Merry Christmas and Happy Holidays to all! (politically correct enough?)
During the past few months I've been picking brains in order to come up with a formula for a stout, yet reliable, street engine. I've been printing and saving these threads, creating a scrapbook, of sorts, I review religiously. I value your opinions to the max, because they're honest answers. Today's topic is camshafts: In order to achieve a reliable, yet stout, street engine, what would the duration and lift numbers be?

Here's what I have to work with so far:
350 cid base engine
Edelbrock Air-Gap RPM manifold
650 cfm carb
Headers
Distributor - undecided

JR

Check out Aftershark's threads. He has some killer SBC recommendations.

jredding said: Today's topic is camshafts: In order to achieve a reliable, yet stout, street engine, what would the duration and lift numbers be? Here's what I have to work with so far: 350 cid base engine Edelbrock Air-Gap RPM manifold 650 cfm carb Headers Distributor - undecided JR

well im gonna give my FAVORITE answer... it depends.

i assume since youre talking street engine that you want torque and gobs of it. youre doing pretty good do far.. but..

the rpm air-gap is for 1500-6500 rpm.. the regular air-gap is for idle to 5500. so depending on where you want your peak torque you may change this.

as for cam.. what kinds of heads are you going to use ?
what kind of transmission? auto or stick..

I just looked at your profile.. 4 speed.. close or wide range.. and what gears are you running ?

on carb.. mechanical or vacuum secondary ? (tranny factors in here too)

headers .. small or large tube ?

distributor.. i think there has been a pretty clear consensus that MSD is the way to go on that.. whether you use a ready to run or use one requiring an ignition controller depends on money and whether you need a tach drive....

but what fran suggested is on the money.. if you havent picked out heads and settled on a carb.. you may want to look at one of holley's topend kits.. cam, heads, intake, carb... all matched..

|UPDATED|12/21/2004 9:45:07 PM (AZT)|/UPDATED|

I agree that a complete setup may be the way to go. I will say though that when my 350 was rebuilt, the rebuilder suggested going with the std corvette 327-350horse cam over the typical 350 cams from the feeling that it was nice for street driving with some cam lope in a 350, but no issues with over heating or low vacuum. Its true it wouldn't give you the ultimate horsepower or torque situation though.

As you can see, I'm at the beginning of my mission. Maybe the camshaft question should come in near the end. So many other factors to consider...To be perfectly honest, haven't even given the heads much thought. BTW, I'm targetting the 350-400 hp range, with a fair amount of torque. Thanks for the manifold tip, I was going to read the specs before buying from Summit...wasn't aware there were two different Edelbrock Air-gaps. I got alot more questions I'll be asking throughout, please bear with me. This is something I really want to do but learning as I go along. Thanks again.

JR

P.S. A kit may be the best way to go, eliminating guesswork.

|UPDATED|12/22/2004 5:01:19 AM (AZT)|/UPDATED|

I agree with Ben and to be quite honest if your not buying a top end kit, the cam shaft is usually the last thing that I pick out. Too many other factors play into which cam would work best.

However if you buy a top end kit remember it may require you to make suttle changes to fit your over all build. If the cam in the kit is fairly large it may cause a lower vacuum then you like and you might want to add a vacuum pump or it may require a change on the torque converter to one with more stall.

You can also buy a top end kit and never use the cam that comes in the kit if its too little or two big. Just sell the cam because its new and get the one you want. Typically the heads in these kits and intakes will work with slightly larger cams. The only reason the kit is there is because it takes the guess work out of the combination for makeing the HP figure you might want. I know the Holley heads out of the box have been on engines that have made 500hp max naturally aspirated. You can't make much more then that with out a little help from a flow bench and grinder. With power adders (nitrous and supercharger) these heads out of the box have made as much as 800 HP, again maxed out.

You can get the same results with AFR, Dart, Brodix, Trick Flow, Edelbrock heads ust need to match them with a good intake, the right cam, right compression, and a decent set of headers.

I've been talking with a lot of engine builders that say most people are over engineering their street engines. Basically you don't have to spend a fortune on the bottom end, because all the power comes from the intake, heads and cam. And todays aftermarket parts are much more advanced then they were 10 yrs ago. Its hard to get it wrong.

If you need help selecting a cam its fairly simple. Right down the goal, ie what Hp you need, what accessories do you want to run, how do you want the engine to sound, how do you want the engine to drive. etc.

List out all the parts you plan to use. Once you have it written out look at the parts to see if they fit your goal. If your goal is to make 500 hp and you have stock steel heads you will see that piece on your list won't foot the bill. So right in the part that will. Go though each part on the list if it works leave it if it don't replace it. After you have all the parts picked out call up a cam company and tell them your combination of parts, and your goals, ie vacuum to run accessories, lope you want, power level. He will then make some recommendations and might even suggest changes to your overall engine combination. If you get the right guy to be upfront with you and he has enough experience he will tell you whether the combination will make the power.

I do this all the time with editorial projects and it takes time. I've worked on my own engine combination for almost 3 months and I bet I have refigured the compression ratio 10 times and changed my cam selection 4 times. I think I have finally settled on a cam. What has me changing my mind was a new cam line Lunati just cam out with that they have spent over a year designing revolutionary new cam lobes that out peform similar camshafts currently on the market.

here is a link to the website to get more details:
http://www.voodoocams.com

After Shark said: because all the power comes from the intake, heads and cam. And todays aftermarket parts are much more advanced then they were 10 yrs ago. Its hard to get it wrong. here is a link to the website to get more details: http://www.voodoocams.com

I just looked at the cams offered there.. pretty cool..

i wish i had the 268/276 instead of the 270/270 i currently run.. i would gain 18 hp and 16 lbs of torque

he is absolutely right.. heads, intake and cam are the most important factors..

|UPDATED|12/22/2004 4:26:25 PM (AZT)|/UPDATED|

Thanks for the sound advice, Gents. Another printable thread for my scrapbook. Looks like I have some homework to do (if it'd been this much fun back in grade school).

JR

Great thread guys. I have been second guessing myself ever since I built mine. I am now wanting to add the RPM Airgap to mine just to see if it will give it a little more.

one warning guys..

the air-gap will not fit under a stock corvette hood..