206 engine locks up in 3 days?

A charged battery did no good, so eventually I removed the starter. I found out that the engine was frozen in place and would not turn in either direction, by prying on the ring gear through the starter hole. I didn't see any movement, but I could hear a gentle clunk in both directions. The last thing I tried was removing the spark plugs, no change.

The T/A lever was left in low range, That shouldn't make any difference unless the high side clutch still holds when released, should it? Flipping the lever back up didn't help.

Any suggestions would be appreciated.

Thanks!
Kelvin

Between running on Friday and finding it locked up Monday, actually on Saturday, I put the restored headlights, brackets and all on the tractor. I used 1" bolts and apparrently they go in the bellhousing just far enough that they bound up the flywheel. If anyone else ever does this at least they will know what to look at first.
Thanks for all the help!
Kelvin

Sounds like you may have some parts that do not have the proper clearance on the crank, in the cylinders or possibly the oil pump.

If you replaced the main or connecting rod inserts, did you make certain that the caps were on in the proper location and oreintation? If a cap gets inverted, the inserts can spin in the rod or main making the engine go tight.

If you had the cylinders bored, the pistons may not be sized correctly for the bore. Typiclally, the engine will spin when it is cold under this condition and tighten up when warm. This does not seem to be the likely problem but if the pistons were damaged while running it can still lock up.

If you removed the oil pump, there is a clearance requirement when it is reinstalled. It typically requires 3-4 of the shims to get the proper clearance between the crankcase and the gears.

I would suggest you pull the side cover off and inspect your rod and main caps for signs of heat. Hot caps will typically be dry where others will be covered with a film of oil. I would also inspect that the caps are in the proper place and proper orientation for the mains, rods and cam. I would also look at the piston skirts and cylinder walls for any sign of heat or scoring.

With the side cover off, I would open up the distributor and turn the rotor as far as it will go in both directions while watching the oil pump/distributor drive shaft to see if it turns. It will not turn much but you should be able to judge if the oil pump has seized.

When you retorqued the heads, did all of the studs hold torque? I have had studs pull out of the blocks and push the cylinderwalls inward causing an opportunity for the pistons to bind in the bore.

Good Luck! I hope it is something simpler than the things I have outlined here.

This has been one of my most troublesome restorations. I guess that is because its made out of other people's junk. The engine crank, crankcase and blocks were from a 206 diesel. I used a set of junkyard rods. and had the jugs bored .040 over for new pistons and rings. As I recall we had to sleeve one cylinder because the diesel had been run too long with broken pistons.
The crank was turned .020 under. I used a pair of Ebay 206 gasoline heads with Chevy valves in them.
I don't recall any assembly problems, but the original water pump leaked.

I put a new seal and bearing and had the impeller surfaced but it still leaked. If I recall correctly it required 3 different water pumps before I finally had one that held the water in. I must have cracked the fan hub when I put it on pump #2 because it walked forward and the fan nearly went through the radiator before I got it shut down. Then I knocked a hole in the radiator trying to get the water pump off. . . One good water pump and a $459.00 radiator core later I got it running. But I was out of money.
Then about 2 months ago I found that I was getting
water in the crankcase. Somebody suggested that I try re-torquing the heads when it was hot. I checked the oil Thursday evening by removing the drain plug. There was no antifreeze this time. But I thought I should re-torque the head bolts anyway. So I took a light disk and spent about 20 minutes disking our lower garden spot. Then I pulled the valve cover and rocker arm and torqued the head bolts. I found that I could get almost another full turn on the nuts when warm. I was going for 100ft lb. that is what my I/T manual says.

I didn't notice any one particular bolt doing different from any of the others. You probably saw my post on the MM website about the rockers as #2 from the front and #7 had an interference problem with the head studs after I torqued those bolts hot. (I guess that the rocker arm is the place to look for a problem first.)

Thanks for your help. I will look into this as soon as I get time.
Kelvin

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