Initial Timing Question - I found the cam specs...

[Mfr426]

Hello all, some may have remembered me posting my 383 motor and the cam specs to find an initial timing. I was under the impression that the cam was what one tech at Mancini described as "the hemi cam". I thought it was a 284/484 Purple Shaft kit and was told by the tech at Mancini that that cam (the hemi cam) was the only one Mopar made several years ago. I called Mancini to see if they had any records on which cam I purchased as I thought I bought it from them about 6 years ago and could not find the cam specs.

Well, after I got off the phone with this guy I was pissed knowing that I would not have purchased a "hemi cam" for my streetable resto project. I went thru all receipts (thanks to my wife for filing these things) and finally found the original receipt for the cam kit. The kit was actually purchased from Summit Racing and not Mancini Racing (oops sorry Mancini for calling you). The P/N is 4452783. I even found the original ad from the car mag that I ordered it from. The description was "Factory Musclecar Kits" from Mopar Performance Parts. The specs are for the "Super Commando and Magnum/Roadrunner" motors. and are 268/284 duration .450/.458 lift.

So, this cam must be less "aggressive" then the "hemi" cam that I thought had. I'm glad I found this info as the tech claimed this cam never existed. This should be a much more streetable cam setup then previously thought. OK, sorry to be so long-winded. Any comments on the timing based on this cam with a G block 383, a Carter 625v carb, HP manifolds and a stock intake and torque converter? I'm inclined to put it at 5 degrees based on this "musclecar kit" cam that I believe is a stock replacement for a factory Magnum motor?

Thanks all for any thoughts.

Getting there on this car...

Mike R in Reading PA

[firefighter3931]

Mike, let the engine tell you what it wants  I'll bet it runs great at 15* advance at idle....then check the total to see what it is and where it's coming in at.

Basicly, just start the engine and let it warm up. Hook a tach up and advance the timing until the rpm doesn't increase anymore and snug the distributor down. Throw the timing light on to see what you've got....it should be close to 15* at idle. Rule of thumb when setting base (initial) timing ; if the idle speed increases as you advance the timing.....the engine is telling you it wants more spark lead. Listen to your engine...

Ron

[Mfr426]

Thanks Ron! You're like an "Engine Whisperer"...