I don't think so.
It depends on how it's cammed.
I have seen quite a few dyno sheets with the LS3 intakes hanging on to around 6800rpm or so but you do need to aim for a peak RPM of 6500rpm and then it can hang on.
You need the correct IVC and enough duration to get there.

 

You say.....
But in my FIRST post, I stated...….
I think you just ***-hurt because I told the guy that he could use is current cam because of his budget constraints.....even though the most illiterate person on this forum would plainly see I encouraged him to go with a custom grind.

Take a chill-pill....and be sure to wash ALL the sand out of your mangina before you go beddy-bye.

KW

 

Haha.
*** hurt?
If you can read between the lines I was poking a little fun at your sub par recommendation

 

And if you can read between the lines, I was poking fun at....you.

KW

 

Lots of...poking....going on around here. Carry on.

 

Little bit of an update and another question. The block wound up having to have #7 sleeved and final bore is 4.075 so it is time for a cam. I called Cam Motion and gave them my specifics and they spec'd this cam: 233/242 LSA 115.5 .621 intake .604 exhaust. Their sales rep said I should see 625-635 crank HP with this cam, mildly ported stock LS3 heads and a stock LS3 intake and it should pull hard to 6500, which is pretty much where I want it and maintain good driveability.

The question is does this cam seem to have a pretty wide LSA and a lot of lift for my needs and does anyone have a better recommendation and still be able achieve 600+ crank HP and maintain good valvetrain life?

 

That's better.
I have two suggestions for you.
I actually posted in your thread a while ago in regards to this.
For something somewhat aggressive use the Pat G grind I was given.
242/250 113 LSA +4 with 20 degrees overlap. (Probably a bit much for perfect driveability)
238/248 114 LSA +3 with 15 degrees overlap which will drive good in a 416.
235/245 115.5 LSA +3 with 10 degrees overlap.
The valve events are good for the size engine and the intake.

 

If you could scrape 1200 bucks together, you could have Tx Speed CNC port your heads, do a valve job, mill to your spec, and set up the valve springs ($800). Could also have Gwatney port and rod mod your LS3 intake ($400). I have both on my stock cube LS3. It did 500 at the wheels with a baby cam.

 

Call Reher-Morrison ask to speak with Darrin Morgan. He can spec a ln outstanding cam. Reher-Morrison can port your LS3 heads and do a great jon for $1,000 or so plus shipping. Darrin did the port work for the RM CNC program and is one of the very best around.

I worked with Darrin & RM on the heads and cam package for my 416. Very happy with the outcome. I explained my application. Darrin nailed the combo of parts.

Land Speed Cylinder Head can also do the same with fast service and quality.

TEA can also do a very nice LS3 ported head.

 

Another point I should have noted before is that Cam Motion gave me a 4 week leadtime and said that everyone was way behind on grinding cams. That could be a core availability issue, but has anyone else been quoted a long lead time lately?

I will talk to my engine builder about some of the cams suggested next week.

 

Darin is no longer at Reher-Morrison. He has been With Mast since last fall...unless he’s made a move in the last few weeks.

 

Wow! Thank you for the update & info - I didn't realize he'd move.

Lol - I need to edit the post to say call Mast and ask for Darrin

 

It will be good to see what Darin does with Mast's LS7 program.
I just wish there was more data on Mast's heads in terms of power numbers and performance.

 

That really is not a lot of lift in the LS hotrodding world. Modern lobes are very good at those lift numbers. I tried to go back and see, but didn't go very far. Do you have your springs picked out? Often people will just run the BTR .660 dual platinum springs for low to mid .600's lift. Run a beefy pushrod, and you should be in good shape. Blackbird TA on here repeatedly reports that his comp XER lobes lasted something close to 100K in his valvetrain, and those are aggressive. far more so than modern lobes. The ramp rates have more to do with beating up the valvetrain than the gross lift numbers.

 

I already had a set of the BTR .660 springs so I am just going to reuse them unless there is a problem with them when we put them in the other heads I bought.

