So I want to upgrade my hemi motor got tired of it stock lol my budget is from 300 to 500. any suggesting? I want it to respond (torque) as soon as I step on it since im drifting my go kart. I know I should replace my piston rod, flywheel, valve springs, Cam, air filter, and im not sure if I should jet the carb or replace it with a better one? what would be the difference? Im asking for your help because I don't know what best combo will work best with one another.Like I mention above I know what to replace (let me know if I miss something) but don't know how still valve springs, what carb or jet, how long rod, what cam, and how many degrees on flywheel. Ps I will be removing governor
NR racing has a stage 3 kit that comes with every thing you would need. With a muffler included it looks like its about $420 or so. This was with adding a Mikuni 22mm carb to the kit and a billet flywheel. Here is whats in the kit...
Race/Open Air Filter & Adapter,
Choice of Racing Carbs
Dyno Mod 2 Cam
22 lb springs
8 degree Timing Key,
Small Fan,
Valve Cover Gasket
Carb gasket
Billet Rod +.020"
Thin Head Gasket
Optional Header/Exhaust
I would ask them what this all would add for HP but they say depending on cam and combination of the parts you pick from the options they say it should be around 13-15 HP so lets just say around 13HP.
Race/Open Air Filter & Adapter,
Choice of Racing Carbs
Dyno Mod 2 Cam
22 lb springs
8 degree Timing Key,
Small Fan,
Valve Cover Gasket
Carb gasket
Billet Rod +.020"
Thin Head Gasket
Optional Header/Exhaust
I would ask them what this all would add for HP but they say depending on cam and combination of the parts you pick from the options they say it should be around 13-15 HP so lets just say around 13HP.
I would suggest running the Black Mamba Jr cam versus the Dyno mod 2, the mod 2 is a good cam but is a stock lift cam, but has increased duration, it needs 1.2 or 1.3 rockers to be a great cam. The Mamba Jr. is the max lift for a hemi headed predator at .275 lift, with an unmodified head. If I could go back I would not own a mod 2 cam, but rather a Black Mamba Jr. cam. Just my opinions here. To pick your rod length, you need to pull your head and check your in the hole measurement, the goal is to get to as close to 0 deck height as possible. A .650 bored carb would suit your build very well, and the ease of tuning compared to the Mikuni is nice.
Run one of the below flywheels:
Slipstream 28 degrees timing built in
or
ARC Hemi Flywheel 32 degrees timing built in
[MENTION=47323]OND[/MENTION] did an excellent job on a hemi build here:
OND Hemi build
Run one of the below flywheels:
Slipstream 28 degrees timing built in
or
ARC Hemi Flywheel 32 degrees timing built in
[MENTION=47323]OND[/MENTION] did an excellent job on a hemi build here:
OND Hemi build
OldMiniBikes.com has parts you need to look at!
Here is a great cam...for less money! Gives you .275" of lift but not all the duration to kill low end
https://www.OldMiniBikes.com/super-x-dyno-cam.html
They also have the new ARC .675 CNC bored carbs!
https://www.OldMiniBikes.com/dj-2229-g-cnc-bored-675-box-stock-carb-for-gas.html?category_id=1722
The Hemi engines can't take lift over .300 without machine work to the spring pockets. OMBW also have a complete valve kit with springs that is a great replacement kit
https://www.OldMiniBikes.com/stainless-steel-upgrade-hemi-valve-kit.html
don't buy a .020 billet rod unless you pull the head first. I have seen some at zero deck, and have also seen some a .050 in the hole.
The new tech guy at OldMiniBikes is awesome and can help you!
Here is a great cam...for less money! Gives you .275" of lift but not all the duration to kill low end
https://www.OldMiniBikes.com/super-x-dyno-cam.html
They also have the new ARC .675 CNC bored carbs!
https://www.OldMiniBikes.com/dj-2229-g-cnc-bored-675-box-stock-carb-for-gas.html?category_id=1722
The Hemi engines can't take lift over .300 without machine work to the spring pockets. OMBW also have a complete valve kit with springs that is a great replacement kit
https://www.OldMiniBikes.com/stainless-steel-upgrade-hemi-valve-kit.html
don't buy a .020 billet rod unless you pull the head first. I have seen some at zero deck, and have also seen some a .050 in the hole.
The new tech guy at OldMiniBikes is awesome and can help you!
We bought a cam from NR Racing 4 or 5 years a go it to was a 274 lift cam for short track racing....plenty of torque.
Cam number is 274-0207
NR RACING THE LEADER IN HONDA GX & CLONE PERFORMANCE
Cam number is 274-0207
NR RACING THE LEADER IN HONDA GX & CLONE PERFORMANCE
I would just buy a crate racing engine..I'm lazy and not an engine builder..:biggrin: . Racing Go Kart Mini Bike Drift Trike Engine Briggs Local Option 206 10 HP NIB | eBay
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What about doing a Predator 420? There only $320. They make 13 HP and 18 FT-LBs It would weight more but if you can fit the motor it would make more power than a lightly modded 212. Getting the extra parts for the motor like the clutch and such would eat the rest of your budget up. Later if you had the money to mod the 420 it would be a monster of a motor. Even with the governor in I bet you could mod the motor and make an insane amount of power. Air filter, exhaust, mill head, advance timing and convert to alcohol.