cam lobe

[thump16]

I found the source of my engine troubles. my 350 had three rocker arms super tight so I set them to specs and while running the engine only one rocker doesn't move with the others so I am thinking i wiped a lobe on the cam. I am going to put onei myself. Do I need anything else besides the new camshaft, lifters and grease? Also would this worn cam cause a small knock during start up?


Sledge

[ratfreak8871]

shouldn't cause a knocking, maybe a ticking/tapping at best. my engine has a slight knock when cold and i tore the whole engine apart trying to find it, i have come to accept it as piston knock, like forged pistons do when cold, even though mine are hyperutectic(sp). other than cam, lifters, and lube you will need a timing cover gasket and might as well do the seal while your there. also try using lucas oil during cam break in along with the lube.both me and my brother had the same problem and the lucas really helped

[cjracing15]

You are going to need a cam & lifters,Intake,valvecover,timming cover gasket and front seal. You may need a carb gasket if you take it off the intake. good luck.

Jamie

[thump16]

Thanks guys. I am going to start this week. The knock is only heard during start up when cold.


Sledge

[f.monroe]

My 77 I drove in high sshool had a cam go flat . It sounded like a rod trying to let loose . My uncle checke it and said a cam would fix it . I didnt believe him but he was right . Hope yours goes well . I would pull the oil pan also . The timing cover is designed to go on first , then the oil pan last . If you try to force the timing cover on , it will sometimes push the seals out and it will leak . Make sure you have a harmonic balancer puller . I also use an installer to reinstall it but a large hammer will work if you have no other choice . In our area , Autozone has a tool loan program that comes in helpful . Also be sure you pull the fuel pump before you try to pull the cam . You should also replace the timing chain and upper gear at the minimum if they are original . I do not know what your level of mechanics is but I would also set it on TDC for number one cylinder before I tore it apart . Makes it easier to reassemble . Frank

[75sierraclassic]

I just had that happen to me last year. The exhaust lobe on my cam had almost completely worn down. If you have A/C in your truck, you will have to remove the condenser to allow for the cam to clear when you pull it out (if you're not pulling the engine).
Also, it would be good to pull off a main cap and check your cam bearings. With all the metal that wore off the cam, it could have done some damage to your bearings.
I pulled my mains off and there was copper showing. I plastigaged them and they were in spec so I threw them back on and crossed my fingers. I also didn't have time to pull the crank.
Get ready for a sore back, it sucks leaning over the engine bay all day!
Good luck, hope everything goes well for you.

[thump16]

Hey F.Monroe,
I am a 15 year Air Force mechanic . I work on air compressors, hydraulic systems, Diesel generators and Gas turbine engines. I got a little experience under my belt but this will be the first time working on a truck engine not to mention my personal vehicle so I might stretch it out a couple of days to make sure everything is good. I really appreciate all the help though especially with the rod knock symptoms. I just want to drive it again.

Sledge

[thump16]

I put the truck in the garage today. Since the arrival of our new born I don't have time to work on it. Hopefully by the april i will have time to mess with it again.


Sledge

[mhicks]

Maybe just a lifter problem?

[jamis]

Originally Posted by cjracing15

You are going to need a cam & lifters,Intake,valvecover,timming cover gasket and front seal. You may need a carb gasket if you take it off the intake. good luck.

Jamie

Jamie's on the money, also you may
add a timming chain set as well, check your dizzy gear if its original.
Check your push rods worn tips or if bent, also make sure they are not clogged with sludge.
Check you rockers and valve tips for wear as well.
Carefull not to damage your cam bearings taking it out and putting it back in. I use a couple of long phillips screw drivers in the timing gear bolt holes to help with that.

Buy some cam break in lube (Moly) and run at 2,000 for 30 minutes to break in.

[Slonaker]

I followed this, for the most part, when I changed the cam on my old engine.

http://www.73-87.com/7387garage/drivetrain/cam.htm

You have to cut the core support (I had to, anyway...) to get the cam out. I cut it with a hacksaw, and screwed it back together with a piece of scrap sheetmetal and four self drilling sheetmetal screws. Painted black, it isn't visible, and it was quite strong.

I didn't remove the condensor. I just unbolted all of the hard lines from the fender, and lifted it up just enough to clear the cam.

Let me know if you have questions.

Slonaker

[thump16]

The motor was built last year. I found out that a shady mechanic supposedly adjusted the rockers but all the parts are new.


Sledge