help....missed shift rpm hit 7k

[twolo4u2c2]

I missed a shift and my 347 hit 7k for a split second and I did hear the valves float when that happened......It was fine till now...a couple of days after that missed shift I was gong along and shifted it at 5500-6000k and I herd a loud metallic click. off the gas and its gone. It does not do it till about 1200k and gets louder from there.....under that and its quiet, no sound. I baby it all the way home and open the hood and hit the throttle and it sound like a broke rocker and the push rod or something is hitting the valve cover towards the back. this morning I pull the valvevcovers and nothing. no bend pushrods , no broken studs or rockers. I turn the engine over and all rockers move fine and none are loose in anyway. ok what is it. I'm hoping somthing let loose in the clutch area and is hitting the bellhousing because it dosent sound like a rod....its to high in the motor. oh yea...no filings in the oil either and no loss of power

please help.

thanks

 

[twolo4u2c2]

before anybody else says it.....I do need the get a chip for the 6al to limit the rpm when that happens.:SNSign:

 

[bubba-dough]

before anybody else says it.....I do need the get a chip for the 6al to limit the rpm when that happens.:SNSign:

Here is a little bit of experience I have had. I have had the release bearing fork wear out and wobble. That was allowing it to hit the cover and rattle like it was my topend on the motor.

 

[25thmustang]

My friend did this in his car, and it was a bent pushrod (we replaced it at the track and he made more passes). My guess was he also hurt a valve or two and this could be your issue?

 

[BlooDReigN]

You sure it isn't detonation you are hearing up top?

 

[twolo4u2c2]

NO! definatly not....it something hitting something. It rises and falls with RPM till below 1200 rpm than its quiet.

 

[Hissing Cobra]

Could the rocker arms be hitting the baffles in your valve covers? I had this problem on one of my engines and we had to remove the baffles so that there would be enough clearance for the rocker arms.

 

[Mr. Rustypwnz]

Lifter?

 

[Tarik916]

This happened to my 306 and it was my valve hitting my piston. I had valve float and the piston bent the valve so that it would no longer seat itself bach into the head. I got a valve job, stronger valve springs, hardened pushrods and the problem was solved.

 

[fastranger347]

did you actually pull the valve train to see if anything was bent or did you just "look at it"

 

[Daggar]

I'm going to go down the same road as a lot of these guys but have a slightly different approach...

Pull the top end apart but leave the heads alone. Inspect every accessible, moving part in the drivetrain until you find your problem.

If you're unable to find it, then pull the heads and inspect the valves.

There are a lot of good suggestions here and I could see any of them being the culprit. Time to get a good look at it all before spending any dough on fixes.

I'll make one other insepction suggestion and that is to look at all the lifter dog-bones and ensure that they're intact. A rotating roller lifter can cause the noises you're descring as well. It can also tear up other parts of the drivetrain if not identified as the additional lift can bend a pushrod or break a rocker or stud if given the opportunity.

I wouldn't be driving it until the problem was found. How mcuh would it suck to find out a cylinder is slowly filling up with unspent fuel over time.... boom.