Biggest valves on LS1
06-27-2012, 11:53 AM
#3
Like previously posted once you get over the 2.02 size you really don't see enough pick up to make it worth it. We did some flow bench testing a number of years ago on our 5.3l heads and found that a 2.04 valve actually lost midrange and posted the same top end flow results as the 2.02 valve we use in them now.
06-27-2012, 12:22 PM
#4
TECH Senior Member
Like previously posted once you get over the 2.02 size you really don't see enough pick up to make it worth it. We did some flow bench testing a number of years ago on our 5.3l heads and found that a 2.04 valve actually lost midrange and posted the same top end flow results as the 2.02 valve we use in them now.
2.055 on correct seats with proper bowl work will yield benefits over 2.02.
Ideally IMO, keeping the valve train the lightest has its benefits as well as well as a matched valve train.
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07-06-2012, 02:58 PM
#10
Like previously posted once you get over the 2.02 size you really don't see enough pick up to make it worth it. We did some flow bench testing a number of years ago on our 5.3l heads and found that a 2.04 valve actually lost midrange and posted the same top end flow results as the 2.02 valve we use in them now.
Stock bottom end 346 right?
Prc 227 heads with a 2.06" size intake valve???
http://www.texas-speed.com/p-1163-pr...der-heads.aspx
Last edited by chrs1313; 07-06-2012 at 03:03 PM.
07-06-2012, 05:49 PM
#12
Awww do you even know what size valves are on the car in your sig??
Stock bottom end 346 right?
Prc 227 heads with a 2.06" size intake valve???
http://www.texas-speed.com/p-1163-pr...der-heads.aspx
Stock bottom end 346 right?
Prc 227 heads with a 2.06" size intake valve???
http://www.texas-speed.com/p-1163-pr...der-heads.aspx
Do you know what an aftermarket valve seat is?
07-06-2012, 09:13 PM
#13
TECH Fanatic
IMO, a 2.055 valve will work on a stock bore. This is the largest that I would use. I hae seen a 2.08 valve flow more on a flow bench. But it didn't make anymore power on the dyno. You will have to change the seat for any valve lager than a 2.04, but this has nothing to do with the bowl area. It has everything to do that the outside diameter of the valve will be on aluminum instead of steel.
07-07-2012, 02:28 AM
#14
IMO, a 2.055 valve will work on a stock bore. This is the largest that I would use. I hae seen a 2.08 valve flow more on a flow bench. But it didn't make anymore power on the dyno. You will have to change the seat for any valve lager than a 2.04, but this has nothing to do with the bowl area. It has everything to do that the outside diameter of the valve will be on aluminum instead of steel.
07-07-2012, 07:13 AM
#15
TECH Senior Member
07-07-2012, 09:06 AM
#17
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I ran a set of ETP 5.3 (2.055 intake, 1.60 exhaust) heads on my ls1 motor with a 228/228 112 cam. Did not see much gain over the stock 241 heads, but the ETP 5.3 heads are setup for a minimum 4" bore.
What is the valve angle of the head's you are looking at?
What is the valve angle of the head's you are looking at?
Last edited by RQSGTO; 07-07-2012 at 11:57 AM.
07-07-2012, 02:38 PM
#18
Yes I know what valves are in those heads. This is a complete aftermarket casting head that does not have a stock valve seat. Why would we go and spend all that time and money to make an aftermarket casting and leave a stock valve seat in it?
Do you know what an aftermarket valve seat is?
Do you know what an aftermarket valve seat is?
OP just states he wanted to know about large valves, not stock castings and stock seats...your post didn't explain all options and could be read that going anything bigger than a 2.02 valve is a waste...
09-15-2014, 02:04 PM
#19
Ive got a set of 243 heads that I just had valve jobed. Im on my first ls build so when the machinist said he used 2.055 / 1.60 valves I didnt hesitate nor did I research valve size and seat combinations for these heads. So the heads were valve jobbed with the stock seats. Now I find out through major head porting companies TEA, AI, ect.... that the stock seats on the 243 wont allow any bigger than a 2.04. So im stuck with new REV valves. Im sending my heads off for cnc port so they are going to replace my intake seats and revalve job. Will the stock exhaust seat fit work with the 1.60? Ive heard you cant go bigger that a 1.575 on a stock seat.
09-16-2014, 09:03 AM
#20
Ive got a set of 243 heads that I just had valve jobed. Im on my first ls build so when the machinist said he used 2.055 / 1.60 valves I didnt hesitate nor did I research valve size and seat combinations for these heads. So the heads were valve jobbed with the stock seats. Now I find out through major head porting companies TEA, AI, ect.... that the stock seats on the 243 wont allow any bigger than a 2.04. So im stuck with new REV valves. Im sending my heads off for cnc port so they are going to replace my intake seats and revalve job. Will the stock exhaust seat fit work with the 1.60? Ive heard you cant go bigger that a 1.575 on a stock seat.