OxCatLuv
08-01-2012, 08:19 AM
Hey all I have heard of some people swapping out the heads on their chevy 2500 HD 6.0 head for Camaro or Corvette heads. Might be dumb question but what are the advantages here.
New LS1 Owners - Newbie Tech - LS3 Head ?
View Full Version : LS3 Head ?
Sales2@Texas-speed
08-01-2012, 09:20 AM
I'm still a big fan of a cathedral port head on a heavy vehicle with dished pistons (low compression). The LS3's flow great out of the box and better once ported, but they have a massive intake runner that needs special attention in the combo to make the big power (RPM and/or cubes to excite the intake runner). You also have to buy 8 new rockers, a different intake manifold and fuel rail, so cost effectiveness often is not there.
OxCatLuv
08-01-2012, 09:51 AM
Matt thanks for the info. Much appreciated.
garygnu
08-01-2012, 08:24 PM
look into a good torque cam for more power.comp 54-455-11.
Fbodyjunkie06
08-03-2012, 08:36 AM
Matt is completely right.
Also what some people just don't get is the specifications on the type camshaft it takes to make these heads perform.
I've spec'd a couple cams for rectangle port heads, and the people I did them for looked at the specs and thought I was crazy because of the amount of intake/exhaust split each had and such a wide lobe separation. I try to preach it's all about valve events and not numbers. Numbers are just a by-product and coefficient to the end camshaft package.
Also what some people just don't get is the specifications on the type camshaft it takes to make these heads perform.
I've spec'd a couple cams for rectangle port heads, and the people I did them for looked at the specs and thought I was crazy because of the amount of intake/exhaust split each had and such a wide lobe separation. I try to preach it's all about valve events and not numbers. Numbers are just a by-product and coefficient to the end camshaft package.
My6speedZ
08-03-2012, 10:30 PM
Aren't rectangular port cylinder heads alot more sensitive to valve timing because they run a larger valve?
Fbodyjunkie06
08-03-2012, 10:41 PM
Aren't rectangular port cylinder heads alot more sensitive to valve timing because they run a larger valve?
It really comes down to intake to exhaust flow.
If you compare a LS3 head that flows 380cfm on the intake with a Cathedral Port head that flows 340cfm on the intake I bet 9/10 times the cathedral port heads flows just as much if not more on the exhaust side as the rectangle port head.
EVO has to be early early early on a rectangle port head while still utilizing some form of scavenging especially on a N/A motor.
It really comes down to intake to exhaust flow.
If you compare a LS3 head that flows 380cfm on the intake with a Cathedral Port head that flows 340cfm on the intake I bet 9/10 times the cathedral port heads flows just as much if not more on the exhaust side as the rectangle port head.
EVO has to be early early early on a rectangle port head while still utilizing some form of scavenging especially on a N/A motor.
My6speedZ
08-04-2012, 06:57 AM
It really comes down to intake to exhaust flow.
If you compare a LS3 head that flows 380cfm on the intake with a Cathedral Port head that flows 340cfm on the intake I bet 9/10 times the cathedral port heads flows just as much if not more on the exhaust side as the rectangle port head.
EVO has to be early early early on a rectangle port head while still utilizing some form of scavenging especially on a N/A motor.
Is this due to poor exhaust gas velocity because of the larger port cross section?
If you compare a LS3 head that flows 380cfm on the intake with a Cathedral Port head that flows 340cfm on the intake I bet 9/10 times the cathedral port heads flows just as much if not more on the exhaust side as the rectangle port head.
EVO has to be early early early on a rectangle port head while still utilizing some form of scavenging especially on a N/A motor.
Is this due to poor exhaust gas velocity because of the larger port cross section?