[Z06] 2006 Z06 noise/miss? Katech Torquer and PRC heads
10-26-2017, 10:27 PM
#41
Sorry I missed this. Yes, happy I noticed the squeak right away. 50k on the car. PRC heads were new at 35k.
Big picture... you caught it early. Mod it, make it stronger, more reliable. How many miles on the car?
I was recently at a shop where a ZR1 lifter went... half of the wheel was gone... It was pretty bad... Luckily the owner still has a C7Z he can cruise around in while the ZR1 is down. GL w build...
I was recently at a shop where a ZR1 lifter went... half of the wheel was gone... It was pretty bad... Luckily the owner still has a C7Z he can cruise around in while the ZR1 is down. GL w build...
10-26-2017, 10:28 PM
#42
As I recall, TSP's guides are a step-cut guide. The part of the guide that presses into the head is the same diameter as the OEM guides but the top of the guide is a bit larger in diameter. I believe they do this because it makes it easier to "locate" the guide in the head. You just press it in till the guide "shelf/lip" seats itself in the head. The only real difference that AHP needs to worry about is getting a spring perch with the right ID for their new guides.
FWIW, I have the PRC 265s with a bit over 20K miles on it. My next wiggle test, assuming a "good" test, I'll be replacing PRC's dual springs with PSI's beehives. I researched and bought a set of spring perches with the "correct" ID for the PRC guides.
All this being said, AHP's Moldstar 90 guides will work with your heads. They just need the correct spring bases for your spring setup.
FWIW, I have the PRC 265s with a bit over 20K miles on it. My next wiggle test, assuming a "good" test, I'll be replacing PRC's dual springs with PSI's beehives. I researched and bought a set of spring perches with the "correct" ID for the PRC guides.
All this being said, AHP's Moldstar 90 guides will work with your heads. They just need the correct spring bases for your spring setup.
By the way, why the spring change?
10-26-2017, 10:42 PM
#43
Team Owner
Springs on a high lift, high duration cam, revving to 7k don't last forever. It is common to replace them every ~20-25k miles. I replaced mine at 22k miles, no issues. PRC 285 heads.
10-26-2017, 10:46 PM
#44
This I get. I probably wasnt clear. I meant why the change from the PAC duals to the beehives. Springs in the car are PAC .660 duals with less than 10k miles on them.
10-26-2017, 11:36 PM
#45
Team Owner
10-27-2017, 08:25 AM
#46
Safety Car
Member Since: Dec 1999
Location: Virginia Beach, VA & Port Charlotte, FL (snowbird)
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As unreal said, performance valve springs have a limited life span, the more radical the camshaft and the harder you drive it, especially HPDEs, the sooner they need to be checked and/or replaced. 20k-25k miles seems to be an adequate replacement plan for most applications.
In my situation, the reasoning is more slanted to ****-poor springs that PRC provided early-on with their heads (the infamous .675" springs). FWIW, I was one of the first here to use PRC's heads (October of 2011). Katech's early bought and paid for spintron testing showed PSI's 1511 beehive valve springs having better control (less valve bounce) over the valves then they tested dual springs. That was true even with the tested heavy solid stemmed stainless steel exhaust valves. As I recall, this was even true with the cam I'm running, Katechs Torquer 110. FWIW, different cams and springs could produce different results.
In my situation, the reasoning is more slanted to ****-poor springs that PRC provided early-on with their heads (the infamous .675" springs). FWIW, I was one of the first here to use PRC's heads (October of 2011). Katech's early bought and paid for spintron testing showed PSI's 1511 beehive valve springs having better control (less valve bounce) over the valves then they tested dual springs. That was true even with the tested heavy solid stemmed stainless steel exhaust valves. As I recall, this was even true with the cam I'm running, Katechs Torquer 110. FWIW, different cams and springs could produce different results.
10-27-2017, 09:17 AM
#47
Interesting. So this car had a torquer 110 when the lifter failed. Not sure yet whats going back in as Im taking a rec from DRM. It did have the 675 springs at one time. One did fail and they were replaced with the 660’s. Also, we’re going with solid stainless exhaust valves. Funny how this all relates huh? We were talking about going to different springs and perches. So, the PSI 1511 beehives and the proper perches seem to be the way to go?
10-27-2017, 11:59 AM
#48
Safety Car
Member Since: Dec 1999
Location: Virginia Beach, VA & Port Charlotte, FL (snowbird)
Posts: 4,407
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Interesting. So this car had a torquer 110 when the lifter failed. Not sure yet whats going back in as Im taking a rec from DRM. It did have the 675 springs at one time. One did fail and they were replaced with the 660’s. Also, we’re going with solid stainless exhaust valves. Funny how this all relates huh? We were talking about going to different springs and perches. So, the PSI 1511 beehives and the proper perches seem to be the way to go?
I already have the right ID perches for the beehives and the original PRC guides, assuming they are still in spec. If they're not then I'll send them to AHP for some MS 90s.
I have 109K on the car now and I'm the original owner, buying it 12/06.
Another juicy tidbit... A With 88K on my engine I changed to the PRCs just to be safe. I then sent my factory heads to WCCH and every-single-valve-guide was within GM's specs. I guess I'm one of the few.
