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Max torque from a SMW 127 Ultima@ 2500-4500: How do you build it?
Engine experts help me out! I do have a couple of dollars to spend on this motor, however, I like to do things right the first time. What exhaust, carb, air filter, and head work would you recommend to get this bike to run strong in the normal riding rpms.
Don't get me wrong, this motor is very strong right now even on a bad tune(very rich). I just want to get the max from it in the rpm range that i ride in 90% of the time.
Here is what I am running right now and what I am considering changing to.
What I am Running:
2004 BBC Venom Prostreet
127 Ultima "PROOF MOTOR" built by SMW out of Oklahoma (I HIGHLY RECOMMEND THEIR MOTORS!)
BDL w/outer bearing support and ball bearing lock up clutch
Jim's 6 sp tranny
Spike style air cleaner
V&H Big Radius Pipes
S&S shorty G (no mods, jetted rich)
What I am considering:
RB Racing LSR 2-1
Doherty Machine Power Pacc
Mikuni HSR45
Headwork? (not sure who to go with or the extent to have heads reworked to reach my goals) I really need recommendations here as I have no actual experience with worked heads and their benefits.
Last edited by Force; Nov 5, 2009 at 01:47 AM.
Reason: added carb
A Wood 408 or 9B would drive it up, set correctly.
Did a 120" recently that ripped almost 130 hp and was knocking on the 150 ft/lbs door, with a Wood 9B, Rinehart Duals, G carb/Thunderjetted.
BTW, I'd weld that crank, before embarking on this.
Scott
Its running rich. Get it to a competent dyno tuner and sort it out properly before making modifications to it! With a big motor like that it could be way down on its true potential at present. Give it a chance to run right and you might be surprised just how strong it is.
Last edited by grbrown; Nov 5, 2009 at 08:08 AM.
Reason: Spelling
SMW is Southern Motorcycle Works in Ardmore, OK. They build 127s in house with certain parts upgraded. From what I have read and experienced first hand, their motors are more reliable than the "crate" 127s from Ultima.
So far mine has been rock solid with 5k miles and not a single issue.
more compression for the 9f and its more upper rpm cam.
9b is a good cam
scott will do a good job on the heads (does that make ya happy now alibi)
altho if it is not tuned correctly you will never know what the results would be.
also go with a borzilla insted of the lsr its a better pipe. or get a borzilla and modify it to acept super trapp discs and tune it for the rpm you want the tq mostly at.
right now you have 2 major obstals with that bike carb too rich and a shitty pipe.
get it tuned first and get a better pipe before i would worry about anyuthing else.
more compression for the 9f and its more upper rpm cam.
9b is a good cam
scott will do a good job on the heads (does that make ya happy now alibi)
altho if it is not tuned correctly you will never know what the results would be.
also go with a borzilla insted of the lsr its a better pipe. or get a borzilla and modify it to acept super trapp discs and tune it for the rpm you want the tq mostly at.
right now you have 2 major obstals with that bike carb too rich and a shitty pipe.
get it tuned first and get a better pipe before i would worry about anyuthing else.
I plan on getting it professionally tuned after the work. As for the Boarzilla vs the RB, have you used an RB on a big inch motor? If so what were the differences? I'm not going after looks but that Boarzilla is butt *** ugly. The Fat Cat is a different story as far as looks but it is too small from what I understand.
thanks for the help
have not used the rb onany big motor buti also do not know any one who has either.
the borzill works its that simple.
it looks just like the fat cat also what size valves are in youtr head now if they are 2 in then you will need a big primary tube pipe like the borzilla.
see if you can get tthe afr and carb trimmed forst it mightt bring a few more ponies and tq to the table not much down low as the pipes you have just blow it out.
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