Ok thanks that's interesting, I didn't think displacement had much of an effect excluding the obvious changes in bore sizes and shrouding effects, and I would think stroke sizes effecting piston speeds and effecting overall turbulence.

 

Once again, thank you for the helpful insight that's precisely on point, to boot. I'll stay with the BTR beehive springs. They seem a good match for this particular cam based on their design specs. And, they seem to be well-made.

 

Got everything installed over the weekend and she fired right up. Oil pressure is great and she idles smooth with just a little grumble in the exhaust note. Power on the butt dyno is on par with the BTR stage 2 truck cam that was in before this one. Most of all, the valvetrain is nearly silent - just like OEM. This is a sleeper of a cam and I love it.

 

Good to hear you like the cam and good too hear its just like OEM and no extra surprise noises. I know the cam motion cam I put in my 2017 6.2 Camaro is driving me insane with how loud it is. The noise actually isn't really what bothers me, its just more the fact that it makes the car sound like its a broken POS haha. The higher frequency sewing machine clicky sounds pass right through the sound deadening and firewall and you hear it at all rpms, unless you are at high rpm WOT then the noise is overpowered by everything else. I am thinking more and more I need to try longer pushrods and the TSP cam I had before wasn't nearly this loud and cam motion cams are supposedly supposed to be smoother and less inclined to make noise apparently. The pushrod length I have with the cam motion cam gets me closer to the Johnson recommended 0.035 in preload than I had with my older TSP cam which was more about 0.050 in preload. I have also heard that the noises aren't even related to any of that but that not what it seems from what I am seeing.

Anyway, I am really glad you like it and it worked out for you. Can you notice any difference in part throttle and does it accelerate a little more before downshifting? I would need to think about this but I believe if you theoretically added a cam and got more torque, you would have to adjust the shift MPH numbers from stock, if you keep them stock then I don't think you would see a difference but maybe I am thinking backwards?

 

Thank you! The truck has a Black Bear tune and I'll do the datalogging today to send in along with the cam specs for an updated tune, but the performance is very similar to the BTR stage 2 cam. I pulled our 7000 lb camper with it this morning and it runs around 2000 RPMs in 5th on the highway, which is great. Unloaded, part throttle is very similar to the performance of our 2007 XL Denali with the L92 that still has VVT. I know that without VVT it's supposed to give up a little down low in exchange for more performance up high, but I can't detect the loss, while the gains are very noticeable as the revs build. Pulling on the highway today with the trailer behind me, I let it wind out to 4500 rpm and she was pulling really strong. No problem merging into rush hour traffic.

On your valvetrain noise, a guy on the Tahoe Yukon forums swapped his Johnson lifters for Morel 7717's a couple of months ago because of the valvetrain noise, and it quieted his down. It was a big step for him because he was a committed Johnson advocate. He's also running a Cam Motion cam, but with VVT in a 6.2 and I know he farted around with different pushrod lengths but could never get it quiet until he switched to the Morel's. On a side note, his pulls noticeably harder on the low end with VVT than with the OEM cam. He's running mid 5's in the 1/4 mile, so I know I'm giving up some of the low RPM performance I could have had, but since I never had it, I don't miss it.

 

Thanks for the info, I need to look into that, although their is quite the hype about Johnson lifters. I was emailing a guy there and then he stopped responding but maybe he just forgot to respond or had to many emails. They do like to keep mentioning they are the choice of lifters for the COPO Camaro though. And was the 5s in the 1/4 mile a typo? if not he must keep those cam specs locked down haha

 

Oops… yes that was a typo. I meant mid 5’s 0-60.

 

Best I have done in my stock 6.2 L9H with my own "tune" (leaner WOT AFR and slightly higher timing) Sierra Denali is I think 5.83 seconds 0-60. But remember that's with all wheel drive, which makes 99.999% of the difference since its mostly about traction. Also this is with rollout, I can't remember what it was without rollout. I wonder if your buddy had AWD? or if they just had the 6.2 option and not a Denali, although you may have been able to get 2wd Denali's not sure.

So after looking it was actually 5.80 seconds with rollout haha, but Draggy rated it invalid because my slope as -1.50% at its supposed to be above -1% grade. However, I know where I did the run is across a bridge where it initially slopes down then starts to go back up again so it probably wasn't really downhill at least not all the way. Also I have never trusted Draggy's uphill/downhill slope calculation, since I have never had a GPS that was able to get elevation consistent and accurate but maybe it is I don't know. Without rollout it was 6.06 seconds

 

Just a final follow-up here. Pulled our 7000 lb camper through the WV mountains a couple of weekends ago, and noticed a few things: 1/ The engine can hold a higher gear for longer now than with the BTR stage 2 cam I had in there previously - this is especially welcome on modest hills that are the most common we encounter on the interstates around here. 2/ On one of the long climbs on I-64 in WV at >7% grade, I used to have to downshift all the way to 2nd to keep my speed above 45. This time, I was able to do it in 3rd and hold 55 mph for the duration of the climb. 3/ Subjectively, this cam gives a great seat-of-the pants push down lower than the BTR cam did - so much so I had to remember to keep my foot out of it most of the time. I have to chalk all of this up to being a cam designed specifically for the 6.2 and not one originally designed for a 5.3 or 4.8. Lesson learned: If you have a 6.2, get this cam or another designed for the 6.2. Thanks to all of you who responded with your thoughts.

 

Great update Geotrash! Sounds like the Cam Motion was the right call. Did you do the compression bump?