Mordeth

Unreal was referring to another member, not you. And for the record, the people you are talking to have been on these forums for literally decades, are long time committed members of the forum, understand the C6 platform very well (and in particular the LS7) and have seen it all. There is nothing new you can offer up that is a surprise and no real information we haven't heard.

Most of us long-timers legitimately enjoy helping new guys. You can learn from our mistakes, our trial and error and draw on the vast collective knowledge that exists here. It is rivaled only by probably LS1tech on the entire internet for modifying, driving and racing LS motors, in particular in Corvettes.

And as for a cam, yes it would feel good to spec your own. So would performing brain surgery. Except simply put you don't know enough to do it properly (not even close) - and neither do I and I don't mind admitting it. Most of the actual gear heads here who wrench on their cars still use an actual pro like Pat G, Mamo, Kip, Brian Tooley etc to assist in cam selection when they are assembling a motor. There are so many subtle nuances to cam selection that getting an outside opinion from someone that does it every day for 25+ years is the intelligent thing to do. Only an idiot spec's his own cam from scratch with very little knowledge/experience regarding what he is doing on a platform that is completely new to him. In this regard, google is NOT your friend and will lead you astray, filling your mind with a false sense of understanding as you perform random google searches to fill the gaping holes in your knowledge. Only experience can fill these holes. So in the meantime, you should seek help from professionals.

And yes there are some hard heads here. But they all have big hearts, decades of experience/knowledge and are willing to spend their own personal time to help others make good decisions regarding their cars. They answer questions, provide feedback, assist everyone they can and are one of the most honest, straight shooting groups on the internet. I wouldn't be here if it weren't the case.

nuke61

To Innovate - what Unreal says is absolutely true. Not too long ago, a new owner of a C6Z asks for input, gets input, ignores input, blows up motor in a few months time, now he's rebuilding his blown motor.

Please... let someone who knows what they're doing spec your cam. Decide what you want your car to do, and let the experts figure the cam out. Instead of researching cams, my research when coming to the LS7 was, what seems to work well? I took Unreal's input and chose the CPR Alpha cam package, and I'm glad I did. Choose wisely.

Innovate

Ok, I retract what I said about Unreal as I thought he was talking about me.

I do see where pretty much everything has been done on this forum, that is why I came here. I am glad there are people like you on this forum that add a positive light to the forum as I like your posts and find them very informational.

I am talking with a couple of shops on a cam, I found out yesterday before Unreal's post that there is a lobe catalogue that determines the exact specs from what I gather. I definitely will not throw a random cam into a $15k engine and hope it works. I understang about trying to Google everything, that can only get you so far.

I understand there are some hardheads in here, you will have them everywhere. I am glad there are a good many of you who are accepting of new guys.
Ahh ok, I definitely will not ignore input of a ton of guys who have tons of experience. The last thing I want to do is blow up my LS7. I am talking to some guys about a cam, I am not throwing something random in and hoping for the best.

Michael_D

I learned a long time ago to leave cam specifications to the guys who know what the hell they are doing - and I've been building all kinds of engines for decades. Even when I would spin them up on a dyno, I'd usually have two or three cams ready to go, because they rarely behaved exactly like I thought they should.

I have a general idea of how much duration and lift I think the build needs, but when it comes to selecting the actual valve events......no way. To put this into perspective, can you prioritize the valve events? What event is the most important, and why?
IVO
IVC
EVO
EVC

Did you know that opening the exh valve at just the right point in the piston's travel is incredibly important? But it might not be quite as important as when you shut the intake?

So now assuming you are a camshaft guru and you know all that....... what lobe profile should you use on the intake? How about the exh? Should they be the same profile, or???

I can tell already by just looking at the intake duration you noted in your first post......you have a lot to learn, and you are getting some pretty dumb advice.

Innovate

I talking to some guys already about a cam, I not really speccing my own I guess I could say now.
As for your questions at the end, yes for exhaust gasses to escape/you do not want an open intake valve when the exhaust is open and then you would run into PTV issues as well/intake lobe profile depends on what you want in the cam(DD/Drag/all else)/exhaust same reasoning as intake/no due to timing.
I am not going with the setup I posted in the OP, I have been discussing it with Gavin who is doing my heads and we are going with something close to what I want, that he can attest to (he has yet to message me back lol).
Plans may change and I go with something else. I also answered the questions with answers that I found while researching, I know a little about motors and definitely not as much as you as I have built one lol. I definitely do not want to blow my engine over something that could of been avoided.

