F 134

Just an Internet search of ic engine combustion pressure.

We could calculate backwards from drive axle torque, but I don't know the piston crank dimensions.

Dividing the output torque by crank length should give me the force on the piston (ignoring all the losses). Divide that force by the piston area (7.7sqin) should give me the (minimum) combustion psi for that output torque. There's a flywheel, 4 pistons, 4 cycles, compression strokes, etc, etc all at play and they all consume energy, so the calculated pressure is likelly off (lower than actual) but a good place to start.

 

It is also interesting that we were able to do a compression test on my original engine and produce 135 psi in one cylinder. That's more pressure than I can deliver to the cylinder with my shop air compressor (125 psi). So... as evidenced in the compression test, my starter can produce more torque (and piston force), via the flywheel gear, than I'm going to be able to produce with 125 psi compressed air in a cylinder. I sure hope mine is a seizing problem the MMO will effect.

I wonder if thats how the previous owner burned up the starter (i.e. trying to break this stuck engine free.)

 

Sooner or later... it only takes a day to pull the head, and replace it.

 

I agree with Pete. After all the efforts, and soaking with MMO, and still not freed up, I would be pulling the head, oil pan, and timing cover.

 

Where is timgr when we need him? He would certainly have a comment.

 

I'ld pull the oil pan and timing cover before the head. In theory you can only apply pressure to #3 and #4 due to the valves and even then there is the chance they are near top and bottom of the stroke.
Pull the oil pan find out exactly what cylinder or bearing is holding up the show.

 

The cylinder bore of the 134 is so small that there is no practical reason to try to add compressed air to assist with “freeing up” a stuck engine, plus this would only be (minimally) effective if the engine were stuck in the mid-stroke position.
Pressurizing the cylinders could assist with better lubricant penetration/soaking, but again, not very significant.
Attempting to turn the flywheel will be the best approach to unstick the engine, short of dis-assembly. I usually end up with the crankshaft out and the head off, and deal with one piston at a time. Usually, a couple or more pistons free up without much fight, and one or two (on V8’s) are the ones that are locking things.
-Donny

 

I put fresh MMO into the cylinders and tried compressed air (about 150 psig) one by one.

Nada.

I could hear air leaking out of two of the cylinders and they wouldn't build full pressure. Some oil mist was discharged from the inlet port in one case, and from an exhaust port in the other case.

In two other cylinders it blew out immediately as expected, through open valves, one an intake valve, one an exhaust valve.

I'm ready to move to disassembly after Christmas, starting with the oil pan to see where I am there, then with the heads as needed.

Thanks all for your comments. Happy Holidays to all.

 

What am I to look for when pulling the timing gear cover? Or is that just part of the disassembly sequence?

Thanks.

 

With the timing cover off you can pull the gears and spin the camshaft to make sure it's all free and just the bottom end is hung up. Also part of disassembly and making sure the oil holes in the camshaft bearings are where they need to be.

 

I finally got back to my olive drab engine to get it rotating. Since I had exhausted all the non invasive attempts to get it rotating it was time to pull the oil pan to loosen the bearing caps, and then the remove the head and give the pistons a wack.

Removing the oil pan revealed a clogged oil pick up filter. So I cleaned that up.



Losening the bearing caps had no effect on the stuck crankshaft, so on to the head.

I stripped everything off the engine before removing the head. The rocker arm assembly came off as a unit but the two end towers would not come off the shaft. Everything else disassembled easily.

I trimmed a 2x4 to about 3" and cut off the corners until it fit inside the cylinder bore. Two very light taps with the head of a sledge hammer and the pistons broke free.



Rotating the crankshaft revealed two cylinders with some surface rust. These were the two pistons with valves open to the atmosphere:



The head and block surfaces cleaned up nicely with a rotary wire brush on a drill.



My next move will be to remove the ridge in all cylinders, with a ridge reamer. Then I'll remove the pistons and crankshaft. Then i'll use a ball hone to clean the light rust from the cylinders to see where I am...

 

If I test the existing bearings' end/side play, and check all of them with plastigage, is there another reason to replace all the bearings? I can appreciate it may simply be good practice to to install new consumable parts when you've gone this far... but this engine will not travel 1000 mi in a year...

 

If the existing bearings are within specs, and show no significant scoring they may still be serviceable, but with all the crud you found in the oil screen I would be surprised if they are all in good shape.

 

Since this is my first rodeo, I have no idea which bearing and ring sources to trust... But this is a 1000 mi/year car... Maybe it doesn't really matter all that much.

Will dig through ECJ5 old posts for past recommendations.

 

When I can find them I prefer Federal Mogal, but I have bought bearings from RFJP.com which were labeled JMP (Joes Motor Pool), and they seemed good quality.

Hastings brand rings are what I use, and Silvolite pistons. Classic Military Vehicles sells these, as well as the "Best" brand copper head gaskets which is the only head gasket I will use.

BTW - Bearings, pistons, rings and rods are the same for F-134 and L-134.

 

If the bearings measure fine with plasti-gage and don't have visible contamination there is no reason not to run them.

 

Do you have to anneal the copper gaskets? Often times on small engines they leak because they are too hard. I used a fel-pro on mine after the omix one failed instantly. I knew it was crap but i had it so I tried it.

 

No need to "anneal" the copper gasket.

The main reason head gaskets leak is a failure to re-torque after initial heat up.

I have used many Fel-Pro gaskets over the years without complaint, but have been using the Best Copper gaskets for the last few years and have never had any of them leak. I torque the studs to spec on assembly, run the engine until it is hot usually by taking a five mile run to town and back. Let it cool down overnight and re-torque the studs the next day. I again check torque values and adjust if need after putting around 100 miles on the engine, and I check torque again at first tune up.