Precision Race Components Head Pics & Detailed Specs
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From: Texas!
Precision Race Components Head Pics & Detailed Specs I promised everyone I would post additional pics & specs for both the PRC Stage 1.5 & 2.5 cylinder heads.
First The Chambers:
62cc Chambers CNC'd to 3.900" Bore
Valve Options:
2.02" or 2.04" Intake Valves
1.575 Manley Exhaust Valves (2.5 heads) or 1.55" Truck Exhaust Valves For (1.5 Heads)
This Pic Gives You A Look At Both The 1.5 & 2.5 Chambers With Valves:
Intake Port:
Runner Size 218cc
Exhaust Port:
Runner Size 80cc
Spring Options:
Standard Gold Spring Kit @ 1.800" 135# & 380#
or
Platinum Spring Kit @ 1.7850" 145# & 395#
(Platinum Spring Shown Here-->
We basically went in with the new retainer & gave us a little more pressure so guys can run bigger camshafts, more boost, or more aggressive lobes without risking valve float.
The castings are brand new GM heads that we receive fully assembled & tear down for cnc porting
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
CNC Machine Specs:
2001 Haas HS1-5AXT
Complete 5 Axis Machining!
(checkout the Malibu in the background of the next to last pic
First The Chambers:
62cc Chambers CNC'd to 3.900" Bore
Valve Options:
2.02" or 2.04" Intake Valves
1.575 Manley Exhaust Valves (2.5 heads) or 1.55" Truck Exhaust Valves For (1.5 Heads)
This Pic Gives You A Look At Both The 1.5 & 2.5 Chambers With Valves:
Intake Port:
Runner Size 218cc
Exhaust Port:
Runner Size 80cc
Spring Options:
Standard Gold Spring Kit @ 1.800" 135# & 380#
or
Platinum Spring Kit @ 1.7850" 145# & 395#
(Platinum Spring Shown Here-->
We basically went in with the new retainer & gave us a little more pressure so guys can run bigger camshafts, more boost, or more aggressive lobes without risking valve float.
The castings are brand new GM heads that we receive fully assembled & tear down for cnc porting
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
CNC Machine Specs:
2001 Haas HS1-5AXT
Complete 5 Axis Machining!
(checkout the Malibu in the background of the next to last pic
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Thread Starter
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Joined: Nov 2001
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From: Texas!
Lake Wednesday is very good thanks to going in a boat that's not 15 years old! Poor Trevor & Zach was pretty beat up when they got off the tubes!!
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
I bet, they were talking pretty brave the other day. Glad to hear everyone made it out of the water alive. I'll be back up to get more stuff when the money gets back into my pocket. I will let you know about tuning that 85 vette too. Take care and dont kill eachother. Let me know when ya'll are going to be at Hobbs or Penwell.
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Jason,
What's the price on these heads? What's the difference in the 1.5 & 2.5? Just more porting & polishing, thus resulting in better flow? Do these heads raise compression? Would piston to valve clearance be an issue with a big cam? Can these be put on a bigger cubed motor?
So, many heads out there Im kinda stuck as to advantages/disadvantages when it comes to heads.. In the future I was planning on going with a bigger cube motor (once this one blows up or something), so i would like to start buying things for the stocker that i can simple put on the bigger cube motor (and not have to sale and then buy different heads, etc). So, if you can clear this up for me that would be great. Thanks.
What's the price on these heads? What's the difference in the 1.5 & 2.5? Just more porting & polishing, thus resulting in better flow? Do these heads raise compression? Would piston to valve clearance be an issue with a big cam? Can these be put on a bigger cubed motor?
So, many heads out there Im kinda stuck as to advantages/disadvantages when it comes to heads.. In the future I was planning on going with a bigger cube motor (once this one blows up or something), so i would like to start buying things for the stocker that i can simple put on the bigger cube motor (and not have to sale and then buy different heads, etc). So, if you can clear this up for me that would be great. Thanks.
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From: Texas!
The heads are ported the same for 1.5 & 2.5 heads. The only difference is the exhaust valve size 
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Thread Starter
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From: Texas!
I have a 62cc chamber, 64cc chamber, 68cc chamber all ready to roll
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
ask and you shall recieve huh . good info jason 
. information processed and dually noted 
now, if you could throw in a quick thread on some of the reasonings behind some of the cam revisions and testing and information you guys cam up with to finalize the new revisions that'd be pimp too
. good info jason . information processed and dually noted now, if you could throw in a quick thread on some of the reasonings behind some of the cam revisions and testing and information you guys cam up with to finalize the new revisions that'd be pimp too
Thread Starter
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From: Texas!
You got it JRP! I need to get the cam doctor specs for each one so we can look at the differences in how the cams are designed.
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Joined: Nov 2001
Posts: 3,043
Likes: 0
From: Texas and Qatar
Originally Posted by smask04C5
Jason, is that Malibu XTi in the background yours?
VERY nice Jason, thanks for the pics!!! I will DEFINITELY come to you in a month or so for my "custom" set I can't wait to see how they will perform, they look amazing from the pics!
How would you compare the Platinum springs you have to the Comp 921's? I run the 921's right now and have been pleased, no breaking them, etc with my X4, and I need that assurance that the spring will hold 7k rpm!
Thanks again for all the help, Jason and their shop is top notch!!!!
I can't wait to see how they will perform, they look amazing from the pics!How would you compare the Platinum springs you have to the Comp 921's? I run the 921's right now and have been pleased, no breaking them, etc with my X4, and I need that assurance that the spring will hold 7k rpm!
Thanks again for all the help, Jason and their shop is top notch!!!!