Last edited by Undy; 10-27-2017 at 12:00 PM. Reason: added info
10-27-2017, 12:12 PM
#49
Undy, thanks for the reply. My car had Torquer 110 cam put in at 35k miles. It also had GM CTSV high RPM lifters. Lifter failed at about 50k miles. Took the cam with it of course. The PRC heads that were also put on at 35k miles. Had the 675 springs. One of which failed at 42k miles. At that time the PAC 660 duals were put in to replace them. Bronze guides and exhaust valves are shot. About 15k miles on the combo.
Now the car is under the knife at DRM. They are specing a cam. I don't have those specs. GM LS7 regular lifters going back in. CHE kit in the rockers. AHP MS90 guides going back in (thanks to your comment earlier). Sound like they are recommending a solid stainless exhaust valve. DRM didn't seem to have any issue reusing the PAC 660 springs which have about 8k miles on them again.
So, the discussion revolves around exhaust valve choice as well as spring choice.
That is really interesting regarding your original guides....
Now the car is under the knife at DRM. They are specing a cam. I don't have those specs. GM LS7 regular lifters going back in. CHE kit in the rockers. AHP MS90 guides going back in (thanks to your comment earlier). Sound like they are recommending a solid stainless exhaust valve. DRM didn't seem to have any issue reusing the PAC 660 springs which have about 8k miles on them again.
So, the discussion revolves around exhaust valve choice as well as spring choice.
That is really interesting regarding your original guides....
10-27-2017, 12:34 PM
#50
Team Owner
Now the car is under the knife at DRM. They are specing a cam. I don't have those specs. GM LS7 regular lifters going back in. CHE kit in the rockers. AHP MS90 guides going back in (thanks to your comment earlier). Sound like they are recommending a solid stainless exhaust valve. DRM didn't seem to have any issue reusing the PAC 660 springs which have about 8k miles on them again.
Don't go back with the solid stems. If mine goes to AHP they'll be the F2024Ps.
10-27-2017, 01:06 PM
#52
Drifting
Undy, thanks for the reply. My car had Torquer 110 cam put in at 35k miles. It also had GM CTSV high RPM lifters. Lifter failed at about 50k miles. Took the cam with it of course. The PRC heads that were also put on at 35k miles. Had the 675 springs. One of which failed at 42k miles. At that time the PAC 660 duals were put in to replace them. Bronze guides and exhaust valves are shot. About 15k miles on the combo.
Now the car is under the knife at DRM. They are specing a cam. I don't have those specs. GM LS7 regular lifters going back in. CHE kit in the rockers. AHP MS90 guides going back in (thanks to your comment earlier). Sound like they are recommending a solid stainless exhaust valve. DRM didn't seem to have any issue reusing the PAC 660 springs which have about 8k miles on them again.
So, the discussion revolves around exhaust valve choice as well as spring choice.
That is really interesting regarding your original guides....
Now the car is under the knife at DRM. They are specing a cam. I don't have those specs. GM LS7 regular lifters going back in. CHE kit in the rockers. AHP MS90 guides going back in (thanks to your comment earlier). Sound like they are recommending a solid stainless exhaust valve. DRM didn't seem to have any issue reusing the PAC 660 springs which have about 8k miles on them again.
So, the discussion revolves around exhaust valve choice as well as spring choice.
That is really interesting regarding your original guides....
I went with the Johnson 2110's on my build and are what GM specs in all of their new COPO Camaro's. I couldn't be happier as they are super quiet on top of being a better (durability and performance) lifter than the GM LS7.
Slow bleed down lifters have a better ability to maintain lift without collapsing or in other words the repeatability in the common rotation on the cam. Johnson (via GM testing I believe) told me the 2110 lifters maintained their lift 95% of the time where the GM LS7 lifters only maintain their lift about 50% of the time. What this means is that if you for example had a .630" lift cam but your lifters bled down .030" as the lobe of the cam rotates, you'd essentially only be getting about .600" lift out of your cam.
Also, notice in the 2018 COPO specs: CamMotion camshaft, PSI Max Life beehive valve springs, and note that even on these high-end motors, they still use the same lightweight sodium-filled exhaust valves. I went with the Ferrea F2042P's from AHP as well, but Kohle will tell you the GM exhaust valves are not bad, (the Ferrea's are just better for the same price.) Now with that said, LME for example, likes to use the solid one piece exhaust valves on the LS7, but they will build you a motor to meet your specific needs.
http://www.ctsvowners.com/forum/4-en...ew-cams-3.html
https://www.chevrolet.com/content/da...chart-2018.pdf
Last edited by BigVette427; 10-27-2017 at 01:40 PM.
10-27-2017, 01:14 PM
#53
Le Mans Master
As unreal said, performance valve springs have a limited life span, the more radical the camshaft and the harder you drive it, especially HPDEs, the sooner they need to be checked and/or replaced. 20k-25k miles seems to be an adequate replacement plan for most applications.
