motor questions and update

[nhusa]

I took my 1931 $100 motor apart today and found a couple things wrong and a few I don't understand. The motor was covered in grease and oil so I didn't think it was previously rebuilt. When I pulled the head I found a copper gasket and aluminum pistons. the pistons could be moved slightly back and fourth in the bores so I expected there to be significant wear.

question - I expected to find steel pistons and something other than a copper head gasket. Is aluminum and copper normal? Has this motor been previously rebuilt?

The story continues - When I pulled the pan I found small chunks of rectangular shaped metal so I pulled the pistons. The first problem was that the 5/8 socket would not fit most of the nuts so i had to use an 17 mm socket. Later I found that the nuts were slightly deformed - marks on the surface so the 5/8 socket would not fit. I think the babbit looked OK but I found at least three of the oil rings in pieces and the cylinder walls a bit worn. The crank looked good. I now know why the motor was removed from a car.

Next step is to do some measuring and most likely bore it if possible and put in oversize aluminum pistons etc. at least it is a better place to start than the motor that is stuck.

[Gary WA]

Copper gasket is a good thing, the nuts are 21/32. metal could be Babbit material

[Tom Wesenberg]

Clean the top of the piston and you may find .060 or some such marking to indicate the size of the bore. There aren't many engine still left that are standard bore and haven't been overhauled or worked on.

I'm wondering how the oil ring got so broken up?

Model T's came with cast iron pistons, but the A's came with aluminum pistons. Copper head gaskets are very common.

[700rpm]

Save those 21/32 nuts. They're hard to find and original stuff.

[Purdy Swoft]

If a ridge reamer wasn't used before removing the pistons, there is a good possibility that the rings broke when the pistons were removed . Cast iron oil rings are the easiest to break

[nhusa]

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Thanks - I am learning a bunch of stuff -- I now have a strong suspision that it has not been rebuilt or at least not rebuilt recently. The oil rings were most likely broken before I removed the pistons because I found pieces in the pan and in the motor when it was upside down. It was not Babbitt.

There are no numbers on the pistons that indicate they are oversize but two have Ford script and two have L400A The ones with the worse oil rings are the L400A pistons. The bores show signs of rings sticking so they may have been broken if someone tried to unstick the motor without soaking in oil.

In any case I am going to have someone do a rebuild for me - I am quessing -rebore, new pistons and rings, oil pump rebuild and valve lapping/adjustment It has the old mushroom valves.

After that i'll deal with the waterpump, distributor, and carb that all need a bit of work. especially the water pump because it is stuck.

[tbirdtbird]

take your time.
Don't go animal on stuff that is stuck, you will only make it worse. Always think, "I have to be smarter than rust"
Think thru the many various strategies for freeing frozen bolts, nuts, parts, pumps, etc,
such as heat, vibration, soaking with penetrant of choice, tighten-first-then-loosen, etc.
Anyone thinking 'force is required' will lose.

[Keith True]

Sears Roebuck still sells those sockets,or at least they did a couple of years ago.You use an 8 point socket on the main bolts,they have those too.I just went by your place this morning,I was driving a black 30 standard roadster.I went in and out the old Lee road without giving a thought to look for you.

[glenn in camino]

Do you belong to a local Model A club? If so, tell them what you're doing and ask for help or advise. If you live in Northern California, give me your address, and I'll come by tomorrow morning. Model A engines can be rebuilt for much less than the $4000 TO $5000 the so called professionals charge.

[Barber31]

I have 2 $100 engines also. Your post makes me wanna tear them apart and see what I got too. They look to be in pretty good shape from what I can see. Also my other engine I rebuilt, I think I spent somewhere in the $1,000 range for everything (parts, machine work , labor, and specialty tools i needed) and rebuilt it myself.

[James Rogers]

Originally Posted by nhusa

I took my 1931 $100 motor apart today and found a couple things wrong and a few I don't understand. The motor was covered in grease and oil so I didn't think it was previously rebuilt. When I pulled the head I found a copper gasket and aluminum pistons. the pistons could be moved slightly back and fourth in the bores so I expected there to be significant wear.

question - I expected to find steel pistons and something other than a copper head gasket. Is aluminum and copper normal? Has this motor been previously rebuilt?

The story continues - When I pulled the pan I found small chunks of rectangular shaped metal so I pulled the pistons. The first problem was that the 5/8 socket would not fit most of the nuts so i had to use an 17 mm socket. Later I found that the nuts were slightly deformed - marks on the surface so the 5/8 socket would not fit. I think the babbit looked OK but I found at least three of the oil rings in pieces and the cylinder walls a bit worn. The crank looked good. I now know why the motor was removed from a car.

Next step is to do some measuring and most likely bore it if possible and put in oversize aluminum pistons etc. at least it is a better place to start than the motor that is stuck.

Copper head gaskets were used on all original T and A engines till the A was discontinued. Ford only used cast iron pistons in the T. In the A he used aluminum pistons and was the norm.

[redmodelt]

When I pulled my 29 engine down the space between the rings were beat to crap and the rings were in pieces and not from pulling the pistons. So broken rings can happen.

[nhusa]

Originally Posted by Keith True

Sears Roebuck still sells those sockets,or at least they did a couple of years ago.You use an 8 point socket on the main bolts,they have those too.I just went by your place this morning,I was driving a black 30 standard roadster.I went in and out the old Lee road without giving a thought to look for you.

Ken -- if you looked down Meadow Road when you were on Old Lee you would have seen my home about a quarter mile away. The garage was open and the T was visible all day.
Better yet if you had turned down Meadow you would be welcome. We usually have coffee available.

On Saturday we took the T to Newmarket for coffee followed by a trip to Exeter for more coffee. We were discussing a trip to Epping for even more coffee but decided that our Dr would not approve.

If the weather is OK next Saturday, we are firing up the T around 9AM and heading to Portsmouth for a car show that is being sponsored by the Portsmouth High School automotive technology program. You are welcome to join us. Just remember we will be in a slow T with minimum brakes