I was expecting some issues with fuel. The fuel tank has not been really cleaned and I was expecting on getting some debris from the fuel tank. I finally had it going up and down the hills. Then I heard some bad noise. Even the wife said “that is not good”. It died and I pulled over. It started right up and then someone turned on the mosquito fogger. Up on the trailer it went.
I was finally got back to the house and pulled the number 4 piston.
Here is what I found.
Now for the questions:
Is there something I could have done to prevent this?
The pistons are .040 and I was going to go back with the same. Is this ok?
Is this a high compression piston?
Should I replace just the one? The rest seem to be ok.
I did run the finger nail around the cylinder looking for some scratches. I didn’t find any. So I was going to do just a quick hone, nothing major.
What should I be looking for? What should I be watching for? Any and all advice is greatly appreciated.
Here is what the cylinder looks like.
Do you see any issues with the cylinder?
I suspect the pistons were fitted without enough clearance and when the engine got hot they seized and galled. I think you need to consult with Royce or Nolan or both.. What do the other pistons look like?
Haven't pulled the other three. I was hoping to leave them alone.
That cylinder wall does not look good. Are those pits in the cylinder wall or just a bad photo?
Use a good stone hone on all 4 cylinders. Check the piston to wall clearance. Check to see if the pistons have taper, they should. Some pistons have made it into engines that do not have any taper. That,s a problem as the top of the piston has way more material than the bottom. and the top sees way more heat. It will expand more than the bottom and stick if there not any taper.
I think you can clean up the pistons, Hone for a better fit and put it back together. Scott
Looks like and the timing is right for a classic case of insufficient clearance for the pistons. If the problem will occur it will typically be within the first couple hundred miles of use and when the engine is actually experiencing some degree of load. I hope the photos are just bad and you could get away with honing the cylinder to clean up any scars on the walls.
If one was too tight, most likely the others are too. If you are real lucky, you might get away without messing with them but if it were mine, I'd at least pull them and inspect.
A friend of mine had this happen and took the cheap way out by cleaning and then sanding the sides of the pistons, cleaning the ring grooves, honing the cylinders and put it back together. Some 20 years later it still runs fine and doesn't smoke or use any more oil than the next T. That technique should mortify any respectable engine builder but sometime folks do stuff that works even if it sounds bad.
I would check the rods on a gig before reassembly??
I think it is bad pictures. Taken with a phone. I will try to get better pic tomorrow. The cylinder seem smooth.
Mine all did that. Cleaned up the bores and it still runs just fine.
The engine in my 15 seized soon after I started driving it. We were going up a long hill when it started to loose power and finally stopped. You must remember, now, I was a newbie at the time! After I scratched my head a few minutes, the engine had cooled and it turned over, started, and went on up the hill just fine. A couple days later we went over the hill the other direction. Daisy again got hot but this time she made an audible squeak as she came to a stop. That time the crank could not budge the engine. Once home, the head came off and #4 was the obvious culprit, the piston having a similar appearance to yours, but the cylinder wall was scratched an would hook my fingernail.
There was a tour coming up in 2 weeks that I really wanted to go on, so I ordered a new set of pistons and rings. Same size as the damaged ones. Didn't measure the bore, just ran a hone until the wall looked good except 2 deeper scratches. Remember, I really wanted to go on that tour!
I went ahead and put the piston in and went on the tour. The car ran just fine. Didn't even smoke like I thought it might. That was 10 years and probably 30,000 miles ago. I can keep up with anyone not running a high compression setup, and still does not smoke. I imagine quite a few T's were repaired like this in the day. Best to do it right, but at times you do what you have to. At the worst, another piston will be to tight or the car will start to smoke. Then you can pull the engine and do it right on your schedule.
Oh, yes, one thing I did and would suggest you do, install an outside oil line.
Sounds silly but lube the ring grooves and pistons real well on assembly, real well. The pistons must have plenty of lube 'til the splash starts. Any galling caused by a dry start will decrease clearance and doesn't wear off.
Walt wrote: "A friend of mine had this happen and took the cheap way out by cleaning and then sanding the sides of the pistons, cleaning the ring grooves, honing the cylinders and put it back together. Some 20 years later it still runs fine and doesn't smoke or use any more oil than the next T."
I would try filing the high edges off the piston skirt, not sanding, but otherwise try the same approach. Just check the ring gaps and the skirt clearance to the cylinder - should be at least 0.004" down at the bottom of the skirt.
Did it boil in the radiator or show abnormal heat going up the hills?
While you have the head off, check the water jacket around the rear cylinder with a piece of wire from a coat hanger so it isn't full of rust and debris..
And no, it isn't any high compression piston - just the standard style.
(Message edited by Roger K on October 03, 2016)
Looks like it got hot. May be able to save that piston by sanding it with 320, 600, 800, 1000, 1200, 1500, 1800, and 2000 sand paper then polish it.
The bore bust be honed at least. Then check for taper. I bet the bore is not good. You need to hone the bore then find someone who can measure it top center and bottom.
You may need a new radiator too.