Custom Camshaft vs off the shelf @ higher elevation
Thread Starter
Teching In
Joined: Feb 2023
Posts: 2
Likes: 1
Custom Camshaft vs off the shelf @ higher elevation I am new to this forum, as well as this build. I'm not going to be the one who starts going down a rabbit hole and never completes the build. I already have the motor and it's going to the shop for the bottom end + heads to be inspected for cracks, etc. My machine shop recommended a custom cam for my build (450whp). My original question was would it be ok to run an off the shelf (comp cam 54-469-11) vs going with a custom cam? Below is the stroker kit for an LQ4 I was hoping to use. At the moment, I am trying to keep the motor NA with 317 heads. I want to have them ported and machined instead of going to 243 or Trickflow sets. Later down the road, I will go twin turbo like SatanZ did on his LQ9 z31 build before he put the drivetrain in the red rx7 that he currently has. It's a streetcar, and obviously I'm taking on an extensive project. I looked on the forum, but I didn't see a specific answer for higher elevation and camshaft combination for this block. I live in Utah, where the elevation is roughly 6,100 feet above sea level. There are a lot of details that I'm missing, and I'll answer any question you guys throw at me to the best of my ability. Also, is their anyone out there who used this kit from Summit? The stroker kit seems excessive, and again, going forged now to have a piece of mind is better for me in the long run, but please chime in on whether there are concerns with increasing the stroke.
Summit Racing SUM-R244000020 Summit Racing™ Pro LS 6.0L Rotating Assemblies | Summit Racing
Summit Racing SUM-R244000020 Summit Racing™ Pro LS 6.0L Rotating Assemblies | Summit Racing
On The Tree
Joined: Feb 2023
Posts: 109
Likes: 59
At 6000 feet you should consider raising compression much higher. At least 11.5:1 and run 91 octane. I would also definetely get a custom cam. It takes more thinking to get a car to run at high DA. I would contact cam motion, the custom grinds didn't cost any more than a shelf cam. Typically they dial back the IVC event and bump up compression for higher DA. Talk to them before making a decision. Big cams and low compression at 6000 feet will be horrible!
Thread Starter
Teching In
Joined: Feb 2023
Posts: 2
Likes: 1
That makes a lot of sense. Thanks again for the quick response too! i forgot to mention that the shop is charging me $850 for a custom grind cam, but Ive seen off the shelf cams for less than 1/2 that. i didnt want to just automatically assume it was a bad deal, but i will contact cam motion for sure.
TECH Senior Member
Joined: Jun 2016
Posts: 22,293
Likes: 3,617
From: Central Cal.
Many times there are shelf grinds that are within a few duration degrees of the prescribed custom grind, and you would never feel the difference.
The LSA should be within a degree or two, however. That will affect PTV.
The LSA should be within a degree or two, however. That will affect PTV.
That makes a lot of sense. Thanks again for the quick response too! i forgot to mention that the shop is charging me $850 for a custom grind cam, but Ive seen off the shelf cams for less than 1/2 that. i didnt want to just automatically assume it was a bad deal, but i will contact cam motion for sure.
I said what I said.
