rebuild or replace head

[ajnsbdfr]

Help! I am having problems with my '78 124 motor. At one point it was knocking after it warmed up. I adjusted valves with no luck, changed to a heavier oil, no luck, removed camshafts and did not find any real damage to cams or any broken springs. I removed head and other than the valve heads being a little pitted I did not find anything wrong, so I cleaned everything up and replaced with new gaskets. Now it is knocking/clacking intermittently from the camshaft area (sounds more like the intake side). Camshafts are aligned correctly with crankshaft, starts easily, runs a little rough, getting good spark to all cylinders, oil being pumped to camshafts.
I'm at that point where I am not sure if I want to rebuild head myself or buy one for around $500. How hard is it to remove and replace valve guides?

[baltobernie]

Mechanically, you've diagnosed quite a bit. Are you certain it's the valvetrain, and not, say, a worn wristpin or con rod bearing?

Just a WAG: Maybe the pitted valve faces are the result of pre-ignition, and the noise you hear is detonation? Try backing off the ignition timing a little bit, and see if that helps. If it were worn valve guides, you'd get a big plume of blue smoke every cold startup.

[katsi]

Maybe you did not shimm the cams correctly.

[bulldog4444]

I'm kind of with katsi, you may need to re-shim your valves. They will clack like mad with too much play. You just have to be good with your math if you change any out. The shop manual will spell out the correct intake and exhaust clearance needed between the cam and shim. Just add the difference to the number on the bottom of the shim and order the appropriate replacement, minus the clearance specified. It is also advised to have slightly more clearence rather than less if between numbers in shim sizes.

I ordered a remaned head from IAP back in 2005 because of a chipped valve. The reman was very nice and of course all the shims had to be ordered. I kept my original core because it was in beautiful condition and someday will send it off to someone to get it rebuilt. You will need a shim tool to compress the spring to pull out the shims out of the buckets. If I were you I would go with the reman.

[124JOE]

it will always be easy to just get a reman.
it should always be cheaper to rebuild it.
unless you are resizing the valves.
i would have someplace do it for me.
unless its totaly junk.

[seabeelt]

Time vs $$$.. Me I am always in the Time factor because I'm too cheap to spend the money. Now I find I dont have that much time either.

[pro4art]

Help! I am having problems with my '78 124 motor. At one point it was knocking after it warmed up. I. Now it is knocking/clacking intermittently from the camshaft area (sounds more like the intake side).
I'm at that point where I am not sure if I want to rebuild head myself or buy one for around $500. How hard is it to remove and replace valve guides?

==============
Have a machine shop do the guides. It's nothing you should do manually, without previous experience. Giudes don't/can't cause noises.

You are using 2 different desciptions for your problem.
"Knocking" is totally different than "Clacking"
"Clacking noise, intermittantly only, is a common noise in DOHC Fiat engines with higher mileage, over 50K. Usually sounds to be around #3 and #4 cyls.
Possible distributor play allowing the dist shaft to move up and down. Also, worn lifter holes and lifters can cause the noise from either cam. "Intermittant Only" means nothing serious right now, but should be diagnosed. Valve clearances should be at/close, to max stock spec for best performancer, and ease of carb adjusting, and no large variance from valve to valve.
"Knocking" is a serious problem, but is never intermittant.