Continental Z-145 Engine

[MasseyWV]

I have a Massey 135 tractor with the Continental Z-145 4 cylinder gasoline engine. I'm still waiting for the shop manual to arrive, but in the mean time, if anyone knows anything about servicing this engine, your input would be most appreciated.

My understanding is the the Continental Z-134 4 cylinder gasoline engine is nearly identical to the Continental Z-145, except for the stroke and bore, so information about servicing or rebuilding that engine may also be applicable.

Currently, I'm preparing to service the valves by adjusting the valve lash and replacing the valve seals.

 

[Jerry/MT]

I have a Massey 135 tractor with the Continental Z-145 4 cylinder gasoline engine. I'm still waiting for the shop manual to arrive, but in the mean time, if anyone knows anything about servicing this engine, your input would be most appreciated.

My understanding is the the Continental Z-134 4 cylinder gasoline engine is nearly identical to the Continental Z-145, except for the stroke and bore, so information about servicing or rebuilding that engine may also be applicable.

Currently, I'm preparing to service the valves by adjusting the valve lash and replacing the valve seals.

Look on the data plate for the engine on the left side just below the cylinder heas/deck interface. Most of the Z block Continentals have the lash settings on that data plate. The recomendation in the manual will most likely recommend setting them while running. Why are you replacing the valve stem seals? Burning oil at idle?
You best wait til your manual shows up to replace the seals. I've never done them but you'll have to remove the spring on the intake valves and you'll need soemthing to keep from loosing the valve when you remove the spring. Either a special spark plug hole fitting to hold the valve with air pressure form a compressor or getting the piston near TDC so the valve doesn't drop down.

 

[MasseyWV]

Look on the data plate for the engine on the left side just below the cylinder heas/deck interface. Most of the Z block Continentals have the lash settings on that data plate. The recomendation in the manual will most likely recommend setting them while running. Why are you replacing the valve stem seals? Burning oil at idle?
You best wait til your manual shows up to replace the seals. I've never done them but you'll have to remove the spring on the intake valves and you'll need soemthing to keep from loosing the valve when you remove the spring. Either a special spark plug hole fitting to hold the valve with air pressure form a compressor or getting the piston near TDC so the valve doesn't drop down.

You're correct, I'm replacing the valve seals because it smokes (blue oil smoke) at startup and idle. The valves were noisy and I knew they needed adjusted so I figured I'd go ahead and replace the valve seals while I had the valve cover off.

Currently, I've got the sheetmetal and gas tank removed with the valve cover off to perform the needed work. Surprisingly, the inside of the engine, at least under the valve cover, is very clean and free of sludge, but my suspicions about the valve lash needing adjusted were correct

In fact, I've never seen valves so far out of adjustment. I looked at the data plate earlier and if memory serves, on the Continental Z-145 engine, the valve lash should be .015 cold or .013 hot, and currently the valve lash is closer to 1/8 of an inch on the valves I looked at, which tells me that the valve lash has probably never been adjusted. I'll have to turn the engine to check the rest of the valves but I have little doubt that they are the same.

When I replace the valve seals, I'm going to put each cylinder at TDC, then use compressed air to hold the valve in place before removing the spring. The valve spring keepers might be a challenge though, because they're the pin type and if memory serves, aren't the easiest to remove/replace. Having the piston at TDC will ensure that the valve doesn't drop into the cylinder if I should lose compressed air for whatever reason.

As suggested, I'm planning to wait until the shop manual arrives before doing anything more than inspection, because guesswork and engine repair usually results in disaster. I still need to purchase new valve seals so manual or not, I have to wait regardless.

 

[tankerfarmboy]

I would recommend pulling the head right off. I just pulled the head off of my Z-134 engine from my 202 Workbull yesterday. Use a proper valve spring compressor. It will save you from trying to find either the pin or the locks or the spring if it takes off. It will cost you a head gasket but in the long range it will save you a lot of unnecessary words. Just my opinion. Also my book says that "Tappet clearance should be .013" when it is hot and .015" when it is cold. Valve should be set when "hot". Have the engine running (auxiliary fuel tank) at a slow idle at normal temperature." Hope this helps.

 

[MasseyWV]

I would recommend pulling the head right off. I just pulled the head off of my Z-134 engine from my 202 Workbull yesterday. Use a proper valve spring compressor. It will save you from trying to find either the pin or the locks or the spring if it takes off. It will cost you a head gasket but in the long range it will save you a lot of unnecessary words. Just my opinion. Also my book says that "Tappet clearance should be .013" when it is hot and .015" when it is cold. Valve should be set when "hot". Have the engine running (auxiliary fuel tank) at a slow idle at normal temperature." Hope this helps.

I've debated whether or not to remove the head, but I have a good valve spring compressor, and believe I can do it without removing the head. My only concern is the pin-type keepers which may make things a bit more complicated.

Despite the minor issues mentioned above, the engine has good compression (Dry: 155 PSI on all cylinders), runs great, and has plenty of power. However, I'm planning to eventually do a full restoration on the tractor and will also be completely overhauling the engine at that time, so I'm trying to keep the repairs as basic as possible for now.

 

[MasseyWV]

Here are some pictures of my tractor's Continental Z-145 engine with the valve cover removed.

Note the last picture, which shows one of the spring retainers/washers at each end of the rocker arm assembly that are held in place by cotter pins. As it turns out, both cotter pins had failed, allowing the washers to come off the end of the shaft. The resting place of one of the washers is visible in the first picture, and the other one was found stuck to the valve cover.

Fortunately, there appears to have been no damage caused by the loose washers, and I'm not concerned about the missing cotter pins which are either laying at the bottom of the oil pan or were sucked into the oil filter long ago.

More pictures and information about my tractor can be found here: http://www.tractorbynet.com/forums/...rating/241531-my-1966-massey-135-tractor.html

 

[MasseyWV]

I don't know what I was thinking when I said it had the pin-type valve spring keepers. After reading about the possibility that the Continental Z-145 engine may or may not have valve seals, I took a closer look and discovered that it has the traditional split-type valve spring keepers.

However, it appears that it does not have valve seals, which would explain many things. Granted, it's hard to tell for sure until I remove the valve springs, but if indeed it does not have valve seals, I plan to add them to help reduce the smoking at startup and idle. At least until I perform a full overhaul at a later date, when I will replace the valves and valve guides.

Many different types of valve seals are available, so I shouldn't have any difficulty locating the correct seals for this application if none are available specifically for this engine. If all else fails, simple o-rings also work very well.

 

[ThomasH]

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!

 

[Kioti Tom]

Another way to hold the valves in place is stuff the cylinder with a length of clothesline and then bring the cylinder up to TDC. Be sure to leave enough rope hanging outside the cylinder so it can be pulled out.. Method works on aircraft engines. Having air on the cylinder can cause the prop to turn and wack ya..:thumbsup:

Tom

 

[Jerry/MT]

I don't know what I was thinking when I said it had the pin-type valve spring keepers. After reading about the possibility that the Continental Z-145 engine may or may not have valve seals, I took a closer look and discovered that it has the traditional split-type valve spring keepers.

However, it appears that it does not have valve seals, which would explain many things. Granted, it's hard to tell for sure until I remove the valve springs, but if indeed it does not have valve seals, I plan to add them to help reduce the smoking at startup and idle. At least until I perform a full overhaul at a later date, when I will replace the valves and valve guides.

Many different types of valve seals are available, so I shouldn't have any difficulty locating the correct seals for this application if none are available specifically for this engine. If all else fails, simple o-rings also work very well.

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!