I had to do that, with an old engine: pistons allllll gone!
The head is off. It came off with no drama. It was a simple matter to grind the peen off of one of the chain link pins and drift the pin through. Easy peasy. Took all of 5 minutes. The head studs were very clean and the head broke loose and lifted off easily. This was all done with the engine in the car. I figured I might need the weight of the car to provide counterpressure to pull the head off, but it was not needed.
The next step is to pull the engine. The car is largely stripped and I can easily get to all of the bell housing bolts. Is it better to pull the engine and trans as one, or to separate them before pulling the engine?
Thanks again for all the help.
Tim
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Take them out together.
Together. Just did mine, the angle doesnāt need to be severe and you can leave the harmonic balancer on. I used the second row and last row of head studs and a balancer to rock it back a bit.
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Agree, pull them both together. Gearbox tunnel off first of course. Then remove the shift lever. Your mounts will be different from Mitchellās as they changed in mid-production.
You might wanna just remove the top cover from trannyā¦youāll end up doing it anyway. You will have to verify that the āstop pinā (140), or a stop pin or equivalent has been fitted ( some 120s), to limit the movement into 1st gear. Reilly has EXCELLENT info on this. My car had a rather worn stop pin so I went the (equivalent) āwasherā route.
On a different note, Iād like to ask you to do a cooling system check for me (us): since the head is now off and I assume the engine is dry, Iād like to have you fill JUST the intake side of the block with water(thru the coolant slots) to check your blockās water flow characteristics against mine. IF your block is like mine, NO water will appear at the EXHAUST water ports at top of block even as the intake-side water ports are full to the deck surface. I would like to see ALL who have bare 3.4 blocks have this check performed.
It canāt hurt to repeat this, for all LHD 120 when removing the engine, and possibly RHD and 140 as well, that when pulling out the clutch operating shaft through the chassis frame, there is a big spring on the shaft, and there are large flat washers on both ends of this spring. They are there to prevent the spring ends from cutting into the adjacent stationary parts. Be sure that the second flat washer doesnāt drop off and fall inside the chassis frame rail.
Engine and gearbox are out. Iāll check the water jacket, but it may be the weekend before I can do it. The engine held a couple of secrets. None particularly good. The pistons are marked 0.060 over. I didnāt believe it, so I micād the bores. Definitely bored 0.060 over. So it appears that new sleeves are in order. There is also some disgusting gel-like substance in some of the water passages. I have no idea what that stuff isā¦
Next, Iāll pull the crank, see what kind of shape the journals are in and then try to get the pistons out.
Tim
Quote - Iād like to have you fill JUST the intake side of the block with water(thru the coolant slots) to check your blockās water flow characteristics against mine. IF your block is like mine, NO water will appear at the EXHAUST water ports at top of block even as the intake-side
When I cleaned the block of my 3.4 āSā type that is what I observed, the water flow is via the head passages.
Trying to confirm that my block is not an aberration in the sense there is no water circulation in the block by the water pumpā¦the pump only moves coolant up into the head.
I think the path is via the exhaust side of the block into the head, across the head down into the inlet side.
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It is entirely logical that the coolant flow would proceed though the cylinder head from the exhaust side to the intake side. By far, the cooling requirements of the exhaust ports vastly exceed those of the block and intake ports. Every time they open, the intake ports and valves are cooled by a blast of fuel vapor cooled to sub zero by the combined effects of pressure drop and evaporative cooling. On the other hand, the exhaust ports and valves operate as the doors to hell, venting 1,000 degree combustion gasses. The piston passes most of its cooling load to the constant spray of oil slung from the spinning crankshaft, as do the cylinder walls.
Most people are assuming the water in the block circulatesā¦it does NOT in my blockā¦only the head sees water flow. Trying to confirm I donāt have a "faultyā block.
The water pump discharges totally into the block cavity. The flow from the block flows up through exhaust side inlet ports on the head then across the head to the outlet water manifold to the thermostat / bypass housing. No?
Noā¦at the very top of the block, there is a 2 inch deep channel that runs from front to back on the exhaust side of block. The W/P discharges ONLY into this channel, forcing coolant UP into the head, then across it and out the intake maniā¦no path from pump to the lower water jackets surrounding the cylinders. This surprised me during my block clean up.
In fluid dynamics and electricity, the line of least resistance rules all flow. If coolant could circumvent the labyrinth cylinder head cooling passages by short circuiting between the cylinder bores, it would do so and the head would warp in minutes. Even if your block is unusually restricted between the cylinders, I would not be concerned about it. I mean, it apparently ran for several decades in that condition. Besides, how much of the cylinder bore is even jacketed? Maybe half? Most of the cylinder bore is cooled by oil spray.
On many older enginesāadmittedly running at lower temps and rpms-- many had unjacketed lower portions of the bore.
Auburn 6s and 8s of the 20s/40s were that way, and even had a crudely-formed sheet metal brass āmanifoldā that slid into the exhaust side water passage in the block, directling flow up towards the flat head.
The cylinder bore water jackets are quite deep, reaching almost to the base of the bores. Of course, this water serves as a heat sink in this scheme, nothing more.
Jag evidently employed the ācool head, warm boreā principle in their cooling system design, similar to many race engine builders such as Smokey Yunick.
Didnāt we talk about this in Feb '19?
I pulled out some core plugs then just to see.
Here an exhaust side plug is out and you can see through to the intake side.
But here is a pink wire through the water pump port connecting to the upper exhaust side. The two rulers are inserted in all the way they will go. The exhaust side is 2" deep and the intake side is 6" deep.
On the exhaust side these ports at the top do not connect to the core plugs on the exhaust side. There is a web of steel between the upper and lower water jackets on the exhaust side, but not on the intake side.
ā¦
Here is a view from the exhaust side looking through to the intake side, below that separating web.
So there are two chambers on the exhaust side, an upper and a lower. The lower chamber surrounds the cylinders and connects to the intake side. The upper chamber runs directly up to the head at six places.
The steel at the top is much thicker on the exhaust side, and these ports seem to taper away from the cylinders. So I suspect (but canāt be sure without cutting a block apart) that the lower chamber extends up around the cylinders on the exhaust side, but is separated from the upper chamber that connects to the head, and we canāt see it.
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