1968 Camshaft

I've had about enough of my lopey camshaft so I'm considering replacing it with something smoother. My lopey days are over!

Does anyone know of a cam that offers a smooth idle but a little more power than the stock unit?

From what I've been able to figure out here are the specs for the stock cam for my '66 289.
Duration @ 50 = 198 intake & exhaust
Gross Lift = 368 intake, 381 exhaust

The Melling 24212 I'm now running has:
Duration @ 50 = 218 intake & exhaust
Gross Lift = .461 intake & exhaust

This cam just has too much lope for me but I don't know if it's the lift or the duration (or both) that creates the lope. I'm guessing it's the .461 lift causing the problem.

Three cams I'm considering are the CompCam 240H, 252H, and the 255DEH.
CompCam's DEH (Dual Energy) series has longer exhaust durations and greater exhaust lift so they supposedly work better for cars with restrictive exhaust systems, like ours. It sounds good in theory but I don't know if it works in reality.

The 240H seems to be pretty close to stock. It's a little less on the intake duration but stonger on the exhaust, and has a higher lift on both. It's described as having a "very smooth idle". I like the "very smooth idle" description but I don't know how it does on performance.
Duration @ 50 = 192 intake, 200 exhaust
Gross Lift = 416 intake & exhaust

The 252H is a little stronger all around and the numbers place it about half way between stock and what I'm now running, but it's idle is described as "smooth". Is there a difference between very smooth and smooth? With these numbers I'm a little worried it may not be as smooth as I'd like.
Duration @ 50 = 206 intake and exhaust
Gross Lift = 433 intake and exhaust

The 255DEH is made for a 3500# vehicle and has more exhaust flow.
Duration @ 50 = 203 intake, 216 exhaust
Gross Lift = 434 intake, 467 exhaust.
Those numbers look like they definitely may be into lopey territory.

Any thoughts on these cams or any other cam that works well with a 289?

I'm really not picky, I'm only looking for perfection: A perfectly smooth idle with lots of power!!!

do you know what the valve timing is on the cams your considering?
i can look for my cam disc tomorrow, and look up the specs. on those cams.

i have found that valve timing is more critical than lift and duration.
a grind similar to the 351 cleveland cj cam is a good power/smooth idle cam.

Arlie,
Lift has little effect on your "lope". The cam centerline is what creates the lope. The term "overlap" is the time the intake and exhaust valves are open at the same time. The more overlap, the more lope. At idle the overlap bleeds off compression, but as RPM's increase this becomes a moot point and allows for longer duration of the valve opening thus allow more gas in and more exhaust out. The more overlap means for higher hp, but higher in the RPM range. Less overlap means less power, but more at lower RPM's

That is it in simple terms. There are other factors. I will look into this for you. One option if you have a deeper wallet is a hydraulic roller cam. The advantage of a roller cam is the “ramps” up to the “lobe” center at max lift can be “steeper”. Simply put, the valve opens much faster that a flat tappet cam. This allows for the valve to be open longer without creating overlap. Best of both worlds! Longer power band and less lope. Great low end torque and great high end HP

If you want perfection, time to step up and put wheels on your lifters!!!

Rob

Arlie,
This looks like a great street cam! The roller ramp profile lets you run more duration without the lope!!!

http://www.summitracing.com/parts/CCA-31-412-8/

Of course you will need these!!

http://www.summitracing.com/parts/CCA-851-16/

and this!!!!

http://www.summitracing.com/parts/CCA-31-1000/

or!

http://www.summitracing.com/parts/LUN-72335LUN/
http://www.summitracing.com/parts/TFS-21400006/
http://www.summitracing.com/parts/HRS-91168/
http://www.summitracing.com/parts/EDL-97453/

I have an early crane hydraulic roller in my old non-roller motor with the "spider" hold down. Now a days you can buy lifters for non-roller blocks that do not require the spider hold down. They are the last four links.

Want me to get this on order for you? I love to spend other peoples money! After spending nearly $60k on my garage, it is the only pleasure I get!

Rob

You had me convinced until I saw the price! Maybe a lopey cam isn't such a bad thing!!!

Cheaper than a garage!!!