When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've recently been looking for a camshaft to suit my ls6 build.
have fairly much settled on these specifications as the valve timing is spot on for my dynamic compression ratio to be around 8.62 to 1.
227/235@50
277/289 advertised duration. 006
110.5 LSA Plus 1.5
The cam manufacturer said yes they can do it and also gave me @.200 lift duration.
Ive never used the @200 figers so hopefully someone might be able to give me some details as to why it's important for the to even mention it.
Those are very close to rhe specs of a GMPP ASA camshaft, with more lift (ASA is only .525 lift I/E). Depending on your tolerance for poor driveability, and the intended use of the car, that might be a bit too much overlap. An ASA cam was way rowdier than I liked in my LS3. It would be worse in an LS6.
.200 lift numbers are interesting, but not really useful unless you’re comparing to other lobes.
With stock compression of 10.5, I'm getting 8.19:1 dynamic?
Agree with Grubinski, depending on the rest of your setup, you may not like the driveability. Hope you have at least some 3.73s, a 3k-ish stall (if auto), and LT headers.
looks similar to the tsp cleetus mcfarland cam 227/234 .600/.600 111lsa 109icl , ive done two for diffrent buddys ( im not a tuner, just like helping out) and one was in a lq4 truck other a ls1 formula both ran great after a good tune. the truck was a stick and the car got a yank ss 3600 converter very good street set up and sounded like a bigger cam than it actually is, if thats important to you.......
Tells you how fast the lobe accelerates from off the seat to 200. I think Harvey crane was the one who coined the term major intensity, you can use those figures to get an idea of how aggressive a lobe design is and compare it to other designs.
There is a really good podcast you can listen to, to understand a lot of this from billy godbold on the power and speed podcast. You should look it up.
Tells you how fast the lobe accelerates from off the seat to 200. I think Harvey crane was the one who coined the term major intensity, you can use those figures to get an idea of how aggressive a lobe design is and compare it to other designs.
There is a really good podcast you can listen to, to understand a lot of this from billy godbold on the power and speed podcast. You should look it up.
Harvey's definition of major intensity was defined based on subtracting the difference between 0.050" and0.020". Not 0.200" lift. https://4secondsflat.com/Cam_Design.html
However 0.200" it is another data point to to compare cams. Gives you an idea of potential area under the curve as the valve gets in the higher lift region and how it's accelerating over the nose.
Looks like a typo to me. Esp given that they are in the order of "hydraulic", "minor", and "major"; and the other 2 are the comparison between a lobe's .006" to .050", and .050" to .100". Makes no sense whatsoever to add a so-called "major" spec that's in between "hydraulic" (how far the lobe rotates between basically taking up the lash and the beginning of useful flow) and "minor" (how far the lobe travels from the beginning of useful flow to its rapid ramping-up).
I seem to recall Harold Brookshire (rip) using the same metric.
All of the various "intensity" ideas are merely a way to examine how fast the lifters are accelerated.
Look at a typical stock cam; the lobe looks like an egg, with a kinda sharp point for the lobe tip. It spends very little of the total open duration with the valve anywhere near wide open. Look at a typical racing solid roller lobe by comparison: it looks almost "square", with very steep sides and the valve at or near max lift for a MUCH greater portion of the cycle. THAT'S what "intensity" is all about.
Several cam mfrs include the .200" duration spec in their catalogs for exactly this reason. Bullet for example, speaking of Harold.
With stock compression of 10.5, I'm getting 8.19:1 dynamic?
Agree with Grubinski, depending on the rest of your setup, you may not like the driveability. Hope you have at least some 3.73s, a 3k-ish stall (if auto), and LT headers.
the compression ratio I'm running is 11.45 cold start up and 11.15 to 1 when at running temp due to aluminium block expansion. Worked out with .010 expansion of block height.
Those are very close to rhe specs of a GMPP ASA camshaft, with more lift (ASA is only .525 lift I/E). Depending on your tolerance for poor driveability, and the intended use of the car, that might be a bit too much overlap. An ASA cam was way rowdier than I liked in my LS3. It would be worse in an LS6.
.200 lift numbers are interesting, but not really useful unless you’re comparing to other lobes.
just looked up the asa cam and there is also a high lift version of it that is slightly lower in lift but as close as close can be one would say.
The rpm rage for the asa cam is 2000rpm to 7400rpm.
So this tells me I worked out all my maths correctly and it will be a bloody great cam selection for my engine with the 6.3'' connecting rods and 11.15 to 1 static comp when warmed up and the block expansion has played its part in the equation.
with this cam ported head upgraded inlet and custom 4 into 1 headers and full 3''custom dual exhaust system.
It should push the crank hp close to my target 600hp to achieve my target of 400plus adwhp on pump gas.
Hell yeah.
just looked up the asa cam and there is also a high lift version of it that is slightly lower in lift but as close as close can be one would say.
The rpm rage for the asa cam is 2000rpm to 7400rpm.
So this tells me I worked out all my maths correctly and it will be a bloody great cam selection for my engine with the 6.3'' connecting rods and 11.15 to 1 static comp when warmed up and the block expansion has played its part in the equation.
with this cam ported head upgraded inlet and custom 4 into 1 headers and full 3''custom dual exhaust system.
It should push the crank hp close to my target 600hp to achieve my target of 400plus adwhp on pump gas.
Hell yeah.
I hope you get there, but getting 600chp from a N/A 350 LS1/LS6 will probably require more cam than that, and probably more compression. 600hp is a Hell of a number to chase.....
I hope you get there, but getting 600chp from a N/A 350 LS1/LS6 will probably require more cam than that, and probably more compression. 600hp is a Hell of a number to chase.....
