Predator 212cc mods

[Theantibum]

Hello all. I am new here, so I am sorry if I’m posting in the wrong forum. Anyways, I was hoping that y’all can help me out. I have a predator 212cc with a jetted carbeurator, performance air filter and tailpipe, a billet flywheel, 22 pound valve springs and a performance spark plug. I bypassed the governor and have stock everything else. Anyways, I was wondering if I should get an upgraded billet rod and push rod? How high is a safe rpm? I bypassed the governor but did not remove it. Should I remove it? Is there anything else I should do?
Thanks in advance!
-Caleb.

 

[David Ham]

Hello all. I am new here, so I am sorry if I’m posting in the wrong forum. Anyways, I was hoping that y’all can help me out. I have a predator 212cc with a jetted carbeurator, performance air filter and tailpipe, a billet flywheel, 22 pound valve springs and a performance spark plug. I bypassed the governor and have stock everything else. Anyways, I was wondering if I should get an upgraded billet rod and push rod? How high is a safe rpm? I bypassed the governor but did not remove it. Should I remove it? Is there anything else I should do?
Thanks in advance!
-Caleb.

Yes you should remove the governor, as it can break apart at high speeds and possibly ruin the internals of the engine. I would remove the low oil sensor aswell as it will stop the engine when going around a corner, its happened to me...

Sent from my SM-G900I using Tapatalk

 

[bob58o]

Remove the governor gear.
https://www.youtube.com/watch?v=d6tUssrcK1I

Get a billet rod.
https://www.youtube.com/watch?v=owahpOeLYaw

Stock Length (least favorite option, unless you plan on a high lift camshaft).
http://www.arcracing.com/6254-arc-billet-rod-hf-predator-212cc-3-308-std/
or +0.020" (better option for both Hemi and Non-Hemi, unless using a high lift camshaft)
http://www.arcracing.com/6256-billet-rod-hf-predator-020-3-328/

If you have a NON-Hemi, you can use a +0.040" Rod with a Hemi-Flat Top Piston.
http://www.arcracing.com/6252-arc-billet-rod-hf-predator-3-348/
http://www.arcracing.com/6252-arc-billet-rod-hf-predator-3-348/

And if you don't want to reuse the old head gasket after upgrading the rod, then you can get a thinner head gasket for ~$10
https://www.ebay.com/itm/Predator-2...112714017797?_trksid=p2385738.m4383.l4275.c10
Stackable. 1 gasket is 0.009", two is 0.018", all three for 0.027".
Need to keep ~0.030" Piston to Head Clearance.
If piston is 0.020" down in the cylinder when at Top Dead Center, then you can run a 0.009" Head Gasket for 0.029" Piston to Head Clearance. If your piston sits 0.010" down in the cylinder when at top dead center, then you can run two of those 0.009" gaskets for 0.028" for Piston to Head Clearance. If your piston sits flush with the deck when at top dead center, then you can run three of those 0.009" Gaskets for 0.027" Piston to Head Clearance.

Once you get a billet rod, then you can look into camshafts.
Actually if you plan on getting a camshaft, you should take that into consideration when choosing connecting rod length.
Need to keep ~0.065" Piston to Valve Clearance.
http://www.racingheadservice.com/rhs/piston-to-valve-clearance-guide/

http://www.nrracing.com/product-p/200cam-252.htm
Camshaft, 252-0207: SPECIAL HIGH TORQUE GRIND FOR SMALL TRACKS, 6000 rpm, 22 lb Springs Required, 26 recommended. 10 to 1 Compression or higher recommend, however it will work with lower compression ratios. This is one of the best choices for low end power, esp. on small dirt tracks with heavy drivers. (Oval Track)

 

[Nosandwich]

Thanks Professor Bob!!!

 

[Theantibum]

Okay thank you. I do not have enough to get a billet rod now. Is it safe to operate say 7000 rpms? I also have 22 pound valve springs and better push rods. Thanks!

 

[Theantibum]

Thanks for all the replies and advice!! I have one more question. I have a motorscooter with my 212 on it, and together we weigh about 220 pounds. It has 9 inch wheels. I have been looking at a torque converter, and I was wondering, if I install it, what should i make my gear ratio? I do not need crazy torque to where I'm fighting wheelies, but I want it to be able to get up to speed quite rapidly. Will a 1:1 ratio work? I use my scooter mainly for street riding, but sometimes I do tow or take passengers, or both! I do not want it to struggle when doing so. Thanks in advance!!

