I need some help. I just installed comps 278 and valve springs. After starting I can hear a chattering sound like a lifter not pumping up. Comp cams told me that it was not a lifter that its valve to piston clearance issue. If any one is running the same cams and had a similar prolbem or any info. to help would be great.
No the funny thing is as it gets warm it gets louder. When I first start it you can't hear it, but when it starts getting warm you can. If you get over 3000 rpm it real loud.
Did you have your pistons flycut with valve reliefs? If not, then its near impossible to degree the XE278AH's. The noise could be piston-to-valve contact resulting from not properly degreeing the cams, lack of valve reliefs, or both. As for the noise getting louder when the motor is warmed up...the rotating assembly and valves are expanding (due to heat) just a little bit resulting in tighter clearances and even worse PTV contact.
:SNSign: I have 150 shot, p.p. intake manifold, cai, bbk shorties, bbk x-pipe, 2-chamber flowmasters, 4.10 gears, anderson pms, ngk plugs and throttle boby spacer. I:SNSign: just installed comps 278, and beehive springs. I keep reading about degreeing the cams. This is the first I have heard of this. Also the bottom end is still stock, but might be replacing pistons and rods. What piston/ rod combo would you suggest. Also if theres anything else I need let me know. The motor runs smooth, the only thing wrong is the chatter. Thanks for all the help.