Alright heres the deal, over the winter I had a lot of engine work done to my truck, I had a bigger cam installed that was compatible with stock computer and valvetrain while they were doing the rebuild. Anyway, for the past month, I have been hearing this tapping noise while driving, and when i open the hood i can hear it even more...So I brought it back to the shop, finally after 3 days, this dope says he cant hear any "tapping noises", but said he would change the oil to see if that helps at all. I went to pick it up, and what do you know, the motor is still "tapping"....The noise is coming from underneath the valve covers, and it is my guess that it is a valve that is worn due to the bigger lifters from the bigger cam, and that the bigger cam caused premature damage to the stock valvetrain, or the bigger lifters may just need adjusting. After reading this website (http://www.aa1car.com/library/engine_noise.htm) i think i am right on, but i want to know if you guys could give me some incite. I think they told me they didn't hear anything because they knew they would need to replace valvetrain components on their wallet..It's very frustrating.

First thing I would do in your position;

Pull the valve-covers (just the side that's making noise, or both depending on if you want to be on the safe side) and check to make sure everythings torqued down correctly.

yeah good point, i am not gr8 with that kind of stuff, would i need to buy new valve cover gaskets if i pulled it?

I'm not sure what kind of gaskets are on it at the moment, so I can't really answer that.

Wait, so with that new cam did they only install new lifters with it? That's got me pondering if the stock valvesprings can handle the added lift..

Yeah, but it was suppose to be compatible with stock valvetrain so technically it shouldnt have caused any problems, but i beginning to become suspicious

Yea, that would kinda worry me. Just because they've been cycled/worked in that consistent range and then once you put more stress on them I can't help but wonder how they'd react.

Well the thing is.. If the kit was safe for stock valvetrain, did they put new stock valvetrain in?

More than likely either two things happened;

1) its not torqued right (not uncommon)

2) they slipped and didn't put new parts in the valvetrain (not uncommon again)

Well, people routinely swap out just the cams/lifters and don't mess with the valvesprings if they're able to handle the extra lift. Whether or not they BSed you on that or what, I don't know.. Did you find out for yourself before-hand or did they tell you? I'm suprised they didn't pull the covers themselves while they had it (maybe they did?).

Something sounds fishy Road.. thats for sure

I'd be a lil pissed LOL

I'd be f'n livid, man. You're getting into alot of money if anything goes wrong in that part of the engine.

Just a suggestion, but get it checked out by someone more reputable maybe? If you're not comfortable doing it yourself.. I'd be hesitant to drive it much until you do.

I've seen the rockers actually work loose, to the point of falling off... Had a car some kids traded in to the dealership I was working for at the time, a 63 Impala. It ran badly, missing, popping,t he whole thing. Pull off the valve covers, and some of the rockers actually were laying on top of the head, others were way loose. Get them all set, what do you know, the car was a screamer! I would definitely check for loose rockers first and foremost. With the Fords, there is no adjustment, so they just need to be fully tight. The other concern I would have is they didn't break the cam in properly, and it wiped out a lobe or two...

yikes this all sounds bad, i know its not going to be something cheap because they probably would have fixed no problem there usually cool about fixing their mistakes, but this seems to fishy, and I aint about to give up on it, I cant stand the noise and the stress of thinking something bad is about to happen.

Hopefully the techs are along soon to give some advice!

Whenever a "larger" cam is installed, the lift of the newer cam must be compared to the valve spring installed height. Most generally, it is irresponsible to install a camshaft without new valve springs. The greater lift creates stresses on keepers, springs, valves, guides, and rocker arms.

Alright both valve covers deff have something tapping underneath of them and its very very noticable now. I am not going to drive the truck until I get them to take a look at it because I dont want any further damage. I found the new camshaft box in the garage and here are the specs let me know if i miss anything or if these numbers mean anything. I am not sure how these numbers compare to stock but anyway here it is:


Int. Exh.

Duration @ .050" 204 214

Advertised Duration 270 280

Lobe Spread 112

Lash HYDRAULIC

Valve Lift .490 .516

Cam lift .280 .295



Does this info mean anything significant to you guys, or does this cam seem relatively mild?

FordF350Baby said:

Alright both valve covers deff have something tapping underneath of them and its very very noticable now. I am not going to drive the truck until I get them to take a look at it because I dont want any further damage. I found the new camshaft box in the garage and here are the specs let me know if i miss anything or if these numbers mean anything. I am not sure how these numbers compare to stock but anyway here it is:


Int. Exh.

Duration @ .050" 204 214

Advertised Duration 270 280

Lobe Spread 112

Lash HYDRAULIC

Valve Lift .490 .516

Cam lift .280 .295



Does this info mean anything significant to you guys, or does this cam seem relatively mild?

Click to expand...

You need to measure the distance from the head to the top of the springs. Setting up a dial indicator to measure the amount of compression that the rocker arm subjects the spring to. You need a degree wheel as well. The duration figures are the amount of time that the valves are open. If you figure a complete circle is 360 degrees, it means that the valves are open for 270 and 280 degrees. The degree wheel can help in determining the valve overlap, as well as seeing if their figures are correct (packaged a higher lift cam in the wrong box).

so those numbers dont mean anything? Would those type of numbers be to stressful on stock valvetrain? I have no clue what that other stuff is but i am sure they would know

FordF350Baby said:

so those numbers dont mean anything? Would those type of numbers be to stressful on stock valvetrain? I have no clue what that other stuff is but i am sure they would know

Click to expand...

Its been a while since I've had to degree a cam, so don't crucify me if I'm wrong. The numbers do mean something, the cam lift, and valve lift is how much from center, the cam "lifts" the lifter. I'm not sure on the valve lift, but the one looks like .5 inch. Rocker arms can be engineered to increase the lift that the cam provides. Theres 1.5 rocker arms, and 1.7 arms. That means if the cam provides .5 lift, the rocker does .725 valve compression (1.5 arms). If the compression on the valve is more than the spring installed height, it will cause damage. The lifters might compress excessively, causing a collapse, thus loosening the arm, causing the valve train noise. As you can see, its a bit more complicated installing a higher lift cam than just bolting it in. Measurements MUST be taken!

Valve Lift .490 .516

Click to expand...

Im not 100% but that .516 sounds quite large. I had a .512 lift in my 5.0 mustang and had to flycut the piston notches so the valves wouldn't hit. Granted that was a 5.0 not a 460. Pull the valve cover off and rotate the engine by hand see what the valve spring looks like with it full open if you can't see between the coils or fit anything (feeler gauge) thats to tight, if so pull the spring and check for shims, in no shims to remove will have to have the spring seats machined, if you get new springs it comes with an installed height spec. Also if there are adjustable rockers installed someone may had adjusted them wrong, there is a procedure.

If I were to be able to make a deal with these guys to install a new valvetrain on this engine, should I just do that instead of trying to force the issue of using stock components? And would I yield more power if I were to get bigger valves and rockers arms ect?