Too much loss of low-end torque w/ ported heads & STOCK cam?
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Too much loss of low-end torque w/ ported heads & STOCK cam?
Curious.....No, concerned....
I'd like to purchase a set of LS6 (243) ported heads (PRC or PP), but I am concerned about the loss of low-end torque when installing the heads onto my TB-SS with the STOCK (~'01 LS6) camshaft.
Since the TB-SS is hefty (4600#), low-end grunt is pretty critical to get the hulk up and movin'. I am retaining the stock cam for warranty & reliability purposes, but am considering a set of "mildly" ported 243 heads w/ stock int/exh valves & springs to get a bit more uummpph from the motor (but keeping it looking 100% stock, even if the valve-covers are removed). Obviously, TSP-PRC and PP both have low-budget (that's ME!) 243 heads that have very good flow from .200-.500" lifts, which is all I would need.
BUT, the PRCs have supposedly ~235-237cc intake runners, and the PPs have runner volumes of approx 227cc's. Stock 243 runner volume is about 212cc's. So, will this extra runner volume really make a noticable loss in low-end power when coupled with the stock cam? Any guess as to how much? Bear in mind that I'd be using them on a truck that is roughly 1000-lbs heavier than an F-Body, so a "slight" loss of low-end torque as-felt in an FBody would only be amplified if/when installed on a TB-SS.
I want to pull the trigger on this, BUT I am not willing at all to sacrafice low-end grunt if I do this.
Thoughts / opinions / help?
I'd like to purchase a set of LS6 (243) ported heads (PRC or PP), but I am concerned about the loss of low-end torque when installing the heads onto my TB-SS with the STOCK (~'01 LS6) camshaft.
Since the TB-SS is hefty (4600#), low-end grunt is pretty critical to get the hulk up and movin'. I am retaining the stock cam for warranty & reliability purposes, but am considering a set of "mildly" ported 243 heads w/ stock int/exh valves & springs to get a bit more uummpph from the motor (but keeping it looking 100% stock, even if the valve-covers are removed). Obviously, TSP-PRC and PP both have low-budget (that's ME!) 243 heads that have very good flow from .200-.500" lifts, which is all I would need.
BUT, the PRCs have supposedly ~235-237cc intake runners, and the PPs have runner volumes of approx 227cc's. Stock 243 runner volume is about 212cc's. So, will this extra runner volume really make a noticable loss in low-end power when coupled with the stock cam? Any guess as to how much? Bear in mind that I'd be using them on a truck that is roughly 1000-lbs heavier than an F-Body, so a "slight" loss of low-end torque as-felt in an FBody would only be amplified if/when installed on a TB-SS.
I want to pull the trigger on this, BUT I am not willing at all to sacrafice low-end grunt if I do this.
Thoughts / opinions / help?
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Originally Posted by slowpoke96z28
if you are worried about your warranty, don't do it. there is a reason the casting numbers are on cylinder heads, and that's the first thing the dealership is going to look at.
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If you look at dyno graphs of either PRC or PP Ls6 heads...its obvious the gains are across the board. It gains torque even at the lower RPMs so I wouldnt be worried about it. I slapping my PRC Ls6 ers on now.....
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Originally Posted by 67Ranger
i dont know if they do this on the LS6 heads, but my patriot heads say "PATRIOT" real big across the front of them, and the dealer would probably notice.
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Originally Posted by cantdrv65
If you look at dyno graphs of either PRC or PP Ls6 heads...its obvious the gains are across the board. It gains torque even at the lower RPMs so I wouldnt be worried about it. I slapping my PRC Ls6 ers on now.....
Still, that data is somewhat reassuring!
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if you lose low end torque with stock cam and a head upgrade, you picked the wrong heads. pick a head that doesnot have huge monster ports. the good ones properly selected for your application will GAIN you uber torque.
#14
LOL just slap some AFRs on the stock stuff like im doing till my 408s done.
steel is right you shouldnt loose anything on the bottom unless there like a 245cc intake runner. you said you want a mild ported head. this should help across tghe board and really shouldnt hurt. just remember to not go to big!!! best idea is to call patriot or who ever you want to get the heads from. TSP is also a good choice (jason) and tell them what you want to do and they can get you the head that you will need. they will know better than the guys on here , myself included, that are making a good guess at what will happen.
steel is right you shouldnt loose anything on the bottom unless there like a 245cc intake runner. you said you want a mild ported head. this should help across tghe board and really shouldnt hurt. just remember to not go to big!!! best idea is to call patriot or who ever you want to get the heads from. TSP is also a good choice (jason) and tell them what you want to do and they can get you the head that you will need. they will know better than the guys on here , myself included, that are making a good guess at what will happen.