1939 Cadillac LaSalle Piston

[G HIGGINS]

Hi Everyone:
                  I have a 1939 LaSalle was rebuilt in 1980 (Motor) got antifreeze in one cylinder and I need one piston this is a 4 ring piston std size. Thank you. You can e-mail me at georgess@juno.com or call 352-684-5293. Or if someone else would like to split the cost of a set of pistons that would be ok also. Thank You.

[Bobby B]

George,
Hi. Just out of curiosity….If you have anti-freeze in the cylinder, how is a new piston going to help you? Blown head gasket? Hairline crack in the cylinder wall/deck? These engines are known to have overheating problems and hairline cracks. I had three cylinders filled…..
                                                                                                       Bobby

[Steve Passmore]

George,
Hairline crack in the cylinder wall/deck? These engines are known to have overheating problems and hairline cracks. I had three cylinders filled…..
                                                                                                       Bobby

Permit me to come to the defense of these flatheads Bobby as I'm a little bias.       In all my experience overheating has been caused by neglect usually a result of standing for many years and rust and crud settling in the rear cylinders and radiator. When perfectly clean as when new I'm sure they ever had this issue. I clean all my engines spotlessly internally and have had them stood in heavy traffic for over an hour on a summers day without ever overheating. One is still running cool after 20 years.  After all, when new they had to perform in all situations in all States.

I'll agree a certain amount about the hairline cracking but to my knowledge this is only with the later blocks as Cadillac probably in their efforts to get better flow and more BHP made the recess from the  inlet valve to the cylinder much bigger and weaker in the process. This as you know is where it cracks.      In all the pre War and War2 engines I have owned in the last 25 years this is much smaller and I have never seen this problem.   Just last year I had to strip the 48 engine in my coupe to discover it had been cracked, repaired and sleeved. Up until then I have never come across it this large cut away section of the block. 

[Bobby B]

Steve,
   No defense needed.   I will agree, wholeheartedly, that these engines are very robust. In fact, I ran 70 MPH on the highway on 5 cylinders.     After then, I noticed the water coming out of the tailpipe and a slightly rough idle, which brought my suspicion to look further, only to find out disaster had struck. I agree 100% that people have abused these engines over the 70+ years that they've been around. In fact, the previous owner of mine should have been locked up, had there been a law regarding vehicular abuse. The worst being over-heating, only to be followed up by adding cold water to the system, promoting cracks. All three engines I've had were loaded with SO much crud around the rear two cylinders that it was almost cement-like. Yes, there is a lot of neglect going on, so I should not have stated that theses engines are prone to overheating with proper care…Just prone to disaster when not treated respectfully! So far my fresh rebuild has been sitting at the 180-190 degree mark and hasn't budged, so yes, I believe there is hope for me yet. What other engine can idle at 500 RPM and as smooth as glass……...
                                                                                                                                       Bobby

[Brad Ipsen CLC #737]

Just an added theory for discussion as to why the flat heads crack.  First I think all years crack from my experience.  From parting several old engines it is about 50% chance when you buy an engine it will be cracked.  I think it is all because of the crud in them messing up the cooling water flow by reduced flow going to the wrong places in the engine.  We really can't blame the old owners too much because first they did not have the money to buy permanent anti-freeze and inhibitor which was relatively much more expensive then than now and there was not the knowledge of its importance.  When the flatheads were worthless they would still keep running so why spend more money.  Even today people do not change antifreeze like they should in modern cars when it is so simple and easy to do.  When the flatheads are clean and rebuilt now I would bet there is not one that has cracked and I know they do not overheat at least up to 105F air temp.

[G HIGGINS]

George,
Hi. Just out of curiosity….If you have anti-freeze in the cylinder, how is a new piston going to help you? Blown head gasket? Hairline crack in the cylinder wall/deck? These engines are known to have overheating problems and hairline cracks. I had three cylinders filled…..
                                                                                                       Bobby

I filled the cylinder up with penatrating oil and let it sit for a week and it never went down so I feel good about the cylinder will check the head to see if it is warped close look at the gasket the corner near the cylinder looks like it was leaking there. My piston was eaten by the antifreeze looks like moon craters on top LOL  so I want to replace it and see what happens. There was no antifreeze in the oil.

[Bobby B]

I filled the cylinder up with penatrating oil and let it sit for a week and it never went down so I feel good about the cylinder will check the head to see if it is warped close look at the gasket the corner near the cylinder looks like it was leaking there. My piston was eaten by the antifreeze looks like moon craters on top LOL  so I want to replace it and see what happens. There was no antifreeze in the oil.

