Spinmonster cam specs 2009
06-24-2019, 09:08 AM
#81
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We carry Brian's cams and Cam Motion as well. All three of us think in terms of valve events (as do Geoff, John Bewely, and other notables). We plop those events into the Cam Motion or Summit Cam timer (that they licensed us) and Wahlah...out comes a cam's required durations, LSA and advance. We wish those numbers went entirely away so people would focus on the events, but that's never going to happen...so it's best we educate people about the events.
Since the release of the Pro LS line on independence day last year, we've put together some really great videos the explain in great detail what each of these events do. This is our favorite. We have another on how the Cam Timer works.
Finally, once you understand what the events change behaviors and you discover there is no free lunch in camshaft, you want to see a lineup of cams that have very specific increments that clearly define the behaviors from Stage 1 to 4. Pro LS is broken into single plane cams, Automotive, Truck, and Turbo. A good article and video that shows the lineup is here. Finally, we're up to 21 part numbers now and we've got the specs, events and behaviors for you all in one place that I'll post below.
Getting back to Spin's cam, as of 2013 he had a 231 234 114 + 2. Valve events were 3.5 IVO, 47.5 IVC, 53 EVO, and 1 EVC for 4.5 degrees of net overlap. This was a honey of a cam with a factory LS3 intake, typical aftermarket dual exhaust, and could be dropped in with the heads milled .030 to bump torque everywhere. Brian's Stage 3 is a 229/244 113 + 4 and those events change a bit. 5.5 IVO, 43.5 IVC, 59 EVO, and 5 IVC for a total of 10.5 overlap. Brian is trading a bit of idle quality with the earlier intake opening and sacrifices a bit of top end for better low end with his 43.5 EVO. He's a fan of early exhaust blowdown (noisier and trades a little bit of push on the downstroke for less pumping losses on the upstroke. 5 EVC won't be too smelly either going down the road and is the least critical of the 4 events...especially with a closed exhaust system.
Summit's LS3 stage 3 (SUM-8710) is a 230/242 113 + 3 and 10 overlap. Events are 56 EVO, 5 EVC, 5 IVO and 45 IVC. This particular cam allow you to mill the heads about .015 and maintain .061/.081 piston to valve at .045 net piston to head. Our IVC is a little later for more top end and will have the same idle characteristics as the BTR 3..which is to say a tiny bit lopier than Spin's grind.
Since the release of the Pro LS line on independence day last year, we've put together some really great videos the explain in great detail what each of these events do. This is our favorite. We have another on how the Cam Timer works.
Finally, once you understand what the events change behaviors and you discover there is no free lunch in camshaft, you want to see a lineup of cams that have very specific increments that clearly define the behaviors from Stage 1 to 4. Pro LS is broken into single plane cams, Automotive, Truck, and Turbo. A good article and video that shows the lineup is here. Finally, we're up to 21 part numbers now and we've got the specs, events and behaviors for you all in one place that I'll post below.
Getting back to Spin's cam, as of 2013 he had a 231 234 114 + 2. Valve events were 3.5 IVO, 47.5 IVC, 53 EVO, and 1 EVC for 4.5 degrees of net overlap. This was a honey of a cam with a factory LS3 intake, typical aftermarket dual exhaust, and could be dropped in with the heads milled .030 to bump torque everywhere. Brian's Stage 3 is a 229/244 113 + 4 and those events change a bit. 5.5 IVO, 43.5 IVC, 59 EVO, and 5 IVC for a total of 10.5 overlap. Brian is trading a bit of idle quality with the earlier intake opening and sacrifices a bit of top end for better low end with his 43.5 EVO. He's a fan of early exhaust blowdown (noisier and trades a little bit of push on the downstroke for less pumping losses on the upstroke. 5 EVC won't be too smelly either going down the road and is the least critical of the 4 events...especially with a closed exhaust system.
Summit's LS3 stage 3 (SUM-8710) is a 230/242 113 + 3 and 10 overlap. Events are 56 EVO, 5 EVC, 5 IVO and 45 IVC. This particular cam allow you to mill the heads about .015 and maintain .061/.081 piston to valve at .045 net piston to head. Our IVC is a little later for more top end and will have the same idle characteristics as the BTR 3..which is to say a tiny bit lopier than Spin's grind.
