Whatcha think about this cam?

[Ross24]

Hello, I was kinda just planning ahead on performance parts and came across this.

Ebay.com

Andddddd

Ebay.com

I know you guys will probably think these are some clown parts but how do you think they will do against the stock cam? I notice the first one actually shows its lift, duration, etc, so I'm hoping you guys can compare it using that.

 

[Rat]

Hello, I was kinda just planning ahead on performance parts and came across this.

Ebay.com

Andddddd

Ebay.com

I know you guys will probably think these are some clown parts but how do you think they will do against the stock cam? I notice the first one actually shows its lift, duration, etc, so I'm hoping you guys can compare it using that.

Unless you plan on dumping tons of cash into is as a track engine (I cant imagine you wouldn't be asking this if you were) go with the first one. Get one of that sellers "No retard" ignition coils as well if you plan on having it spin harder than 4k.

Factory equipped coils tend to start cutting out around 4k, some can still run reliably up to 4800 but basically your spark becomes unable to keep time so if the engine doesn't start missing because of valve float it will be ignition timing.

The second one is ill advised unless you're going for full billet, and an empty wallet

 

[bob58o]

What are your intentions with this engine?
Are you trying to race?
Backyard fun?
Stop sign to stop sign?

A lot of stop and go? A lot of sharp turning?
Or pedal to the floor for 15 minutes straight and brakes are just extra dead weight?

The first cam is a stock style cam. The duration compared to stock is the same. The lift might be 5% more than stock? The big difference is that the intake center line is retarded a few degrees to push the powerband into a higher rpm range.

If not racing in a class that requires stock style cams, I would not choose a stock style cam. If building a yard kart, I usually wouldn’t want to shift power from lower rpm’s to higher rpm’s.

It is possible that the extra lift makes up for any low rpm power loss. But you could just get a cam that has extra lift and does not have all that built in retardation.

So again, what are your intentions with my daughter?

 

[bob58o]

This is the one you want.

BLACK MAMBA JR CAM (PREDATOR 212 NON-HEMI) - SMALL ENGINE CAMS

.275" LIFT 230° DURATION @ .050" 104° LSA THE ULTIMATE TORQUE CAM! 6,000+RPM! HARDFACE WELDED! DECAL AND SPEC SHEET INCLUDED

smallenginecams.com

 

[Rat]

What are your intentions with this engine?
Are you trying to race?
Backyard fun?
Stop sign to stop sign?

A lot of stop and go? A lot of sharp turning?
Or pedal to the floor for 15 minutes straight and brakes are just extra dead weight?

The first cam is a stock style cam. The duration compared to stock is the same. The lift might be 5% more than stock? The big difference is that the intake center line is retarded a few degrees to push the powerband into a higher rpm range.

If not racing in a class that requires stock style cams, I would not choose a stock style cam. If building a yard kart, I usually wouldn’t want to shift power from lower rpm’s to higher rpm’s.

It is possible that the extra lift makes up for any low rpm power loss. But you could just get a cam that has extra lift and does not have all that built in retardation.

Guess that's more validation that My 208 has a stupid amount of torque... that cam is much better in it than the stock one that refused to pull past 4500. I gained 1k minimum in rpm ability and lost nothing anywhere in power or torque

 

[BrownStainRacing]

Hello, I was kinda just planning ahead on performance parts and came across this.

Ebay.com

Andddddd

Ebay.com

I know you guys will probably think these are some clown parts but how do you think they will do against the stock cam? I notice the first one actually shows its lift, duration, etc, so I'm hoping you guys can compare it using that.

I use both those suppliers.

Jerry Dover from Dover Power (DIY), is my #1 supplier, very nice guy,

Payne from RPQ, I get bored SA carbs from, and a bunch of other stuff. He usally throws small things in for free, magnetic drain plugs, side cover gaskets, head gaskets, main jets, there's usally something he throws in. Hes another good guy to deal with,

But I only get cams from Small Engine Cams (Isky).

I wouldn't use any 1 of those cams, as RLS and BOB mentioned, thay are WOT track cams, not good for alot of on/off throttle.

That 76* intake valve closed cam, from Jerry is gonna need 10.5:1 -11:1 CR for it run the way it was designed.

That's alot a CR from a hemi head, and gonna take $ to get it right.

That cam from Payne has no specs, so I wouldn't know where to start with a build to be able to use it.

