I got a new head that was missing the cam train. I went to the Junkyard today and pulled everything I needed today. Here is my question. Can I just put it all together or do I need a machine shop to do the work. I have never rebuilt a head.
I would hesitate to install unknown wear, old parts on a new head. You may unknowingly damage your new head. If you know they are low milage parts then thats a different story. Just use commen sense and don't mess up the new parts by installing old. I would not use a old cam on the new parts.
Do you mean the entire valve train or just the rocker shafts, rockers, springs, valves and misc. If the cam caps are missing send the head back the cam caps and head are a set they are bored together and must stay together. As for the rest of it examine it very close clean till you are sure its clean and then clean it again. The use of used parts some times becomes necessary because there is just no source for new parts. Even the cam shaft is iffy if you will find a new one, if a used one shows no galling or excessive wear I would mic it (make sure the bearing journals are in spec) and use it. Jlemond does have some new parts you might check with him.I would have a shop grind the valves. DAVE
Rotating and high pressure parts create a wear pattern to each other.
The cam will lap-in to the followers and vice versa.
Installing the old followers on a new cam - or mixing the parts even from the same cam/followers set can cause a lot of damage.
This is why rebuilding an engine and wanting to reuse the same followers/lifters on the same cam is always a crap shoot - even if you keep the lifters in order and put them in exactly the same position in which they were installed in the old engine can be dangerous.
Subtle changes in cam journal position, fore/aft camshaft positioning, angle of the rocker in relation to the head - all make huge differences.
IF the rubbing face of the follower/lifter refracts light - it is not serviceable from that point.
They may not be as bad as those examples - but they will be very soon if you mix old parts with new or old with other old parts.
That means the little refracted lines you can see running parallel to the camshaft itself - if there's a line on the rubbing face, it's become junk. It will 'click', create a false tolerance or clearance and make adjustment very tricky if not impossible.
The pressure on the cam followers is HUGE! It is the single one worst area for wear if you use the wrong oil (Low Emission oil is the worst) and/or you don't change the oil often enough.
Our Isuzus use some really archaic cam and valvetrain designs that have been done away with for the newer roller-rockers and roller-cam systems. Any time you rub two surfaces together at high speed and high temperatures and low oil film viscosity, you are going to have short life and poor reliability.
One of the most glaring examples of poor cam/follower design was the first Datsun Z-engines with their really narrow lobes and narrow rubbing surfaces.
They advised owners right on the oil filler cap to ONLY use Exxon, Castrol or Torco oils in their engine to keep the warranty in effect, and Pennzoil sued them for excluding them from the advised brands.
It was simple - Pennzoil failed each and every time as well as Kendall GT, Quaker State, Royal Triton, Wolf's Head and a slew of others.
I replaced cams and followers in many of those engines when they first came out, as the dealer would walk away for any warranty consideration if the cams went flat. They KNEW one had used the wrong oil if they did.
So - in a smaller basket - you should never mix/match parts in such a critical area as the cam/lifters/followers system.