Predator 212 Valve Noise????
- Thread starter tylershg
- Start date
256??? I hope you don't mean a .265, that's jus another slow lazy ramped cam. None of those .265 are any good. They dont have that low rpm thump to get weight moving. They have to have big compression and big stall to get any power out of em, and that's what they are designed for. Read the descriptions, any cam you have to turn 7000+ rpm is not a good on/off throttle cam for a mini bike.
I like cams that will bust the tire loose right off the bat, and climb the steepest hills on the back tire with eaz. Not some lazy ramped cam that's gonna take a 1/2 mile to get started.
It's your mini, you pick whats best for you.
What do you have?
Your weight??
Tire height??
Terrain you be on most often???
Rpm's you wanna be in most often??
These are important questions.
You can go backwards real fast by piking the wrong parts.
I like cams that will bust the tire loose right off the bat, and climb the steepest hills on the back tire with eaz. Not some lazy ramped cam that's gonna take a 1/2 mile to get started.
It's your mini, you pick whats best for you.
What do you have?
Your weight??
Tire height??
Terrain you be on most often???
Rpm's you wanna be in most often??
These are important questions.
You can go backwards real fast by piking the wrong parts.
That's a 9.5:1 CR pred 224 with .670" bored SA carb, billet rod, pvl flywheel, no governor, 3000 rpm stall
My son's ducar 212 governed at 5400 rpm, with 10.1:1 CR, .615" bored SA carb, dynos cm grind cam, 3600 rpm stall will get on up too. that cam needs more stall, but he only weights 165#. He's only got about 3 more mph, then mine on top end with 4.54:1 gear, 20" tire, but it's scary for me at that 60 mph mark. My 200# butt cant get slowed down fast enough, lol.
My son's ducar 212 governed at 5400 rpm, with 10.1:1 CR, .615" bored SA carb, dynos cm grind cam, 3600 rpm stall will get on up too. that cam needs more stall, but he only weights 165#. He's only got about 3 more mph, then mine on top end with 4.54:1 gear, 20" tire, but it's scary for me at that 60 mph mark. My 200# butt cant get slowed down fast enough, lol.
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Save your money up to get it right the 1st time. There's other things you will need, tools, learn how to set those important clearances, set valve spring install height, set ignition timing, learn more about cam timing (valve events) how, and when they make power. Porting heads and other small things that most overlook and think are not necessary.
The stock flat top piston from the pred 212 hemi will be a very nice improvement in the non hemi. It will bump up the CR to 10:1, with what you already have and that's a very noticeable increase in power, even with the stock cam.
A performance coil that dont retard ignition timing in the upper rpm, and will increase acceleration. I use dover coils, they work. Screw those stock coils, they go in the trash next to that mod2 cam, lol.
You doing a really good job and going the right direction, jus keep it up.
Here's that coil. Dover Power has got really good products and very easy to deal with, down to earth no non sense, good people.
Get some of their magnetic drain plugs too, they work good, all my builds get em. They will have that flat top and ring set for you too.
http://www.doverpoweronlinestore.com/catalog/item/9100750/10483555.htm
http://www.doverpoweronlinestore.com/catalog/item/8223859/10335682.htm
The stock flat top piston from the pred 212 hemi will be a very nice improvement in the non hemi. It will bump up the CR to 10:1, with what you already have and that's a very noticeable increase in power, even with the stock cam.
A performance coil that dont retard ignition timing in the upper rpm, and will increase acceleration. I use dover coils, they work. Screw those stock coils, they go in the trash next to that mod2 cam, lol.
You doing a really good job and going the right direction, jus keep it up.
Here's that coil. Dover Power has got really good products and very easy to deal with, down to earth no non sense, good people.
Get some of their magnetic drain plugs too, they work good, all my builds get em. They will have that flat top and ring set for you too.
http://www.doverpoweronlinestore.com/catalog/item/9100750/10483555.htm
http://www.doverpoweronlinestore.com/catalog/item/8223859/10335682.htm
I have never seen the need to replace a stock Predator cam. The bottom torque is adequate, the midrange is pretty damned strong and with my governors set around 4000 I don't really care about how they act above that RPM. Get your other problems and details taken care of. You can decide whether or not to change the cam later. After you get the tools and knowledge, it only takes an evening to swap a cam.
I agree, some set ups would not benefit any thing from a cam swap.
IMO, the stock cam is too big for the stock low CR predators. When you start uping the CR, that stock cam starts to work really good. We never got above 10.5:1. Even with every thing else being stock, except carb tuning.
We have played with those stock cams, quiet a bit, they both woke up with 1.3:1 stamped steel rockers and 22# springs, on the intake side, with non hemi heads. There's was not enough time or mph gain, with 1.3 rocker on the exhaust side to say it was better or not. They both are dual pattern camshafts anyway.
Now the pred 224 cam (plastic gear) is same lift on the intake and exhaust, .222, so I'm sure it is a single pattern cam and it really shines with 1.3 rockers on both sides.
I'm waiting on my pred buddy to to finish testing the stock 224 cam, outta mine, in 196s and pred hemi 212s. But he told me that in the stock low CR 196, there was a huge gain in the 0- 200ft times and mph, so we thinking it's a faster ramped camshafts then most other stock cams. Time will tell. He's still testing the 196 with mods and upgrades.
IMO, the stock cam is too big for the stock low CR predators. When you start uping the CR, that stock cam starts to work really good. We never got above 10.5:1. Even with every thing else being stock, except carb tuning.
We have played with those stock cams, quiet a bit, they both woke up with 1.3:1 stamped steel rockers and 22# springs, on the intake side, with non hemi heads. There's was not enough time or mph gain, with 1.3 rocker on the exhaust side to say it was better or not. They both are dual pattern camshafts anyway.
Now the pred 224 cam (plastic gear) is same lift on the intake and exhaust, .222, so I'm sure it is a single pattern cam and it really shines with 1.3 rockers on both sides.
I'm waiting on my pred buddy to to finish testing the stock 224 cam, outta mine, in 196s and pred hemi 212s. But he told me that in the stock low CR 196, there was a huge gain in the 0- 200ft times and mph, so we thinking it's a faster ramped camshafts then most other stock cams. Time will tell. He's still testing the 196 with mods and upgrades.
ok so yesterday when I said I found where the noise was coming from... I was wrong with out the crank cover the flywheel isn't perfectly straight so it was rubbing against the coil. today I put the flywheel on and no noise. it has nothing to do with the piston. I found that the noise is the valves going up and down. maybe it's louder bc of the heavier springs. does that make sense to anyone?