In my situation, the reasoning is more slanted to ****-poor springs that PRC provided early-on with their heads (the infamous .675" springs). FWIW, I was one of the first here to use PRC's heads (October of 2011). Katech's early bought and paid for spintron testing showed PSI's 1511 beehive valve springs having better control (less valve bounce) over the valves then they tested dual springs. That was true even with the tested heavy solid stemmed stainless steel exhaust valves. As I recall, this was even true with the cam I'm running, Katechs Torquer 110. FWIW, different cams and springs could produce different results.
In my situation, the reasoning is more slanted to ****-poor springs that PRC provided early-on with their heads (the infamous .675" springs). FWIW, I was one of the first here to use PRC's heads (October of 2011). Katech's early bought and paid for spintron testing showed PSI's 1511 beehive valve springs having better control (less valve bounce) over the valves then they tested dual springs. That was true even with the tested heavy solid stemmed stainless steel exhaust valves. As I recall, this was even true with the cam I'm running, Katechs Torquer 110. FWIW, different cams and springs could produce different results.
10-27-2017, 04:24 PM
#55
Drifting
BTR LS7 II: 230/246 .644"/.630" 115+4
Consider an LS lobe friendly cam from TSP's Landis LT1VE CNC cam grinder, where it only grinds cams for LS and LT motors. They can grind you essentially whatever you want on their .635"/.635" lobes and laser etch the specs on the end.
Cam Motion also has a lot of cool grinds that they've recently added to their website as well and I'm sure they could custom grind you whatever you wanted on their lobes, too.
Titan 1 LS7: 228/244, .648"/.639", 115 LSA, 112 ICL
LS7 Stage 3: 232/246, .630"/.612", 117.5 LSA, 114 ICL
Also, consider your cam overlap - take that into account per your goal.
http://www.wallaceracing.com/overlap-calc.php
Last edited by BigVette427; 10-27-2017 at 04:24 PM.
10-27-2017, 04:59 PM
#56
Burning Brakes
That doesn't exactly sound like a ringing endorsement. Ask them why they think you should go with that cam? Before you pull the trigger, make sure those advertised lobe lifts are measured with 1.8 rockers, not 1.7. Someone on this forum before has received a similar cam and those lifts were actually calculated on 1.7 rockers, even though it was advertised under the LS7 banner. Then, also ask what kind of lobes they are? Ex. endurance lobes.
BTR LS7 II: 230/246 .644"/.630" 115+4
Consider an LS lobe friendly cam from TSP's Landis LT1VE CNC cam grinder, where it only grinds cams for LS and LT motors. They can grind you essentially whatever you want on their .635"/.635" lobes and laser etch the specs on the end.
Cam Motion also has a lot of cool grinds that they've recently added to their website as well and I'm sure they could custom grind you whatever you wanted on their lobes, too.
Titan 1 LS7: 228/244, .648"/.639", 115 LSA, 112 ICL
LS7 Stage 3: 232/246, .630"/.612", 117.5 LSA, 114 ICL
Also, consider your cam overlap - take that into account per your goal.
http://www.wallaceracing.com/overlap-calc.php
BTR LS7 II: 230/246 .644"/.630" 115+4
Consider an LS lobe friendly cam from TSP's Landis LT1VE CNC cam grinder, where it only grinds cams for LS and LT motors. They can grind you essentially whatever you want on their .635"/.635" lobes and laser etch the specs on the end.
Cam Motion also has a lot of cool grinds that they've recently added to their website as well and I'm sure they could custom grind you whatever you wanted on their lobes, too.
Titan 1 LS7: 228/244, .648"/.639", 115 LSA, 112 ICL
LS7 Stage 3: 232/246, .630"/.612", 117.5 LSA, 114 ICL
Also, consider your cam overlap - take that into account per your goal.
http://www.wallaceracing.com/overlap-calc.php
Yeah, that was me. BTR was really cool with sending me out a replacement on a 1.8 rocker ratio tho. A year before DRM completed my HCIE build Doug recommended a cam with specs 232/248 .636/.631 115. Fast forward a year after researching plenty of cams I decided on the BTR 2 on a Cam Motion 8620 grind. I don't know if the lobe profile is different than a BTR cam since it was ground by Cam Motion. I've put over 3,000 miles on it since I picked it up late may and its been great. Minimal drivability loss and it pulls hard to 6500. FWIW, Todd at DRM thought that cam had pretty high lift compared to what he is used to putting in.
Jesse
10-27-2017, 06:12 PM
#57
Team Owner
BTR stage 2 is a well proven great cam. Great suggestion and will drive great with great power.
10-27-2017, 07:50 PM
#58
Sooooooooooo, I have very little idea what Im talking about. This is a high $ learning experience and Im enjoying it. I appreciate all opinions and responses. Alot actually. That said, I respect Todd and Doug at DRM. We’ve had many conversations around the right path and I feel good about our direction. We’ve changed directions directly as a result of this thread and thats awesome.
10-29-2017, 01:26 AM
#60
Melting Slicks
I love my BTR stage 2 cam. It makes great power and torque down low where you want it for a street cam. I have zero desire to go to anything bigger or move the power curve to the right at all, just to gain, what 10-15 peak...