What size cam should I run???

**SSkrobarczyk396** · 02-13-2014, 11:44 AM

Ok so this is a serious street/strip 94 camaro with a 396ci LT1. It will be a daily driver but it will not see much city driving, mainly highway here and there. Okay so it has a completely forged rotating assembly, with comp cams limited travel hyd race lifters, RHS efi single plane intake manifold that has been ported landing with the nitrous outlet sheet metal intake elbow. 58mm tb ported as well, AFR 210cc fully CNC'd, 11:8:1 CR, pacesetter reworked 1.75 headers with a 3" true dual exhaust with moroso spiral flow mufflers. 7,000 rpm motor.

I already have have a camshaft that I hand selected. Specs: 243/251 at .050 with 597/603 lift on a 110 LSA. I want to go bigger and I'm thinking 247/256 at .050 with 61x lift on a 110 LSA. What do y'all think I should run? Are my current choices too small or are they good enough already?

**dawdaw** · 02-13-2014, 11:49 AM

Strictly Na or spraying it?

**blkchevyz** · 02-13-2014, 11:51 AM

got any flow number for your heads?

**SSkrobarczyk396** · 02-13-2014, 12:22 PM

N/A for now and will see a 200hp shot of spray. Heads flow just over 300cfm at 600 lift and exhaust is right at 230 cfm at 600 lift. A4 built 4L60E with ATI built 3200 lockup stall

**SSkrobarczyk396** · 02-13-2014, 12:24 PM

3:55 rear gear and a 26" tall Hoosier drag radial

**Injuneer** · 02-13-2014, 04:09 PM

Have you calculated the dynamic compression ratio based on the cam card for the cam you selected? I'm no expert, so I'm just guessing it might be on the low side with that much overlap. Try making the calculation using an online DCR calculator.

**BadBlackZee** · 02-13-2014, 09:13 PM

Originally Posted by Injuneer

Have you calculated the dynamic compression ratio based on the cam card for the cam you selected? I'm no expert, so I'm just guessing it might be on the low side with that much overlap. Try making the calculation using an online DCR calculator.

I will echo this suggestion - DCR plays a big role in making sure that your motor runs safe on pump gas (since you want to drive the car daily). I had similar goals to you but ended up going too ridiculous on the compression. I had a DCR of 9.1:1 and pump gas territory is 8.5ish:1. Needless to say, car makes great power but only on 110 octane. I posted a thead on DCR/SCR calculations a few years back that might be of interest to you...

http://ltxtech.com/forums/showthread...ase-come-on-in

**SSkrobarczyk396** · 02-14-2014, 12:08 AM

The motor will run fine on pump gas. We calculated the compression ratio to be exactly 11:8:1. Just curious what y'all's opinions are on the camshaft?

**SSkrobarczyk396** · 02-14-2014, 12:12 AM

DCR is around 11.0

**NightTrain66** · 02-15-2014, 08:32 AM

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