Mopar Camshaft advanced

[ohho92]

I've got a question in regards to advancing the mopar 229 cam 4 degrees. I would like to here some of your technical advice on performance. I will be using the rollmaster timing set which gives you the option of advancing or retarding. Usually advancing the timing increases performance, bottom end on that type of cam profile. The problem is I don't want to take the timing cover off once it's assembled.
My new build is a 4.6 stroker low compression (rock crawler version) with the mopar 229. I used the 229 in my previous 4.2 mini stroker and really liked the torque increase. Now that 4.2 is going in my CJ7 and the 4.6 in the XJ. Using the compression calculator I come up with a 9.7 SCR and 7.46 DCR at 5500' elevation. With the 4 degree adv it moves the DCR to 7.6. The only reason for the 9.7 CR is for the altitude. With a 9.0 CR the DCR is below 7.
Is it worth the 4 degrees or just install it straight up? Thanks

[jsawduste]

What are the specs of the cam ? Also trans type axle ratio tire size and how hard do you spin the engine ?

[Russ Pottenger]

Just a couple of thoughts I'll add to John's comments.

It's a common practice to have camshaft advance already built into it from the camshaft manufacture.
So be aware of this possibility before you decide to add any more advance to it.

Lastly, consider the increased cylinder pressure created by the advancing the camshaft timing and the problems
that it can create if you ever decide to run it at sea level on pump gas.
This advice is also based assuming you're running an iron head.

Russ

[ohho92]

Cam specs: 248 duration, 202 at .050 lift, .440 valve lift, 108 degree lobe sep. Cam comes 0 adv/ret.
I currently have the AW4 trans, 4.88 gears with 35" tires. I don't see myself needing anything over 4500 rpm, 90% of the time I'm in the idle to 3500rpm. As for elevation the lowest I travel to is Moab which is around 3500-4000'. I don't plan on going any where near sea level. Most of the trails I run are 7,000-10,500'.
I plan on using the silvolite 2229 pistons dished to 19 cc's with 258 short rods. The engine was given to me so I'll stick to the short rods.

[Russ Pottenger]

I'd advance the camshaft 4° to help gain back some manifold vacuum you're losing with the 108° lobe separation angle.