I suggest you keep the stock cam for now, get with Jerry Dover, he will email you back the same day.

Let him build a carb for what you want and expect, he knows his stuff, and don't play kids games. He's a no bs, no non sense guy.

This way you can have a great carb that works for any upgrade you will be doing in the future.

Carburetors (All Engines)

 

[bob58o]

This is the one you want.

BLACK MAMBA JR CAM (PREDATOR 212 NON-HEMI) - SMALL ENGINE CAMS

.275" LIFT 230° DURATION @ .050" 104° LSA THE ULTIMATE TORQUE CAM! 6,000+RPM! HARDFACE WELDED! DECAL AND SPEC SHEET INCLUDED

smallenginecams.com

View attachment 144770

I posted a non-Hemi Predator cam.
If you need a gx/clone/Hemi cam. It’s this one.

BLACK MAMBA JR CAM (GX200/CLONE/HEMI) - SMALL ENGINE CAMS

.275" LIFT 230 DURATION @ .050" 104° LSA THE ULTIMATE TORQUE CAM...6,000+RPM! HARDFACE WELDED! DECAL AND SPEC SHEET INCLUDED

smallenginecams.com

The cam is the brain and nervous system of the engine. Cam choice should be based on application.

 

[Ross24]

What are your intentions with this engine?
Are you trying to race?
Backyard fun?
Stop sign to stop sign?

A lot of stop and go? A lot of sharp turning?
Or pedal to the floor for 15 minutes straight and brakes are just extra dead weight?

The first cam is a stock style cam. The duration compared to stock is the same. The lift might be 5% more than stock? The big difference is that the intake center line is retarded a few degrees to push the powerband into a higher rpm range.

If not racing in a class that requires stock style cams, I would not choose a stock style cam. If building a yard kart, I usually wouldn’t want to shift power from lower rpm’s to higher rpm’s.

It is possible that the extra lift makes up for any low rpm power loss. But you could just get a cam that has extra lift and does not have all that built in retardation.

So again, what are your intentions with my daughter?

View attachment 144769

Lol, mostly parking lot racing. So there's some WOT there. Of course, I wouldn't want to just lose all of my low end power.

 

[BrownStainRacing]

Lol, mostly parking lot racing. So there's some WOT there. Of course, I wouldn't want to just lose all of my low end power.

Heres a short video I made a couple months ago when I installed a RPQ .675" bored SA carb on a ALL STOCK INTERNALS Ducar 224, including the stock cam it came with. Only 8.6:1 CR engine, no head port work jus plain stock, the way it came outta the box.

Stock cams can be nasty, if it's got good parts around it to make it work.

I made the header, replaced the stock coil with a Dover Power performance coil.

Jus those parts, turned this junky roto tiller motor, into a pi$$ed off chain saw.

The sound at idle alone, is worth the cost of a good built carb,.....the performance was jus a bonus,

It never hit over 2800 rpm with jus a flick of the throttle, I had 3100 rpm stall springs in the driver. Spinning 19" tires like that, and not even up in the power yet. WTF????

After the video, I lowered the RR air pressure and it was launching with both front tires off the ground.

Those bored SA carbs, will wake up a stock cam for you.

 

[Ross24]

Heres a short video I made a couple months ago when I installed a RPQ .675" bored SA carb on a ALL STOCK INTERNALS Ducar 224, including the stock cam it came with. Only 8.6:1 CR engine, no head port work jus plain stock, the way it came outta the box.

Stock cams can be nasty, if it's got good parts around it to make it work.

I made the header, replaced the stock coil with a Dover Power performance coil.

Jus those parts, turned this junky roto tiller motor, into a pi$$ed off chain saw.

The sound at idle alone, is worth the cost of a good built carb,.....the performance was jus a bonus,

It never hit over 2800 rpm with jus a flick of the throttle, I had 3100 rpm stall springs in the driver. Spinning 19" tires like that, and not even up in the power yet. WTF????

After the video, I lowered the RR air pressure and it was launching with both front tires off the ground.

Those bored SA carbs, will wake up a stock cam for you.

Haha, I love the title

That ducar looks like a beast of an engine, how's it compare to a pred 224?

So ur thinkin a cam isn't all that compared to a simple carb upgrade? I figured with it running stock parts and power, the engine is pulling all it needs from the stock carb.

