$16 14cc head on 212?

[karl]

Here is my situation

I have a hemi predator with ,

Stock length arc rod

Arc flywheel with stock key 32 degree advance

Arc filter adapter and top plate

Might as well be sponsored by them

18 lbs valve springs

Mod 2 cam

Header with Rvl muffler


So I am running stock compression ratio.
It pulls good but I want more. Increasing compression ratio and bigger carb should help alot.

I still want to run pump gas (93 octane)

So my options seem to be mill the 18cc stock head .050 or get a gx160 head.

On ebay you can find bare heads cheap.

I am confused about a few things.

From my searching, new and old style 160 heads are different. From the pic in the ad it looks like the old style. Im no expert.

Then there is shrouding valves , or spark plugs .I am clueless here.

Idk, flatheads are so much simpler.

What I want to do is take valves , rockers, and all from my current head, put it all in the ebay head, and bolt on my motor.

Other then dowel pins, and valve cover, what issues might I run into? Is this a good idea?
Should I port the head, or run as-is?
I need some education on these chinese ohv things.

 

[bob58o]

I charge EZ^2 $50 per hour to study at the GAB Institute of Motor Karting. But for you, the first lesson of your education is free. LOLOLOL

Hemi heads use shorter springs than the non-hemi heads. ARC's 18lb springs won't work in the Hemi head. Did you check for coil bind? A professional builder at ARC says they will bind with a stock cam shaft in the hemi. Somebody makes 18lb springs for the hemi, but not ARC. If they are like 1.5" tall, then they are the big ones that will coil bind in the Hemi head. They are ok in the non-hemi. You'd want 22lb springs if using the Hemi head.

Hemi's use shaft mounted rocker arms, non hemi's (including gx160's) use stud mounted rocker arms.

I've never used a gx 160 head. Predators (excluding the newest non-hemi) use valves with 5.5mm stems and 3/16" pushrods. The gx160 also uses 3/16" pushrods, but they are shorter than those in the Hemi.

I think the 160 uses 5.5mm valve stems, but the valve faces are smaller in the 160 head. Your big 27mm intake valve will at least need the valve seat done in the 160 head (cut or maybe replaced with bigger ones). The 160 uses 25/24mm valves and the hemi uses 27/25mm valves.

A thinner head gasket is like $15. Replacing the stock 0.045" Gasket with a 0.009" gasket would bump you up about a full point of Compression.


YOU SHOULD CHECK PISTON TO VALVE CLEARANCE WHEN USING AFTERMARKET CAMS AND INCREASING COMPRESSION. ESPECIALLY REQUIRED WITH THE HEMI HEAD.

 

[bob58o]

BTW.... Hemi's do not have an 18cc stock head. Try more like 22cc. Figure about 1cc per 0.010" milled.

0.040" milled from the Hemi head will get you to about 18cc.

A 14cc head with stock length rod and stock thickness head gasket with stock flattop piston on a Hemi Predator will put you above 11:1 static compression ratio. You might be at the limits of pump gas. I use 100 Octane in my engines with 11:1 CR.

---------- Post added at 05:03 AM ---------- Previous post was at 04:40 AM ----------

http://www.csgnetwork.com/compcalc.html

You can play around here.

70mm Bore
55mm Stroke
70mm Head Gasket Bore
0.045" Head Gasket Thickness
22cc Combustion Chamber Volume
0cc Piston Dome/Dish (Flat top has no dome or dish)
~0.025" Piston to Deck Clearance

These number give 8.3:1 Static Compression Ratio.
I think Harbor Freight says like 8.5:1.
Put 14cc instead of 22cc and get 11.15:1

 

[karl]

Thank you , You just prevented me from doing something stupid lol.

I have ran the 18lbs springs for a while, I should look into that. I think I got them from ebay.

I will definitely check clearances.

That straightens things out.

 

[karl]

I have not messed with my engine yet.


At work I got a genuine honda gx160 out of the scrap bin.


Bore and con rod seem ok. I did not take pic before teardown but it is complete.

What does one do here? I can get race gas (cam 2?) or e85 at local gas stations.

Swap whole head, valves ect, and port it out?

What can I do with a gx160 ?

So many options. I know someone here can supply some gab. Opinions please?

 

[OzFab]

The list is endless, depending on how deep your pockets are...

The 14cc head will be better suited to this block as opposed to the Predator; fitted with stock GX160 valves & port/polish will give you a significant torque increase when combined with the usual high flow intake & exhaust...

Then there's the extreme mods like cam, billet rod, H/D valve springs, billet flywheel (in that order)...

 

[bob58o]

Then there's the extreme mods

Kidding aside, you probably should get a billet rod before upgrading camshafts, IMHO.

 

[karl]

Well does anyone know what kind of gx160 I have?
Apparently newer and older ones use a diffrent piston and rod.
I might need to know before buying a billet rod and new rings.
should i go longer on the rod to bump up compression,then use factory head gasket, ect?

 

[ezcome-ezgo]

I'm thinking find the serial/model #

 

[karl]

I'm thinking find the serial/model #

model # sticker is not on the cover .
i did not see a serial , im not by it now.
was hoping someone knew about this and could tell right away.

its around a 2012 if that helps.

 

[ezcome-ezgo]

The engine serial number is stamped into the side of the engine. All Honda engine serial numbers have a 4 or 5 letter prefix followed by a 7 digit number.