Continental Z-145 Engine

[MasseyWV]

If it is smoking at start up, that is a sign of worn valve guides, which if I were you I would have replaced while I was working on it, along with a valve job.

Good luck!

I agree that the valve guides could be worn, and I'm seriously considering removing the head to inspect/replace them (if necessary) and lap the valves. Removing the head would also enable me to inspect the cylinders and clean out any carbon that has built up on the piston/head over time from the oil consumption.

After speaking with a local Massey Ferguson parts guy who is familiar with the Continental Z-145 engine, I learned that it may have valve seals afterall. He told me that if it has valve seals, they would be located just under the valve spring cap, which means they would not be clearly visible when looking through the valve spring.

Fortunately, the shop and owners manuals I ordered are at the post office waiting for me to go pick them up, so I should know much more shortly.

 

[MasseyWV]

If it doesn't have valve seals and is smoking at idle and low power then your valve guides maybe worn. many times even if it had valve seals, you won't find them on an older engine like this. they have long ago disintegrated.
It's worth a try to put seals on and see if that helps. You must have really been down on power if the valve lash was 0.125 inches! The valves were barely opening!

I also wondered if the valve seals may have disintegrated, which would also explain why they appear to be absent. If it uses the o-ring type valve seals, this is entirely possible.

The valve lash gap was more than I had ever seen on an engine and I'm sure that proper adjustment should yeild a considerable power increase.

 

[MasseyWV]

I finally got a chance to tear into it to replace the valve seals, which is easy enough to do. However, the valve guides are worn a bit more than I'm willing to live with, so I've decided to go ahead and pull the head to give it a full valve job, complete with new valves and guides.

Before I began, I shined a flashlight into each cylinder with the piston at the top of the bore, and there was fresh oil on top of all pistons. Despite the oil, I proceeded to remove the first valve spring, and verified that the valve guide was worn by lowering the piston just enough to allow the valve to move. I was able to move the piston and valve because I opted to use rope inserted into the cylinder, as opposed to compressed air, to prevent the valves from dropping into the cylinder.

After a quick glance online, it looks like a complete valve train overhaul kit will be about $200, plus the cost of a head gasket and other gaskets, as needed. I'll know more after I call my local MF dealer to price the parts tomorrow.

 

[Jerry/MT]

I finally got a chance to tear into it to replace the valve seals, which is easy enough to do. However, the valve guides are worn a bit more than I'm willing to live with, so I've decided to go ahead and pull the head to give it a full valve job, complete with new valves and guides.

Before I began, I shined a flashlight into each cylinder with the piston at the top of the bore, and there was fresh oil on top of all pistons. Despite the oil, I proceeded to remove the first valve spring, and verified that the valve guide was worn by lowering the piston just enough to allow the valve to move. I was able to move the piston and valve because I opted to use rope inserted into the cylinder, as opposed to compressed air, to prevent the valves from dropping into the cylinder.

After a quick glance online, it looks like a complete valve train overhaul kit will be about $200, plus the cost of a head gasket and other gaskets, as needed. I'll know more after I call my local MF dealer to price the parts tomorrow.

There 's nothing magic about rebuilding the head that requires you to go to a MF dealer. A good automotive machine shop can install the guides for you unless you have a press and the appropriate tools.They can also grind the valves and valve seats to match, check for flatness and grind if required. Get several bids before you decide where to take it. There is usually a wide range of prices for rebuilding a head.

 

[MasseyWV]

There 's nothing magic about rebuilding the head that requires you to go to a MF dealer. A good automotive machine shop can install the guides for you unless you have a press and the appropriate tools.They can also grind the valves and valve seats to match, check for flatness and grind if required. Get several bids before you decide where to take it. There is usually a wide range of prices for rebuilding a head.

I've rebuilt many engines and heads before, but don't have all the proper equipment like I used to, so I'm planning to press out the valve guides myself, then take the head to a local machine shop and have the new valve guides pressed in. I could press the new valve guides in myself, but don't want to risk damaging them. I'm also going to take the rocker arms with the new bushings and shaft to the machine shop to have the new bushings pressed into the rocker arms and reamed to fit the new shaft.

I may or may not have the valve seats ground/replaced by the machine shop, but won't know for sure until I finish removing the head to inspect them. Either way, I plan to lap the valves myself, just to be sure they are right. I'm picky.

As for which local machine shop to use, there is only one that I trust, which I've been using for many years. They are very good, and reasonably priced.

I was planning to wait until I overhauled the entire engine to do the head, but removing the head and doing it now will give me a chance to do many things which will be required for the eventual restoration. For example, I can sandblast and paint the intake/exhaust manifold with hi-temp paint and replace the gaskets which were leaking badly due to semi-loose bolts.

 

[MasseyWV]

I removed and disassembled the rocker asembly. As expected, the rocker bushings and rocker shaft are heavily worn, probably because the valve lash was allowed to go without adjustment for too long.

Also, I removed the head and have begun soaking the valve ports in carb cleaner to remove the accumulated carbon deposits caused by burning excessive oil. After pouring the carb cleaner in the valve ports, I discovered that 3 valves are leaking, probably because the valve guides are worn beyond tolerances, causing the valve seats to wear unevenly.

Fortunately, the cylinder walls are in great shape, and only show minimal signs of wear, indlcated by a very slight ridge at the top of the cylinder. No noticable scratches or score marks are present.

 

[MasseyWV]

Last night, I finally got around to removing the valve guides from the head, using a special tool I made for my air hammer.

The tool was made by tack welding a bolt, that was cut and ground to the proper size, to an old pointed chisel air hammer bit that I wasn't using. The valve guides were pressed out from the top to aviod being jammed by carbon deposits, and came out easily. Note that it was done without heating the head.

When the time comes to fit new valve guides, I will have the machine shop do it, because the valve seats must be precision-ground whenever the valve guides are changed.

 

[MasseyWV]

I've read that the Continental Z-145 and Z-134 engines used the same cylinder head and head gasket, but wasn't sure until after I had removed, cleaned up, and disassembled my Continental Z-145 cylinder head to give it a full valve job.

While I can't be certain if the Continental Z-145 and Z-134 cylinder heads are identical, I do believe they use the same casting. Here is a picture of the number (Z134 A801) cast into the top/side of my cylinder head, above the intake/exhaust ports. The Z134 part of the number leaves little doubt, but I'm uncertain what the A801 part of the number means. Perhaps it's some sort of machining identification number.

The numbers were very faint, but the head gasket was identified with the number (Z134A 401).