What size cam should I run???

[Puck]

If it is a daily driver, the 396 and AFR 210's will make tons of TQ and pull to 6400-6500 RPM or so with the 243/251 cam.

Make sure you have the upgraded springs (155 lbs on seat instead of 135 lbs on seat).

The cross section of the AFR's 210's (actually cc about 202-203 cc) will be 2.10" if using AFR's CNC job. This will make peak HP at 6000 RPM or so on the 396. It can hang on longer but peak Hp will be dictated by the cross section at the PR pinch.

Some AFR 227's would work great but I understand if you already have them, might as well use them. I'm just preparing you for what to expect.

You are in the right duration range for a hyd roller in your set 24x/25x depending on the gears, stall and driving style.

If you plan on going to that track often, have 3600-4000 stall and want another 10 HP at 6500 RPM, go with a 247/255 duration cam.

If the extra 15 ft lbs of TQ below 2800 RPM is more important, go with the 243/251 duration cam.

Depends on your driving style and how often the car will be above 6000 RPM and how often it will be below 3000 RPM and how important the extra HP up top ot TQ down low in each RPM range is to YOU.

Lloyd

Spoken by the man himself - you could not have gotten a better answer .

[Injuneer]

DCR is around 11.0

You might want to check your calculations:

http://cochise.uia.net/pkelley2/DynamicCR.html

This lowering of the compression ratio, due to the late closing of the intake valve, is the primary reason cam manufactures specify a higher static compression ratio for their larger cams: to get the running or dynamic CR into the proper range.

Caveats: Running an engine at the upper limit of the DCR range requires that the engine be well built, with the correct quench distance, and kept cool (170º). Hot intake air and hot coolant are an inducement to detonation. If you anticipate hot conditions, pulling some timing out might be needed. A good cooling system is wise. Staying below 8.25 DCR is probably best for trouble free motoring.

>>Unless you have actually measured the engine (CCed the chambers and pistons in the bores), these calculations are estimations, at best. Treat them as such. The published volumes for heads and pistons can, and do, vary (crankshafts and rods, too). It is best to err on the low side. When contemplating an engine of around 8.4 DCR or higher, measurments are essential, or you could be building another motor.<<

[NightTrain66]

11.0 doesn't sound right at all for DCR.

With 160 T stat, good tuning and 93 octane, you can get by with 8.8-9.0 on a good mail order tune and some have gotten by with 9.5-9.4 with there own tuning equipment and playing with timing/A/F at certain TPS settings.

This is based on an efficient chamber, no sharp edges, edges chamfered around the chamber after milling to reduce sharp edges, a good tight quench (.035 or so) and a lil colder plus (Autolite 104's gapped at .035 for factory castings).

Lloyd Elliott
972-617-5671
Elliottsportworks.com