Zig

i'd start with a degree wheel.

i didn't mean to imply that that was i speaking. it was a quote from the article.

HITMAN99

Surprise, surprise!

CYA-Vett

When is the last time a shop degreed a cam for a routine LS cam swap?
99.99% of them simply line up the dots, spin the motor twice and make sure they are still lined up.
While you're at it, check the PV clearance too. And measure all of the springs to make sure they apply the same amount of pressure. Don't forget about an adjustable push rod to measure for the correct length.

Zig

hey wait... that came out worse than i expected.

i was simply quoting the article to back up what i mentioned.

i've done cam swap, head work , intakes, carbs. etc. etc. etc.

my last daily driver ('74 Camaro LT) had a 360 cu (350 with a bit of an overbore), a pair of 302 heads (67cc chambers if i recall correctly, 2.02/1.60 valves), lunati bracket cam, high ratio rockers, holley Double pumper - jetted, etc. Edelbrock Performer Dual Plane intake, 1" carb spacer, shaft mounted fan, no a/c, heater core bypass, about 28 - 32 degrees of timing advance, Mallory magnetic breakerless distrib., MSD ignition, headers, no cats, dual - straight pipes - exhaust with turn downs at the axles, etc.

i do all my own work.

in the middle of summer pulling uphill i would get some preignition but otherwise she ran great. currently, she's sitting in a garage out back waiting for my son to get a little older.

ever seen a sbc blow a perfect smoke ring with 'winter exhaust condensation' ? i had to make a stop once, on the way to work, as i closed the trunk i saw this 'smoke ring' floating away. i couldn't believe it , i even looked under the car to see what was going on. i then just there with this silly grin on my face, making sure i saw what i saw.

HITMAN99

P/V clearance is pretty easy with a little clay, especially if the engine is being put together on a stand. Have to admit, I don't know how you go about it with the heads on. I never run big cams, so I've never had to worry about it.

Haven't seen too many guys using an adjustable pushrod. Most guys I know go with 7.4" unless the heads have been milled .030", then they go 7.35". Gets interesting when someone decides to mill their heads .020", or some other offbeat amount.

Zig

touche', i was just providing some additional information as requested.

yep, there are many a shop/tuner/mech. that will just line-it-up and stick-it. not saying it's right or wrong, just providing additional info.

CYA-Vett

I understand, and I admit it is proper to degree a cam install, however, there are so many proven grinds working in so many LS motors with the dots lined up, it has become a lost art. I'm sure a thorough engine builder will still do it. Us backyard mechanics cut corners

Blue02Z06

Well after spending a good 12+hrs on the car today i have the LPE firewall mod completed for the FAST Manifold. I have the heads/headers off and the blocks cleaned, i have the timing cover off and also have the oil pump off. Tomorrow i will be swapping the cam and putting everything back together. The only thing that really bothered me was when i took off one of the passenger side rocker arms i accidentaly dropped it being careless. To make matters worse i was standing on a stool next to the engine bay and when i stepped down of course i walked on the rocker arm and bolt. Ive already contacted Gene to get a new one because i dont trust the sound it made when i came down on it. I guess it could have been a lot worse...

Ill have another update tomorrow night.

Dave

CYA-Vett

Your rocker arm and bolt go through a lot more harsh conditions inside the motor. They will be fine....but if you didn't replace them, you'de always have a bad feeling in the back of your mind....Good work so far and keep the updates coming!
Dave

mfinocc

After reading the article on doing the cam swap in October issue of Corvette Magazine, I'm not sure I want to do it. Seems like a big job. How much HP will this net with the right cam? And what is the right cam? I don't mind something a little lumpy but not too much this is my daily driver. Will it be worth the effort?

m3brad

I'm looking for the same thing

CYA-Vett

50 RWHP
Sure it s a big job, but it's not difficult.
Certaintly worth the effort

Vet

As a general rule, you can't get something for nothing.

A bigger cam shifts the torque peak up the rpm band so that peak horsepower is increased... but at the EXPENSE of some torque in the lower rpm range. So, unless you are spinning your engine up past 4k or 5k rpm or so on a daily basis, swapping in a bigger cam may only serve to decrease power where you use it the most.

I suppose there are some cams that are not too much larger than stock that may actually give you a little boost all along the rpm band... maybe... but then indeed it's a question of whether or not it's worth a cam swap project for just a small boost overall.

A big cam that will give you a noticeable HP boost up top will give you a noticeable torque drop down low... and you may not like it. Guys who are into racing don't mind or maybe do not even notice the drop in low end torque because they have either swapped in lower gears in the rear, or simply like to burn the clutch off of every start.

But if you use your car as a daily driver and like to take off in a mild clutch-saving manner a lot of the time, you will notice the loss of torque.

For just driving around town in the 1,200 - 3,000 rpm range, I know I personally like as much torque as possible in that range... because that's where I use the engine the most. I'd personally rather have less peak HP and more low-end torque. If you are trying to win races at the strip however, it's a different story.

For racing, all the fury is going to occur probably in the 5k rpm and up range. If you go around running your engine up to 6,500 rpm every day in your daily driver, you will not only beat the living daylights out of your car, you will also waste a ton of fuel and probably get arrested. Again, for racing, good, for street use, bad.

Last time I mentioned something negative about racing cams here I got flamed into the next dimension. I will say this... years ago, I had done a lot of hands on testing of different cams in a Pontiac V8... everything done scientifically, all cams were degreed, carb and ignition tuned perfectly per cam, etc... and I got to feel a bunch of cams hands on... in fact I drove each cam in all conditions for weeks.