06-24-2019, 09:11 AM
#82
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Doesn't surprise me.
Brian is such a good guy to talk to on the phone.
Unfortunately Darth I had no choice but to use 5/16 0.80 pushrods with my LS3 heads because the 3/8 size would not fit due to head fouling. I also have Isky high rpm short travel lifters too so that should help.
The ones my tuner uses are a custom hardened version that he gets from this private company direct. They have some type of special forging or something but they are expensive.
Don't know the details.
I remember when my LS2 got a tune only it pulled really well right to the 6500rpm red line, Torque was very flat with minimal drop off even after 5500rpm and this was with the stock intake.
Maybe you have a valvetrain issue? Fix it and see the engine shine.
Brian is such a good guy to talk to on the phone.
Unfortunately Darth I had no choice but to use 5/16 0.80 pushrods with my LS3 heads because the 3/8 size would not fit due to head fouling. I also have Isky high rpm short travel lifters too so that should help.
The ones my tuner uses are a custom hardened version that he gets from this private company direct. They have some type of special forging or something but they are expensive.
Don't know the details.
I remember when my LS2 got a tune only it pulled really well right to the 6500rpm red line, Torque was very flat with minimal drop off even after 5500rpm and this was with the stock intake.
Maybe you have a valvetrain issue? Fix it and see the engine shine.
06-24-2019, 09:41 AM
#83
TECH Addict
Thread Starter
We carry Brian's cams and Cam Motion as well. All three of us think in terms of valve events (as do Geoff, John Bewely, and other notables). We plop those events into the Cam Motion or Summit Cam timer (that they licensed us) and Wahlah...out comes a cam's required durations, LSA and advance. We wish those numbers went entirely away so people would focus on the events, but that's never going to happen...so it's best we educate people about the events.
Since the release of the Pro LS line on independence day last year, we've put together some really great videos the explain in great detail what each of these events do. This is our favorite. We have another on how the Cam Timer works.
Finally, once you understand what the events change behaviors and you discover there is no free lunch in camshaft, you want to see a lineup of cams that have very specific increments that clearly define the behaviors from Stage 1 to 4. Pro LS is broken into single plane cams, Automotive, Truck, and Turbo. A good article and video that shows the lineup is here. Finally, we're up to 21 part numbers now and we've got the specs, events and behaviors for you all in one place that I'll post below.
Getting back to Spin's cam, as of 2013 he had a 231 234 114 + 2. Valve events were 3.5 IVO, 47.5 IVC, 53 EVO, and 1 EVC for 4.5 degrees of net overlap. This was a honey of a cam with a factory LS3 intake, typical aftermarket dual exhaust, and could be dropped in with the heads milled .030 to bump torque everywhere. Brian's Stage 3 is a 229/244 113 + 4 and those events change a bit. 5.5 IVO, 43.5 IVC, 59 EVO, and 5 IVC for a total of 10.5 overlap. Brian is trading a bit of idle quality with the earlier intake opening and sacrifices a bit of top end for better low end with his 43.5 EVO. He's a fan of early exhaust blowdown (noisier and trades a little bit of push on the downstroke for less pumping losses on the upstroke. 5 EVC won't be too smelly either going down the road and is the least critical of the 4 events...especially with a closed exhaust system.
Summit's LS3 stage 3 (SUM-8710) is a 230/242 113 + 3 and 10 overlap. Events are 56 EVO, 5 EVC, 5 IVO and 45 IVC. This particular cam allow you to mill the heads about .015 and maintain .061/.081 piston to valve at .045 net piston to head. Our IVC is a little later for more top end and will have the same idle characteristics as the BTR 3..which is to say a tiny bit lopier than Spin's grind.
Since the release of the Pro LS line on independence day last year, we've put together some really great videos the explain in great detail what each of these events do. This is our favorite. We have another on how the Cam Timer works.
Finally, once you understand what the events change behaviors and you discover there is no free lunch in camshaft, you want to see a lineup of cams that have very specific increments that clearly define the behaviors from Stage 1 to 4. Pro LS is broken into single plane cams, Automotive, Truck, and Turbo. A good article and video that shows the lineup is here. Finally, we're up to 21 part numbers now and we've got the specs, events and behaviors for you all in one place that I'll post below.
