well said
Head and cam combo. 515 HP
Former Vendor
Joined: Oct 2006
Posts: 278
Likes: 17
From: Auburn/Dacula/Lawrenceville Georgia
I agree the TFS 215 heads are some of the best out there for a 346, but a ported 243 can come within 10 imo if not a radical cam that needs more PTV. I made a measely 447 with ported 5.3 heads on our stingy dyno (compared to all other local dynojets) through 4.10 gears and went over 127mph in positive DA.
We use TFS stuff on our big cube builds, but I do not find them necessary what so ever on anything 6.0L or below. A ported 243, or even Advanced Inductions high compression 241 program produce OUTSTANDING results with the right camshaft and a good tuner. We average 440-470rwhp on 5.7L applications and 460-480rwhp on 6.0L applications utilizing a stock ported casting with stock valves. You don't have to buy aftermarket rockers either.
On the summit site, it says the rockers are Harland Sharp, are those good?
Last edited by Josh@SpartanLSX; Jan 10, 2014 at 09:48 AM.
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
Melting Slicks
Joined: May 2007
Posts: 2,014
Likes: 48
From: Dayton Ohio
Cnc heads can make good power but not as good as an aftermarket purpose built casting like Trickflow
I Made 427/400 on a dynojet in my LS1 M6 GTO with:
Ported Fast85/85 (modified 78)
Prc stg 2.5 5.3 heads
comp 228/230 .588/.592 112+2 cam
Lt headers no cats
390 gears (loose a bit of power on dyno)
GTO drivetrain in general lays down less.
Same combo in Vette on stock gears would be 440-460 id guess
I Made 427/400 on a dynojet in my LS1 M6 GTO with:
Ported Fast85/85 (modified 78)
Prc stg 2.5 5.3 heads
comp 228/230 .588/.592 112+2 cam
Lt headers no cats
390 gears (loose a bit of power on dyno)
GTO drivetrain in general lays down less.
Same combo in Vette on stock gears would be 440-460 id guess
Last edited by PEETYZ; Jan 10, 2014 at 04:58 PM.
Melting Slicks
Joined: Nov 2009
Posts: 2,536
Likes: 15
OP...........
build towards a defined goal......not a hp number. The goal will define your engine parameters. Without a defined direction......a lot of time and $$ gets wasted, maybe multiple times.
Good luck with your project.
build towards a defined goal......not a hp number. The goal will define your engine parameters. Without a defined direction......a lot of time and $$ gets wasted, maybe multiple times.
Good luck with your project.
Instructor
Joined: Mar 2011
Posts: 163
Likes: 1
From: Wichita Kansas
I have questions about similar head cam packages as I expect to upgrade my 2001 stock LS1 in about a year. My car has low miles and looks like its 3-4 years old so I worry that if I don't keep my 241 heads and use a cam that idles fairly smooth that I'm just risking losing some of its value. I do want to increase low to mid-range response so that the car runs more like a modern Vette. I'm new to Corvettes.
Back in the 70's and 80's I hot-rodded GTOs. I had a stock 1970 GTO in high school and I figure my light-weight Vette is a little stronger but things changed in the 80's. I had a lightweight 1974 GTO that I transplanted a 455 into with a set of 1969 400 HO heads. Gave me about 11.25 to 1 compression and even the hot cam I was running couldn't "bleed" off enough compression to run the 93 octane 10% ethanol blend we had back then. Even with additives I had to retard the timing a little to keep the valves from chattering and the engine from "Dieseling" on shutdown. So I got a pair of passenger car 455 heads that had smaller valves and lowered the compression to about 9.5 to one. Man did that do the trick! I had small valves but the .5 inch lift of the cam made up the difference. I could rev the engine to about 1600 rpm and slowly let the clutch out in fourth gear with no pinging. What a torque monster!
Back to my 'Vette. Unless I plan on racing, and I don't, what do I have to gain by doing more than having my 241s CNC ported and running a cam with .59 lift and being a little conservative on the duration? I know all about how modern combustion chamber design and computers have allowed us to run higher compression engines again but that knife cuts both ways. 61cc chambers on 91 octane? If that works its because the computer is retarding the timing (loss of power) and the camshaft has enough overlap to bleed it off (loss of torque).
Maybe I'm old and out of touch with what an Corvette LS1-6 can handle. If I am, please take me to school because my research and experience says 63cc chambers and a cam with more than .6 lift is gonna give me a car I don't enjoy driving (just wanna keep up with those Mustang GTs). I even think second gear in my 6-speed 3.42 rear is ridiculously low. It reminds me of the wide-ratio 4-speed I pulled out of a 4 cylinder Vega to put in my '74 GTO because I couldn't afford an appropriate rear end at the time.
Take me to school y'all. What do I have right and where do I need correcting?
Back in the 70's and 80's I hot-rodded GTOs. I had a stock 1970 GTO in high school and I figure my light-weight Vette is a little stronger but things changed in the 80's. I had a lightweight 1974 GTO that I transplanted a 455 into with a set of 1969 400 HO heads. Gave me about 11.25 to 1 compression and even the hot cam I was running couldn't "bleed" off enough compression to run the 93 octane 10% ethanol blend we had back then. Even with additives I had to retard the timing a little to keep the valves from chattering and the engine from "Dieseling" on shutdown. So I got a pair of passenger car 455 heads that had smaller valves and lowered the compression to about 9.5 to one. Man did that do the trick! I had small valves but the .5 inch lift of the cam made up the difference. I could rev the engine to about 1600 rpm and slowly let the clutch out in fourth gear with no pinging. What a torque monster!
