I have a 289 that is almost ready, except for the camshaft. I'm looking for up to 300 ft/lbs of torque and the best gas mileage possible for a daily driver. I've got a edelbrock 600, headers, ported heads, the works. I have been looking at the edelbrock performer flat tappet cam, and also some of the comp cams xe cams. If anyone has any actual experience with a cam that can meet my requirements, please let me know. Thanks for your time.

 

How much compression are you working with? Also we need the vehicle specs (weight/tranny/rear gear).

For reference;
Look at the cam in my sig. It is the same as the Edelbrock performer plus cam.

This idles and drives very nice with the stock torque converter. I can't tell you how it would be in the 289 but with the other mods and my heavy truck it guzzles the gas.

 

I will have 10:1 compression ratio. About 3500 pound vehicle weight (i think), a nv3550 manual transmission, and 4.56 gears.

 

First thing I want to make sure of; is this compression measured or what was advertised from the parts ordered. This can and will make a huge difference in how the motor will respond. Everything needs to be physically measured like; piston to deck/ combustion chambers/ valve relief pockets/dome etc. Otherwise a ballpark figure will just give you a ballpark result. I have been, and seen many, be disappointed with the final results with guessing at the compression. You only need two specialty tools to measure this; A dial gauge with a bridge (about $50 for a cheap one) and a kit to measure the combustion chambers (plexiglass/burrette/stand).

The bad part of this build is the compression. In order to run pump gas your motor will need a cam about the size of the Comp XE268 - 224/230 @.050 lift - .509/.512 gross lift.

This would be a very good motor, just not exactly built for mileage. With a 289 it will give a pretty hefty lope at idle. This would work powerband wise with your tranny and gearing, on the strip.

If you still have a choice in the pistons, I would shop for some that would give you closer to 9.5 so you could use a cam closer to the XE256 - 212/218 @.050 .477/.484 lift. Or you could always use a head with larger combustion chambers.

The XE256 would still give you a noticeable idle but be much more responsive down low and use a little less gas. This would be my choice with 9.5 SCR for the street.

 

Thanks Bill my compression is right at 10.1:1. The piston are hypers set at zero deck. My heads were milled .03 in., and now have 54cc chambers. I have really polished the chambers and ported the exhaust runners. I am planning to run the high octane gas. Do you think I could still use the XE256 cam without detonation? It looks like this cam has a really steep lobe almost like a roller cam. What will this do for engine longevity?
By the way, how goes the 351w stroker? Thanks for your time.

 

Good if those numbers are accurate then you would be good for premium grade and a careful timing curve with the XE256. This will put your DCR in the 8.3 to 8.4 range. The highest DCR premium gas can handle is 8.5. On initial startup/ break in I would set the timing at, no higher than, 8 deg btdc so you can break the cam in properly without fear of detonation (just a safety margin). Once the break in is done then you can dial in the timing.

I can't say enough how critical those compression measurements are, especially when on the high end such as yours. With the calculated 8.3 DCR, if we are off just a little it could be the difference of premium grade and race gas. If it does end up too high you could always use a thicker head gasket to raise it a bit. I will however advise to use an adjustable vacuum advance, your going to need it. If your distributor doesn't have one, Crane makes a unit that you can add to yours.

The XE line has more aggressive ramps and therefore the rest of the valvetrain should be upgraded as well. Well with the XE256 I would at least swap the springs for the recommended ones from Comp. Just make sure to check the installed height and pressures. Coil bind shouldn't be an issue with that mild of a lift but worth checking anyway. A good time to do this is when checking the pressures.

Well the stroker's on hold right now, can't find a block (small town) and I really haven't had time either. I still have a 351M/C6 combo that I need to sell (in the way) but haven't had the time to show it. Thanks for asking.

 

Call comp cam or crane and let them decide, no offense 90f150moneypit.