Getting back to Spin's cam, as of 2013 he had a 231 234 114 + 2. Valve events were 3.5 IVO, 47.5 IVC, 53 EVO, and 1 EVC for 4.5 degrees of net overlap. This was a honey of a cam with a factory LS3 intake, typical aftermarket dual exhaust, and could be dropped in with the heads milled .030 to bump torque everywhere. Brian's Stage 3 is a 229/244 113 + 4 and those events change a bit. 5.5 IVO, 43.5 IVC, 59 EVO, and 5 IVC for a total of 10.5 overlap. Brian is trading a bit of idle quality with the earlier intake opening and sacrifices a bit of top end for better low end with his 43.5 EVO. He's a fan of early exhaust blowdown (noisier and trades a little bit of push on the downstroke for less pumping losses on the upstroke. 5 EVC won't be too smelly either going down the road and is the least critical of the 4 events...especially with a closed exhaust system.
Summit's LS3 stage 3 (SUM-8710) is a 230/242 113 + 3 and 10 overlap. Events are 56 EVO, 5 EVC, 5 IVO and 45 IVC. This particular cam allow you to mill the heads about .015 and maintain .061/.081 piston to valve at .045 net piston to head. Our IVC is a little later for more top end and will have the same idle characteristics as the BTR 3..which is to say a tiny bit lopier than Spin's grind.
Because your 230/242 camshaft has a 3 degree later Evo compared to the 229/244 camshaft does this mean they will pull to about the same rpm even though the summit cam has a 1 degree later ivc?
This is an interesting subject for me.
06-24-2019, 10:13 AM
#84
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Also, wanted to point out the LS3 head is really prone to reversion with it's big CSA intake runner and valve size and a closed exhaust. That was Spin's original reason for getting the exhaust valve closed as early as it did. Up into that point, people were putting tons of split on the cam to offset the "poor" intake and exhaust %. The problem is they were adding too much to the exhaust closing point rather than opening because they were hooked on normal sounding LSA and advance numbers at the time.
We do have a couple engine dynos but we don't find crank horsepower translates so well in this day and age and people tend to like third party reporting best. To that end, Richard Holdener did a test on our LS3 Stage 4 cam (SUM-8711) in a 5.3L Truck motor and the article will be coming out soon. It did something that we think a lot of us will find really cool...but I'll keep it a secret until the article hits.
Last edited by Summitracing; 06-24-2019 at 10:24 AM.
06-24-2019, 10:28 AM
#86
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Yes, the 11/32 are interchangeable with the 5/16 and you won't have to grind on the heads. Radially there only .016 in. closer to the runner. 28% less deflection than a normal .080 wall 5/16. We've got them in .025 increments too to help out you guys with short travel lifters.
06-24-2019, 12:40 PM
#87
Interesting thread. This is a throw back thread with modern twists, so on modernity I will add.
Back when, early cam swap days its clear Geoff Skinner ruled the roost with his cams which to my knowledge the fastest cam only sbe 346 LS1 is STILL the Trex which is old as stonehenge nowadays. Clever man and EPS grinds made lots of people happy in the later years, myself included.
The old days were so filled with embellishments, dynos tuned up to be proud and different dynos giving different numbers on the same car. My own car was 28hp different same cam tune etc less than one month apart on two dynos yet my trap speed for years remained the same so theres that. A lot secret sauce cam promises with this that and the other than turned into blah but a few stood out. Guys like TSP, Tooley, Skinner, Kurt etc etc etc all working the data game ride high now and its easier to get better info as the internets shrink and the data get harder to embellish. As for Spin? Who knows what hes up to? Probably hasnt owned an LS car for years as many havent. Life changes and peoples interests change. Its the few of us die hards who like the same things again and again. Hard to believe it but LS engines are now skirting into "old tech" land. Crazy
When i was right into it I had a 6.2L profile I liked. It was 228/240 on soft lobes. I tossed around cam numbers like mad in the midst of it all to see who would bite and what the results would be. Those were fun times while it was all still improving. Now Im onto simpler cams and quiet exhausts and reliable driving vs peak power so Im farrrrrr removed from knowing the ins and outs of the latest cam tech. On that note I will enjoy reading y'alls opinons on such
Back when, early cam swap days its clear Geoff Skinner ruled the roost with his cams which to my knowledge the fastest cam only sbe 346 LS1 is STILL the Trex which is old as stonehenge nowadays. Clever man and EPS grinds made lots of people happy in the later years, myself included.
