Comparing Truck Cams
Last edited by speedtigger; Jul 4, 2024 at 12:39 PM.
As for BTRs lobes, they have come a long way in the last several years and most of their stuff that I have seen is well designed. With that said, keep in mind that valve weight from various LS based engines will vary. This can impact which cam lobes and valve springs that you choose. For example, and LS3 has hollow stem valves that weigh about 87 grams, whereas an 823 headed 6.0 or 6.2 liter truck engines will have solid intake valves that weigh about 108 grams. I have done actual dyno tests where the valves floated on a solid stem valve head that would remain stable on a hollow stem valve head in the same RPM range. So, do your research for sure.
If you are interested, here is a Cam Motion custom VVT camshaft using their XA lobes that I ran on the dyno with DrTuneEmAll a few weeks ago.
214/224 113.5+8 .553" valve lift
We retarded the camshaft 4 degrees at 5200 RPM and here are the results: Green is using the VVT as described, blue is leaving the VVT locked.
As for BTRs lobes, they have come a long way in the last several years and most of their stuff that I have seen is well designed. With that said, keep in mind that valve weight from various LS based engines will vary. This can impact which cam lobes and valve springs that you choose. For example, and LS3 has hollow stem valves that weigh about 87 grams, whereas an 823 headed 6.0 or 6.2 liter truck engines will have solid intake valves that weigh about 108 grams. I have done actual dyno tests where the valves floated on a solid stem valve head that would remain stable on a hollow stem valve head in the same RPM range. So, do your research for sure.
If you are interested, here is a Cam Motion custom VVT camshaft using their XA lobes that I ran on the dyno with DrTuneEmAll a few weeks ago.
214/224 113.5+8 .553" valve lift
We retarded the camshaft 4 degrees at 5200 RPM and here are the results: Green is using the VVT as described, blue is leaving the VVT locked.
https://youtu.be/Zudc_gBXUD8?si=1EuK1VTAnzxM_sMJ
https://youtu.be/LZ3BlzKgSXU?si=7x9pBXP_X-h2kkar
I mostly want to delete the VVT because I don't like how it drives at part throttle. It's like a switch that's flipped at 2k rpms and makes it hard to accelerate smoothly. Not sure an aftermarket cam would change that or not. Plus it was very hard to find anyone doing gen 4 5.3 versions of the VVT cams anymore, almost everyone was doing gen 5 stuff or gen 4 6.2 which I assumed would be a little too big for my wants. Looking at your chart there, its interesting there aren't any low rpm gains from the VVT like gm claims it was for.
Here are the cams I am looking at:
https://cammotion.com/in-stock-ready...206-210-115-5/
https://briantooleyracing.com/btr-ca...r31218110.html
Last edited by 1bdbrd; Jul 4, 2024 at 06:15 PM.
On the 1st run he was running in parked position the whole time. 2nd run also started with the camshaft in parked position, then the VVT was "activated" meaning the camshaft was retarded 4* starting @ 5000rpm. That's why both look exactly the same up to 5k. He did not do a full run with it only retarded. If it had been, yes there would have been a significant loss of torque.
As for BTRs lobes, they have come a long way in the last several years and most of their stuff that I have seen is well designed. With that said, keep in mind that valve weight from various LS based engines will vary. This can impact which cam lobes and valve springs that you choose. For example, and LS3 has hollow stem valves that weigh about 87 grams, whereas an 823 headed 6.0 or 6.2 liter truck engines will have solid intake valves that weigh about 108 grams. I have done actual dyno tests where the valves floated on a solid stem valve head that would remain stable on a hollow stem valve head in the same RPM range. So, do your research for sure.
If you are interested, here is a Cam Motion custom VVT camshaft using their XA lobes that I ran on the dyno with DrTuneEmAll a few weeks ago.
214/224 113.5+8 .553" valve lift
We retarded the camshaft 4 degrees at 5200 RPM and here are the results: Green is using the VVT as described, blue is leaving the VVT locked.
https://youtu.be/Zudc_gBXUD8?si=1EuK1VTAnzxM_sMJ
https://youtu.be/LZ3BlzKgSXU?si=7x9pBXP_X-h2kkar








