Tapping Noise and Studdering 460ci

[FordF350Baby]

I recently had some work done to my 460 engine, I had a bigger camshaft and lifters put in, and had the timing advanced. Anyway, its been about 2 months since the work has been done, and I starting noticing a tapping noise coming from the motor, what sounded like from under the driver side valve cover. I also have been experiencing motor cutouts at idle, so I brought it back to the shop that did the work. The guy listened to motor and said he was convinced it was a misfire, maybe from a bad plug or wire, and said the tapping noise I was hearing was probably a form of pinging due to bad timing from the misfire. Does this sound possible. He said if it was a bad valve or something lose in the valve train that it would be way louder than what i was hearing. Any thoughts guys?

 

[Skandocious]

What timing are you running and what octane fuel?

 

[FordF350Baby]

set for 93 octane, and running 93 octane

 

[john112deere]

Where are you finding 93 octane? I haven't bought gas south of Augusta in a while, but up here dang near all the stations have started selling 91 instead of 93, and I've heard complaints of the same from further south...

 

[blacksnapon]

I recently had some work done to my 460 engine, I had a bigger camshaft and lifters put in, and had the timing advanced. Anyway, its been about 2 months since the work has been done, and I starting noticing a tapping noise coming from the motor, what sounded like from under the driver side valve cover. I also have been experiencing motor cutouts at idle, so I brought it back to the shop that did the work. The guy listened to motor and said he was convinced it was a misfire, maybe from a bad plug or wire, and said the tapping noise I was hearing was probably a form of pinging due to bad timing from the misfire. Does this sound possible. He said if it was a bad valve or something lose in the valve train that it would be way louder than what i was hearing. Any thoughts guys?

The only thing I'm scared of, when putting big cams in, is the skill of the engine builder. Remember, when a cam has a larger lift, it compresses the valve spring more. Was that taken into account when this installation was done? Possible valve train damage is a realistic result. Imagine that the cam forces the spring to compress more than its available travel. Stuck/bent/damaged valve with noise, and a misfire. You have to closely inspect any modifications to eliminate them as a possibility for the problems before moving on to something else.

 

[Skandocious]

The only thing I'm scared of, when putting big cams in, is the skill of the engine builder. Remember, when a cam has a larger lift, it compresses the valve spring more. Was that taken into account when this installation was done? Possible valve train damage is a realistic result. Imagine that the cam forces the spring to compress more than its available travel. Stuck/bent/damaged valve with noise, and a misfire. You have to closely inspect any modifications to eliminate them as a possibility for the problems before moving on to something else.

The lopy cam was also my concern... If your hearing it from the valve covers and you've got stock valves/springs/rockers/lifters then the cam has probably damaged something.

 

[FordF350Baby]

john112deere: Down here in the Portland area the only two gas stations that I find 93 is all Mobile stations, and some Gulf Stations, but mostly Mobile, and its about $3.90 now along with 6-8MPG it aint so great. Now back to the camshaft deal, when they installed the cam, i had them find one that would be compatible with the stock valvetrain, because I was running on a tite budget, and didnt have the extra money to get a bigger cam that required bigger valvetrain, but if this cam is in fact to big, it isnt gunna be on my wallet because they bought it and installed it, so if it is a bad valvetrain, I will pay for the part, but not for the labor required to do the job if in fact it is a bad valvetrain. I am hoping it isnt but it very well could be.

 

[blacksnapon]

Extensive measurements on valve spring installed height are necessary. All of these specs usually come with the camshaft. Adjustments are made with shims, or grinding the spring seats.

 

[FordF350Baby]

I am confident with the guy who did the motor, most mechanics are afraid to tackle any job on 460's, but this guy not only put on the dreaded headers, but dismantled the entire top end with no problems, so for that I respect him, he also was very nice and did an excellent job, unfortunately I am experiencing this problem, but I hope he is able to fix it and I can move on.