Mike Morris

iTrader: (55)

Go and look at people that ran Comp Cam trunions. They start to fall apart right away. Mine looked terrible after 3k. Lucky I caught it

My EPS Comp cam was on the way out after 7K just like what was mentioned in this thread. Good thing I checked that too. I have sworn them off


https://ls1tech.com/forums/generatio...comp-cams.html

JoeNova

All of the BTR/LJMS cams are just comp cams. Comp used to do cams for TSP and they still do them for one other company.

That thread is from 5 years ago. Its likely that whatever issues they had then have been resolved.

truckdoug

iTrader: (25)

recently put a stage 2 summit truck cam in a bone stock 220,000 mile 5.3 2002 silverado 1500

with some tuning it was a nice little bump. would guess maybe 35 wheel? wish I had access to a dyno that didn't cost an arm and a leg.

omc8

iTrader: (7)

Does Summit have any plans in coming out with a High Lift version of the truck stage 2 and Stage 3

Summitracing

The SUM Pro LS Truck Swap Stage 1 .550 lift version that will be released by Oct. 10. That part number will be a SUM-8719.

A higher lift version of Stage 2 Truck is possible. We're at .545 on the Truck Stage 3 and 4. Here's the conundrum. Going beyond .545 to .550 in the Truck lineup takes us out of LS6 beehive springs and the peace of mind of long valvetrain life that comes with them. Not to mention $73/set affordability. We're ALWAYS open to suggestions though. If people would like a .600 lift version etc., let us know what you would like to see!

omc8

iTrader: (7)

Well count me in on ....... for the high lift version .I think if you offer it , it would become a better seller Imho than the current Stage2/3

Summitracing

Are you feeling .600 lift?

wannafbody

iTrader: (2)

I'm not going to argue about poor quality of Comp trunions and they've had some spring issues. But if your trunions were bad, that explains the cam wear. Also, comp sources their cores from the same place other cam manufacturers do. I'd lay more blame at overly aggressive ramps and mismatched springs. Although it's possible for a bad cam to make it to a customer.

Summitracing

Things that happen up top can have an effect on a cam...such as an AFM lifter failure. What is more common is grinding the right lobe on the wrong core. The following is be part of the article we wrote on the subject: "Because Summit Racing’s Pro LS Camshafts are already tailor-milled specifically for individual part profiles before they reach this step, the most that will need to be ground away in the finishing operation is .015 inch. This creates a more uniform part with more case depth. Why is that important? Some cam manufacturers use a standard core for multiple part profiles, which may require as much as .050 in. of material to be removed. This could cause localized hot spots on the cam lobes—spots that may lose temper and eventually fail."

When we do large runs of cams like we do, milling them to near-net before heat treat makes a lot of sense for multiple reasons. Custom grinds don't get dedicated cores, so that is a downside.

omc8

iTrader: (7)

Yes .600 to .61x

truckdoug

iTrader: (25)

if you do offer a high lift version I hope you'll add some budget roller tipped rockers to your line up.

Mike Morris

iTrader: (55)

Both were not used together on my car. When Trunions started to fail I pulled my Cam Motion cam out. It was fine. Comp sucks and never helped anyone when all of this happened. Their Trunions will fail. Period. No matter what the cam is used. I have yanked 8 sets of them from peoples cars in last 3 years and all started to flake.. If Comp is so good why did many Vendors including EPS,TSP dump them? Feel free to go ask them. I can't tell you how many Comp crap stuff failed on Vettes here in Florida just working at Ecklers. More than I can count.

ddnspider

iTrader: (26)

Glad to see you guys refuse to sell a cam with lift than exceeds the max spring lift of the LS6 springs, unlike another vendor on here.

Summitracing

We can't comment on anyone's decision making process, but it seemed the .550 and .600 were good targets...along with our .625 number on the Stage 4 automotive cams. The TFS-2500286 spring kit checks all the right boxes after the LS6 springs sign off. We mentioned on another thread this morning, but it's a Pacaloy dual with 160 at 1.800 seat, 395 @ .600 lift, 405 @ .625 lift. They are 1.050 @ coil-bind, so .661 lift isn't a problem if 1.8 rockers are used.

Swansonic

G Atsma

This is why I have made negative remarks about Comp in the past, and I caught some flak for it. Their trunnion kits are a fiasco, and they don't stand behind them. PLUS the flaking cam lobes... Comp is so big they don't feel they need to admit guilt for shoddy products.

Summitracing

Thank you, we have not done a valve-drop test with these as they are no re-classified as single plane cams due to lobe separation. They are both easy on the valve train. At first glance, looking at the SUM-8702, it's likely to require flycutting. SUM-8704 should be ok, but you would need to verify depending on if you've milled or put bigger valves in etc.

You may want to look at the SUM-8708 Stage 3 and the SUM-8709 Stage 4. Those have wider lobe separation and a little less exhaust split to make them clear more consistently. The "LS3" grinds Stage 3 SUM-8710 and Stage 4 SUM-8711 were also ground to maintain clearance...with the Stage 4 LS3 netting just a bit more than the standard Stage 4.

Swansonic

Texas Blue

iTrader: (7)

I agree with this and the money would fly out of my wallet.

Summitracing

Ok, we see where you're going with this. LS6 springs accommodating the lift of the SUM-8704 and having most of the valve events that you are looking for. It would work will a small converter and more weight, but it sounds like you're covered in that department-so we're going to recommend going a little bigger with the Stage 3 with 231/238 duration 113 lobe separation, 3 degrees advance, and .600/.600.

The Stage 3 SUM-8708 has the same intake opening (read intake clearance) as the SUM-8704 and closes the intake valve four degrees later (46 degrees vs. 42), so we're going to move the powerband up. That will be fine with at 3500 converter and the extra .050 worth of lift helps too. All while keeping you in an affordable spring pack. If you're looking to keep costs low, the SME-k-14300 upgrade valvetrain kit accommodates the lift and has trunnions and other things to get it back together inexpensively and reliably.

If you're really on a budget, the TFS-16918 single beehives work with your retainers...and you could just pick up new keepers (SME-143008) and locks (SME-143009). The CMB-09-0029 cam kit includes front gaskets, seals, ls2 chain, balancer bolt and valve cover gaskets.