and it does have a larger cam in it if that matters......

 

What all was done for your rebuild? On the exhaust lifter, were the marks grooved into the lifter face? The exhaust lobe on the cam may me ground differently, what make of cam is it? In my experiences with wiped cam lobes, they just make a ticking noise and the motor runs odd. I think at this point I'd be removing the intake and looking the cam and all the lifters over. I know it sucks, I had the same issue with my 340. It may require you to shim up the rocker shafts or get different push rods. I wouldn't run it much more until you got a look at the cam and lifters as you could be circulating metal through your motor.

 

they weren't "grooved" into the lifter face, just worn in an uneven manner....
it is a comp cam Magnum 270h cam. If you think it sounds like it's limited to the cam, I will pull it apart. I don't think the cam is any "special" grind.
did yours quiet down at idle??

 

and would disconnecting the spark plug for that cylinder cause it to quit making noise? if it were a wiped cam lobe?

thanks for all of this great info. I'm just a little freaked out cause i've been working on this for SOOOOOO long. and there is nothing worst than every one going " whats that ticking noise" AAAAAHHHHHH

 

Sounds like a hurt cam to me.
Did you check the filter?
Does that rocker open as far as the other ones?

 

I did not check the filter cause I just changed it after about 40 miles. The rocker appears to open as far as the others...everything "looked" good while it was running with the valve cover off.
is there any way to verify that it is the cam before I start tearing into it? thanks for your quick reponse.

 

I totally understand your frustration, I've been through the same issues with my 340. My cam would just make a tapping noise. it would speed up and slow down with revs and never really got any louder. If your lobe is worn, it would make noise weather or not you have spark applied, if it is indeed a lifter/cam. At this point I'd pull the intake and inspect all the lobes and lifters. Sounds like the preload is somehow messed up. Either you have the wrong lifters, push rods, heads/block milled, something is just not right. If it were me, and I had to do this on my 340, I'd pulled it, replace the cam/lifters, (as my lifter had a 1/8" swip out of the center and the lobe was rounded), pull the pan and clean it, replace the oil pump and clean the pick up and if your worried about rod bearings inspect them all. Up on istallation of your rocker shafts, check the preload, there might be a spec somewhere. I'd also inspet that specific rocker, the pivot for the shaft could be out of round or the rocker it's self got bent. Good luck, keep us posted, and trust me, when you get frustrated, quit, think about it, and come back later.

 

great advice............... thats what i'll do.. cause i'ml definatly frustrated. I'm just not sure why It's only on one lifter and cam lobe. if I had a milled head or pushrod length issue, wouldn't it be on more than one? your right though, it's time to start to investigate the cam with the intake off....

thanks so much. I'll post back when I get a closer look at the cam.


Brad

 

Cut the filter open. It taked ten minutes & costs five bucks and will tell you a bunch.
Cam break in has been problematic this past few years - and seems to indiscriminately kill one lobe.

 

No, it shouldn't.

But cut the filter open anyway and see what's in it - it's an easy way to see if something shredded before going any further.

 

O.k, so I still had the original filter that was on for the break in and the first 30 miles, and by this point the engine was making the noise big time. I only have about 15 miles on the current filter so I thought the original one would be a good indicator. Well it had NO particles anywhere. I couldn't believe how clean it looked. It looked great.
So I guess this is really bad news since a wiped out cam lobe would leave quite a bit of metal behind.....
I'm at a loss.

 

what is the best way to check for a wrist pin issue?

 

Good question. Pull the spark plug wire and see if the noise stops (which you already did).

If it's a top-end type of tick or knock that goes away when you pull the spark plug wire, it's piston/wrist-pin related.

Hopefully someone else will come along and help with this one. I haven't had much experience with wrist-pin issues. But usually, they make noise at idle, cruise, and go away or quiet down when you're on the go-pedal hard.

Does it tick when you decelerate?

 

Good question. Pull the spark plug wire and see if the noise stops (which you already did).

If it's a top-end type of tick or knock that goes away when you pull the spark plug wire, it's piston/wrist-pin related.

Hopefully someone else will come along and help with this one. I haven't had much experience with wrist-pin issues. But usually, they make noise at idle, cruise, and go away or quiet down when you're on the go-pedal hard.

Does it tick when you decelerate?

 

It does tick when I decelerate.
and it does get a bit quieter under load.