Planet Minis

reynolds_brad

So from my dealings with Thailand i aquired an extra head from a Honda NICE 110 motor. I decided to have it ported and rebuilt with all honda parts. I opted for some rockers from a honda 70 head and had them lightened, the springs are also from the honda 70 so they are much like the HD springs people put in their race heads. Both the intake and exhuast were ported and the carb intake was ported to match. Im running a Takagawa R20 cam for the time being. Its got a longer duration then a TB cam.

First off i had to make sure that the stud pattern was the same between the two motors. Some people told me that it wouldnt work because they heads have diff stud sizing. They were wrong they are exactly the same. Its the heads from the zongshen and lifan 120s that are different.

The outter Cam bearing is different, its the same as a e22 outer cam bearing. Luckly i had one i could swap out on and put on the r20 cam.

Ide like to give credit to Ray Perez at Bike World for the porting job, and rocker shaving. He does amazing work and is a great guy to deal with.

This first pic shows the valve size diff between it and a stock 50 head.

in this pic you can see that the cam gear cover is much larger. The NICE motor has a much larger Cam gear cover. something i still need to find a gasket for.

here you can see the intake size diff.

and this one the exhuast.


and lastly here is a pic of the 70 rockers after they were lightened. This allows them to rez up faster.

p3racer

Thats Gonna Run On Topend And What Are You Doing With A Flameslider

reynolds_brad

ahh nothing, i just pulled it off my GSXR that im selling.

p3racer

Oh Ya I Remeber Seeing Pics Of It With Them I Used To Sell A Lot Of Them. I Figured You Might Be Making Something Cool From It For One Of The Bikes

Motarded

How much was taken off the rocker arms?

reynolds_brad

You would have to ask Ray as he does it to most of the heads he builds. The 70s rockers are a bit beefyer then the crf50 stock rockers. I just looked at them side by side and there is much more that can be taken off then on a 50 rocker.

p3racer

Why Not Just Run 50 Rockers Thats What I Run The Ratio Is Even A Little Different From What I Remember

Brent878

what size are the valves?

reynolds_brad

Well its cause i heard on the UK forums that the 70 rockers are exactly what is needed for a NICE head when running a cam from a aftermarket 50 head.

reynolds_brad

Same as a XR70 head.

p3racer

hmm it could be the ratio part of it

Kurlon

Hrmmm... I just put 50 rockers into my DRP Ultra head... wonder if I should yank'em and drop 70 rockers in?

p3racer

let us know what u come up with when looking at the 2 different ones side by side

2wheeltyson

what piston are you going to run, that has a big dome like a ct70 head right?

reynolds_brad

for now im going to run a 52 mil piston off a takagawa hyper r bore kit. and yet it does have a similar dome to a ct70 head.

sanoman23

Damn!! You got some serious porting done!! It must flow like a mother!!

Nice job!

Sanoman23

d0n

nice work!

cyclerider57

Here are pictures comparing a stock 50 rocker to a TB race head rocker (same as 70 I believe). From what I can tell the ratio itself isn't much different. Other than the head on the cam slider side the difference is the angle and and I think the reason is because the original base of the cam on a stock style head is a lot smaller so there needs to be a bigger bend for the rocker to hit the tip of the valve at the right angle. In some of the pictures one looks longer than the other. They really aren't it's just the angles of the picture. When you're holding them you can tell a lot better.

50 rocker on the bottom in all of the pictures...

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reynolds_brad

FYI guys for those interested i just measured out the ports this morning. the intake is 28mm and the ex is 22.

mdkuder

So what size carb are you planning on?