PRC heads or Patriot heads?
Thread Starter
12 Second Club
iTrader: (27)
Joined: Feb 2006
Posts: 606
Likes: 0
From: Texas....thank God.
PRC heads or Patriot heads? Ok. I have narrowed my selection down to two cylinder heads. I am considering the TSP trqr v.2 .Which heads would you go with, and why?
#1. PRC stg 2.5 LS6 CNC'd heads with 2.04/1.57 valves and PRC double valve springs, milled for increased compression(11.25 area).
or
#2. Patriot CNC'd 243 castings with 2.00/1.55 valves, 227 runners, and Patriot Gold spring kit. Flow in the 300 range.
#1. PRC stg 2.5 LS6 CNC'd heads with 2.04/1.57 valves and PRC double valve springs, milled for increased compression(11.25 area).
or
#2. Patriot CNC'd 243 castings with 2.00/1.55 valves, 227 runners, and Patriot Gold spring kit. Flow in the 300 range.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
They are both the same casting (LS2/LS6-243)
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
Thread Starter
12 Second Club
iTrader: (27)
Joined: Feb 2006
Posts: 606
Likes: 0
From: Texas....thank God.
Damn, Predator-Z, you are on top of this stuff arnt you! Do you think that either of these combinations can get me to 450RWHP? Maybe a different cam? Thank all of you for your opinions!
TECH Fanatic
Joined: May 2003
Posts: 1,292
Likes: 6
From: RainbowCity,Alabama
I am not sure the trqr v.2 will go to 450 rwhp.I would run the MS3 cam with the PRC stage 1 heads with stock valves.It should clear p/v and it has produced above 450rwhp.Check out the dyno section for results of PRC head combinations.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo Thread Starter
12 Second Club
iTrader: (27)
Joined: Feb 2006
Posts: 606
Likes: 0
From: Texas....thank God.
Wow...ok, now I am getting confused. I thought that I had the perfect plan! LOL Guess that is what I get for "thinking!" So, I guess I need to rephrase this....someone get me to 450+RWHP, without flycutting. Milling and increased compression is fine. I want to buy the **** and bolt it on.
Originally Posted by PREDATOR-Z
They are both the same casting (LS2/LS6-243)
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
Originally Posted by PREDATOR-Z
They are both the same casting (LS2/LS6-243)
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
If you plan on the TV2 112 then it won't fit with 2.04 valves.
Either get PRC Stage 1 or PP stage 1 (both are 64 cc), difference is the CNC program.
PRC is ~ 235 cc intake runners and PP is ~ 227 (both have stock valves 2.00/1.55)
Either is a good choice. The PP would probably make a little more trq below the curve due to the smaller runners.
The PRC will maybe make a couple more peak Hp.
I've never seen any test on that, this is just speculation.
PRC heads flow more than patriots and our bench is a little stingy, we have had customers independently test the PRC heads and go way more flow than what we advertise. Personally I wouldn't think twice about going with PRC heads. Also we set up each customer's heads with their desired cam in mind, so if you do go MS4, MS3....etc, we can sink the valve and shim the spring for added P/V clearance, also allowing you to run a thinner gasket and bump up compression.
If you want more info on the heads just let me know!!
Zach
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by Zach@Texas-Speed
The Torquer V.2 will fit with the stage 2.5 heads. You could also run the MS4 on some stage 1 heads if your sticking to a budget and trying to make the most power.
PRC heads flow more than patriots and our bench is a little stingy, we have had customers independently test the PRC heads and go way more flow than what we advertise. Personally I wouldn't think twice about going with PRC heads. Also we set up each customer's heads with their desired cam in mind, so if you do go MS4, MS3....etc, we can sink the valve and shim the spring for added P/V clearance, also allowing you to run a thinner gasket and bump up compression.
If you want more info on the heads just let me know!!
Zach
PRC heads flow more than patriots and our bench is a little stingy, we have had customers independently test the PRC heads and go way more flow than what we advertise. Personally I wouldn't think twice about going with PRC heads. Also we set up each customer's heads with their desired cam in mind, so if you do go MS4, MS3....etc, we can sink the valve and shim the spring for added P/V clearance, also allowing you to run a thinner gasket and bump up compression.
If you want more info on the heads just let me know!!
Zach
You sink the valves, you loose flow, not recommended unless absolutely necessary.
IMO unless you go with aftermarket valve seats, 2.02 should be maximum.
(because come to find out that stock seats are 2.02, so 2.04 valves will not seat "properly", meaning you won't really benefit from them over 2.02s)
Now don't get me wrong, 2.04 will work, but there is no real gain in doing so.
TV2 112 will have less than .080 intake clearance on a 2.04 valve, not recommended for street.
Just remember that not all motors are created equal, and piston deck height varies from .005 to .01 out of hole (average around .007/.008), so why risk it?
From my personal experience on the TV2 get the 112 and whatever head you decide, stick with stock valves, they are plenty.
Last edited by PREDATOR-Z; Aug 15, 2006 at 04:51 PM.
We have done many Stage 2.5/TQ2 setups without having to sink valves, while using 2.04 intake valves, stock gaskets
Sinking the valve does not lose flow unless your doing something extreme, the amount it would take to get something close to fit would not lose any flow at all.
