Gen 3 Non-Hemi Valves

[bob58o]

I keep seeing OldMiniBikes stuff saying the Gen 3 Non-Hemi's with the 5.0mm stems have 25mm/24mm valves. Is this correct? I was under the impression that the new non-hemi's came with the larger (27/25mm) valves.

https://OldMiniBikes.zendesk.com/hc/en-us/articles/115004774207-Predator-212cc-Valve-Sizes

Can anybody confirm the size of the valves in the new Predator 212's for me.

Thanks

 

[DeadPixel]

I know one of the predators have the 5mm valve stems but its a 25/24mm valve. I don't build predators though so don't know which one. The hemi predator has same valve stem as a normal 196 clone 5.5mm. I know cuz I have a JT clone head with predator 27/25 valves in it.

 

[bob58o]

Well I also found this thread at Bob's....
Jody from ARC says the Gen 3's have the larger valves....
Perhaps there are a few different styles with the 5.0mm stems????

https://karting.4cycle.com/showthread.php?76115-What-gen-is-my-predator-engine

"The easiest way to tell the difference in a Hemi vs a Non Hemi predator engine is the valve cover. If you look at the link below you will see the difference, and which flywheel goes with what engine. The blocks are different and take different top plates. Both are 212cc engines and take the same connecting rods, but different cams. The Hemi will take the clone cams and sidecover while the Non Hemi takes a specific Predator cam. If you are not confused yet the Non Hemi engine has two different generations. Gen1 have small valves like a Clone 25mm/24mm. The latest generation Gen3 has bigger valves 27mm/25mm with smaller valve stems 5mm instead of the 5.5mm the other engines have and also has an automotive style split retainer. The Hemi which is Gen2 also has big valves 27mm/25mm with the 5.5mm stems. If that confuses you even more feel free to give me a call and I can explain it to you a little better... "

 

[CarPlayLB]

The latest batch of Gen 3 212's have 27 intake and 25 exhaust, with 5mm stems. The older Gen 3's had 25 intake and 24 exhaust with 5mm stems. [MENTION=54144]bob58o[/MENTION]

 

[DeadPixel]

Not to thread jack but dose any one know if there is much of a difference in flow between the 5mm and 5.5mm valves? Durability on modified motors with the 5mm valve?

 

[ddubizl]

I’d sure like to know about the durability of those valves too. Cause I’m running a gen 3 head stock valves and rockers hi lift cam and 22lbs springs plus a long list of other performance upgrades but for now I would like to to know to longevity I might see be for the valves start to fail. Obviously the flow would most likely be improved slightly by a thinner stem cause it blocks less air and exhaust flowing through the head. But how tough are these stock 27/25 X 5mm with split auto keeps. I’ve spun mine at 8500 twice so far....

 

[DeadPixel]

I’d sure like to know about the durability of those valves too. Cause I’m running a gen 3 head stock valves and rockers hi lift cam and 22lbs springs plus a long list of other performance upgrades but for now I would like to to know to longevity I might see be for the valves start to fail. Obviously the flow would most likely be improved slightly by a thinner stem cause it blocks less air and exhaust flowing through the head. But how tough are these stock 27/25 X 5mm with split auto keeps. I’ve spun mine at 8500 twice so far....

If you have spun it that high I'm good cuz I don't spin motors that high. If the valves handle 6K there good enough for me. I might have to get one of these heads and try one out.