Thinkin about a 124/126 CI motor for a winter project for my trike

[Sloride]

Hey guy's,

I love this trike, but I am craving more power. My 2010 RGC trike has a 103 with 255 HD cams Dragos H-pipe exhaust and Power Vision Tuner. It runs "OK" kinda peppy from Idle to about 3800 to 4000 RPM and then it just falls flat. (i understand that is the design of this cam)

I understand it is the weight that is killing my performance (1260#'s). I want to build/buy a Torque monster. If I am going to do this, I want to do it right or not do it at all

I am looking for advice from you guys that are running BIG CI motors.

What motor you went with?
Are you satisfied with your selection?
What you would do different, if you had it to do over again? (if anything)
How much difference it really made in day to day riding?

I am not looking for a race motor, I want a 2000 to 5000 RPM power band that makes some serious torque

[NHBAGGER]

Define serious torque?

[Sloride]

Define serious torque?

I am not sure, but above 120#'s from 2500 to 5000 RPM

[NHBAGGER]

Just changing cams to the TTS100 would get you about 100 ft-lbs from 2000-4500 and 110 from 3000-4000. Pretty good bang for the buck. With just some mild headwork and a good tune you'd probably be within 5 of your goal for pretty cheap money considering what swapping motors would cost.

[Sloride]

Just changing cams to the TTS100 would get you about 100 ft-lbs from 2000-4500 and 110 from 3000-4000. Pretty good bang for the buck. With just some mild headwork and a good tune you'd probably be within 5 of your goal for pretty cheap money considering what swapping motors would cost.

NHBAGGER,

Thank you for your reply

I really looked at going the route your talking about. Durability is as important to me as power. If going that route, I know it's probably overkill, but I would need to do the Timken conversion and a welded Crank with S&S lifters and rocker arms to make it nearly bullet proof.

There is only about $2000.00 difference between that build and a new 124 CI motor , I would rather have a big CI motor for the difference.

[msocko3]

Hey guy's,

I love this trike, but I am craving more power. My 2010 RGC trike has a 103 with 255 HD cams Dragos H-pipe exhaust and Power Vision Tuner. It runs "OK" kinda peppy from Idle to about 3800 to 4000 RPM and then it just falls flat. (i understand that is the design of this cam)

I understand it is the weight that is killing my performance (1260#'s). I want to build/buy a Torque monster. If I am going to do this, I want to do it right or not do it at all

I am looking for advice from you guys that are running BIG CI motors.

What motor you went with?
Are you satisfied with your selection?
What you would do different, if you had it to do over again? (if anything)
How much difference it really made in day to day riding?

I am not looking for a race motor, I want a 2000 to 5000 RPM power band that makes some serious torque

I your looking to scratch build a 120+ engine PM FLTR2008TRIKE, he's running a 124" engine built to his specifications.

[FLTR2008TRIKE]

My advice if you like riding around in the lower rpms is to build a 117". That will keep your stroke the same but the same bore as a 124" such as mine. A 124" requires you to keep your rpms up higher due to the longer stroke

You will make a ton of torque with a 117" which will move your trike through all the gears. Just don't get caught up reading horsepower numbers. Unless your going twist your engine above 5250 rpms

Tom

[FLTR2008TRIKE]

I see your in Texas. I would suggest speaking with Steve # GMR Performance in Keller Tx. about what your wanting for engine power. He has a very good reputation

[Sloride]

I see your in Texas. I would suggest speaking with Steve # GMR Performance in Keller Tx. about what your wanting for engine power. He has a very good reputation

Thanks Tom, I will give Steve a call

[Downtown Cowtown]

Truett and Osborne, did make or still make a set of flywheels that are both big wheels, not one thick and one skinny, built for torque, im thinking on doing this to a evo i have. I rarely ride in the top range. low and mid range even on two wheels, but this double big wheel (flywheels) has been roaming around my brain for a while.

