How to identify Long/Short rod motors?
#1
Tech Regular
Thread Starter
How to identify Long/Short rod motors?
Hi, I just want to know how I can identify whether a motor has a Long/Short rod? I have a few mt-12's and Nova Mega's and I know that mt-12's are long rods but not too sure about the Mega's. Help would be appreciated
Thanks.
Thanks.
#2
I'm not sure if this is correct but here goes. I have purchased 3 motors this year. The first 2 I know are long rod MT-12's. The 3rd is a new JP RS-12. I think it is probably a new short rod motor. The visual difference from the outside is that on the JP, the piston sleeve is recessed into the block (crankcase). I don't know if that's the reason for it or not, but it sort of makes sense.? The button is also twice as thick to keep the cooling head above the block (crankcase). I tried using a new stock Novarossi button, with a new Kawahara Zac cooling head, and they wouldnt work. When the head was tightened down, the button was still loose. Like I said, that may or may not be a way to tell from the outside.
#3
This may be a bit dumb, but, what is the effective difference between the long and short-rod motors?
I read someone saying that the long-rods are dead. . .?
MT-12 is long-rod? If so, dang, I love mine. . .fastest motor I've had yet. . .
I read someone saying that the long-rods are dead. . .?
MT-12 is long-rod? If so, dang, I love mine. . .fastest motor I've had yet. . .
#4
Quite simple really...for the short conrods, there is a channel cut into the side of the conrod this is in 2 sections, the long rods has one channel all the way down.
There are quite a few other differences already mentioned like the almost flush sitting cyclinder. Another indication is a 'flat' cut into the back plate...which should be facing upwards when installed on the short rods....
And of course....the short rods are physically shorter!!!
There are quite a few other differences already mentioned like the almost flush sitting cyclinder. Another indication is a 'flat' cut into the back plate...which should be facing upwards when installed on the short rods....
And of course....the short rods are physically shorter!!!
#5
Originally posted by Boomer
This may be a bit dumb, but, what is the effective difference between the long and short-rod motors?
I read someone saying that the long-rods are dead. . .?
MT-12 is long-rod? If so, dang, I love mine. . .fastest motor I've had yet. . .
This may be a bit dumb, but, what is the effective difference between the long and short-rod motors?
I read someone saying that the long-rods are dead. . .?
MT-12 is long-rod? If so, dang, I love mine. . .fastest motor I've had yet. . .
Short rods- More power at higher revs.
Long rods- More low end torque
This is being very "simplistic"!
#6
Tech Regular
Thread Starter
Thanks for the info guys.