The big bore allows a taller gearing setup. Put a 15t countershaft on 250 and a big bore for your apples to apples comparison. The extra torque and hp of the big bore will pull the gearing easily. The 250 can do it but not as well. So I believe the big bore will have a higher top speed when geared up as the 250 will struggle to reach the same rpms on top with higher gearing.

 

Has anyone ridden both the 351 and 331 to see if there is really any noticeable different characteristics between the two?

 

 

I really doubt it, the 351 probably has a slight edge due to the extra 20cc's of displacement but that would most likely only be able to be discerned on a dyno.

 

Even when doing my research on the TM36 carb install on the KLX, I don't think I saw any dyno info on any KLX with this carb. Anyone aware of one existing? I searched but didn't find one. I've seen stock setups and some all the way to the 351 with a TM33...just no TM36.

 

if i remember correctly, somebody posted a dyno comparison before...and, the hp curves looked similar....max hp and max torque were similar i think too...but, the 351 torque curve came up to max very early on the lower rpm compared to the 330...anybody remember the dyno posts on here?

 

The torque is great. Luggin the thing at 15 mph in 5th I can still get on the throttle and feel some nice, thumpy acceleration.

 

Now that this thread is officially off track,,,,
Lets continue. The original statement was that the poster was hoping to get another 5mph of top speed out of his already maxed out ( I assume max rpm's) bike. if the bike is already maxed out, then wind resistance and/or his weight is a non issue. in fact all variables are non issues IF he is already MAXED OUT.( meaning he has enough power to meet the limitations of the RPM and gear) therefore,, more POWER will not make him go faster (top speed) unless he either achieves a higher RPM or changes his gear to a taller gear.

Back to your small block big block chevy,,, gear your truck with 4.11 in the 454 and tell me it will have a higher top speed that the small block geared with 3.23's?? the only way that will happen is if you have 5 tons of load in the back of the truck going up hill.
That is where the power overcomes resistance. Something that has been already done in the original post ("MAXED OUT").
Ok i am done now.
Just gear your 351 up to 15 tooth in front and you will be happy. That 351 will cart your 240 lbs around quite nicely and have power to spare, and enough speed to make you smile!!!!

 

IF the smaller engine/ wheel combination has enough power to overcome the resistance, both combinations will have the same top speed.

The smaller HP combo will be working harder than the larger one because of the power diferential however, both will be turning at the same speed.

 

Sure they are going the same speed but that is not taking into account how fast they get there and how much torque it has at said rpm.