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Send it, 43* IVC is key. Going to make good midrange power with that narrow lsa which you want coming off corners, no need to spin it to 7k and can shift it at 6600 like stock.
I'd be concerned with a few things though. First being idle quality and off-idle usability. I forgot but I think you got a manual, so it matters. If you had a, for instance 2800 stall then no, it wouldn't matter..
Second would be valvespring life. I realize that it has endurance lobes, but the lift is more than average, and after all it's designed for power, especially under the curve. But 90% RR is quite some, how many of those equate to how many endurance races ?
Last is emissions. I don't believe you will pass with 10 degrees of overlap, even on a 6.2. You're looking at failing the sniffer test, but of course, does this even matter, depends on the application..
No emissions here so no worries there. Streetability not a huge concern. It really gets minimal street time.
Cam came in today. I'll post some parts pics when I get home.
I'd be concerned with a few things though. First being idle quality and off-idle usability. I forgot but I think you got a manual, so it matters. If you had a, for instance 2800 stall then no, it wouldn't matter..
Second would be valvespring life. I realize that it has endurance lobes, but the lift is more than average, and after all it's designed for power, especially under the curve. But 90% RR is quite some, how many of those equate to how many endurance races ?
Last is emissions. I don't believe you will pass with 10 degrees of overlap, even on a 6.2. You're looking at failing the sniffer test, but of course, does this even matter, depends on the application..
Peak lift isn’t as important as the ramp rates of the lobes acceleration opening/closing and jerk as to how much wear and tear the valve spring and seat will see. Curious how many cams you have speced and how it compares to the number Pat G has?
I have 232/234 @ 112 +4 and I like it, but I've been wondering if a slightly earlier intake closing would have been better. It would mean slightly less peak power, but it would also move the powerband down a little bit, which would be nice for a couple of corners on my home track. And that's basically what you'd get with the specs Pat G provided if installed at +4 rather than the +2 he called for.
So my advice would be to get that cam plus an adjustable timing set. Start with his suggested advance, but check piston-to-valve clearance with 4 degrees more advance. Then run it in the default position, and if you want to trade off some top end for more bottom end, advance it 2 or 4 degrees. I'd like to try advancing mine, but I have no idea how much PTV clearance I have left. (So I raised my rev limiter to 7000 instead. What could possibly go wrong?)
44* a big reason that range is popular is because that’s where the OE plastic intake likes to peak, of course other things can affect that though the intake runner length is a big factor.
I have 232/234 @ 112 +4 and I like it, but I've been wondering if a slightly earlier intake closing would have been better. It would mean slightly less peak power, but it would also move the powerband down a little bit, which would be nice for a couple of corners on my home track. And that's basically what you'd get with the specs Pat G provided if installed at +4 rather than the +2 he called for.
So my advice would be to get that cam plus an adjustable timing set. Start with his suggested advance, but check piston-to-valve clearance with 4 degrees more advance. Then run it in the default position, and if you want to trade off some top end for more bottom end, advance it 2 or 4 degrees. I'd like to try advancing mine, but I have no idea how much PTV clearance I have left. (So I raised my rev limiter to 7000 instead. What could possibly go wrong?)
EVO is the second most important valve event and advancing opens the exhaust earlier bleeding off power potentially depending on the rpm range, but the rule of thumb is 100 rpm change in peak for every degree change in IVC all else being equal.
Peak lift isn’t as important as the ramp rates of the lobes acceleration opening/closing and jerk as to how much wear and tear the valve spring and seat will see. Curious how many cams you have speced and how it compares to the number Pat G has?
Originally Posted by NSFW
I have 232/234 @ 112 +4 and I like it, but I've been wondering if a slightly earlier intake closing would have been better. It would mean slightly less peak power, but it would also move the powerband down a little bit, which would be nice for a couple of corners on my home track. And that's basically what you'd get with the specs Pat G provided if installed at +4 rather than the +2 he called for.
