super m dyno #'s

rtb321 · Sep 12, 2009

i bought a 53 stage II super m last spring and recently put it on a m&w dyno. after tuning up the carb and dist it'll pull 58hp. a friends 52 super m pulls 49hp, and his 54 400 pulls 55hp. does anyone have any guess whats been done to make that much hp? would just an overbore kit make that much more hp? the date codes match the engine to the rest of it, and it doesn't appear to have been apart in many years. it is a 264 block with 125psi compresion.

Rick(MN) · Sep 12, 2009

So many variables. First question is are these readings taken from the same dyno with the same operator? My dyno's vary by 3 to 5 hp. Dyno operator can create or lose a couple hp as well. 58 hp is a darn good running Super M. I've always heard and am a firm believer that there is 5 hp to be found on most every 50hp tractor just by putting it on the dyno and getting all little things right. Quarter turn on the main jet, couple degrees of timing, couple thousandths of point and valve setting.......can easily be the difference of several hp. This is all before even discussing which sleeve and piston kit the different tractors are sporting.

rtb321 · Sep 13, 2009

same dyno same operator. i ran it on the dyno three different times and it was pretty consistant. i did gain about 3 hp tuning it under load and gained 1hp with valve adjustment. at 1/4 throttle, 200 pto rpms it'll pull over 50hp before it loses rpm. i was just curious what might be in it, but it runs way too good to just tear it apart to see. to me it seems to run a little too strong to just have an overbore kit in it. i was hoping someone might have one that runs similer dyno #s that knows what's inside it.

Rick(MN) · Sep 13, 2009

I've put a number of M&W sleeve and piston sets in M through 450's over the years. The kits used to come with a bigger main jet for the carb. To have them dyno out in the high 50's after installing them was pretty common. I'm told that IH's high altitude set produces the same results, but I cant say that for sure. I've only been around a couple of them that had an M&W crank and they both were just a shade over 60.

scot in pa · Sep 14, 2009

Dyno's are also weather sensitive. Race engine shops have climate controlled rooms to run their dyno in. Altitude, atmospheric pressure, temperature, humidity, all affect the final reading.

super m dyno #'s

rtb321

Member

Rick(MN)

Member

rtb321

Member

Rick(MN)

Member

scot in pa

Member

Similar threads