MTPZ06

A couple important things to know about this car (LS7)...

The first (as you're learning) is that he cam selection is extremely important to not only dictate how the car performs (power band not just peak power), but also how it behaves form a driveability standpoint as well as valvetrain stability/longevity standpoint. IMO, too many people over cam this car for their needs. With the right supporting mods, and the right cam selection (proven or custom spec'd by a pro), you can often wind up with more usable power than most people can handle...and have valvetrain longevity.

Take this CPR thread for example...( https://www.corvetteforum.com/forums...ler-power.html ) Cust had "fixed" heads with a huge .660/.660 cam on OE rockers, and the guides were trashed in only 4K miles! In goes CPR's Alpha cam which has a much more modest lift (in the ~.630 IIRC), made a couple tweaks on the parts combo (MSD for Fast, ARH for Kooks), and the car actually picked up HP/TQ with 119* ambient conditions!

Second thing to learn about the LS7...detonation is no joke. It's real easy to crack a sleeve or break a ring land/shatter a piston. Choose your tuner very carefully...there's tons of "tooners" out there that think because they know how to tweak an Evo or a WRX; an LS7 should be the same. Wrong. You need someone who understands how much timing can safely be applied, what optimum AFR should be, and a whole slew of other parameters that should be left up to the experts...certainly not just some tooner with a dyno and a lap top that is looking to wring every ounce of HP out of your car. Horror stories of turning down or disabling KR, etc. Just some real incompetence out there.

A hot tune, high compression (milled heads), crap gas (91 octane, etc.) and a heavy right foot have destroyed many LS7's. Many of these factors can be mitigated or avoided altogether...especially the tooner aspect.

Innovate

Good information, I will check out the thread and I understand about overcamming the car. I do want to avoid that and detonating the engine of course and having the heads junked up in 4k miles. I do want my combo to last.

As for the tuner, I will be using Nemesis Racing in SC that does a good bit of Corvette LS7 work and have found a good number of people use him. I was going to use another guy but he has tuned zero LS7 cars, which scared me (he also was high priced). Cam-wise I am talking to a guy about one and if I grab one already made there are a few have already caught my eye.

Michael_D

Uh....no......

All IC engines NEED both intake and exhaust open at the same time when the piston is near TDC exh stroke. That's the overlap/scavage stage.

You do not want to open the exh valve too late or you loose blow down. Open it too soon and you lose too much, usable energy. Knowing the right point to pop it is quite important. And that's just one of four events. A good cam guy will weigh all of these, while fitting the correct amount of duration of both lobes.

Innovate

Mordeth

I literally just got my motor back in my car about a month ago after a complete rebuild. My car is road raced heavily and modified - but is still the original LS7 block and OEM LS7 core heads with work done to them by AHP. Part of my rebuild including replacing a high lift Lingenfelter spec'd cam I had stuffed in there previously. I contacted Pat G and gave him a complete list of my mods, what changes I was making, what I needed the engine to do, how I use the car, how much power I needed and where I needed it in the power band.

So he spec'd my cam (much smaller than I was expecting or I would have spec'd) and magically predicted exactly what it would do (despite my initial and incorrect protests to his specs), which ended up equaling precisely what I needed for the racing class with NASA I race the car in (weight/hp limited). It was easy to tune to my power requirements, has more in her if I feel like running in an unlimited class and motor is happy to exist here (565/539). This is where I PUT the car power wise (not where it ended up, like most people do). And I needed a true cam expert to help me. Also has a good idle, no surging/bucking, sounds great, pulls like a freak of nature and will eat my poor, but pretty C7Z for lunch.

Around page 5 below is my dyno sheet that I certified with NASA.

https://www.corvetteforum.com/forums...er-mods-5.html

Ultimately, all of the science and art of engine building and assembly needs to produce the desired results. And those results are what happens on the street and on the race track - not on the internet or on a dyno graph. This is where experience is important - and it takes years of trial and error. So you don't throw parts at a car and see what happens. You define your goals for the car and then you build the car to meet those goals. And this is where experience trumps everything.