Join Date: Nov 2000
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Re: HEI in 258 - port or manifold vacuum?
Switched to ported vacuum. Big difference. I can now drop the pedal all the way at about 1400 rpm and have the engine just roar to life. I am finding that less accellerator pump gives me more throttle response. This is odd. I have the pump linkage on my MC2100 set at the 2nd lowest setting. The lowest setting I can't get the rod retainer to hook up, so I can't try it. Perhaps this carb is jetted too rich, or the Power Valve is set to kick in too early. I am very impressed with the setup and performance of the MC2100 and HEI. I am interested in fine tuning to get the best out of it that I can. The 258 has all the performance I could ask for, and I sense that I can tweak even more out of it.
Thanks for your suggestion to use ported vacuum. I will experiment with the adjustable vacuum advacne some more, as well as using lighter spring on the mechanical advance.
84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, Lockright, full cage & belts, Xenon flares, AMC 20 1pc axles, GM dual diaphragm brake booster