Several LS experts found it extremely difficult to improve on the stock LS7 low shock technology. People who do stock rebuilds on LS engines often buy OEM LS7 lifters to maximize durability at a good price. What you said about SAE 9310 is interesting. People who build new AR-15s sometimes use SAE 9310 at the bolt as an alternative to the C158 originally used in the first one. It has been said that with the right heat treatment, they make it 10% stronger than C158. You stated that nickel is bad for the wear characteristics of these alloys? Why are some of the high nickel blocks considered to be the best? What does it take to weld these alloys? Sometimes an engine failure might happen after a race, and the only timely solution is a weld up and regrind before the next race. 17:21 Is it wise to use the Mitutoyo measuring tool that is frequently used in cylinder honing? 56:38 I found it interesting that the Hyundai Genesis Coupe had a 2.0L turbo engine, port fuel injection, 9:1 compression, and permitted 87 octane gasoline. Higher octane did allow more power, but the manual permitted 87 octane. I think the later Genesis Coupe 2.0T was rated at 260 HP on 87 octane, and 280 on premium. GDI turbos sometimes have even higher compression that port injection turbo engines, but that complicates the subject. The first turbo car that fascinated me was the Nissan 300ZXTT. Those had 8.5:1 compression, and premium unleaded was a must.
Do you have low shock technology for a SBC Chevy hydraulic roller? Is it necessary? And with conical valve springs? Just wanting to make my valvetrain reliable.
Awesome content!!! I would have loved to hear him talk about tightening valve lash and how it effects lifter life.....aaaand what all options he has available as far as lash ramps on his "Low Shock" series of lobes or are they all based on a single lash ramp IE: .018" or .020"....
@ 54:00:00 The real world is indeed very different then the dyno....Unless you have a so called vector dyno , used in F1 , which can simulate the vibrations in the crankshaft and valve train when driving over the curb stones. Even that influences valve train stability. Or this type of dyno can replicate the accelerations on the track which are much higher then the 500 or 750 rpm/sec on a normal dyno.
Pratt an Miller corvette had access to one and used it to find a valve drop issues that they ran into only at the track. Turns out their downshift spark cut strategy was overly violent and the explosion happening in the exhaust was shocking the locks off the exhaust valves.
Actually the pushrod load is highest at maximum lift, and your measuring equipment is probably cancelling out on the SpinTron? however contradicting that therory is> the acceleration rate is probably highest, @ between 30 to 50% lift. My guess is because that is most probably how you designed the lobe to work? Also, I don't agree with your preferred choice of pushrod to to rocker geometry angle, @between 30 and 50% lift, because I've been there done that. Having said that, I have to thank Compcams for all of my Compcams camshafts components. Thankyou.
At the exhaust its at opening.....the residual pressure in the cylinder can be up to 220 psi in atmospheric engine...resulting in huge forces. Residual pressure in tractor pull supwrcharged diesel or top fuel exceed 50 bars which is 700 psi or so that equals about 2200 lbs to open the exh valve ....and with rocker ratio of 1.7 about 3500 lbs on pushrod when opening exhaust valve.....
Several LS experts found it extremely difficult to improve on the stock LS7 low shock technology. People who do stock rebuilds on LS engines often buy OEM LS7 lifters to maximize durability at a good price.
What you said about SAE 9310 is interesting. People who build new AR-15s sometimes use SAE 9310 at the bolt as an alternative to the C158 originally used in the first one. It has been said that with the right heat treatment, they make it 10% stronger than C158.
You stated that nickel is bad for the wear characteristics of these alloys? Why are some of the high nickel blocks considered to be the best?
What does it take to weld these alloys? Sometimes an engine failure might happen after a race, and the only timely solution is a weld up and regrind before the next race.
17:21 Is it wise to use the Mitutoyo measuring tool that is frequently used in cylinder honing?
56:38 I found it interesting that the Hyundai Genesis Coupe had a 2.0L turbo engine, port fuel injection, 9:1 compression, and permitted 87 octane gasoline. Higher octane did allow more power, but the manual permitted 87 octane. I think the later Genesis Coupe 2.0T was rated at 260 HP on 87 octane, and 280 on premium. GDI turbos sometimes have even higher compression that port injection turbo engines, but that complicates the subject. The first turbo car that fascinated me was the Nissan 300ZXTT. Those had 8.5:1 compression, and premium unleaded was a must.
I've had really good profiles and serve from Comp Cams thank you
I've always shot for the largest cam base circle when it could fit. The loft was reduced tremendously. Also use a wider duration compared to lift.
This is some very good information. Thanks for posting!
We are glad you liked it. Billy did a great job, so we wanted to make sure people could access this.
Just got stage 2 lst cam kit with johnson lifters. Haven't started it yet but I'm excited after hearing this
I put the ls3 low shock stage 2 cam kit and this cam kit is amazing sound good and runs great wow
What u put down and hows the tq I got the stage 1 I haven't installed yet
515 on e85 15 camaro 1le
@@brodricksmith2156 ahh nice that's what I got a 15 1le 👌
Do you have low shock technology for a SBC Chevy hydraulic roller? Is it necessary? And with conical valve springs? Just wanting to make my valvetrain reliable.
Solid logic- Much appreciated.
Great information.
Awesome content!!!
I would have loved to hear him talk about tightening valve lash and how it effects lifter life.....aaaand what all options he has available as far as lash ramps on his "Low Shock" series of lobes or are they all based on a single lash ramp IE: .018" or .020"....
For more from Billy, check out his presentation from engineperformanceexpo.com
@ 54:00:00 The real world is indeed very different then the dyno....Unless you have a so called vector dyno , used in F1 , which can simulate the vibrations in the crankshaft and valve train when driving over the curb stones. Even that influences valve train stability. Or this type of dyno can replicate the accelerations on the track which are much higher then the 500 or 750 rpm/sec on a normal dyno.
Pratt an Miller corvette had access to one and used it to find a valve drop issues that they ran into only at the track. Turns out their downshift spark cut strategy was overly violent and the explosion happening in the exhaust was shocking the locks off the exhaust valves.
I'd like to see the idle vac on the Jeff Smith LST comparison.
Actually the pushrod load is highest at maximum lift, and your measuring equipment is probably cancelling out on the SpinTron? however contradicting that therory is> the acceleration rate is probably highest, @ between 30 to 50% lift.
My guess is because that is most probably how you designed the lobe to work?
Also, I don't agree with your preferred choice of pushrod to to rocker geometry angle, @between 30 and 50% lift, because I've been there done that. Having said that, I have to thank Compcams for all of my Compcams camshafts components.
Thankyou.
At the exhaust its at opening.....the residual pressure in the cylinder can be up to 220 psi in atmospheric engine...resulting in huge forces.
Residual pressure in tractor pull supwrcharged diesel or top fuel exceed 50 bars which is 700 psi or so that equals about 2200 lbs to open the exh valve ....and with rocker ratio of 1.7 about 3500 lbs on pushrod when opening exhaust valve.....
1:07:40