I need some advice guys. I aquired a good used 2.8 v6 from a 85 firebird to rebuild on the side for my 88 camaro. The bore and crank journals spec'd out within tolerances so I replaced rings, brgs, cam/lifters, oil pump, tim/set, gaskets, and sent the heads out to the machine shop. Both engines are identical except for the belt drive accessories, tim.cover, and oil pan. Both are "s" engine code butthe f-bird is from an automatic transwhile mine is a 5spd so I just swapped over the flywheel.

The problem I'm having is the engine vibrates over 4000 rpm. The idle is alittle shaky but not bad at all, just the upper rpm. My question is, are the flywheels balanced for each engine? Both are code "S" engines. Also I had a little difficult time sliding the engine onto the trans. Is it possible I broke the pilot bushing which may cause the vibration? The vacuum reading at idle is about 15.5 hg which is normal according to the cam card. Any suggestions to check is greatly appreciated.

 

Do you have to be driving for this to occur? Or is it when you are parked somewhere...

 

Now that I drive it more in hopes the ecm needed time to relearn, I'm thinking maybe the cam maybe a tooth off,..****!!! I didn't use a degree wheel. I just lined it straight-up and rechecked it again. I'm quite sure it's set correctly but I gotta pull it this weekend for piece of mind. It does vibrate if you rev it in neutral. I tried playing with the base timing. It almost wants to die at "0" degrees and runs better when set to "12" deg. base timing somore so it might be the cam being off.Thanks for the reply or any other input is still appreciated.

 

Before ripping the engine apart, check for a misfire or crossfire, they will give you plenty of bad vibes.

 

Ok, I removed the Timing cover to recheck my timing sprockets and they are set correctly. I also rechecked the lifter preload to see if I made them to tight/loose. I energized each injector under fuel pressure to check for a good spray pattern. I even checked for cross fire. I reset the TPS to .6v at idle. I even replaced the clutch thinking the other was off balanced. I'm thinking maybe the cam specs are not computer compatible as the supplier claimed? Can someone take a look at my cam specs and tell me what they think? Dur@.050 I=204 E=214, Adv dur. I=270 E=280, Lift I=.420 E=.443, Lobe center I=107 E=117. This is a stage 2 cam from ARI (Anderson Racing Industries) and they claim no computer modification but I'm still having vibs at 4K and it idles rough with 15 in. Any other help or suggestions before I kick my self in the *** for not swapping in a V8.