[Steve Cole]

Be careful of what you wish for! Looking for something that you may never use is something many get caught up into. Go out and ride what you have and really pay attention to the RPM range you truely use, most of the time. If you ride like most trike owners you will find that you spend 90 +% of the time from 2000 - 3500 RPM and 0 - 45% TPS. If that is you, then build the best for that area and do not worry about the WOT numbers above 4000 RPM as the few times you ever use it just isn't worth it. Take the money you save and put it into the other items your going to need to handle the bigger torque your going to build. Like clutch, trans and cooling.

[Sloride]

Be careful of what you wish for! Looking for something that you may never use is something many get caught up into. Go out and ride what you have and really pay attention to the RPM range you truely use, most of the time. If you ride like most trike owners you will find that you spend 90 +% of the time from 2000 - 3500 RPM and 0 - 45% TPS. If that is you, then build the best for that area and do not worry about the WOT numbers above 4000 RPM as the few times you ever use it just isn't worth it. Take the money you save and put it into the other items your going to need to handle the bigger torque your going to build. Like clutch, trans and cooling.

Steve,


what is your opinion of the 117 TQ coming in earlier than the 124 TQ.


My normal RPM riding range is about 2000 to 5000 max RPM


I want roll on the throttle make you smile "Throttle Response" not high RPM HP,

Clutch and cooling will be addressed with the build

[clint44]

My advice if you like riding around in the lower rpms is to build a 117". That will keep your stroke the same but the same bore as a 124" such as mine. A 124" requires you to keep your rpms up higher due to the longer stroke
Tom

Tom,correct me if I'm wrong here but all else being equal,a shorter stroke allows higher revs and a longer stroke almost always will create more torque down low,as well as have lower rpm limits. The above statement seems to contradict this. Help me understand what I'm missing here.

[FLTR2008TRIKE]

Tom,correct me if I'm wrong here but all else being equal,a shorter stroke allows higher revs and a longer stroke almost always will create more torque down low,as well as have lower rpm limits. The above statement seems to contradict this. Help me understand what I'm missing here.

Your statement is correct in regards to the longer stroke having the mechanical advantage of making more torque at lower rpms.

Because we are dealing with a 45 degree Vtwin there is a lot more stress on the components of a longer stroke engine making the torque at a lower rpm compared to a shorter stroke Vtwin engine.

Piston speed at the bottom and top of the longer stroke are faster on the longer stroke due to the thrust and pull of the longer arm.

Having the larger bore engine with components working together in a shorter stroke engine can make similar torque at the lower rpms helps lower the stress on the connecting rods.

It's not good to lug any of the 96" and up twin cam engine as it built from the factory.

Added:

A Harley 120" has a 4 5/8" stroke. However the pin placement of the connecting rod is higher resulting in a shorter connecting rod. The S&S 4 5/8" flywheels use a longer connecting rod. There is a 124" kit now made to up the bore of the HD 120"

[clint44]

Thanks for the explanation,Tom.

[FLTR2008TRIKE]

Thanks for the explanation,Tom.

YW. There was a guy who built a 117" engine that made over 150tq/hp for his Streetglide. He ended up building a 124" that wasnt as radical on the street.

[msocko3]

YW. There was a guy who built a 117" engine that made over 150tq/hp for his Streetglide. He ended up building a 124" that wasnt as radical on the street.

Sounds like TXChop, way radical engine. It would have been a hoot as a bar hopper, but traveling would have sucked.

[FLTR2008TRIKE]

Sounds like TXChop, way radical engine. It would have been a hoot as a bar hopper, but traveling would have sucked.

Yes sir!!

[clint44]

I've built a few street cars and bikes in the past with too-radical engines & drivetrains,also. Won't make that mistake again.
How do you think one of the new 120ST engines would work in a trike?

[FLTR2008TRIKE]

I've built a few street cars and bikes in the past with too-radical engines & drivetrains,also. Won't make that mistake again.
How do you think one of the new 120ST engines would work in a trike?

Granted the 120st comes with a throttle body. For the amount being spent. I would suggest the S&S 124lc. Spend a little more and get a better engine with the reliability that is proven.

Harley still uses lousy lifters and there is a greater chance of the flywheels shifting compared to the S&S built engine.

If you crunch the costs of building your engine you could save some money. Obviously there is no warranty.