George,
   Hi. If the rings are in good condition and it's not too bad of a leak, sometimes you"ll just burn it out the tailpipe during combustion.  Eventually, it becomes worse. Obviously it took it's toll on the head of the piston, but maybe you caught it in time, before Hydrostatic Lock occurred. Did you do a compression and /or leak-down test before you pulled it?
                     Bobby

[G HIGGINS]

Hi Bobby:
               Had a race shop building race motors for 34 years, could not turn over motor found antifreeze just on the tip of the #1 spark plug so pulled that head and found where the head gasket had leaked into the cylinder. Just got this car last year but could not work on it then the man I got it from had it for the last 40 years. He said he ran the car about one year ago nice guy but he is 89 years old and I think he missed that by about 5 years. lol car only has 53,115 miles on it. they rebuilt the motor around 1980 and did the interior and painted the car. Overall the car is really nice, had a lot of cars over the years but impressed how the door key locks and trunk lock works and door push down button to lock.
            I ordered wind shied wiper blades they sent me a anco # 20-09 but this doesn't fit my wiper arm. Wiper arm has canada 1936-38-39 and patents numbers on it. Also the end where blade hooks on says canada 1935.
              Car seems right as motor number matches the frame number.   

[Bobby B]

George,
Hi. So after you pulled the head what was the diagnosis by the shop? Outcome / Plan of attack? I'm not getting the part why the motor was frozen. I got stuck with a similar situation. 90+ year old man who owned the car forever. I don't know who was working on it, but he must've got taken for a lot of money. I can't believe that he was actually driving the car around…..Keep me posted.
                                                    Bobby

[gary griffin]

I am entering the conversation with egg on my face.  I just had the water in the cylinders problem myself. The engine ran fine when rebuilt but then sat too long. Rebuilt had the thick copper gaskets with softer filler between the copper sections. I did not re-torque as I should have. A couple of old sages in the club have since told me I should have re-torqued the head bolts several times with those gaskets.  Luckily I have found no serious problems. Since WD-40 is   heaver than water I filled each cylinder with it to a level higher than the water was. (About 1/2 inch on a couple of cylinders) A few drops of water came to the top. My biggest surprise is the amount of sludge in the pan and some of the lifters had lost their prime which was probably good because I don't know what would have occurred if the engine had started? New gaskets coming today and hopefully I will be running the engine tomorrow or Sunday. The sludge bothers me a little though.

[Bobby B]

Gary,
Hi. Every one of these engines that I've opened that hasn't been rebuilt, has about a solid 1-2" of muck in the bottom of the pan. You need a metal blade putty knife to manage that nightmare.
                                                                                                      Bobby

[Steve Passmore]

Gary,
Hi. Every one of these engines that I've opened that hasn't been rebuilt, has about a solid 1-2" of muck in the bottom of the pan. You need a metal blade putty knife to manage that nightmare.
                                                                                                      Bobby

Me too Bobby but I think Gary is talking about his re-built engine which is a bit disconcerting.

[jackworstell]

    Steve......I'm helping my friend with a 1937 Cadillac series 60.     The engine has recently been rebuilt and has been run a little.   Looks like we should re-torgue the heads    ( 1941 heads on what I think is a 1938 block...no draft tube for the crankcase........ and a rope seal for the rear main, not a slinger )

    What torque  ( in ft-lbs ) should we use ?    In this regard does it matter what sort of head gasket was used ?

     Incidentally the engine is still set up for positive crankcase ventilation  eg  there is a small line venting the crankcase to a small opening in the bottom of the intake manifold and another vent line running to the top of the carb.

Jack Worstell   #7558

[Bobby B]

Me too Bobby but I think Gary is talking about his re-built engine which is a bit disconcerting.

Steve,
Hi. Gary and I had a nice conversation the other evening. He seemed to think that it was the head gasket from a visual inspection. Hopefully, he's getting the new gaskets over the weekend and is going to try and get it back together and report back. If I were closer to him, I would lend a hand, but I'm not. We're on opposite ends of the coast. We'll be keeping our fingers crossed…..
                                                          Bobby

[harry s]

It is pretty amazing how much variation there is on the head bolt torque after a run to operating temp. I think it is a good idea to run and re torque at least twice (65-70 ft#) and also to re torque the manifolds as they will vary greatly also (25-30 ft#). Gary, Glad you were able to find your problem and it wasn't any worse than it is.    Harry

[Steve Passmore]

Hi Jack.  Harry has given the answers you need.  Re-Torque it no matter what gasket you use. You may find the copper asbestos will go down more than the composite type.

[quote author=jackworstell
     Incidentally the engine is still set up for positive crankcase ventilation  eg  there is a small line venting the crankcase to a small opening in the bottom of the intake manifold and another vent line running to the top of the carb.
Jack Worstell   #7558
[/quote]

When I tore my 38 engine down Jack I was checking to see if all the pipework was clear and discovered the pipe you speak of attached to the underside of the manifold from the crankcase was completely blocked. Nothing seamed to shift the blockage so I ran a small drill bit through there and to my surprise I was drilling out cast iron? Anyway, put it all back together and it ran dreadfully, would not idle at all. Screwed a small bolt into the fitting and she ran great again.  The engine just couldn't stand that sudden loss of manifold vacuum. Perhaps Cadillac discovered this and rather than changing production just opted to not drill the manifold out because full crankcase ventilation was on the drawing board??

[jackworstell]

Steve....thanks for the tip.

Eventually we will remove the intake and exhaust manifolds so we can double-check several things....including
the vent hole on the underside of the intake.

Jack Worstell  #7558