Jeep Strokers

I took one of the 30ab cams I have to Reed cams to have it profiled. Here are the specs they gave me. Advertised duration 260([email protected]). Duration @.050 200. Valve lift .453. Lobe speration 108. Timing events @.006 with intake centerline 104(4 degree advance)...
IVO 26
IVC 54
EVO 62
EVC 18
Flash, would you like to run these numbers on your desktop dyno. We can see how this cam will perform with it advanced 4 degrees. I also would like to see the numbers using a 1.7 rocker ratio.

Flash already ran them straight up...

Here they are with the Comp 231 as a comparison...

RPM - Comp/30ab Horsepower
1500 - 78/76
2000 - 112/110
2500 - 142/141
3000 - 172/171
3500 - 201/203
4000 - 217/225
4500 - 217/231
5000 - 200/220

RPM - Comp/30AB Torque
1500 - 274/267
2000 - 296/290
2500 - 302/301
3000 - 302/301
3500 - 302/305
4000 - 285/296
4500 - 254/270
5000 - 210/232



So, as with other discussions, these numbers are for comparison purposes and may or may not be accurate to any engine or combination of parts. Your results may vary....


k.

using stock bore, stock 4.2 crank, and the numbers provided, this is the difference i came up with for 30AB and 30AB w/1.7 ratio.

To find the 1.7 ratio, i am doing .453 / 1.6 = 0.283125 * 1.7 = 0.4813125 or .481. I also slightly changed the ramp speed of the lifters to suit the higher ratio. I know Flash uses different settings for the head then i do, so his numbers are a little higher, but for comparison, this is my Desktop Dyno run

Both runs have +4 on cam timing

30AB with factory rockers
Peak Tq = 300 @ 3000 rpm
Peak HP = 211 @ 4000 rpm



30AB w/ 1.7 rockers
Peak Tq = 304 @ 3000 rpm
Peak HP = 216 @ 4000 rpm

Isn't the advertised duration 256*, or does that @.006 make it 4* more?

advertised lift is also .450, but reed seems to have spec'd it at .453

gradon wrote:Isn't the advertised duration 256*, or does that @.006 make it 4* more?

Different cam companies use different pionts of lift to measure advartised duration....004, .006, .008 etc. Reed uses .006 for thier advertised duration, thats what they profiled it at.
That is why you should use [email protected] when comparing cams. I have read that mopar uses faster ramps on thier cam lobes, taking advantage of the .904 lifter dia. Most companies use cam proflies for .842 dia lifters(SBC), even for the mopar cams they sell. Mopar Jeep and AMC use .904 lifters.
You can also use dur.@ .006, .050, .100, .200 etc. to see how fast the cam lobe is(If you can get those numbers from the cam companies). You can use a faster ramp on the cam lobes with a .904 dia. lifter, without the lifter digging into the cam lobe.

dwg86 wrote:I took one of the 30ab cams I have to Reed cams to have it profiled. Here are the specs they gave me. Advertised duration 260([email protected]). Duration @.050 200. Valve lift .453. Lobe speration 108. Timing events @.006 with intake centerline 104(4 degree advance)...
IVO 26
IVC 54
EVO 62
EVC 18
Flash, would you like to run these numbers on your desktop dyno. We can see how this cam will perform with it advanced 4 degrees. I also would like to see the numbers using a 1.7 rocker ratio.

PM Sent


Flash

me too

Since the 30ab cam is no longer avaiable, the Comp 231 seems like a good subsituite. Differences are not huge, and the Comp seem to have the torque peak where you need it.

I was talking to Charles at Camcraft Cams, he said he could probably grind a copy of the 30ab, but did not think there was much demand for it.

I have the specs for the 30ab cam. I had one profiled before I sold it.

The plus to using the 30ab cam is it has the wide lobes instead of the skinny ones on the comp. I am one of the lucky few, when I bought my cam there was only 3 left in country.