 

[BrownStainRacing]

Haha, I love the title

That ducar looks like a beast of an engine, how's it compare to a pred 224?

So ur thinkin a cam isn't all that compared to a simple carb upgrade? I figured with it running stock parts and power, the engine is pulling all it needs from the stock carb.

I have a built pred 224, same carb, headwork, 9.6:1 CR, Isky Black Mamba Jr cam, 26# springs installed at .0840" - .850", billet +.020" rod, billet side cover, ft piston, PVL flywheel at 28* of ignition timing. Dover Power performance coil. All spec'ed, clearanced, and tuned myself.

It's a bad dude, nasty outta the hole, slams the driven pulley into high around 40 ft and pulls very hard to 5900 rpm, it's can be scary . 4.6:1 gear, 20" tire, 3000 rpm stall springs.

The Ducar 224 will take less money, less time and make more power in the same rpm range if somebody wanted to build it.

It's clearances are spot on right outta the box, I can't say that about the pred 224, they were all over the place. It took alot of time to get them in spec.

My pred 224 has a pred 212 blower housing, starter cup, and recoil on it. The stock pred 224 parts are too wide for my mini bike.



I don't launch it like this on hard pack surfaces, it'll leave me on my butt.


As far as you stock carb, it's good to 4900, if you have the right parts to help it.

Flywheel, is the 1st thing you need to change, I can't remember if you mentioned that or not.

After a good, safer aftermarket flywheel, then port work in the head, a good carb and header, then you can easily hit 5500 + with the stock cam and valve springs. I wouldn't push the stock rod passed 5300, but that's me.

 

[Rat]

Haha, I love the title

That ducar looks like a beast of an engine, how's it compare to a pred 224?

So ur thinkin a cam isn't all that compared to a simple carb upgrade? I figured with it running stock parts and power, the engine is pulling all it needs from the stock carb.

The short and simple fact of the matter is that a Ducar (196, 212, 224) are factory race kart built engines unlike a predator of any size which is intended as a stationary equipment engine.

Just about any engine can be built to race quality, but getting one that is designed for it means better quality, and as a bonus a bit of a short cut

 

[Ross24]

Hey guys, they updated it to show the specs. This cam

How does it compare to some of the well known cams? Like that black mamba Jr for example.

What power would this make and in what part of the RPM band?

 

[BrownStainRacing]

Hey guys, they updated it to show the specs. This cam

How does it compare to some of the well known cams? Like that black mamba Jr for example.

What power would this make and in what part of the RPM band?

its a lazy ramped cam, made for upper rpm power 7000+ rpm. Jus another track only cam.

That 88* intake valve closing is gonna need about 12:1 CR. That means the piston is way up in the cylinder before the intake valve closes.


It's not gonna build power til late into the rpm.

If I was FORCED to use that cam, I would make dam sure the t/c or clutch was stalled to 4800 rpm. Any thing less, and that cam will not pull up outta the hole.

It's gonna be very easy on the valve train, but......so are stock cams.

The Dyno Cams cm grind and that cam would be very close in performance.

Learn to read a cam card. What the numbers mean.

If you add the intake open, and intake valve close together, then add 180, you will come up with the advertised duration. Same with the exhaust side.

That cam has 318* advertised duration. There's only 360* in a circle.

That means that intake valve spends alot of time opened, and needs a bunch of CR and rpm to make it work like it was designed.

The BMJ cam has around 282 advertised duration, the BM cam has around 295.
Both of the isky cams will pull harder up outta the hole, get to max rpm in a shorter distance, and not need crazy CR to make em work.

Heres a ECCarbs cam card with advertise duration numbers and .050" numbers.

Do the math yourself and learn how to read a cam card.

Any questions, jus ask.

TTS-689 Tennessee Thunderstix Cam for Predator 212 Hemi & Clone Style Engines

www.eccarburetors.com

Here's Dyno Cams card for the cm-grind, advertised specs. It's very close to the RPQ cam.

Racing Cams and Parts | CM Grind, Clone, Hemi | CL-CM | DynoCams

Explore a World of Parts: Find the Components You Need for Your Projects. From Mechanical to Electronic, Discover a Vast Selection of High-Quality Parts to Fuel Your Creativity. | CL-CM

www.dynocams.com

Here's some more math for you. Let's use the cm-grind specs

Add the intake open and close together, then add 180, that gives you 321.8 * advertised.