So my advice would be to get that cam plus an adjustable timing set. Start with his suggested advance, but check piston-to-valve clearance with 4 degrees more advance. Then run it in the default position, and if you want to trade off some top end for more bottom end, advance it 2 or 4 degrees. I'd like to try advancing mine, but I have no idea how much PTV clearance I have left. (So I raised my rev limiter to 7000 instead. What could possibly go wrong?)
Agreed with both. The cam isn't that big for a LS3 should run great.
I nerd out to an extent as well. Vettenuts has great topics in C5tech and LS1tech.com on measuring pushrods. Katech has a video as well. I very much recommend measuring them and running the largest diameter the head will clear. 243s is 11/32" I don't know about LS3s. Stability is reliability. I am on a LS6, Johnson 2110s, WCCH Edelbrock 215 cathedrals, CamMotion 232/236 112+2 .612/.612, and 3/8" oil restricted Manton pushrods. The system doesn't have many miles on it, it makes great power and runs great thus far.
Well this is embarrassing, I missed that this is an LS3. What I proposed about more advance might not actually be all that helpful, as the extra displacement vs my LS6 will shift the powerband down a little for the same IVC. I don't know how to quantify that (like how many degrees change per 100 RPM change) but Pat G probably does.
Well this is embarrassing, I missed that this is an LS3. What I proposed about more advance might not actually be all that helpful, as the extra displacement vs my LS6 will shift the powerband down a little for the same IVC. I don't know how to quantify that (like how many degrees change per 100 RPM change) but Pat G probably does.
The rule of thumb for cubic inches is 50ci per 8* intake duration which is 4* change in IVC, so ~ half that given the displacement difference between LS6 to LS3.
Pat G speced out a cam for me years ago. It was for a stroked LS2 (402) with L92 heads (pre LS3). He has been doing this for a long time, so I think he has a good handle on what works.
If you need to borrow any tools and happen to be passing my way or headed to the track let me know. I think you're on the right path here. I've got the angry xe-r lobe with less lift I think a less aggressive lobe with a touch more lift will get you a lot of the same without the valvetrain issues I have.
Used this Powerhouse LS Trunnion Tool. Made breaking down the stock rockers super easy. Beautiful CHE Precision Trunnion Kit A touch of OCD for the installation Rocker assemblies all ready to go My first time doing a cam swap/valve spring swap. A little nervous but have been doing tons of reading and watching YouTube. I used the compressed air method and it worked out fine. I had 2 instances where the valves started going down when I was compressing the springs. Just had to back off the spring compressor and tap the retainers with a rubber mallet. Finagling the locks was kind of a pain but I got into a groove on how to do it. All done with the installation of the TSP .660" POLISHED Dual Spring Kit w/ PAC Valve Springs, Titanium Retainers, & PRC Integrated Seat/Seal
If you want to talk OCD, I measured the end play on each rocker (also used CHE's) and shimmed accordingly. I don't remember what I was setting them to.
Stock cam ready to come out My (our) first cam swap Custom PatG spec'd cam Going in with plenty of Amsoil assembly lube. Note: I should have drained the oil. I thought I could get away with lowering the pan with the car full of oil (t was still fresh!). I made a mess when the stock oil pump came out and it started to drip everywhere. New cam in with ARP cam sprocket bolts and red Loctite 262 Notice the little Katech logo for the C5-R Timing Chain Timing chain dampener (same as LS7 since I have the dry sump LS3) Blue Katech oil pump in Valvetrain eye candy More eye candy Top end almost complete ATI Super Damper - biggest headache of whole job. I tried ATI's installation instructions of torquing to 230 lb ft and you're good to go. I didn't notice the damper wasn't seated all the way until I started to put the PS rack back in place. Also, I had to lower the rear of the car onto ramps to keep the engine from turning over. Ended up putting the stock bolt in and torquing to 240 lb ft to get balancer to seat then reinstalling ARP bolt at 235 lb ft. That was a workout. Reassembly complete! Katech belt tensioner Just needs oil and coolant flush First fill with this funnel and I think I like it. It locks in like the oil cap
Recheck and top off oil and coolant flush later today and tuning appointment this afternoon!
04-26-2020, 11:36 PM
