I took the Vette to a very well recommended guy to have him install the new cam, intake, heads, and carb on the 454. After waiting nearly a month for it, he finally got it running Thursday. This thing is wicked!! Everything was as to be expected on initial start up, and he kep the revs up around 2000-2500 for what seemed like 10 minutes or so. He had painted the headers and side pipes and they were smokin' us out of the shop. Anyway, he says he wants to run the valves again after it cools down. They did sound a bit noisy for a hydraulic flat tappet. He said he'll run them the next morning around 11. I showed up at 10 expecting to watch him check the valves, adjust the carb, set the timing, etc. Unfortunately he says the engine is rattling like hell and has no compression in number 1 or number 7. Apparantly he had already done everything and was letting it sit there idling for a bit when all of a sudden it started making a weird banging noise, then it it sputtered and died. It never fired up again.

He said I probably broke a rod. I waited for him to pull the pan. All rods were intact. Then he said it was probably a piston skirt. Looking from the bottom, they all looked to be intact also. But, when we use the starter to spin the crank, you can still definitely hear a knocking somewhere in the engine. He says he wants to pull the engine out instead of messing with it in the car.

My question to you guys: Is this an obvious screw up on his part? I was not there when it died, so I have no proof of what he was doing. But I did see it run without a single problem the day before. Was 10 minutes long enough break in time? The rocker arms were still moving. Do you guys have any ideas what to tell this guy? I just have a gut feeling I am about to screwed.

HEEEELP!

Thanks!


[Modified by Black Magic, 8:17 AM 3/23/2003]

 

If it started making noise while still in in the shop,and you never drove it,then theres no way that you should pay for this..
My .02 is on that he didnt check for valve clearence and bent a couple of valves.. :smash: :smash:

 

Best bet is that a few cam lobes went flat. If break-in doesn't go well, the lifters will start digging into the cam lobes, and valve clearance will go out the window. Lots of noise follows... It tough to blame him for this one if he followed the cam manufacturers recommendations. Since you were there, you probably know.

Does the new cam have more lift? If it does, you could have smacked a piston and bent the valve. Once that happens, the valve won't seat all the way, so the valvetrain will be loose and make lots of noise.

Your mechanic should have definitely checked this stuff before digging into the oil pan for pistons and rods. I wouldn't trust him. :rolleyes:

 

:iagree:

The initial rattling could have been caused by some kind of mis-match in other valve train parts like pushrods, guideplates, rocker arms, ect. Also the valve lash may have been too loose initially causing the rattling. If, in an attempt to quiet it, he simply tightened the lash, he may have tightened it too much causing a valve to piston clearence problem. This can cause contact between valves and pistons which will usually bend the valves. With bent valves you will have no compresion as you stated is the case in #'s 1 and 7. No matter how you look at it, if there are bent valves, its an error on his part. Either by not checking the compatability of parts, or by inproper procedure. Valves contacting pistons can also cause other damage like cracked pistons and damaged crank, rods, or rod bearings.