How much difference will there be between these runner sizes?
Thread Starter
Joined: Dec 2007
Posts: 1,885
Likes: 1
From: Southern California
How much difference will there be between these runner sizes? I am about to order the heads for my H/C swap. The two versions I am torn between are the TSP 5.3 stage 2.5 (2.02"/1.575" w/ 220cc intake runners) and the new 2.5R heads Jason just finished up (2.055"/1.575" 226cc intake runners).
Obviously I will get more flow from the larger valves but I am concerned with runner size. My cam is a 226/232 .609"/.604" 113+2. Right now my car has the LS6 intake but when I do the swap I am sure I will also be installing a FAST 92/92 maybe or maybe not ported. This is on a stock 2001 58k mile shortblock. Will I loose low end power going with the larger runners?
I have put alot of time into this getting just the right compression ratio and all of the parts just right and really think this is going to be a nice setup.I just want some opinions and if anyone has had experiences with such things I would really appreciate the help.
Also, I have contacted Jason at TSP about it but my problem is that with the time difference it is very hard for me to call him and we are limited to one email per day on the subject and now I am being sent out of state for work on Monday and need to order my parts before that. Thanks for the help!
Obviously I will get more flow from the larger valves but I am concerned with runner size. My cam is a 226/232 .609"/.604" 113+2. Right now my car has the LS6 intake but when I do the swap I am sure I will also be installing a FAST 92/92 maybe or maybe not ported. This is on a stock 2001 58k mile shortblock. Will I loose low end power going with the larger runners?
I have put alot of time into this getting just the right compression ratio and all of the parts just right and really think this is going to be a nice setup.I just want some opinions and if anyone has had experiences with such things I would really appreciate the help.
Also, I have contacted Jason at TSP about it but my problem is that with the time difference it is very hard for me to call him and we are limited to one email per day on the subject and now I am being sent out of state for work on Monday and need to order my parts before that. Thanks for the help!
i would say the 2.05 intake valve might be too large and too close to the cylinder walls.This just means the bigger valve will not help at all and could possibly hurt performance.I would call up TSP and see what they recommend.
And the added runner size is probably just from having the bigger valve and needing to open up the bowls a little to accomodate the valve.As far as the 6cc difference,you wouldnt notice any difference in low end torque,if there even was a difference.My runners are 230 and i am pushing 350 ftlb torque at just 3k rpm,which is pretty good imo.
Thread Starter
Joined: Dec 2007
Posts: 1,885
Likes: 1
From: Southern California
Well I think the decision was made for me...when I got home from work I had a haevy box and expected it to be my headers but instead it was my heads, I havent measured yet but im sure they are the 2.02". Well if I wont gain anything its not worth teh extra $2-300.Thanks for the input Redtail I really appreciate it.
