Tickin lifter still 351m

[Mercmarquis]

Heres little backround on the truck first. I bought it in January. The motor was rebuilt by the previous owner and looks like it has. Real clean inside. Had a ticking lifter then and it dropped a valve. Whoever did the heads before had them cobbled together. Different style retainers on different valves, just real ugly. I've since put in a smaller cam, new lifters, had the heads rebuilt with new springs, guides, seats...ect... I had the machine shop check my pushrods and rockers and they were all in spec. Broke the truck in like every other cam swap I've done, no issues till now.

The other day I was cruising down the highway to go to my doctor's appointment. I started hearing the infamous ticking. Sounds exactly like before except it only does it from 1500rpm up and quiets down around 3000. Doesnt do it at idle like before. Has good oil pressure. The truck runs awesome other wise. I'm not sure whats happening but I'd like to fix it. I want to hear what you guys think it could be. I'm out of ideas now.

[gadget73]

You replaced the lifters with the camshaft right? I'm also assuming those are adjustable rockers on an M motor? Maybe one of the adjuster nuts backed off a bit.

[Mercmarquis]

Yep new lifters..and nope, pedastal mount rockers. I'm gonna order another set of valve cover gaskets tomorrow and pull the v/c. I torqued em to 25ft/lbs...maybe they backed off. I dont know at this point.

The thought of swapping in a 429/460 is running through my head at the moment now. Same motor mounts and bell housing.

The rear main seal is leaking, I dont really want to know what else could be wrong in there and who rebuilt the thing. Boggles my mind!

[Pirate]

You have one of the three following problems:

1. Junk lifter.

2. low oil pressure

3. cam lobe going south

[Mercmarquis]

I have pretty good oil pressure...20-22psi hot idle and it goes to around 40psi driving along the highway at 3000rpm. Its a brand new cam, I used comp break in additive and broke it in like i've done with every build. The truck had a lifter tick when I bought it. I inspected the old cam and there were no bad lobes. Everything looked good. I'm gonna pull the V/C today to make sure the rockers are torqued if I can get a pair of gaskets. the truck runs awesome other wise. I'm wondering if it could be something else besides a lifter making that noise. Fuel pump? Flex fan? I'm gonna ask around campus to see if someone has a video camera and take a video and post it to see what you guys think. If all else fails maybe I should try another set of lifters.

[Pirate]

Its a brand new cam, I used comp break in additive and broke it in like i've done with every build. Maybe I should try another set of lifters.

Please refer to my "Flat Tappet Failures" article in the Circle Jerk forum.

[Mercmarquis]

I read it a while back mang

[Mercracer]

I read it a while back mang

Pull your valve cover and check lifter preload..... That will tell the tale....

[P72Ford]

Please refer to my "Flat Tappet Failures" article in the Circle Jerk forum.

You should add this onto that thread... (sorry, I can't post in there)

http://www.racingheadservice.com/Information/ArticleDetails.asp?ID=-1228096506

[Mercmarquis]

Rockers were all tight, I'm gonna get another set of intake gaskets this weekend and pull the lifters. If the lifters look like there are no lobe problems I will try another set.

[Mercracer]

Rockers were all tight, I'm gonna get another set of intake gaskets this weekend and pull the lifters. If the lifters look like there are no lobe problems I will try another set.

Lifter preload has absolutely nothing to do with the rocker bolts being tight......

[Mercmarquis]

I'm sorry mang I had a brain fart, preload didnt register in my head. With pedastal mount rockers you use a straight edge and scribe the push rods right?

[Mercracer]

I'm sorry mang I had a brain fart, preload didnt register in my head. With pedastal mount rockers you use a straight edge and scribe the push rods right?

It is difficult to get accurate measurements that way. Parallax is an issue. You can check it the same way as adjustable or stud mount positive stop. Adjustment is just trickier... With both valves closed at TDC compression stroke, unbolt the rocker and then screw it down slowly by hand just until the end play/lash is out of the the pushrod. It will just be resting against the lifter piston. It will still spin, but there will be a slight drag.
Then you count the revolutions of the bolt until it is just snug. This is your preload. You are compressing the piston in the lifter.