 

[Nosandwich]

Okay thank you. I do not have enough to get a billet rod now. Is it safe to operate say 7000 rpms? I also have 22 pound valve springs and better push rods. Thanks!

Absolutely NOT!!!

And don't use those springs without a billet rod.

 

[landuse]

Thanks for all the replies and advice!! I have one more question. I have a motorscooter with my 212 on it, and together we weigh about 220 pounds. It has 9 inch wheels. I have been looking at a torque converter, and I was wondering, if I install it, what should i make my gear ratio? I do not need crazy torque to where I'm fighting wheelies, but I want it to be able to get up to speed quite rapidly. Will a 1:1 ratio work? I use my scooter mainly for street riding, but sometimes I do tow or take passengers, or both! I do not want it to struggle when doing so. Thanks in advance!!

You are still going to have to gear at 5:1 or 6:1

 

[mckutzy]

9" wheels???

Is that OD of the tire or rim size???

Need to know the measured OD of the rear tire...

 

[bob58o]

9" wheels???

Is that OD of the tire or rim size???

Need to know the measured OD of the rear tire...

If it is a scooter, then it might have 9" OD tires.


If you attempted 1:1 with a 30 series TC, then you would be going 179mph at 6000 RPM and 107mph at 3600 RPM.

It will still be scary fast with a 3:1 sprocket reduction.
12T on TC with 36T on rear,
10T on TC with 30T on Rear,
8T on TC with 24T on Rear,....

60 mph at 6000 RPM


How fast do you want to go?
It is going to be tough to not fight wheelies with one person, and also not struggle with two people.

Gear for no struggle with two people and it will wheelie with one.
Gear for one person and no wheelies and it will struggle with two.

Clutch might be better than TC, if you don't want to fight wheelies.

---------- Post added at 12:23 PM ---------- Previous post was at 12:13 PM ----------

For 1 person, maybe 2.75:1 a regular clutch and governor set. 3600 RPM = 36 mph. 5000 rpm = 50 mph.

For two people, maybe no governor, a regular CC and 4.5:1 gear ratio
6000 RPM = 36mph

 

[Nosandwich]

WOW....1:1...shades of FreeRunner.

 

[Theantibum]

9" wheels???

Is that OD of the tire or rim size???

Need to know the measured OD of the rear tire...

Yes I have nine inch wheels. The drive wheel is nine inches.

---------- Post added at 12:54 AM ---------- Previous post was at 12:49 AM ----------

If it is a scooter, then it might have 9" OD tires.


If you attempted 1:1 with a 30 series TC, then you would be going 179mph at 6000 RPM and 107mph at 3600 RPM.

It will still be scary fast with a 3:1 sprocket reduction.
12T on TC with 36T on rear,
10T on TC with 30T on Rear,
8T on TC with 24T on Rear,....

60 mph at 6000 RPM


How fast do you want to go?
It is going to be tough to not fight wheelies with one person, and also not struggle with two people.

Gear for no struggle with two people and it will wheelie with one.
Gear for one person and no wheelies and it will struggle with two.

Clutch might be better than TC, if you don't want to fight wheelies.

---------- Post added at 12:23 PM ---------- Previous post was at 12:13 PM ----------

For 1 person, maybe 2.75:1 a regular clutch and governor set. 3600 RPM = 36 mph. 5000 rpm = 50 mph.

For two people, maybe no governor, a regular CC and 4.5:1 gear ratio
6000 RPM = 36mph

I am not trying to go 180 mph haha I will limit my throttle down to like 50. I just don’t want to fight wheelies and rev high to go high speeds. Would I have good acceleration with maybe a 2:1 with a torque converter?


Also I will post pictures of what I have tomorrow I just haven’t had time lately.

 

[bob58o]

2:1 with 30 series TC is 89 mph at 6000 RPM and 53mph at 3600 RPM.

This whole build is out of whack. You have an overpowered, built up engine and want to add a torque converter to a tiny vehicle with tiny wheels, but you don't want the torque. You have an engine that will spin 6k RPM, but only want to use half throttle.

 

[Theantibum]

Yes that sounds about right lol.