are itr intake valves lighter or bigger, or both compared to the GSR? i mean will it be a straight swapout

 

Do a search in this forum. I just did a comparison post a while back.

 

i did a search and could not find anything

 

they are around15% lighter, and you do need to machine the head for them to seat right since they have a light valve job.

 

Also, they do flow better, but yes you have to get the valve seat machined to get them to fit correctly because the valve seat angles are different on a ITR head.

 

Search: archived under my SN and you'll see all the posts.

https://honda-tech.com/zerothread?id=237641

 

the differences in power will be hardly felt. they are a better valve, yet unless you decide to do a whole head service I dont see the need for them. I had them put in and I cant tell you that they did anything significant. The intake valves are not a area of great risk in the GSR head for valve float... this happens on the exhaust side first... trust me on this. I bent valves enough and it took 7 out of 8 bent on the exhaust side with 2 cracked guides in #4 to have an even somewhat questionable intake valve in that cylinder.

They will raise CR slightly as the dished section is smaller than the GSR valve with more flat area, expect .15cr

my next interation is a 10K stock 2001 GSR head with stock HG and 01 ITR bottom end, I am expecting 11:1 cr out of it. I need to break in good for a while.... then we'll see some cams and higher CR, head porting, valve job and full tuning.

I would reccomend doing ENDYN or Skunk2 SS racing valves with forged internals
if you can plan it.