Check my numbers

[brokenujoint]

Ran my numbers through the cruncher(calculator) and would love some opinions/inputs:

4.56 liter
SCR : 9.59:1
DCR: 8.57:1
Quench 0.0645

With this set up, whats my realistic octane rating on the street at sea level?

[brokenujoint]

The above numbers are with a Mopar 28AB cam..
Here are some other numbers with Mopars 29 cam

SCR 9.47
DCR 8.4
Quench of course remains at 0.064

Obviously the 29 cam is a better set up, but I am using the stock springs rated at .430 and the 29 cam is rated at .440. I am never going to race this engine as it's more of a rock crawler/trail rig and would see maybe 85mph tops on the freeway. Can I get away with this cam or should I stick with the 28AB with the lower .430 lift?

[Cheromaniac]

With a DCR that high I think you'll need at least 91 octane.

[gradon]

My 4.6 has a 8.57:1 DCR and needs 93 octane at sealevel.

[brokenujoint]

I am thinking i might just have to run a stock 96 cam to keep the compression in the low 8's. Seems a shame but in cali we dont even have 93. Only 91 and im favoring even less than that if possible. I have a 96 cherokee cam now. Think ill just throw that in.

[Muad'Dib]

FYI the 29AC is just fine with stock springs... even the cam recommendations say to use the stock spring part number. Just make sure yours are good. I went ahead and purchaced all new ones since i felt weary about the lift being .440 and the springs only supporting .430. Its been working fine for me.

Id also tighten up your quench to be only your head gasket compressed thickness.. My build is also 8.5 DCR and i dont ping at sea level with premium. Quench @ 44

[brokenujoint]

Blocks going to the shop for a zero deck height. Gonna port/polish the exhaust ports and do a mild bowl cleanup. And sticking with a stock cam for now . That will get me in the super low 8's with dcr.