The old days were so filled with embellishments, dynos tuned up to be proud and different dynos giving different numbers on the same car. My own car was 28hp different same cam tune etc less than one month apart on two dynos yet my trap speed for years remained the same so theres that. A lot secret sauce cam promises with this that and the other than turned into blah but a few stood out. Guys like TSP, Tooley, Skinner, Kurt etc etc etc all working the data game ride high now and its easier to get better info as the internets shrink and the data get harder to embellish. As for Spin? Who knows what hes up to? Probably hasnt owned an LS car for years as many havent. Life changes and peoples interests change. Its the few of us die hards who like the same things again and again. Hard to believe it but LS engines are now skirting into "old tech" land. Crazy
When i was right into it I had a 6.2L profile I liked. It was 228/240 on soft lobes. I tossed around cam numbers like mad in the midst of it all to see who would bite and what the results would be. Those were fun times while it was all still improving. Now Im onto simpler cams and quiet exhausts and reliable driving vs peak power so Im farrrrrr removed from knowing the ins and outs of the latest cam tech. On that note I will enjoy reading y'alls opinons on such
06-24-2019, 12:46 PM
#88
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Yes, the 11/32 are interchangeable with the 5/16 and you won't have to grind on the heads. Radially there only .016 in. closer to the runner. 28% less deflection than a normal .080 wall 5/16. We've got them in .025 increments too to help out you guys with short travel lifters.
Of course with good springs and rockers too
06-24-2019, 12:52 PM
#89
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Thread Starter
Interesting thread. This is a throw back thread with modern twists, so on modernity I will add.
Back when, early cam swap days its clear Geoff Skinner ruled the roost with his cams which to my knowledge the fastest cam only sbe 346 LS1 is STILL the Trex which is old as stonehenge nowadays. Clever man and EPS grinds made lots of people happy in the later years, myself included.
The old days were so filled with embellishments, dynos tuned up to be proud and different dynos giving different numbers on the same car. My own car was 28hp different same cam tune etc less than one month apart on two dynos yet my trap speed for years remained the same so theres that. A lot secret sauce cam promises with this that and the other than turned into blah but a few stood out. Guys like TSP, Tooley, Skinner, Kurt etc etc etc all working the data game ride high now and its easier to get better info as the internets shrink and the data get harder to embellish. As for Spin? Who knows what hes up to? Probably hasnt owned an LS car for years as many havent. Life changes and peoples interests change. Its the few of us die hards who like the same things again and again. Hard to believe it but LS engines are now skirting into "old tech" land. Crazy
When i was right into it I had a 6.2L profile I liked. It was 228/240 on soft lobes. I tossed around cam numbers like mad in the midst of it all to see who would bite and what the results would be. Those were fun times while it was all still improving. Now Im onto simpler cams and quiet exhausts and reliable driving vs peak power so Im farrrrrr removed from knowing the ins and outs of the latest cam tech. On that note I will enjoy reading y'alls opinons on such
Back when, early cam swap days its clear Geoff Skinner ruled the roost with his cams which to my knowledge the fastest cam only sbe 346 LS1 is STILL the Trex which is old as stonehenge nowadays. Clever man and EPS grinds made lots of people happy in the later years, myself included.
The old days were so filled with embellishments, dynos tuned up to be proud and different dynos giving different numbers on the same car. My own car was 28hp different same cam tune etc less than one month apart on two dynos yet my trap speed for years remained the same so theres that. A lot secret sauce cam promises with this that and the other than turned into blah but a few stood out. Guys like TSP, Tooley, Skinner, Kurt etc etc etc all working the data game ride high now and its easier to get better info as the internets shrink and the data get harder to embellish. As for Spin? Who knows what hes up to? Probably hasnt owned an LS car for years as many havent. Life changes and peoples interests change. Its the few of us die hards who like the same things again and again. Hard to believe it but LS engines are now skirting into "old tech" land. Crazy
When i was right into it I had a 6.2L profile I liked. It was 228/240 on soft lobes. I tossed around cam numbers like mad in the midst of it all to see who would bite and what the results would be. Those were fun times while it was all still improving. Now Im onto simpler cams and quiet exhausts and reliable driving vs peak power so Im farrrrrr removed from knowing the ins and outs of the latest cam tech. On that note I will enjoy reading y'alls opinons on such
When I first got on the forums years I was only reading.
