Originally Posted by MrMayhem
Originally Posted by jwb123
Just to throw it out there, I agree would have tried more timing. The BSFC numbers look poor, it is using a lot of fuel to make the power, but the A/F ratio is close. Did you degree the camshaft? First thing I would do is get a cranking compression reading, might tell you if cam is not right.



Cranking pressue was-190psi...

251 intake duration 256 exhaust 108 lobe separation: 78 degrees of split overlap per the builder

So if I were to look at a cam swap, what would be the reconmendation?


190 psi cranking sounds in the ballpark for those cam specs. I still don't understand the BSFC numbers. The best cam I got for my 540 wedge was from Jones cams https://www.facebook.com/Jones-Cam-Designs-173457799374053/

The other issue to investigate would be the heads. I have seen heads that backed up, flowed less at higher lifts, and they just killed the engine. Sometimes you have to flow them at 35 inches or so the catch them doing it. I have seen some CNC programs that backed up so don't think all CNC programs are perfect. Usually, a little grinding on the short side will straighten them out. I have messed with big block mopars a lot and most like 36 degrees timing. If the O2 numbers were calculated I would trust the color of the plug more than the calculations. Did they try leaning on the jets? I still like exhaust temp readings as well, many times a cam not right will give you high exhaust temps. If the exhaust ports are dragging out part of the fuel charge at high rpm during the overlap that would give you the poor BSFC numbers, and usually exhaust temps will be high as well.