kdizzle wrote:I have a 01 that has over 80 hrs ont he top end. I took it apart for fear or grenading and found a PRO-X in there that seemed to be aok. I am having the bore measured but have immediately noticed there is no relief or scallops on the exhaust bridge. The bore looks ok, some minor scuffing at the bottom of the bore which cleaned up easily with some fine grit sandpaper. the bore looks good now, but it still needs to be measured.
my scallops were gone at .040 so you might be .040+
questions i have:
if i am slapping another prox in there do i need the bridge relief? is there any pictures of a properly relieved bridge i can reference? i have searched the forums hight and low.
if you relief the bridge is up to you. some may argue against it for cast piston but either way this is how honda does it.
what is the stock bore supposed to be? 89.5? i have a shop manual on the way (btw).
89
I have a complete 86 motor on my bench. Can i directly bold the head onto this 01 motor for a boost of compression as i have read? is this a direct bolt on? or does any modification need to be done to the head or piston? roughly what kind of compression will i have then? will i need race gas at that point?
![Question :?:](./images/smilies/icon_question.gif)
i think all the heads interchange, but im unsure the dome cc. newer bikes were 6.8:1, '87 motors were advertised at 7.4:1. cylinder pressure is easy to find with a gauge if thats what your looking for. however if you want trapped compression ratio (ratio between cylinder volumes when exhaust closes and volume when piston is TDC) :
CR=
(V1+V2)
---------
(V2)
CR= compression ratio
V1= cylinder volume at exhaust closing
V2= combustion chamber volume
or traditional compression ratio:
CR=
(V1+V2)
---------
(V2)
CR= compression ratio
V1= combustion chamber
volume plus piston
displacement from
TDC to BDC
V2= combustion chamber
volume
i can give you my input on how i think of this. i think my bike lost compression because i raised the exhaust, but i didnt shave down the head enough. i think i need to shave more off the head to get alot of compression back. maek sense ?