I couldn't really contribute anything.
It was all learning.
Those same guys are still at the top but are very similar now and they all agree with smooth lobe designs.
LS are becoming old in that sense but they are still making more power per litre than the current generation Italian exotic engines NA. And they pull faster times too.
The LT platform would make more but it will be some time before these engines are tested thoroughly in the aftermarket world with more parts.
The LS has been around for so long.
We know the limits, what heads work, camshafts etc.
The combinations are just endless.
You can build so many different combo's and the parts are there.
06-24-2019, 01:19 PM
#91
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The ls3 is the best overall engine for reliability.
You get such good gains whether you stroke it or add boost.
It will handle it.
You don't need to change the heads either.
06-24-2019, 03:38 PM
#92
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Yes and well beyond that. The Made in America HDR pushrods are the thickest/strongest "drop-ins" possible with great material and finishing. We added the 210 ball ends in for the high lift guys. They are sold for $144-$149 in LS and Small block and $169 for the BBC pushrod sets. We buy a bunch of these and price them fairly. As others have noted, the extra $50 for the strength is a bargain for what it adds to valvetrain life and stability.
Last edited by Summitracing; 06-25-2019 at 07:15 PM.
06-24-2019, 04:50 PM
#93
TECH Veteran
Brotus, you got to turn your motor higher than 7000 RPM to take advantage of those heads you got.
06-24-2019, 05:48 PM
#94
https://www.yellowbullet.com/forum/s...d.php?t=410450
Brian dropping knowledge bombs. None of what we're discussing is new, nor is it a one size fits all kind of generality. As someone likes to say, it is already seen and known.
This is one of my favorite threads I have bookmarked that I go back and read from time to time. I forgot I had it bookmarked. There are some really interesting things in here and is what got me really looking into valve events and different combinations and trying to think more about dynamically what is happening in the engine.
When you apply valve events as a written rule you're doing nothing different than saying this head needs XYZ split and this LSA and +4 advance. It is the same thing. No different than saying LS6 wants a 44* IVC, LS3 48* and LS7 52* full stop. You can't just go into every thread with an LS3 and say it needs an IVC of 48-50* (or whatever rule of thumb you're proposing). If you did that literally every engine would wind up with the same camshaft and that just isn't a fair assessment of engine tuning. I think this is why a couple people got a little upset in this thread. For 95% of corvette forum an LS3 that trades 500rpm of peak rpm to gain 50ft lb at 3000 rpm and go rumpity rumpity is going to be a hell of a lot more fun to drive and FEEL faster than a 500whp car. A cam only vette with exhaust manifolds, stock gears, stock intake etc would appreciate aggressive lobes, short duration, tight centers, and an early *** IVC point.
It's like Smokey saying that CSA is what matters most and everyone else are idiots, but he's literally just back calculating an average CSA from runner CC's. Unless the tools are being used properly it is the same damn thing.
When you derive valve events based on component selection and performance characteristics of the engine that you're looking for such as peak power rpm, powerband, power past peak, drivability etc is when it really starts working. There's been a lot of blind recommendations recently under the veil of a higher level of understanding because valve events. If you're doing that just order whatever flavor of the month stage 3 camshaft is out there with pretty dyno sheets and slap it in.
I want to take some time to build an excel calculator someday that plots estimated valve lift vs piston position and try to make sense of the timing of the valve events with regards to engine dynamics. I don't know if any of that would be useful...but I assume it would be handy to see valve events relative to valve lift and piston position, because that's really what matters.
My goal will be to plug in some known combos, like my stroked LS2 with LS3 heads and stock intake and exhaust manifolds, LS3 with victor jr, stroked LS3 with the same victor jr...etc, and plug in peak torque and peak power RPM's. I would imagine that some very clear patterns will start to form. The most important parameters I imagine will be .050" duration, advertised duration, lift, LSA and ICL, valve events, intake runner length, exhaust size and type, cylinder head specs, and engine stroke.
