DirtyScotty
Oct 21st, 05, 02:44 PM
I recently rebuilt my engine. I had a very slight tick or knock after break-in. After listening to it, it sounded most apparent from the fuel pump. When I took the pump off you couldnt hear the tick. I put a new fuel pump on and the noise was still there. I dont think it is a rod or main bearing because I have excellent oil pressure, all my specs that have been checked during assembly over and over are well within spec and the tick sounds like every revolution of the cam not the crank. Today I thought I would pull the valve covers to watch the valvetrain operation. I marked all the pushrods. One pushrod is not rotating. A few are slow, like a full revolution is about 25 seconds. The rest turn at a good pace. I am assuming that the lifter under the one pushrod is not rotating also? One of the very slow rotating pushrods is closest to the fuel pump eccentric on the cam. I am wondering if this tick is going down the fuel pump pushrod to the pump and worsening the noise? What are your recommendations at this point? :( This sucks cause I am not comfortable driving this car. I have driven it maybe 200 miles and it runs good and strong just this noise cant be good so no more driving it.
DirtyScotty
Oct 22nd, 05, 09:12 AM
If the lifters are bad will the cam be junk too? What would cause the lifters to go bad when they are new and the cam was installed and broken in properly? What would cause the lifters to not rotate in their bores? We spun them during assembly. What can I do to avoid this happening again? If I look through the lifter bores will I be able to see the conditions of the lobes good enough to determine the condition of the cam? Thanks
Xx-007-xX
Oct 22nd, 05, 07:30 PM
I put a targetmaster 350 in my 68 back in 93 and all the while that I had it running before I took it apart(which is now) it had a tick in it too. It was coming from the fuel pump area, I just figured it was how the engine sounded and since it was a target master engine, I just ignored it. I have never had a problem with it. I am going to put it back into the car for a while till I can afford a kick butt engine to put into it, and if it still ticks then I'm just going to ignore it, besides the tick isn't very loud and the only time you can really hear it is with the hood open and even then you have to tune the sound into your hearing to notice it. Most mechanics I talked to said that it isn't anything to worry about, so I say don't worry about it.
PS- it is a known fact that 90% of things people worry about-never happen........................007
Everett#2390
Oct 24th, 05, 04:35 AM
If the lifters are bad will the cam be junk too? What would cause the lifters to go bad when they are new and the cam was installed and broken in properly? What would cause the lifters to not rotate in their bores? We spun them during assembly. What can I do to avoid this happening again? If I look through the lifter bores will I be able to see the conditions of the lobes good enough to determine the condition of the cam? Thanks
Mis-machined lifters will not spin. Remove the problem lifter and view the bottom with a straightedge up against a light.
You should see a round bottom. This round bottom and a slanted lobe are the ingredients to a turning lifter/pushrod. If there is a groove worn in the bottom of the lifter from not spinning, then replace it.
The cam lobe is slanted, but not the nose, its flat across. The lifter runs on the edge of the lobe on the base circle and maybe halfway up the lobe, then full contact comes into play as the nose of the lobe, point of max lift, goes through.
Not much you can do to prevent it, if running a GM cam, use GM lifters. Ask me how I know. I would use the cam manf recommended lifters. Most aftermarket cams & lifters are soft material. They don't seem to be as strong as OEM, some brands anyway.