Honestly, I am more surprised by the 115.5 LSA that Cam Motion spec'd. The TSP cam that I originally had in the 376 has more lift and 112 LSA.

 

As Darth has stated around 600 ish lift is very normal for a camshaft for these engines.
Not excessive at all.
LS3 heads like lift and respond well to it.

 

it's a longer discussion, but I'll try to condense it. Four valve events. Intake valve open and close, and exhaust open and close. Generally, you will find that the intake valve close has the most to do with determining when an engine (i.e. what rpm) will make its best power. Exhaust valve open will generally influence this as well. And also how well the engine carries past peak vs falling off fast after peak power. Intake open and exhaust close determine what you will see called "overlap" which determines the "behavior" of the engine. More overlap is gnarlier. Less overlap is tamer. More overlap helps an engine carry past peak, and is necessary to build high rpm at all.

Now, for an illustration. The cam motion cam: 233/242-115.5. I'll assume for now it's straight up, but I actually suspect there's a couple degrees advance in there (+4 for example after the LSA). For this purpose, I'll just use it at zero. Now, I'll propose a completely hypothetical cam for comparison that is likely more in line with your LSA expectations. 240/249-112. Call it a Darth Stupidity cam for all I care. And now you're thinking "wow, I like that LSA better, but that looks like a huge cam". And you're right. It's huge. Here's the deal

Valve Event.......CamMotion.......DarthStupidity
IVC......................52......................5 2...................degrees after bottom dead center compression stroke
EVO....................56.5...................56.5 ................degrees before bottom dead center power stroke

EVC....................5.5.....................12. 5................degrees after top dead center intake stroke
IVO.......................1......................8 .....................degrees before top dead center exhaust stroke
Overlap...............6.5....................20.5. ................degrees intake and exhaust valve open at the same time for .050"

Now, your IVC and EVO determine the power band. Bigger engines will generally operatoe with later IVC and earlier EVO in order to breathe. Both cams will basically make their peak power and torque at the same RPM's, because the IVO and EVC are identical. The Darth Stupidity one will build more peak torque, build more power, and carry further past peak power, but be a real pain in the ***. The cam motion one will build less torque, make less power, fall off a bit faster past peak, but be much easier to tune and drive. The Cam Motion one will have much better off idle grunt, whereas the Darth Stupidity cam will not really do much until 3500 rpm, at which point it will hit like a 50 shot of nitrous.

Here's the point. LSA by itself is just a number. Without the context of duration, it doesn't mean anything. When you break the cam down into its valve events, what you see is that the increased duration with fixed IVC and EVO is the reason the LSA drops. The cam motion recommendation makes sense given this excerpt from post 7:

 

I agree with you completely. I had a Futral cam (a company you should consider) in my 427 Darton Sleeve motor. It was 232/236-112 lobe sep. angle. Loved it. You're only 1-1/2 cubes/cylinder smaller. If you're tracking/racing it, sure, go for 240+ duration intake/250+ exhaust, maybe .625 lift. If you go much more than .625 lift, it's hard on valve guides. Good luck......

 

The Cam Motion spec'd cam: 233/242 LSA 115.5 .621 intake .604 exhaust sounds like an excellent cam. Reasonable IMO lift if used with stock rockers. Ideally use some rocker stand shims to get the best wipe pattern to reduce side loading the valve.


Darth is correct about the cam ramp rates being the valve spring killer not the duration etc. The newer lobes are much much better these days!

FWIW - Ran an224/224 .581/.581lift XER cam 130,000+ miles no issues on a set of stock LS1 lifters. Rocker stands were shim'd for best wipe pattern. Motor is good & sitting on a stand waiting to find a new home. Just let motor warm up fully and replace valve springs, retainers etc ever so often. My set up had 3 sets of springs etc. Was told multiple times back in the day an XER cam'd engine wouldn't last 30,000 miles and to totally forget seeing 70k miles out of it.

 

Darth,
thank you for posting that cam timing info. While I don’t have the time to read it carefully NOW, it will make a good read this weekend. Ok break time it over

Jim