Now subtract the intake .050" lift duration number (236.9*) from the 321.8*, and that leaves you with a difference of 84.9.

This 84.9 number is VERY IMPORTANT, to me. I dont wanna see more then 65.

This number tells me how fast the intake valve will come off the seat and how fast it goes back on the seat from .050" lift.

The smaller this number, the "faster ramped" cam it will be.

The ISKY BMJ cam is around 50-55 difference in advertised and .050".

ECCarbs has fast ramped cams. Some can be as low as 47. Fast punching, hard hitting, cams in the whole powerband, but can be hard on the valve train. I don't recommend them for beginner builders.

Dyno Cams BP2 grind is a fast ramp cam.
Do the math, you will see.

Racing Cams and Parts | BP2 Grind, Clone, Hemi | BP2-HT | DynoCams

Explore a World of Parts: Find the Components You Need for Your Projects. From Mechanical to Electronic, Discover a Vast Selection of High-Quality Parts to Fuel Your Creativity. | BP2-HT

www.dynocams.com

If you jus learning cams, I suggest you stick with the stock cam for now. Get the CR up to around 10.5:1, add a pair of 1.3:1 stamped steel ratio rockers and 22# springs.

The extra pressure and ratio rockers changes the way the stock cam works. It will come on faster, and revs up quicker and higher.

Jus my 2 cents, good luck, learn, and have fun,

 

[Ross24]

its a lazy ramped cam, made for upper rpm power 7000+ rpm. Jus another track only cam.

That 88* intake valve closing is gonna need about 12:1 CR. That means the piston is way up in the cylinder before the intake valve closes.


It's not gonna build power til late into the rpm.

If I was FORCED to use that cam, I would make dam sure the t/c or clutch was stalled to 4800 rpm. Any thing less, and that cam will not pull up outta the hole.

It's gonna be very easy on the valve train, but......so are stock cams.

The Dyno Cams cm grind and that cam would be very close in performance.

Learn to read a cam card. What the numbers mean.

If you add the intake open, and intake valve close together, then add 180, you will come up with the advertised duration. Same with the exhaust side.

That cam has 318* advertised duration. There's only 360* in a circle.

That means that intake valve spends alot of time opened, and needs a bunch of CR and rpm to make it work like it was designed.

The BMJ cam has around 282 advertised duration, the BM cam has around 295.
Both of the isky cams will pull harder up outta the hole, get to max rpm in a shorter distance, and not need crazy CR to make em work.

Heres a ECCarbs cam card with advertise duration numbers and .050" numbers.

Do the math yourself and learn how to read a cam card.

Any questions, jus ask.

TTS-689 Tennessee Thunderstix Cam for Predator 212 Hemi & Clone Style Engines

www.eccarburetors.com

Here's Dyno Cams card for the cm-grind, advertised specs. It's very close to the RPQ cam.

Racing Cams and Parts | CM Grind, Clone, Hemi | CL-CM | DynoCams

Explore a World of Parts: Find the Components You Need for Your Projects. From Mechanical to Electronic, Discover a Vast Selection of High-Quality Parts to Fuel Your Creativity. | CL-CM

www.dynocams.com

Here's some more math for you. Let's use the cm-grind specs

Add the intake open and close together, the add 180, that gives you 321.8 * advertised.

Now subtract the intake .050" lift duration number (236.9*) from the 321.8*, and that leaves you with a difference of 84.9.

This 84.9 number is VERY IMPORTANT, to me. I dont wanna see more then 65.

This number tells me how fast the intake valve will come off the seat and how fast it goes back on the seat from .050" lift.

The smaller this number, the "faster ramped" cam it will be.

The ISKY BMJ cam is around 50-55 difference in advertised and .050".

ECCarbs has fast ramped cams. Some can be as low as 47. Fast punching, hard hitting, cams in the whole powerband, but can be hard on the valve train. I don't recommend them for beginner builders.

Dyno Cams BP2 grind is a fast ramp cam.
Do the math, you will see.

Racing Cams and Parts | BP2 Grind, Clone, Hemi | BP2-HT | DynoCams

Explore a World of Parts: Find the Components You Need for Your Projects. From Mechanical to Electronic, Discover a Vast Selection of High-Quality Parts to Fuel Your Creativity. | BP2-HT

www.dynocams.com

If you jus learning cams, I suggest you stick with the stock cam for now. Get the CR up to around 10.5:1, add a pair of 1.3:1 stamped steel ratio rockers and 22# springs.

