Wildcat 223 build ???

#1
I have a WC223 with stage 1. With a TAV and 60T it was great on my CT200U-EX. I'm now planning on building it up some for my new full suspension MB200S. I don't really want a high revving engine. I want low end torque. I spoke with tech at EC (they're great) he suggested. A pinnacle rod, this creates more lift and so the compression ratio goes up too 10.5-1, 1.2 ratio roller rockers made by NR Racing, 26lb valve springs, 6 degree key that will put timing at around 32 degrees, set valve lash for intake at 0 and intake at .001, 6000rpm limiting coil, with stock carb use a .36 jet if running a header with muffler .38 open header. I might even go with a WC22 blueprinted slide style carb. I've already done some port matching and porting/polishing. He said I should see a significant HP and Torque increase. How does this sound too y'all ?
 
#3
Sounds like you're going to feel the difference. Lash at 0, huh? And pinnacle rod is a push rod?
No, it's a billet/forged connecting rod, that's a bit longer than the stock rod. In stock form the piston on the 223, does not hit top of cylinder, with this rod the piston will be topping out. He said that doing 0 lash on this Hemi would not hurt it at all. Explained it would flow better with those valve lash settings. Surprised me too !
 
#4
I know some are wondering what about the flywheel and using a billet flywheel. I did too. I do have a 3x thicker than stock blower housing cover, that EC designed. Just in case that flywheel that is suppose to be good for up too 7500rpm lets loose.
 
#5
I have a WC223 with stage 1. With a TAV and 60T it was great on my CT200U-EX. I'm now planning on building it up some for my new full suspension MB200S. I don't really want a high revving engine. I want low end torque. I spoke with tech at EC (they're great) he suggested. A pinnacle rod, this creates more lift and so the compression ratio goes up too 10.5-1, 1.2 ratio roller rockers made by NR Racing, 26lb valve springs, 6 degree key that will put timing at around 32 degrees, set valve lash for intake at 0 and intake at .001, 6000rpm limiting coil, with stock carb use a .36 jet if running a header with muffler .38 open header. I might even go with a WC22 blueprinted slide style carb. I've already done some port matching and porting/polishing. He said I should see a significant HP and Torque increase. How does this sound too y'all ?
What cam? I have one of these and am thinking about modding it some..
 
#7
What cam? I have one of these and am thinking about modding it some..
I'd get the flywheel if I were you.
The idea behind this build is to have an engine that performs in the lower rpm range. Using the 1.2 ratio roller rockers with the stock cam and the pinnacle connecting rod along with the timing advance the new key does, gives you this. Since you will still be in the safe area of rpm's you don't need to use a billeted flywheel or remove the governor. I'm going too remove the governor on mine and do some crankcase pressure release and balancing. That's why I'm going too use a rev limiting coil. The WC223 is a Hemi/Stroker engine, which is designed for lower RPM torque band performance. That's why I got this engine to begin with. I built V8 stroker racing engines for years. Same concept applies here, low RPM torque beast. While my 223 with a stage 1 is impressive. I want it too go from 0-40mph faster and not have to rev above 5500 rpm to get there.

If your wanting a higher revving engine, then I personally would not use a Hemi/Stroker. I'd get a 212/224 non Hemi.
 
#8
How do you plan to balance it? Do you have a balance factor in mind? Remember without a balance shaft or other mechinical means the primary and secondary imbalances can only be moved around not cancelled.
 
#9
How do you plan to balance it? Do you have a balance factor in mind? Remember without a balance shaft or other mechinical means the primary and secondary imbalances can only be moved around not cancelled.
Balancing is probably the wrong term, maybe equalizing would be better. I was referring to crankcase pressures, not actual mechanical balancing.
 
#11
Got it, best way is to use check valves on your breathers so there is an average negative pressure in the crankcase.
I'm still learning on these single cylinder 4 strokes. I understand what a check valve would do, I think, it would only allow crankcase pressures to release. Would I then only need one line coming out of the hole from governor, to a check valve, then to a filter or oil catch ? I've seen numerous performance setups with 2 lines and one of them have a oil catch filter. Did not see or hear anything about using a check valve. I'm now very curious about this, sounds good. Could you please go into more detail on how too do it and what check valve/valves to use.
 
#12
Various check valve setups. The third picture shows the EC sidecover with a large black check valve fitting which I vent to a breather. For the govenor hole I will drill to 1/4" then press in a aluminum tube and connect to the valve cover then I remove stock baffle plate and press in and jb weld a brass tube that fits tightly into a GM power brake booster check valve usually sold at any auto store. Then into a catch can
 

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#13
Very nice, thank you ! I had looked at those EC billeted side covers and went no further, when I seen you could not use the stock gas tanks. I will do a different tank etc.. when I do a higher performance build, for a dirt drag bike. Since I'm planning on keeping my rpm's below 5500 and probably will not often get above 5000. Do I need to worry much about doing a lot of crankcase pressure release ?

I learned many years ago building 1/4 drag cars. I started off going for 11 second machines and near the end I was running 8 and 9 second cars. I'm learning and don't want too take real big steps to start, learned this with the cars and my motocross bikes.

I truly appreciate you contributing to this thread and helping me, possibly others.
 
#16
No the stock breather is a check valve just add a filter on the output of the valve cover hose. For your application it will work fine.
Make sure your rockers do not hit the baffle plate in the valvecover. The roller rockers I use will not clear the baffle plate.
Never thought about it being a check valve. I got a filter on it already, did that with the Stage1 kit. How often do you need to change them filters ?

While checking my valve lash yesterday, I was wondering about how those NR racing 1.2 roller rockers would clear. The baffle plate appears to be just pressed in. The tech at EC did tell me that they are in process of making their own roller rockers for the WC223.

I started a notebook on what I'm going to need an do on my next higher performance engine build. Got all the things you told me in it. Now just have to decide what platform to start with. Not sure if I want too build another WC223 or get a Till non hemi. With the WC if you start changing cams etc.. then you will have too start dealing with more clearance issues. Changing pushrods etc... I built enough high performance V8's and 2 strokes that this does not concern me too much. Just working on these small 4 strokes are a bit different.

Respect brother ! I truly appreciate and thank you for taking the time too share your wealth of knowledge. I became a supporting member, because of members on here like you.

EDIT: I got valve covers mixed up in my head. The baffle plate on the WC223 is held in place with screws. So if there is a clearance issue with the Roller Rockers, it's ok to remove that baffle plate ?
 
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#17
There is a very heavy and thick plastic shroud that covers part of the head on this engine. I got to remove it, so I can get rest of the old gasket scrapped off for the valve cover. Does it have too go back on ? Seems to me the engine would run cooler without it.
 
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