Clone 212 help.

bagger

New member
I am new to this. I have a clone hemi and a non-hemi. The hemi has a .009 head gasket , larger carb, pipe, and a 6-degree key. Have I done the right things?
This is on a mini bike.
What are the advantages of running th hemi head on the non-hemi block? I would like to be about 11 to 1 comp.

Thanks,

jim
 

flattop1

Dawg 89
Mostly .
Typically you put the non hemi head on the hemi .
For more compression.
11-1 is hard to achevie .
 

flattop1

Dawg 89
Its not going to give you 1 hp .
If its already in I would leave it be.
Just be sure you torqued the flywheel nut good .
 

flattop1

Dawg 89
A bigger carb , you changed out the air filer assembly ?
From what you have desribed your there . Next step is billlet flywheel , cam , springs , port work and rod .
 

bagger

New member
Air filter was a given...Thinking of the f/w and rod.
How does one go about boring one? Is it done with a hone? I knew of a machine shop that did that on small engines.
I guess I need to see a head that has been reworked. I have done port work on Cushmans and Mustang engs with quite good results.

Thanks,

jim
 

flattop1

Dawg 89
Kart shop is best bet for boring unless you have a ridgid hone .
Porting is basic , until you go to the nth degree .
Plenty of pictures on port shapes here abouts plus the web .
Search function on top right corner of page , little magnifying glass symbol.
 

bagger

New member
After holding 2 different heads in hand, I believe that a non- hemi head with a flat top piston will yield the best compression. Correct me if I'm wrong and please tell me why. I know the hemi head has a larger intake valve.
 

flattop1

Dawg 89
Why oh why oh me oh my :)
Post #2
 

flattop1

Dawg 89
No harm no foul .
So tell me why you feel the non hemi head will have more compression vs the hemi ?
 

bagger

New member
Combustion chamber size. I have not measured it, but it looks smaller.

3 things make hp in internal combustion engines. Cam, compression, and carburation or fuel injection. That is what I have learned over the years. Does it change in these small engines?

I am just trying to learn this eng. I have very little experience with small engines. The things I am trying to do have nothing to do with racing. I want a higher h/p eng for my minibike. Looks to me like a small combustion chamber with a flat top piston will give the compression I want. Which head has better flow numbers, ported, and unported?
 

flattop1

Dawg 89
Correct it has a smaller chamber .
The same basics still apply .
Flow numbers might be on here i do not know them off hand .
 

bagger

New member
My eyes are not failing.
Just trying to learn the ins and out of this.
I put a head on my belt sander and milled/sanded quite a bit off. Then put it on a glass plate and find it is absolutely true. Now to use a finer grit and smooth it up.

Thanks ,

jim
 
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flattop1

Dawg 89
Fuel injection in itself will not make more horsepower .
It is better at giving the optimum fuel air ratio in more conditions .
Cam alone maybe , it is actually the increase in volumetric efficiency the cam may provide .
Maybe in reality VE is the only thing that improves power .
Everything else just helps that main goal .
Fuel type would be another thing though it may be considered a power adder .
When Fred got Barney to help they went faster :giggle:
 
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HB10103

New member
i have a 212 Hemi with a .397 billet cam, .065 long rod, slipstream flywheel, tct "carb", fully ported and polished with stainless valves (27mm-25mm) and billet spring retainers. Should I look into stroking and boring my block and put a non-hemi head on with 1.3 gauge rockers with chromoly pushrods and billet lifters. running a 4bt Cummins turbo with EFI and nitro meth soon. any other suggections? inta is hulkbuster10103 if you want to see the little build
 
i have a 212 Hemi with a .397 billet cam, .065 long rod, slipstream flywheel, tct "carb", fully ported and polished with stainless valves (27mm-25mm) and billet spring retainers. Should I look into stroking and boring my block and put a non-hemi head on with 1.3 gauge rockers with chromoly pushrods and billet lifters. running a 4bt Cummins turbo with EFI and nitro meth soon. any other suggections? inta is hulkbuster10103 if you want to see the little build
That's some serious turbo for a single cylinder powa.
 
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