The bottom line per my hands on tests, the bigger the cam, the less low end torque, more twitchy low-end operation, etc... to me this is not acceptable for a daily driver street car. My first choice was a cam not much bigger than what would be considered "stock"... had a rerlatively tight lobe seperation for minimal overlap and minimal "lope". Anything that had a lopey idle was not good for daily street use. Sure, a rumpity-lumpity idle sounds super cool... but are you going to trade good low-end power and good low-end manners just for a cool sound?

If you are a true daily driver, look at other ways to increase power. Focus on crisping up your low and mid range band and don't worry too much about top end. Perhaps a good tune?

For me, after owning / driving a lot of very powerful classic muslcecars, the stock C6 is just perfect AS IS for daily driver street use. Again, racing is another story. If your goal is to collect trophies at the track then ignore this post.

The Clevite Kid

. Thanx for your perspective based on experience. And since I agree with you completely, you must be right .

.

CYA-Vett

The losses down low are minimal, if that, obviously you don't have a cam

Zig

that's one of the reasons i believe in swapping in higher ratio rockers. the cam basically keeps it's profile but you get the added benifit of 'more lift' and 'quicker opening/closing rates'.

rockers, imo, have a pretty good cost/performance ratio.

mfinocc

Vet,

Thanks, great info.
Have you installed any mods in your C6? If so, what have you done?

Vet

There is one hole in my report: the hands on testing I've done with cams was on a 1970's car with a carburetor... no computer. It does make sense that a modern engine with fuel injection and the ability to tune everything perfectly via the computer would result in less of a low-end torque loss from a mod such as a larger cam. No, I have never tested different cams in a C6... thus I am not by any means claiming to be any kind of an authority on cam swaps in a C6. But I DO stand by my GENERAL assessment of cams and how they relate to daily driver use.

Also... seems that very few people will ever agree on what is "best" or "appropriate" for daily driver street use. I've talked to guys with total drag race set-ups, including ridiculously large cams, 4.11 rears, giant slicks etc that maintain that their cars are perfect for daily driver street use. Well, I would not agree. To each his own. CAN you drive a totally tricked out drag racer on the street? I guess you can. But is such practical by any stretch of the imagination for TRUE daily driver street use? That means taking it to work every day in the heat of the summer, cold of the winter, severe traffic, long highway trips, etc??? Ummmm... NO. But that's just me.

Not knocking anyone's decision to swap in a cam.... hey, I've done it too (in the past). But just alerting those with less experience that, at least for a daily driver car, a cam MAY not necessarily be the best way to go. I think a lot of novices hear a cool lopey idle and decide that they want that same sound, not realizing that a lopey idle and daily driver street use generally does not go hand in hand very well.

A lopey idle GENERALLY means you're spitting fuel out the exhaust, not sure how the car will ever pass emissions, plus the engine will feel weak and twitchy in the very low rpms. When I had a "big" cam in one of my cars, trying to start out in 1st gear at a relatively low rpm (in order to not smoke the clutch off of every light) was a b*tch. I was pretty much forced to slip the clutch at a pretty high rpm to avoid a stumbling, near stalling condition. Then the car would just be pretty dead until the rpms got up past about 2k rpms or so... it sucked bad in traffic... to me, for DAILY driver street use, this is just not acceptable.... but others may disagree... that's cool. To each his own.

I suppose my only goal in typing any of this here is to just alert those considering a cam swap what they may or may not be getting into, especially those who are not familiar with all these concepts. I met a kid once who had a big cam put in his car and then complained about how it ran. Turns out he did not even know or understrand what OVERLAP was, and the consequences of too large an overlap, etc, etc. I then asked him WHY the heck he had a big cam put in if he didn't even understand anything about it? (A few months later he sold the car cheap and bought something else, just like everyone else who accidentally "over-mods" for their situation... I've seen it too many times.)

So... in sum, not arguing with anyone, not saying a cam swap isn't a good thing... but before buying a new cam, at least think about and consider the POTENTIAL downsides of a cam swap, and think about how YOU will use the car MOST... and then hopefully you will arrive at the best decision for YOUR car. Don't just blindly follow the pack, because others may use their cars differently than you will.

For me personally... daily driver street use, long distance high speed trips, mountain carving... I keep my C6 bone stock because in that form, it is PERFECT for what I do. If I ever stop using my C6 as a daily driver and go back to drag racing, I will surely be here asking about available cam grinds for the LS2, headers and all that other fun stuff.

Ok, I know I don't really belong here in the Tech section since most of you here are drag racers... and I'm just a wimpy high performance "street" guy, haven't seen a drag strip in years... so I'll go back to C6 General where I belong.

Blue02Z06

Ok well tonight i got everything back together except for the FAST intake manifold and Vararam which i will be completing tomorrow. Everything went smoothly except for that LPE Firewall mod. I dont mean to talk bad about a company but that thing is pretty much worthless without templates or directions (the ones listed on their webpage are incomplete and impossible to decipher)

All-in-All id DEFINITELY do it all over again. To be honest its not difficult at all, simply time consuming. This is my 3rd day putting in a good 12 hrs while taking my time and after all the cuts/bruises/swallowed vehicle fluids i feel pretty damn good knowing i just saved myself a couple grand on the install cost. Now im just hoping she fires up without any problems. Do you guys think its safe to fire up without a tune, or should I get a tune first?

Another thing i learned is that Dex-Cool tastes wonderful, just wish it wasnt so damn bad for you

Thanks a million for that writeup Dave, youre dead on with your instructions

***oh yeah, as for the rocker arm the actual arm is going to be ok, but i did notice one side of the bolt head was rounded off from the pavement, anyone know where i can get one fast?

Dave

Zig

, now that's funny... imo, you've provided some excellent info, that some may or may not have known/thought about.

i totally agree with, 'learn what the mod does, and how it will interact with other mods' before you mod.'