The Stovebolt Site Forums The Shop Area The HiPo Shop cam advice for a 327

any one know what is a good average duration and lift for a 62'-62' 327? its bone stock (for the moment) i just would like a little more umph out of it! im in the tear down process at the moment but will be in the rebuild stage in about 2 weeks. im going to be running new exhaust manifolds with a 2.5" or 3" collector and an H pipe, and intake manifold, and i may have some head work done, but that im going to base off the cam. something like a mild street/strip cam. was thinking of having the heads shaved and port matched. if you have advice on the cam and any necessary head mods relating to the lift and duration, and even suggested pistons if needed(though the ones in the block are in good condition) i would greatly appreciate the help!

also this is going in a 66 C-30 with a 4 on the floor. not going to be towing much or haulling much either, but it is going to be a daily driver. good low end torque would be more valuable to me over top speed. thanks!

I'm using a comp 286 magnum cam. It's not a 327, rather a 350 bored .030 over, flat top pistons, 64 cc double hump heads (194 intake, 160 ex), full roller rockers, holley 650, Edlebrock RPM Air Gap intake.

It's spicey and has a bit of a lumpy idle, but not too bad. It is very dependable.

Sent private message.

i didnt get that message gazim. hey Avette4me what is the lift and duration on you cam? that little bit of a lumpy idle is what id like-just enough to make people wonder what your running, but not enough to attract the unwanted city and state attention. (we have special teams that check your engine when you get pulled over-anything questionable or noticeably no street legal- your car gets impounded.)

Lift: .490'' Duration: 286° RPM Range: 2200-6200.

That 286 is going to be a bit much for a 327, especially if you're not running a high stall speed torque converter or fairly low ratio rear end gears with a standard transmission. I've built several small-displacement engines with the Comp Cams 268H High Energy cam. It's got a pronounced idle lope, but it also had pretty good low end and midrange power. It also works with about 9:1 compression and moderate cylinder head work- - - -you don't have to go overboard with valve, port and exhaust pipe size. That kills low and midrange power, and you end up with a high speed only engine. The old 300 HP 327 used 2 1/2" exhaust manifold outlets and pipes, which will cary the volume of exhaust well without letting the exhaust stream slow down enough to kill the scavenging effect of the gas leaving the cylinder. I like to use 64CC heads with 1.6" exhaust valves and 1.94" intakes. The 2.02" intakes are too big for a 327 unless you're running above 3,000 RPM all the time. Do a little pocket porting under the valves, but don't go overboard on port size, intake or exhaust. Too big of an exhaust system, combined with a small-displacement engine with big ports results in a total loss of low-end torque. To have plenty of exhaust flow without killing the scavenging, run 2 1/2" pipes from ram's-horn 300 HP 327 manifolds, not headers, mid-70's Cadillac mufflers with the same size pipes in and out, and run the 2 1/2" pipes all the way out the back. One of those mufflers is designed to flow enough exhaust to handle a 500 cubic inch engine. Two of them on a 327 gives you the flow of a straight pipe, without the irritating exhaust note of a Flowmaster or a Cherry Bomb. All I get from loud pipes is a migraine!
Jerry

well thats cool, the truck came with a set of corvette ram horn exhaust manifolds on it (65-67 327 300hp-350hp). are those the ones your talking about? so i got another question- im looking at the numbers on summit; if the duration numbers are at an advertised lift of .50 but im going with a smaller lift (say .490) does that make the durations shorter? and if so, is there a formula i can use to figure out what the actual durations are with different lifts?

Lift doesn't always make the durations shorter as most mfg's make different grinds.

Here are the rest of the specs on mine. I realize yours is a 327, and although Jerry has a ton more experience than I and may differ, I think they're similar.

350 bored .030 over, flat top pistons, 64 cc double hump heads (194 intake, 160 ex), full roller rockers, comp 286 magnum cam, holley 650, Edlebrock RPM Air Gap intake, stock ram horns (probably my biggest restriction), 2.5" exhaust (had to flare it a bit after the ram horns), flowmasters dumped just ahead of the rear axle. I'm running a saginaw 4 speed and 3:35 rear gears.

I've pulled trailers loaded with stuff from a 1/2 ton pickup to fencing materials including cement, as well as a boat. The truck performs very well and I can run 70 on the highway at 2700 RPM when I'm not pulling - when pulling, I usually max about 60 by choice and can hold it well.

For my taste, it's really not that loud. Here are a couple of clips made about 3 months ago..

http://smg.photobucket.com/albums/v228/Avette4me/video/?action=view&current=20091127173140.flv

http://smg.photobucket.com/albums/v228/Avette4me/video/?action=view&current=20091127173255.flv

Anyway, that's my .02.

Have fun with your build...

Brian, you missed a decimal point there. The timing figures for degreeing the cam are given at a valve lift of .050", because
it's difficult to see the beginning of the lift just a few thousandths off the clearance ramps. Total duration on the 268H will be 268 degrees, intake and exhaust, with a lift of about .450", IIRC. A .500" lift is too much, unless you plan to check the piston/valve clearance very closely.
Jerry

Here's another thought for you. Edelbrock's "Performer" series components are dyno'd to work together and produce gains in torque and hp from idle to 5500 rpm. I've used the manifold, cam, lifters, and 600 cfm carb on 2 different SBC's and both had great throttle response, kick in the pants torque, absolutely no tuning issues, worked right out of the boxes. The Performer cam is not "rumpy", it's very docile at idle. I liked the idea of having dyno tested components rather than a trial and error approach, too many bad things can happen with mis-matched parts.

I am running a 327 bored .060 over, double hump heads, 1.6 ratio roller rockers, performer intake, Edlebrock 600 cfm carb, headers. Cam is a Comp Cam XE262H-10. Motor has lots of torque / power. Has a slight " lope " at idle

I am not a fan of Comp Cams, very hard on the drive train. I would suggest a Isky 270 mega cam. Has very good low end torque, and has lump. Good LSA as well.

I'm using the Edelbrock Performer cam and carb with an old Offy hi-rise intake between them.