dwg86
05-22-2007, 09:58 AM
I hear alot about this happening, and although it has been a few years since I have built an amc engine, a 304 and 401. But what is going on with the newer cams? Also it seams this is not only an amc problem.
I didn't have any problems with the cams I used(and like I said its been a few years). I used a comp cams 280h in the 304 and a custom ground REED cam in the 401(intake 228 dur @ .050/.512 lift, Exhaust 232 @ .050/.518 lift 110 center). Break in on both cams 2000 to 2500 rpm for 30 mins. I couldn't run for the whole 30 mins at one time due to eng getting hot.(due to timing and carb misadjustment on initial break in). I don't try to fine tune anything until the cam is broke in.
I like to use an electric fuel pump so gas is ready as soon as the eng turns over. My Dad showed me a trick years ago for timing an eng to get it close enough to run for cam break in, and it works pretty good. Put the #1 cylinder on the timing mark on the balancer(i.e. 10 btdc) on the compression stroke. With the rotor pointing close to the #1 position on the cap take the coil wire off the center of the dist. and hold it close to a good ground with the other end still connected to the coil. Turn the distributor until you see a spark. Lock down the distributor, because thats when #1 will fire. Gas/spark ready to go.As soon as it starts...go to 2000-2500 rpm.
I am getting parts together to build a 4.0 stroker for my 2003 Wrangler (258 crank/rods in a 4.0 block). Flattening lobes seams to be a problem some people are having when they build the 4.0 also. What gives?
I didn't have any problems with the cams I used(and like I said its been a few years). I used a comp cams 280h in the 304 and a custom ground REED cam in the 401(intake 228 dur @ .050/.512 lift, Exhaust 232 @ .050/.518 lift 110 center). Break in on both cams 2000 to 2500 rpm for 30 mins. I couldn't run for the whole 30 mins at one time due to eng getting hot.(due to timing and carb misadjustment on initial break in). I don't try to fine tune anything until the cam is broke in.
I like to use an electric fuel pump so gas is ready as soon as the eng turns over. My Dad showed me a trick years ago for timing an eng to get it close enough to run for cam break in, and it works pretty good. Put the #1 cylinder on the timing mark on the balancer(i.e. 10 btdc) on the compression stroke. With the rotor pointing close to the #1 position on the cap take the coil wire off the center of the dist. and hold it close to a good ground with the other end still connected to the coil. Turn the distributor until you see a spark. Lock down the distributor, because thats when #1 will fire. Gas/spark ready to go.As soon as it starts...go to 2000-2500 rpm.
I am getting parts together to build a 4.0 stroker for my 2003 Wrangler (258 crank/rods in a 4.0 block). Flattening lobes seams to be a problem some people are having when they build the 4.0 also. What gives?