I know it's a very tall order to achieve that hp from a ls1/6.
Things that are getting overlooked with the build is the longer rods.
With longer rods you can use a smaller cam duration as the piston hangs at TDC longer than a shorter rod.
The longer rod also has other advantages too.
The ring pack is higher up the piston helping burn all the gasses and the piston dwel time being slightly longer allowing more burn time for combustion process to happen. Gives a bigger bang for buck so to speak.
Also because the piston pulls away slower from TDC it allows the valve to open more before the piston hits peak speed and sucks harder on the then open valve at a higher lift.
Also it allows for slightly more time on overlap to create better exhaust scavenging between intake and exhaust overlap cleaning the cylinder of any unwanted Burt gasses that don't help make power.
So I'm effectively using a bigger cam by using a longer rod than the normal build sheet of a ls1/6 .
I have the option to bump the compression up higher yet when I do my heads.
If I drop from a 68cc chamber to a 65cc chamber with .010 out the hole cold ill have 11.83 to 1 static cold and close to 11.5 when warmed up.
This will push the dynamic compression upto 8.89 when warm and over 9.1 to 1 when cold.
Tell us more about the "ported head upgrade" Longer rods are neat but I think you're still going to need a lot more compression, cam duration, and RPMs even if the heads flow really well
Tell us more about the "ported head upgrade" Longer rods are neat but I think you're still going to need a lot more compression, cam duration, and RPMs even if the heads flow really well
because the rods are longer and the piston sits at TDC slightly longer the valve open further meaning higher flow is achieved earlier in the intake cycle.
So instead of the valve being open .050 it will be say .075 open.
08The heads are going to be Ported for as small as possible cc size and 300cfm flow. That is enough to support over 600hp at the crank.
I understand how longer rods work but it's not that significant of a difference, There have been a lot of tests on this in the past on other platforms. It's really not That significant like you're saying, stock LS has a pretty good rod ratio factory and everybody's favorite little 4.8l is even better still but that's not a replacement for displacement. For what you want to spend on all of this moonbeam stuff, you could just build a much bigger motor and actually hit your target. Nobody here is worried about compression changes due to block expansion after the engine is warmed up. I don't understand that at all. We just make sure everything measures out right. It's clean and it turns freely and we bolt it together.
Even with the longer rods piston dwell is going to help achieve the VE to each 600hp. Assuming a high velocity head flow with minimized CSA, and if the total CFM was calculated at valve lift with the appropriate bore size, I think the intake/exhaust durations are going to fall short. The intake manifold efficiency relative to head flow would have to be extremely high and plenum volume, runner length, and cross section perfectly tuned for that specific rpm range. Then of course, you have the exhaust efficiency and wave tuning to consider. With a heavily ported intake and large headers with efficient full flow through exhaust, I'd estimate at least another 10* duration added to both sides. And probably expect the engine will be run past 7k to reach it.
As for calculating the DCR with/without block expansion, I'm not really seeing the value here. One's not going to start a 600hp car that's sitting for hours, and immediately go full WOT. You'd let it get up to operating temperature first. In any case, any potential concerns about donation due to a difference in DCR would be offset by not being up to operating temperature. The only case where it might be relevant is if one was trying to run ultra-tight quench.
Even with the longer rods piston dwell is going to help achieve the VE to each 600hp. Assuming a high velocity head flow with minimized CSA, and if the total CFM was calculated at valve lift with the appropriate bore size, I think the intake/exhaust durations are going to fall short. The intake manifold efficiency relative to head flow would have to be extremely high and plenum volume, runner length, and cross section perfectly tuned for that specific rpm range. Then of course, you have the exhaust efficiency and wave tuning to consider. With a heavily ported intake and large headers with efficient full flow through exhaust, I'd estimate at least another 10* duration added to both sides. And probably expect the engine will be run past 7k to reach it.
As for calculating the DCR with/without block expansion, I'm not really seeing the value here. One's not going to start a 600hp car that's sitting for hours, and immediately go full WOT. You'd let it get up to operating temperature first. In any case, any potential concerns about donation due to a difference in DCR would be offset by not being up to operating temperature. The only case where it might be relevant is if one was trying to run ultra-tight quench.
Exactly what I said. I don’t care how long the rods are, that cam is too small to make 600hp from a 346 cube motor. The LS7, with far better flowing heads and an admittedly milder cam, is nearly 100hp lower than your target, with 80 more cubic inches. I just dont see it with that cam.....
A longer rod engine will allow more air in the cylinder at a given crankshaft degree compared to a short rod engine, but the difference is extremely negligible for the few degrees of rotation that it actually matters. And to take full advantage of this, you’ll want to cam for the longer rod engine. The longer rod engine will be more “tolerant” of a later intake valve closing, which means it will be more forgiving of a little too much camshaft duration…comparatively speaking, of the same build with a higher rod ratio. You might see a few more horsepower if the combo is perfect here. The real advantage of a lower rod ratio (longer rod engine) will be less cylinder wall “stuffing” at high rpm, which cuts down on skirt wear and cylinder wall temperature. Endurance engines are designed around as long a rod as feasible, simply to cut down on cylinder wear and temps. The few ponies gained from the longer rod optimized build are simply a bonus.
Well after the feedback here and watching some YouTube videos of ls1 builds . I think 550 @ the crank is more likely to be what it will produce. Given aone of the videos showed a 5.7 with stock comp tunnel ram and bigger cam 239/255@50 on a 114lsa made 579@ the crank.
so with the smaller cam but more comp it should be around the 550hp zone. Still a tough ls1 stock stroke engine.
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.
7 Most Reliable High-Performance Engines GM Has Ever Built
Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Camshaft question 