I started going down this rabbit hole with the "cam timing vs runner length" thread I started, but the next step is going to take a bit of legwork. Basically valve events are handy, but air takes time to move, and the more RPM you turn the less time you have. I want to try and identify some trends through empirical data to better understand where the valve events will truly impact engine performance, and predict performance when things are tweaked a bit such as runner length or cam timing.
Just buying a software dyno program is probably a better use of time, but it might be a fun exercise. If something like this exists already, even minimally, I'd be interested to know about it.
Brian dropping knowledge bombs. None of what we're discussing is new, nor is it a one size fits all kind of generality. As someone likes to say, it is already seen and known.
This is one of my favorite threads I have bookmarked that I go back and read from time to time. I forgot I had it bookmarked. There are some really interesting things in here and is what got me really looking into valve events and different combinations and trying to think more about dynamically what is happening in the engine.
When you apply valve events as a written rule you're doing nothing different than saying this head needs XYZ split and this LSA and +4 advance. It is the same thing. No different than saying LS6 wants a 44* IVC, LS3 48* and LS7 52* full stop. You can't just go into every thread with an LS3 and say it needs an IVC of 48-50* (or whatever rule of thumb you're proposing). If you did that literally every engine would wind up with the same camshaft and that just isn't a fair assessment of engine tuning. I think this is why a couple people got a little upset in this thread. For 95% of corvette forum an LS3 that trades 500rpm of peak rpm to gain 50ft lb at 3000 rpm and go rumpity rumpity is going to be a hell of a lot more fun to drive and FEEL faster than a 500whp car. A cam only vette with exhaust manifolds, stock gears, stock intake etc would appreciate aggressive lobes, short duration, tight centers, and an early *** IVC point.
It's like Smokey saying that CSA is what matters most and everyone else are idiots, but he's literally just back calculating an average CSA from runner CC's. Unless the tools are being used properly it is the same damn thing.
When you derive valve events based on component selection and performance characteristics of the engine that you're looking for such as peak power rpm, powerband, power past peak, drivability etc is when it really starts working. There's been a lot of blind recommendations recently under the veil of a higher level of understanding because valve events. If you're doing that just order whatever flavor of the month stage 3 camshaft is out there with pretty dyno sheets and slap it in.
I want to take some time to build an excel calculator someday that plots estimated valve lift vs piston position and try to make sense of the timing of the valve events with regards to engine dynamics. I don't know if any of that would be useful...but I assume it would be handy to see valve events relative to valve lift and piston position, because that's really what matters.
My goal will be to plug in some known combos, like my stroked LS2 with LS3 heads and stock intake and exhaust manifolds, LS3 with victor jr, stroked LS3 with the same victor jr...etc, and plug in peak torque and peak power RPM's. I would imagine that some very clear patterns will start to form. The most important parameters I imagine will be .050" duration, advertised duration, lift, LSA and ICL, valve events, intake runner length, exhaust size and type, cylinder head specs, and engine stroke.
I started going down this rabbit hole with the "cam timing vs runner length" thread I started, but the next step is going to take a bit of legwork. Basically valve events are handy, but air takes time to move, and the more RPM you turn the less time you have. I want to try and identify some trends through empirical data to better understand where the valve events will truly impact engine performance, and predict performance when things are tweaked a bit such as runner length or cam timing.
Just buying a software dyno program is probably a better use of time, but it might be a fun exercise. If something like this exists already, even minimally, I'd be interested to know about it.
06-24-2019, 06:17 PM
#95
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06-24-2019, 06:37 PM
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Originally Posted by spanks13
https://www.yellowbullet.com/forum/s...d.php?t=410450
Brian dropping knowledge bombs. None of what we're discussing is new, nor is it a one size fits all kind of generality. As someone likes to say, it is already seen and known.
This is one of my favorite threads I have bookmarked that I go back and read from time to time. I forgot I had it bookmarked. There are some really interesting things in here and is what got me really looking into valve events and different combinations and trying to think more about dynamically what is happening in the engine.