Sinking the valve does not lose flow unless your doing something extreme, the amount it would take to get something close to fit would not lose any flow at all.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by Zach@Texas-Speed
We have done many Stage 2.5/TQ2 setups without having to sink valves, while using 2.04 intake valves, stock gaskets
Sinking the valve does not lose flow unless your doing something extreme, the amount it would take to get something close to fit would not lose any flow at all.
Sinking the valve does not lose flow unless your doing something extreme, the amount it would take to get something close to fit would not lose any flow at all.
I'm talking about a 112LSA,
What was your average clearance value, intake/exhaust?
and I've not said that you need to sink them, but out of curiosity, how do you sink 2.04 valves on a 2.02 seat?
Last edited by PREDATOR-Z; Aug 16, 2006 at 12:46 PM.
When comparing apples to apples, you will be hard pressed to find a better head than our CNC ported 243 castings. It may be that an OEM ported casting with a much larger runner will out flow our head, but that is to be expected.
We produce a quality product that performs as we say it will. Flow numbers are not inflated or made up. We send a flow sheet with every set of heads. This sheet is specific to that set of heads.
Soon the trend of high quality at a reasonable price will continue with our Predator heads. They have taken longer than we would have liked, but it takes time to produce a quality product from scratch.
We produce a quality product that performs as we say it will. Flow numbers are not inflated or made up. We send a flow sheet with every set of heads. This sheet is specific to that set of heads.
Soon the trend of high quality at a reasonable price will continue with our Predator heads. They have taken longer than we would have liked, but it takes time to produce a quality product from scratch.
Originally Posted by N4cer
I like the PRC's due to the higher compression, but I'm not a big fan of the large valves in them.
Zach
Originally Posted by Zach@Texas-Speed
We can put whatever valve size you prefer in the heads. We offer the stage 2.5 heads with 2.02 or 2.04 intake valves!!
Zach
Zach
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by PREDATOR-Z
Zach,
I'm talking about a 112LSA,
What was your average clearance value, intake/exhaust?
and I've not said that you need to sink them, but out of curiosity, how do you sink 2.04 valves on a 2.02 seat?
I'm talking about a 112LSA,
What was your average clearance value, intake/exhaust?
and I've not said that you need to sink them, but out of curiosity, how do you sink 2.04 valves on a 2.02 seat?
NO ANSWER???
If I'm talking nonesense please correct me, for it is better to recognize ones fault then to live in darkness.
Adding to my questions is what ICLs are clearing the 2.04, and when clearing, by what margin ??
This is good education so we know where we stand in our purchases.
(When I purchased the TV2, I requested that my margins be at least .080 int and .100 exhaust, the answer I got was only the 113+0 will give those, and that 112 while still "fitting" would be tighter than that)
So could you verify the clearances at 112+0, 112+2 and 112+4 please.
This is on a stage 2.5 (2.04/1.57)
Ok here's the best way I know to explain this.
You can cut up to a 2.04" valve job in a stock seat. Therefore any valve up to that size can be put into the stock seat. With our cnc valve job machine we can instantly adjust the valvejob size for bigger valves or for different valve depths. If you design a port for the valve set to a certain depth then you can easily keep the valve at that depth. Installing a 2.04" intake valve with a 2" installed height would definately hurt p/v pretty bad, but sinking them .015" or so helps to offset a lot of the bigger valve. We've spent hundreds of hours testing different valve sizes, depths, and angles. Rest assured that if I say we can sink the valve a little bit without compromising flow, then it won't.
The torquer 2 has been installed many times with several competitors cylinder heads that have 2.02 & 2.055 valves. We've built Stg 2.5 heads countless times to work with the T2. If anyone has any questions or concerns call the shop & talk with Jason, he's built enough different valve/depth configurations to make you go CRAZY!!
What a lot of guys don't understand is we can instantly change ANY length or angle on our valve job. VERY VERY few shops in the entire country have this ability. When you can have complete adjustability in your valve job, you can make changes to adapt to different depths & different flow characteristics.
You can cut up to a 2.04" valve job in a stock seat. Therefore any valve up to that size can be put into the stock seat. With our cnc valve job machine we can instantly adjust the valvejob size for bigger valves or for different valve depths. If you design a port for the valve set to a certain depth then you can easily keep the valve at that depth. Installing a 2.04" intake valve with a 2" installed height would definately hurt p/v pretty bad, but sinking them .015" or so helps to offset a lot of the bigger valve. We've spent hundreds of hours testing different valve sizes, depths, and angles. Rest assured that if I say we can sink the valve a little bit without compromising flow, then it won't.
The torquer 2 has been installed many times with several competitors cylinder heads that have 2.02 & 2.055 valves. We've built Stg 2.5 heads countless times to work with the T2. If anyone has any questions or concerns call the shop & talk with Jason, he's built enough different valve/depth configurations to make you go CRAZY!!
What a lot of guys don't understand is we can instantly change ANY length or angle on our valve job. VERY VERY few shops in the entire country have this ability. When you can have complete adjustability in your valve job, you can make changes to adapt to different depths & different flow characteristics.
Last edited by Zach@Texas-Speed; Aug 16, 2006 at 02:00 PM.