The extra pressure and ratio rockers changes the way the stock cam works. It will come on faster, and rev up quicker and higher.

Jus my 2 cent, good luck, learn, and have fun,

That is extremely helpful, thank you.

All I could decipher was that lift and of course me being a noob, that blinded me.

 

[BrownStainRacing]

That is extremely helpful, thank you.

All I could decipher was that lift and of course me being a noob, that blinded me.

Been there done that.

Me and cheap cams don't get along. They jus ain't worth it to me. They never perform in the low to mid range.

Theres jus nothing like a good hard hitting cam that you can cruise, drag or jus have some good ole back yard fun with, any time you need it to.

 

[Ross24]

If you jus learning cams, I suggest you stick with the stock cam for now. Get the CR up to around 10.5:1, add a pair of 1.3:1 stamped steel ratio rockers and 22# springs.

So I've got some 22# springs coming soon, along with a billet rod. Do you happen to know any ratio rockers that work with the HEMI predator 212?

 

[BrownStainRacing]

So I've got some 22# springs coming soon, along with a billet rod. Do you happen to know any ratio rockers that work with the HEMI predator 212?

Nope, not for the hemi head. They too expensive.

Your are going to be very limited on mods for the hemi head.

You can get very good power from the hemi, you jus can't go too far before you limited the stock head, then comes very expensive machine work, custom piston, longer valves, and that unnecessary crap is jus not worth it.
There's much better non hemi heads out there that dont cost near as much and work extremely good, BETTER IMHO.

A aftermarket flywheel is a MUST.

What you can do is get the CR up, with a longer rod, and head gasket thickness. Measure the piston to deck height before you order a rod. It's ez.

Then pick a longer rod to get the piston as close as possible to the deck without it popping above the deck.

Then pick a head gasket thickness to get the piston to head clearance around. 030".

This will get the most CR outta the hemi you can get without over kill, machine work and still be able to run 87 or 89 octane. I'd say about 9.5-10:1, depends on the cc of the head.

Port the head while you have it off.

A Dover Power performance coil would be my next mod.

Set coil air gap .045"- .060", and ignition timing 28*-30*.

A header pipe about 6-8" long, .880"- .890" I.D, add a muffler.

Then order Payne's (RPQ) .675" bored SA carb.

This will be a nasty lil engine, with down low pull that will make you change to a higher gear. And it will have the balz to pull a higher gear on the high side.

Then maybe give that BMJ cam a try, you might not want it after the above mentioned mods,

Here's a CR calculator I use for every build. Open advanced mode and you will see DCR.

Keep the DCR 7.7- 8.1, and you will have a big ol smile on you face every time you fire it up.

Those so called high dollar, over rated, thrown together parts motors, won't know what passed their butt,

If the numbers get confusing or you can't find them, jus ask.
Some use mm, in, and cc.

Compression Ratio Calculator (Static and Dynamic)

The compression ratio calculator finds both the static and the dynamic compression ratio of your combustion engine.

www.omnicalculator.com

 

[Rat]

So I've got some 22# springs coming soon, along with a billet rod. Do you happen to know any ratio rockers that work with the HEMI predator 212?

You are far better off getting a Wedge head! (common non Hemi) Not only only will it provide a bump in compression being paired with the flat top, but there are WAY more cam and valve options available since smashing against the piston is far less likely. It's so unlikely that you'd need to have the head milled all the way to 12cc and it would still need more cam lift than it can run with

 

[Ross24]

Ok, So I was looking at the Mongoose 272 from NR racing. How does this cam look, would it kill any low end? Given it has more info than the others like ICL, ECL, and lobe separation.

Lift		.272"​
Duration @ .50	245​
ICL		106.5​
ECL		117​
Lobe Separation	112​

Specs	Intake	Exhaust
0.050"	18	btdc	239	btdc
0.100"	2	btdc	213	btdc
0.150"	16	atdc	206	btdc
0.200"	38	atdc	185	btdc
0.250"	66	atdc	155.5	btdc
Max Lift	.275"		.275"
0.250"	147	atdc	78	btdc
0.200"	175	atdc	49	btdc
0.150"	196	atdc	28	btdc
0.100"	213	atdc	11	btdc
0.050"	229	atdc	5	atdc