Serious predator 212 differences?

[Thepartsguy]

you must keep in mind I have two predator 212’s now. this engine was a $20 return and I asked no questions. the pull cord letters are red. the internal oil shutdown/gov deleted. It was well and truly blown up. that’s where my knowledge ends. the head has a pushrod guide plate for both pushrods and Non roller rockers. NOW the 212 I’ve built for the mini bike in the past few days DOES have roller rockers but no guide plate? This 212 I just purchased has stiffer springs? the cam is labeled rs and a5 and looks to have a pretty decent duration on the exhaust lobe only? Mod cam? what is the better setup? The roller rocker/no guide plate or the non roller rocker/guide plate? Can the roller rockers be made to work with the guide plate and bigger cam? If it is bigger?

 

[Thepartsguy]

252 rattlesnake??

 

[BrownStainRacing]

Measure base circle (side to side) then Measure lift (top to bottom), subtract base from lift to get the true lift of the cam.

Stock preds will be .224" on intake and .231" on the exhaust. Multiply that # by the rocker ratio for the total valve lift. Stock non hemi rockers can be all over the place, from 1.01:1-1.06:1.

Stock preds have more lift and duration on the exhaust side, known as dual patterns cams, they 're crap. These heads flow good on the exhaust side and don't need help by holding the exhaust valve open longer.
You can actually pick up power, in the same rpm range by adding a 1.3:1 rocker on the intake side only, on a stock dual pattern cam. This changes the intake valve opening and closing points, (crank degrees) creating more pressure on top of the piston. The faster you can get the intake valve completely close, the more pressure is applied to the air/fuel mix.

That other engine didn't seem like a good candidate for roller rockers.

Were they roller tip, or true rollers???

 

[BrownStainRacing]

@Thepartsguy

I see now.

I looked closer at the other pred, "locked up", thats a hemi head with stock hemi rockers, not rollers. Pedestal mount.

The 1 here, is a non hemi, or wedge head and needs a guide plate. Stud mount.

 

[Thepartsguy]

@Thepartsguy

I see now.

I looked closer at the other pred, "locked up", thats a hemi head with stock hemi rockers, not rollers. Pedestal mount.

The 1 here, is a non hemi, or wedge head and needs a guide plate. Stud mount.

the locked up predator on the mini bike has no guide plate. And a flattop piston. this engine does Have a guide plate and here is a picture of the piston and head I just pulled from this engine with red face letters. I figured this was a hemi and the other one was a flattop..

 

[BrownStainRacing]

Hemis come factory with flat tops. Non hemis come with dished pistons, but the combustion chamber is around 1cc smaller.

Hemis come outta the box with 8.3:1 CR.

Non hemis come 7.8:1 CR.
Add a hemi flat top piston with a .009" thick head gasket, to that non hemi head, it will get it up to 9.8-10.1CR. And thats when that lil turd motor stock cam starts talking to ya.

 

[Thepartsguy]

Guessing the hemi is preferred? are the rockers better on the hemi or non hemi? this block is cracked at the top so it’s not gonna get anything done with it. I saw billet rods for 90$ and standard 3/4 cranks for 27$ and thought it was a good deal. set my piston on a billet rod all on a new crank and where I saved the 134$ for the new In box one I could buy a 135$ flywheel. gamble taken a gamble lost.

 

[BrownStainRacing]

I perfer the non hemi "wedge" heads.

I posted a good video about the hemi head, somewhere. I cant find it now.

The pred 212 non hemi crank, can use that $40 lightweight flywheel. The rod is a odd ball size, only good 1's available for it is billet.

I don't trust the stock pred rods.

Keep your eyes open for a 196 clone. Jus need a 68mm flat top piston and any cam with clone size journals.

The pred 212 non hemi cam has bigger cam journals and different side covers, so they don't interchange with the hemi or clones.

 

[Hellion]

Guessing the hemi is preferred? are the rockers better on the hemi or non hemi? this block is cracked at the top so it’s not gonna get anything done with it. I saw billet rods for 90$ and standard 3/4 cranks for 27$ and thought it was a good deal. set my piston on a billet rod all on a new crank and where I saved the 134$ for the new In box one I could buy a 135$ flywheel. gamble taken a gamble lost.

Lots of people seem to prefer the non-hemi Preds, defying the conventional wisdom, which I find very interesting.

I think at the time the first Predators caught on, all you could find were speed-parts for the standard non-hemi head engines and they were more well established in the scene so there's that.

 

[Hellion]

Dude, throw down a tarp or something before you work.

The possibility of contamination, lost parts, etc is assaulting my cleanliness + OCD predilections.

 

[Denny]

The wedge heads are said to flow better with bigger valves. I like the wedge combustion chamber better than the hemi. No quench with the hemi.

 

[68pishta]

HF had 2 suppliers for that 212 Predator to keep up production and hedge any factory issues. Hemi seems to be the orphan due to some non standard design, ie crank taper. The hemi has a cast valve cover while the non hemi had a stamped one. Hemi should be more efficient with slightly more HP but can't be hopped up as easily as the wedge. Stock hemi best out of the box, wedge is more easily modded.

 

[panchothedog]

Of the 2 pictures I can see, I see stock stamped pedestal mounted rockers. If you are going to run shaft mounted rockers like Champions, or true roller rockers like Gage, you can run either of those without using a guide plate.

 

[pearl111]

Dude, throw down a tarp or something before you work.

The possibility of contamination, lost parts, etc is assaulting my cleanliness + OCD predilections.

Or plywood, old carpet, anything other than the bare ground.