Predator 212 performance parts expectations

[Coverfire]

Hello, I have some questions about my engine build and was hoping for some info/advice from y'all. I'm currently running a non-HEMI Predator 212 (on a Murray Explorer) with the governor removed, stage 1 air filter, .038 jets in the carburetor, 18lb valve springs, and a header pipe. Now, I'm upgrading the carburetor, flywheel, rod, and Cam. Here is the list of the exact parts:

.22mm Mikuni carburetor
ARC Billet Flywheel (8 degree built in timing advance to bring the ignition timing to 32 degrees)
ARC Billet Rod
MOD2 Grind Core Dyno Cam

I'm a novice at engine tinkering and I'm just trying to get my head around what kind of differences I can expect in performance. From what I'm gathering the Mikuni will allow a little more oxygen into the engine so that will give me a little more power there. The flywheel will advance my timing (as well as making it safe to run with no governor) and with the 8 degree advance in timing I can expect a little more power in the high end but less low end power? The rod won't add power but will be able to handle the power gains/higher RPM. The MOD2 grind cam will keep the valves open longer and give more high end power vs low end? Am I sacrificing low end/torque power for higher end power with this set up? My goal is to have more all around power but I want to keep this a more off road build with some nice low end power and torque. Thanks for any help in advance.

 

[chimmike]

Cams move power in the powerband, and in that case it moves the powerband "right" on the dyno curve, to higher rpm. Basically yes, you're shifting away from low end torque and your torque and horsepower peaks will be higher in the rpm. Should be a fun little cart with those parts installed, for sure.

 

[Coverfire]

Cams move power in the powerband, and in that case it moves the powerband "right" on the dyno curve, to higher rpm. Basically yes, you're shifting away from low end torque and your torque and horsepower peaks will be higher in the rpm. Should be a fun little cart with those parts installed, for sure.

Thank you! I appreciate your input! Yeah, its already a fun kart so I'm really looking forward to it after the new modifications. I'm sure that I'll have to upgrade to a 40 series torque converter? I have a cheap 30 series off Amazon that is already slipping after a year of barley driving it. So I'm sure with added power it will shread the cheapo 30 series?

 

[OPmini]

you are going to get high-end power, but less power at the low end. As for your CVT you definitely don't need a 40 series just get a genuine comet 30 series from go power sports.

 

[Coverfire]

I was under the understanding that anything in the 8 to 18hp range would need a series 40 and with the modifications I'm installing I'd be near 12 to 14 hp? I'm not trying to argue at all, I'm just genuinely trying to learn.
Plus, I'd be happier with a 30 series given the cost of a 40 series.

 

[OPmini]

I was under the understanding that anything in the 8 to 18hp range would need a series 40 and with the modifications I'm installing I'd be near 12 to 14 hp? I'm not trying to argue at all, I'm just genuinely trying to learn.
Plus, I'd be happier with a 30 series given the cost of a 40 series.

Correct, but those are more of suggestions when it comes to small blocks, but when you get into big-block single-cylinder and twin-cylinder engines (301cc, 420cc, 670cc) a 40 series becomes mandatory, due to the fact that these engines can produce more raw torque than any 'built' small block, and will smoke CVT belts like its 4:20. In addition, the choice of what CVT to use is based on your engine build and application. I have never seen a 40 series on any small block, not even methanol/stroker engines. I suggest buying some genuine comet springs and belt for your 30 and see what happens! I don't even think the mounting holes are in the right place to fit a 40 on a small block plus the shaft diameter on a 212 is 3/4in and the shaft diameter on a 40 clutch is 1in

 

[Coverfire]

Wow! Thanks for the information! I really appreciate it. I'm learning as I go here so this is exactly the kind of information I need from the community to keep me from making mistakes.

 

[65ShelbyClone]

The flywheel will advance my timing (as well as making it safe to run with no governor) and with the 8 degree advance in timing I can expect a little more power in the high end but less low end power?

Conceptually yes, but it's complicated to explain why and how much. In short, more timing on an engine with fixed advance won't really cost low-end power, but will make the engine more octane-sensitive under load in the rev range that the advance is not optimized for.

The MOD2 grind cam will keep the valves open longer and give more high end power vs low end? Am I sacrificing low end/torque power for higher end power with this set up? My goal is to have more all around power but I want to keep this a more off road build with some nice low end power and torque. Thanks for any help in advance.

Cam design is another complicated topic. A very (very) crude rule of thumb is that increased lift increases torque, more duration increases power, and more overlap raises the RPM that everything has to happen.

Outside of complex solutions like superchargers or turbos, a variable transmission (like a TAV) is the most direct way to maximize output from an engine that may have high power output over a fairly narrow rev range.

 

[Coverfire]

Conceptually yes, but it's complicated to explain why and how much. In short, more timing on an engine with fixed advance won't really cost low-end power, but will make the engine more octane-sensitive under load in the rev range that the advance is not optimized for.



Cam design is another complicated topic. A very (very) crude rule of thumb is that increased lift increases torque, more duration increases power, and more overlap raises the RPM that everything has to happen.

Outside of complex solutions like superchargers or turbos, a variable transmission (like a TAV) is the most direct way to maximize output from an engine that may have high power output over a fairly narrow rev range.

Awesome, thank you for chiming in! The more you guys can educate me the better so I appreciate it!

 

[ThunderKart79]

Go Powersports also sells a new 30 series driver called the juggernaut and that driver was developed for high performance small blocks. Another benefit is that the juggernaut does not limit the number of RPMs you can turn. If I remember right a normal 30 will only allow the engine to turn 6000 RPMs. Trust me now that you turned down this awesome road you would probably be better just buying a juggernaut.

 

[Coverfire]

Go Powersports also sells a new 30 series driver called the juggernaut and that driver was developed for high performance small blocks. Another benefit is that the juggernaut does not limit the number of RPMs you can turn. If I remember right a normal 30 will only allow the engine to turn 6000 RPMs. Trust me now that you turned down this awesome road you would probably be better just buying a juggernaut.

Yeah, you know what I recently saw a video (I think it was buildbreakrepeat) of the Juggernaut. I totally forgot about it. Thanks for mentioning it! I'll have to wait a bit for any more new parts. Maybe I'll blow up the old cheapo series 30 and HAVE TO get a new torque converter though. Probably wont be long. I felt it slipping the last few rides.

 

[65ShelbyClone]

If I remember right a normal 30 will only allow the engine to turn 6000 RPMs.

There's nothing in the TC itself that prevents RPM from going past any point, but the driver housings often cannot withstand the forces and can distort or the weights can come apart. The Juggernaut looks like a copy of a Comet 340 driver that instead can use the asymmerical belt of a 30 series.

 

[ThunderKart79]

Thai you I was trying to remember exactly what I read , it also mentioned that the belt would slip at higher RPMs.

 

[65ShelbyClone]

To be fair, most engines around 200cc don't have the power to pull 6k with a TC in full overdrive.

 

[ThunderKart79]

That is true but I have learned the hard way many times that a component that is a little overkill is a lot cheaper compared to several belts garter springs and aluminum weights. Especially if you have to pay several shipping changes. Also the GCP tourqe converter and cvt systems seem like high quality products.

 

[ThunderKart79]

I also have a 44 magnum C that fits a 3/4 crank but like mentioned before that is not a cheap route to take and I 100% agree that a Comet driver would be a huge step up so it would be wise to compare prices and also to study each product.