When you apply valve events as a written rule you're doing nothing different than saying this head needs XYZ split and this LSA and +4 advance. It is the same thing. No different than saying LS6 wants a 44* IVC, LS3 48* and LS7 52* full stop. You can't just go into every thread with an LS3 and say it needs an IVC of 48-50* (or whatever rule of thumb you're proposing). If you did that literally every engine would wind up with the same camshaft and that just isn't a fair assessment of engine tuning. I think this is why a couple people got a little upset in this thread. For 95% of corvette forum an LS3 that trades 500rpm of peak rpm to gain 50ft lb at 3000 rpm and go rumpity rumpity is going to be a hell of a lot more fun to drive and FEEL faster than a 500whp car. A cam only vette with exhaust manifolds, stock gears, stock intake etc would appreciate aggressive lobes, short duration, tight centers, and an early *** IVC point.
It's like Smokey saying that CSA is what matters most and everyone else are idiots, but he's literally just back calculating an average CSA from runner CC's. Unless the tools are being used properly it is the same damn thing.
When you derive valve events based on component selection and performance characteristics of the engine that you're looking for such as peak power rpm, powerband, power past peak, drivability etc is when it really starts working. There's been a lot of blind recommendations recently under the veil of a higher level of understanding because valve events. If you're doing that just order whatever flavor of the month stage 3 camshaft is out there with pretty dyno sheets and slap it in.
I want to take some time to build an excel calculator someday that plots estimated valve lift vs piston position and try to make sense of the timing of the valve events with regards to engine dynamics. I don't know if any of that would be useful...but I assume it would be handy to see valve events relative to valve lift and piston position, because that's really what matters.
My goal will be to plug in some known combos, like my stroked LS2 with LS3 heads and stock intake and exhaust manifolds, LS3 with victor jr, stroked LS3 with the same victor jr...etc, and plug in peak torque and peak power RPM's. I would imagine that some very clear patterns will start to form. The most important parameters I imagine will be .050" duration, advertised duration, lift, LSA and ICL, valve events, intake runner length, exhaust size and type, cylinder head specs, and engine stroke.
I started going down this rabbit hole with the "cam timing vs runner length" thread I started, but the next step is going to take a bit of legwork. Basically valve events are handy, but air takes time to move, and the more RPM you turn the less time you have. I want to try and identify some trends through empirical data to better understand where the valve events will truly impact engine performance, and predict performance when things are tweaked a bit such as runner length or cam timing.
Just buying a software dyno program is probably a better use of time, but it might be a fun exercise. If something like this exists already, even minimally, I'd be interested to know about it.
Brian dropping knowledge bombs. None of what we're discussing is new, nor is it a one size fits all kind of generality. As someone likes to say, it is already seen and known.
This is one of my favorite threads I have bookmarked that I go back and read from time to time. I forgot I had it bookmarked. There are some really interesting things in here and is what got me really looking into valve events and different combinations and trying to think more about dynamically what is happening in the engine.
When you apply valve events as a written rule you're doing nothing different than saying this head needs XYZ split and this LSA and +4 advance. It is the same thing. No different than saying LS6 wants a 44* IVC, LS3 48* and LS7 52* full stop. You can't just go into every thread with an LS3 and say it needs an IVC of 48-50* (or whatever rule of thumb you're proposing). If you did that literally every engine would wind up with the same camshaft and that just isn't a fair assessment of engine tuning. I think this is why a couple people got a little upset in this thread. For 95% of corvette forum an LS3 that trades 500rpm of peak rpm to gain 50ft lb at 3000 rpm and go rumpity rumpity is going to be a hell of a lot more fun to drive and FEEL faster than a 500whp car. A cam only vette with exhaust manifolds, stock gears, stock intake etc would appreciate aggressive lobes, short duration, tight centers, and an early *** IVC point.
It's like Smokey saying that CSA is what matters most and everyone else are idiots, but he's literally just back calculating an average CSA from runner CC's. Unless the tools are being used properly it is the same damn thing.
When you derive valve events based on component selection and performance characteristics of the engine that you're looking for such as peak power rpm, powerband, power past peak, drivability etc is when it really starts working. There's been a lot of blind recommendations recently under the veil of a higher level of understanding because valve events. If you're doing that just order whatever flavor of the month stage 3 camshaft is out there with pretty dyno sheets and slap it in.
I want to take some time to build an excel calculator someday that plots estimated valve lift vs piston position and try to make sense of the timing of the valve events with regards to engine dynamics. I don't know if any of that would be useful...but I assume it would be handy to see valve events relative to valve lift and piston position, because that's really what matters.
