Honda Motorcycles - FireBlades.org banner

1 - 5 of 5 Posts

·
Registered
Joined
·
46 Posts
Discussion Starter #1
I purchased a spare 03 cylinder head with 1500 miles of use.
I want to shave the head for more compression.
My question is, how much can I shave to get a full point in compression and will I have a valve clearance problem?
I think I will be fine moving up 1 point but any ideas from others may save me some time and money.

Thanks :knockout: :
 

·
Registered
Joined
·
998 Posts
I did some rough calcualtions a little whille back and worked out that machining 0.4mm of the head would raise the compression ratio to a little over 12.5:1 although as I didnt have the exact measurement of the chambers Its only a ballpark figure if you can cc the chambers I could work it out exactly for you, if you can set the head up to be level (use a good spirit level) and use alcohol or similar to cc the chambers (you will need to coat the valve seats with petroleum jelly as the alcohol will quickly disapear! I think the chambers would be between 18-22cc (just a guess) Anyway if you feel like doing this I will calculate how much needs to be machined off.
 

·
Registered
Joined
·
3,203 Posts
I don't know if you can take enought off the head to raise it that much with the stock pistons, the valves are going to get real close to the pistons. Probaly would need hi compression pistons.
 

·
Registered
Joined
·
998 Posts
yeah Good point G-Force, Im not really sure how much clearence there is there? I think there would be enough just going off a few other modded 954's Ive seen that had around about 12.5:1 with std pistons and larger cams, But that would definately be something that would need a closer look once you had it apart!
 
1 - 5 of 5 Posts
Top