Best Cam for 302

Robspiceman · #1 (**permalink**) 06-18-2008, 11:51 AM

I've got a 302 bored +30, with Edelbrock performer heads and manifold in my ERA 289 FIA. The cam is from Cam Techniques. The pistons are flat top and I am quessing about 9:1 (never pings on 91 octane, no matter what the timing). I'm looking to replace the cam with a roller. Any suggestions?

jdean · #2 (**permalink**) 06-18-2008, 11:59 AM

We put in a hydraulic roller "Thumpr" cam in a 289/302 FIA car belonging to Jim Jacobs. It has 10.4 CR. It makes lots of mid-range to top end power, not as stout before 2000 RPM but it really screams. Look at the latest issue of Hot Rod, where there is an article of the top 5 best selling cams. The Thumpr proved to be the best overall. I am glad they did the test because many had the impression that this series of cams was more about sound than power.....not true.

You need the "Spider" installed to position the lifters to retrofit a non-roller block.

Motor had Edelbrock heads (milled) RPM intake, flat pistons.

olddog · #3 (**permalink**) 06-19-2008, 10:03 AM

My advise is find some people with engines similar to yours (who have their cam card). Listen to the engine and see how it behaves on the street.

My 347 stroker has 236/242 duration @ 0.050" lift and .550/.575" lift intake/exhaust. It has a Mass Flow fuel injection using a Edel Victor Jr single plane intake. The previous owner told me he had a carb on it and the EFI calmed the idle down a bunch. The idle has a killer sound - I love it. When cold, it will buck, if you try to run bellow 1600 rpm. Warmed up your can get away with 1400 rpm. It doesn't smooth out until 1800 rpm. If you run bellow 2000 rpm the fuel milage goes into the toilet. Torque comes on strong by about 3000 rpm (by the feel of my pants). I cannot tell if the torque drops off at the top end. I try to shift by 6000 and have let it get to 6500 by accident a couple times. The rpm come up so fast I cannot feel any loss of torque.

Hope that helps some.

Rickd · #4 (**permalink**) 06-19-2008, 10:14 AM

I have a Keith Craft 331 Stroker with AFR 165 heads. This motor Dynoed 436 HP at 6000 rpm at Keith Craft and after break in I had it Chassis Dyno tuned and it made 326 rwhp at Mustang Specialties in Fort Lauderdale, FL. Keith Craft says they get very good results from the Trick Flow Stage II cam, and that's what they used in mine. It is a split duration cam, as I recall 226/232 at .050 is the duration and I would have to check the lift but I recall max lift was .550. This is set up with an Edelbrock Performer RPM air gap intake, and a Quick Fuel Tech carb. Mustang Specialties recommended a different carb, but after adjusting mine, they said it's good to go. The motor pulls like a bandit from 2000 rpm up to 6000, that's where I stop - but the tuner said "I'd take her to 6500 cause she is still pulling". The little AFR 165's are great heads, and you don't need more cam than the Trick Flow Stage II (they are actually made by Crane for TF). Rick

Robspiceman · #5 (**permalink**) 06-25-2008, 12:34 PM

I quess by biggest concern is a cam to work with the edelbrock performer heads. These have the smaller valves, so I think they should be good for torque. I checked and the compression is 9.6:1. Any thoughts?

olddog · #6 (**permalink**) 06-25-2008, 03:48 PM

The most important thing, is make certain your cam swap doesn't destroy your engine. Increase in lift, durration, and ramp rates results in less piston to valve clearance. If they hit you will loose the engine. Next, too much lift for the springs. Depending on the springs, valve length, and total set up there is a maximum lift before the coils bind.

For every cam there is a specification on required spring fores. Most people recomend changing springs with the cam.

Now you have to decide where you want the engine to make its torque. There are compromises and you cannot have it all. One compromise is street manors.

I think your manifold is dual plane. Most dual plane intakes give great low to mid range, but suck at top end. Single planes just the oposite. You should look at the rpm range for your intake. A high durration cam with an intake designed for idle to 4000 rpm will result in a dog just about everywhere.

My point to all this blabber is you need to give more information about what you have and what you want, before anyone can give you good advice. The cam manufacturers should be able to tell you a bunch if you give them all the facts. Especially the car weight and gearing.

I hope this helps you.

PS
How many rpm are you willing to turn your engine. Don't build it to peak on hp at 7000 if you are not willing to turn it to 7500. Your hp should peak about 500 rpm before your shift point give or take depending on gearing.