Compression Changes

The Rookie

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I'm thinking about bumping my compression up a bit for a fun build, that I've upgraded with better internals. I'm considering a Honda flat top piston, or a Honda 18cc head. What's the better way to go? Stock head w/flat top or 18cc head with stock piston?

No class, no rules, just for fun, but not wanting to get too crazy.
 
assuming you have a 'stock' 22cc head it would be the same JMO, around 8.8 with a gx200 .010 head gasket and the piston .035 in the hole, how deep is your piston in the hole?, and what head gasket are you using?, IMO you should go with the 18cc head and a .010 head gasket, or get ahold of a 14cc clone head if your not milling it, if you are milling the 18cc head, mill it .050 , if your just doing bolt-ons 14cc is the way to go jmo, i have a 'real' honda 14cc head to sell if your intrested
 
I'm thinking about bumping my compression up a bit for a fun build, that I've upgraded with better internals. I'm considering a Honda flat top piston, or a Honda 18cc head. What's the better way to go? Stock head w/flat top or 18cc head with stock piston?

No class, no rules, just for fun, but not wanting to get too crazy.

Do both.
 
Yes, 'stock' head is a JT03 22cc head. I'm not sure of how far in the hole the piston will be right now. I'll be working with some different cranks and an ARC rod to get it up as high as possible. I have a .010 gasket that I'll be using, and I do have a new 14cc clone head, but I figured that may be too much for a basically stock build.
 
Yes, 'stock' head is a JT03 22cc head. I'm not sure of how far in the hole the piston will be right now. I'll be working with some different cranks and an ARC rod to get it up as high as possible. I have a .010 gasket that I'll be using, and I do have a new 14cc clone head, but I figured that may be too much for a basically stock build.

i would use the 14cc head you already have, with a .009 headgasket and flat top piston. From your previous post, it appears your piston may be a good bit in the hole, and both mods mentioned in this post will bump your compression up. Avoid milling if you can, otherwise you get into needing shorter pushrods to correct the valvetrain geometry. If your wanting to keep it basically a stock type build, bolt on the 14cc head, .009 or .010 headgasket and flat top piston. Maybe even throw a set of stamped 1.3 ratio rockers in there for a little more added lift and power. This will allow you to still use the stock carb and just rejet.
 
With current crank, piston, and ARC rod, piston is .031 in the hole. Have another crank that measured out with .005 more stroke.

What IS a 'good' depth?
 
Do as above and you will be fine with a .010 gasket. I have same setup except max stroke crank and standard billet rod. In the hole ~.012 with 14cc head flattop honda piston and .010 gasket. No problems and good power. Work your carb. Im running a BP2 cam with 1.3 on intake valve. I suggest solid dowels in your sidecover though. I should have at least.
 
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