[mnasty169]

want to change my displacement where can i get a 3mm kit. and where can i get a qb carbin airbox

 

[mnasty169]

oh yeah and for those of u who have already done it. what will the displacement be after the 3mm.i was told anywhere betwenn 1120-1250

 

[denzee]

Assuming you are talking about bore, 3mm will give you about 1060 cc according to my calculations. Stock being 100 X 63.6.

pi X r squared X stroke X cyls. Don't know how to put the proper characters in.

It would take a 10 mm increase in bore to give you 1288 cc. Of course to go that big you would generally increase the stroke to go with it.

Not at all easy to get big cubes.

 

[zerogara]

Going from 100mm to 103mm bore your increase is about 6.1% or 1060cc
How are you planning on doing this? Have you located a replating service accessible to you?
Now if you were to have a stroke that was 3mm longer you would need a 1.5mm shorter rod to keep deck height the same. This increases your piston speed and you may lose some top end rpm (which is where extra hp would be gained).
HRC had a kit for this motor, it may still be available, why not go that proven and tested direction? On the other hand why not go for a 1098/1198 for the same money of your completed project?