Gun Drilling

[bwawuz02]

Stock 3.1 valve = 102.15grams
SI 3.1 replacement= 88.2g

so basically a 13 - 14% weight savings

for a ball park, 102.15-88.2=13.95

we'll say the DOHC valves are smaller so let's say there's only a 10g difference in those. now that's 10g x 24valves = 240g i'd say it's significant.

[GPXSS]

DOHC valves weigh almost half of what 3.1 valves weigh... so it would be roughly 14% off 55-60grams

[Ross96GTP]

Thanks for the link on valves. I recently found a set of 96 heads that I'm going to rebuild and then swap into my 96 gtp. And I definitely would avoid drilling the valves unless you have a serious budget. I think the EVO valves are hollowed, but sodium filled to add strength. And if it doesn't work and you break a valve, that motor is going to be toast.

Anyone know anyone in the Charlotte, NC area that does head work on these things (GPXSS?). I am not a machinist, nor do I have the tools to port/polish. I could probably get them flowbench tested afterwards at school though.

Ross

[joey b]

what do I have to do to remove the valves? Just remove the cam carriers?

[SappySE107]

You have to remove the heads, then compress the valve springs and pull out the locks to get the valves out.