Will a GR650 Head fit a GS500 engine?

[djg42]

Hello,
I am interested in swapping a GS500 motor in my GS450, or using the GS500 top end. I read some of the threads and everyone says the problem is th GS500 exhaust comes straight out, hitting the GS450 frame. I have also read the GR650 head has similar exhaust outlets to the GS450. Does anyone know if this combo might work?

[Ghostgs1]

There are several threads on here that talk about bigger bore twins. Do a search on GR 650 head or 450 big bore. Ray

[Mekanix]

all you need to know is in here ->

http://www.thegsresources.com/_forum/showthread.php?t=179485

and

http://www.thegsresources.com/_forum/showthread.php?t=172422

the jist of it is:

1 gs 500 top end with drop right on. problem is the exhaust.
2 gr 650 is not swappable at all. one problem is the cylinder height and the 450 has a shorter stroke length.


hope this helps

[Big Rich]

I believe dlg meant keeping the gs450/500 cylinders and using just the head from a GR650. Right?

[pete]

The 500 engine is doable though:

http://www.thegsresources.com/_forum/showthread.php?t=173100

[Billy Ricks]

The 650 head would probably have too much volume without going with the cylinder block as well. You will probably lose some compression just doing the head. The 500 would be better if the bolt pattern is right.