the way. As Paul said, dollar per horsepower they are simply the best option.

I now have two of these available, brand new. $40 each shipped to your door

One set of heads and intake are sold. Parts below still for sale

Complete set of 23hp heads with rockers, $100 shipped to your door

23hp intake left $35 shipped

Package deal with 23hp heads and matching intake, $125 shipped

If you can't find anything used, go to the BMI karts and supplies website. They some of the best prices on new axle parts.

ARC racing or Midwest Super Cub. They both sell nice flywheels for Kohler v-twins.

Good start so far. I would move the motor towards the front several inches for more even weight distribution through the chassis. For the tracks guys run on here it makes a big difference in handling, and keeps you from having to add extra weight to the front of the chassis. This will also help you keep the weight goal you are going for.

Briggs Vanguard v-twin 21/23hp 38ci Heads and Intakes. I have two sets of heads and two intakes available.

One set of 38ci heads in good condition complete with rockers, $100 shipped to your door

One set of 38ci heads in usable condition just a little dirty. Includes just the heads with valves and springs, no rockers or valve covers. $80 shipped obo

Two 38ci intake manifolds. Both in equally nice condition, stock intakes ready to use. $35 shipped (each) obo

In oval dirt track racing, big bore short stroke motors with long rods is a great combo. If built correctly, they rev quickly, and can make big hp at high rpm.  Torque, horsepower, and rpm are all very closely related and similar results can still be achieved different ways.  HP = TORQUE x RPM ÷ 5252. If you want your engine to have 50hp at 5000 RPM plug in those numbers and do the math, and it will take 52.52 ft lbs of torque to make 50hp at 5000 rpm. However, at 8000 RPM, it only requires 32.825 ft lbs of torque. That is why some of the lighter engines with small cubic inch turning higher rpm can run beside or beat a bigger ci engine turning lower RPM. Now take a big CI motor and build it for spinning high rpm, then you have a monster.

But to answer your question, i prefer the big bore short stroke engines with long rods to achieve the nice rod/crank geometry i am looking for, and spin them high rpm.

Still for sale. $40 shipped!

A good friend of mine worked at Murray for a number of years when they installed a lot of the opposed twins and flat head single engines. Although some of the models are actually different,  he was told (at that time period) the motors with the small differences in HP was for advertisement only and was simply a different sticker from Briggs. It was done simply to attract more buyers with an extra .5 or 1hp. He has a lot of new opposed twins labeled 21hp and 21.5hp as well as 12.5 and 13hp flathead singles that he bought in pallets sold off when they didn't start right up or got damaged on the assembly line.