My goal will be to plug in some known combos, like my stroked LS2 with LS3 heads and stock intake and exhaust manifolds, LS3 with victor jr, stroked LS3 with the same victor jr...etc, and plug in peak torque and peak power RPM's. I would imagine that some very clear patterns will start to form. The most important parameters I imagine will be .050" duration, advertised duration, lift, LSA and ICL, valve events, intake runner length, exhaust size and type, cylinder head specs, and engine stroke.
I started going down this rabbit hole with the "cam timing vs runner length" thread I started, but the next step is going to take a bit of legwork. Basically valve events are handy, but air takes time to move, and the more RPM you turn the less time you have. I want to try and identify some trends through empirical data to better understand where the valve events will truly impact engine performance, and predict performance when things are tweaked a bit such as runner length or cam timing.
Just buying a software dyno program is probably a better use of time, but it might be a fun exercise. If something like this exists already, even minimally, I'd be interested to know about it.
06-24-2019, 06:57 PM
#97
TECH Veteran
Can't wait till the LS Fest to kick it with Brian. Its cool to talk to him on the phone about cams, intakes, heads, etc but its another thing to talk that stuff in person.
If he likes your personality he always go deep in details in a conversation in person but make it where a average guy like me can understand the phsics of making power.
If he likes your personality he always go deep in details in a conversation in person but make it where a average guy like me can understand the phsics of making power.
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Che70velle (06-24-2019)
06-25-2019, 06:52 AM
#99
I heard there was but the most famous of all was the original spec.
The BTR stage 3 has 10.5 degrees of overlap, not 15.
The transmission probably took a dump because it could not handle the power of the BTR cam. Haha.
We use them all the time down here in Australia.
They make really good power and make great low end too in an LS3.
Stage 3 being the most popular.
We used to all use narrow splits down here in the beginning but for the last few years most have switched to the wider splits for these heads.
They work better while keeping the low end in tact.
You will notice cams with narrow splits always fall off in the top end in ls3 engines. Why would you want the camshaft to drop off earlier than the stock cam??
Doesn't make sense to me. You need to get a camshaft that at least matches the stock camshaft's 6500rpm red line.
I see it all the time where they make more power but drop off power 3 or 400rpm earlier than stock.
The BTR stage 3 has 10.5 degrees of overlap, not 15.
The transmission probably took a dump because it could not handle the power of the BTR cam. Haha.
We use them all the time down here in Australia.
They make really good power and make great low end too in an LS3.
Stage 3 being the most popular.
We used to all use narrow splits down here in the beginning but for the last few years most have switched to the wider splits for these heads.
They work better while keeping the low end in tact.
You will notice cams with narrow splits always fall off in the top end in ls3 engines. Why would you want the camshaft to drop off earlier than the stock cam??
Doesn't make sense to me. You need to get a camshaft that at least matches the stock camshaft's 6500rpm red line.
I see it all the time where they make more power but drop off power 3 or 400rpm earlier than stock.
Brian Tooley said it best IMO "The first thing to understand is: There are no magic camshafts, everything is just a trade off, and those trade offs are far smaller than you would think"
The spinmonster cam doesnt fall off till 6500 typically (peak of 6.4K). The stock LS3 cam definitely starts falling off at 6100 (peak of 6k). Redline is not peak power, redline/shift point should be whatever puts you back into peak power. And FWIW I havent met a stock head that didnt accept 11/32 pushrods.
06-25-2019, 07:18 AM
#100
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The spinmonster cam doesnt fall off till 6500 typically (peak of 6.4K). The stock LS3 cam definitely starts falling off at 6100 (peak of 6k). Redline is not peak power, redline/shift point should be whatever puts you back into peak power. And FWIW I havent met a stock head that didnt accept 11/32 pushrods.
Example. If you are making 350 lbs of torque at 6300 rpm but that's where you make peak power, and you land on 4200 rpm with 410 lbs of torque you drop 800 lbs of torque on the 1-2 upshift, assuming 4.11 rear gear and t56 ratios. Now, say you get to 6900 and torque has now fallen to 275. Do the same math, you land on 4600 in second still at 410 lbs, and you have lost zero on the upshift.
Or the shortcut version -- power past peak