Back to my 'Vette. Unless I plan on racing, and I don't, what do I have to gain by doing more than having my 241s CNC ported and running a cam with .59 lift and being a little conservative on the duration? I know all about how modern combustion chamber design and computers have allowed us to run higher compression engines again but that knife cuts both ways. 61cc chambers on 91 octane? If that works its because the computer is retarding the timing (loss of power) and the camshaft has enough overlap to bleed it off (loss of torque).
Maybe I'm old and out of touch with what an Corvette LS1-6 can handle. If I am, please take me to school because my research and experience says 63cc chambers and a cam with more than .6 lift is gonna give me a car I don't enjoy driving (just wanna keep up with those Mustang GTs). I even think second gear in my 6-speed 3.42 rear is ridiculously low. It reminds me of the wide-ratio 4-speed I pulled out of a 4 cylinder Vega to put in my '74 GTO because I couldn't afford an appropriate rear end at the time.
Take me to school y'all. What do I have right and where do I need correcting?
Race Director
Joined: Dec 2006
Posts: 12,395
Likes: 2,912
From: Fort Worth, Texas
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Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
I have questions about similar head cam packages as I expect to upgrade my 2001 stock LS1 in about a year. My car has low miles and looks like its 3-4 years old so I worry that if I don't keep my 241 heads and use a cam that idles fairly smooth that I'm just risking losing some of its value. I do want to increase low to mid-range response so that the car runs more like a modern Vette. I'm new to Corvettes.
Back in the 70's and 80's I hot-rodded GTOs. I had a stock 1970 GTO in high school and I figure my light-weight Vette is a little stronger but things changed in the 80's. I had a lightweight 1974 GTO that I transplanted a 455 into with a set of 1969 400 HO heads. Gave me about 11.25 to 1 compression and even the hot cam I was running couldn't "bleed" off enough compression to run the 93 octane 10% ethanol blend we had back then. Even with additives I had to retard the timing a little to keep the valves from chattering and the engine from "Dieseling" on shutdown. So I got a pair of passenger car 455 heads that had smaller valves and lowered the compression to about 9.5 to one. Man did that do the trick! I had small valves but the .5 inch lift of the cam made up the difference. I could rev the engine to about 1600 rpm and slowly let the clutch out in fourth gear with no pinging. What a torque monster!
Back to my 'Vette. Unless I plan on racing, and I don't, what do I have to gain by doing more than having my 241s CNC ported and running a cam with .59 lift and being a little conservative on the duration? I know all about how modern combustion chamber design and computers have allowed us to run higher compression engines again but that knife cuts both ways. 61cc chambers on 91 octane? If that works its because the computer is retarding the timing (loss of power) and the camshaft has enough overlap to bleed it off (loss of torque).
Maybe I'm old and out of touch with what an Corvette LS1-6 can handle. If I am, please take me to school because my research and experience says 63cc chambers and a cam with more than .6 lift is gonna give me a car I don't enjoy driving (just wanna keep up with those Mustang GTs). I even think second gear in my 6-speed 3.42 rear is ridiculously low. It reminds me of the wide-ratio 4-speed I pulled out of a 4 cylinder Vega to put in my '74 GTO because I couldn't afford an appropriate rear end at the time.
Take me to school y'all. What do I have right and where do I need correcting?
Back in the 70's and 80's I hot-rodded GTOs. I had a stock 1970 GTO in high school and I figure my light-weight Vette is a little stronger but things changed in the 80's. I had a lightweight 1974 GTO that I transplanted a 455 into with a set of 1969 400 HO heads. Gave me about 11.25 to 1 compression and even the hot cam I was running couldn't "bleed" off enough compression to run the 93 octane 10% ethanol blend we had back then. Even with additives I had to retard the timing a little to keep the valves from chattering and the engine from "Dieseling" on shutdown. So I got a pair of passenger car 455 heads that had smaller valves and lowered the compression to about 9.5 to one. Man did that do the trick! I had small valves but the .5 inch lift of the cam made up the difference. I could rev the engine to about 1600 rpm and slowly let the clutch out in fourth gear with no pinging. What a torque monster!
Back to my 'Vette. Unless I plan on racing, and I don't, what do I have to gain by doing more than having my 241s CNC ported and running a cam with .59 lift and being a little conservative on the duration? I know all about how modern combustion chamber design and computers have allowed us to run higher compression engines again but that knife cuts both ways. 61cc chambers on 91 octane? If that works its because the computer is retarding the timing (loss of power) and the camshaft has enough overlap to bleed it off (loss of torque).
Maybe I'm old and out of touch with what an Corvette LS1-6 can handle. If I am, please take me to school because my research and experience says 63cc chambers and a cam with more than .6 lift is gonna give me a car I don't enjoy driving (just wanna keep up with those Mustang GTs). I even think second gear in my 6-speed 3.42 rear is ridiculously low. It reminds me of the wide-ratio 4-speed I pulled out of a 4 cylinder Vega to put in my '74 GTO because I couldn't afford an appropriate rear end at the time.
Take me to school y'all. What do I have right and where do I need correcting?
Things have changed since your earlier experiences. Many have gone as low as 59cc on 91 oct. It all depends on your tune. No additives are needed for most setups. BTW, I'm running 10.95:1, and maxing out at 8.5lbs of boost, with a stock shortblock. (on 92 here in WA.)
Race Director
Joined: Dec 2006
Posts: 12,395
Likes: 2,912
From: Fort Worth, Texas
I agree, combustion chamber design has come a long ways and ultimately DCR is more important than SCR for octane requirements erufle...I will be running 11.8:1 on 93 octane fwiw
Last edited by PRE-Z06; Jan 13, 2014 at 02:55 PM.