My Long Rod Conversion Report

[BILTIT]

Just I heads up I have a par 12.5 head from chad and his pcv tune for 92oct and I have found the sled runs best with 5gal av gas and 5gal premium. Torco works but I don't think it does what it says on the bottle.

What elevation? What year sled? That is alot of octane for such a low compression head. That's about what i run with my 13.6 head at 2200.

 

[ak]

Most of these are in Alaska running around sea level and up

 

[Snodawg]

Interesting report since I have been told by some top engine builders that these motors actually lose HP by utilizing a LR and/or an increase in case volume yet everybody that runs these motors swears by the seat of the pants feel. And from what I have read, a shorter rod (with stroke staying the same) will increase torque and acceleration whereas a longer rod will increase rpm's. I do understand how a longer rod will decrease side loading of the piston. What am I overlooking here that makes these motors perform?

 

[BILTIT]

Decreased side loading= increased ring seal possibly?
I have never ridden a stock engine to compare to my LR so not really able to give much info. I have run many engines though (both 2&4stroke) and this LR runs smooth and strong.


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[rmscustom]

Since most getting this have a worn out or blown up engine getting a fresh motor with properly fitted pistons probably plays a big part in the seat of the pants increase.

 

[turboless terry]

I would like to ride one. I actually have a buddy that had over 4000 miles on it so he did one. I know my 13 would put my hands to sleep.

 

[BILTIT]

My 04 pro-xr 800 vibrates more than my LR pro rmk.


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[Sheetmetalfab]

On power....

My indy specialty long rod pulls 2 grams per arm more than my brothers mtntk fix kit pro.
We both have the same 12.5-1 head.
Pcv tuned similar ( little more fuel in mine up top)
Slp green pink primary spring in both
His 68 gram mtx 2g heel 1g tip.
Mine 71 gram mtx 2g heel.
Stock sec spring both.
his helix 60-42-36
Mine 62-42-40
Both 2011 163's
Stock pipes.

I removed the tied clutch after swapping secondary's with him earlier this year and gaining trackspeed from my previous best setup with the tied.