Honda Grom banner

1 - 13 of 13 Posts

·
Registered
Joined
·
1,542 Posts
Discussion Starter #1 (Edited)
Wife bought me a Koso 170 piston and cylinder kit. Looking to get a ported head with larger valves and possibly a cam if you have it.

I'm verified with PayPal and can pay with that.

If this doesn't work, I'm going with a Finbro head from HR. Just thought it wouldn't hurt to see if anyone had anything taking up space on their shelf.

Edit: Cisco came through in a big way on this. A huge thanks to him and for the offer made by m_in_sc. You guys are such awesome examples of what make this community great.
 

·
Registered
Joined
·
3,743 Posts
I have a head, with longer valves fo a high lit cam with strong spring. . and a(dare I say) yuminashi camshaft. I actually liked the cam, its very aggressive. however I have no rocker arms as they went into another head. Id let it go for 125 shipped cont us, finbro head was 250-ish when I had one done for a 164. just fyi. hit me up if interested.
 

·
Registered
Joined
·
1,542 Posts
Discussion Starter #3
I have a head, with longer valves fo a high lit cam with strong spring. . and a(dare I say) yuminashi camshaft. I actually liked the cam, its very aggressive. however I have no rocker arms as they went into another head. Id let it go for 125 shipped cont us, finbro head was 250-ish when I had one done for a 164. just fyi. hit me up if interested.
Awesome. PM'ed!
 

·
Registered
Joined
·
1,542 Posts
Discussion Starter #7
The 31/26mm finbro head most likely wont work with the koso piston. Youll probably need to get valve pockets flycut in.
Judging by the amount of valve relief that the piston in the finbro 183 kit from HR has, I suspect you're very correct. Thanks again.
 

·
Registered
Joined
·
1,542 Posts
Discussion Starter #9 (Edited)
there is the smaller upgraded grom head with like 1mm bigger valves, for 160ish
I saw that. I'm just worried it wouldn't allow enough flow through and I'd end up wanting a bigger one. I wish there was something in the middle.

What head did you use on your 164 kit, or is that the Yuminashi kit that comes with the longer valves and stiffer springs for the stock head?

Edit: Just checked your build thread. You have a kitaco kit (good choice) and finbro springs in the stock head.
 

·
Registered
Joined
·
2,372 Posts
I saw that. I'm just worried it wouldn't allow enough flow through and I'd end up wanting a bigger one. I wish there was something in the middle.

What head did you use on your 164 kit, or is that the Yuminashi kit that comes with the longer valves and stiffer springs for the stock head?

Edit: Just checked your build thread. You have a kitaco kit (good choice) and finbro springs in the stock head.
I used the stock head, and ill tell you it doesnt like to flow much past 9.5k rpms. You can tell something is choking it and if i had to guess its the stock valves. I used a Kitaco 164 kit.

Reason i kept with the stock head though is to make parts if necessary readily available, if down the road i do want to refresh the top end, its all stock grom parts.


Finbro springs are only for safety of valve float, It will rev to 12.5k in 1st n barley in 2nd if you let it, so i threw those in while i had it apart.

Part of me does wish i got the slightly larger valve head that finbro sells but 1mm extra in valve diameter probably wouldnt make that much of a noticeable difference.
 

·
Registered
Joined
·
1,542 Posts
Discussion Starter #12
I used the stock head, and ill tell you it doesnt like to flow much past 9.5k rpms. You can tell something is choking it and if i had to guess its the stock valves. I used a Kitaco 164 kit.

Reason i kept with the stock head though is to make parts if necessary readily available, if down the road i do want to refresh the top end, its all stock grom parts.


Finbro springs are only for safety of valve float, It will rev to 12.5k in 1st n barley in 2nd if you let it, so i threw those in while i had it apart.

Part of me does wish i got the slightly larger valve head that finbro sells but 1mm extra in valve diameter probably wouldnt make that much of a noticeable difference.
Is your head ported?
 
1 - 13 of 13 Posts
Top