Need advice on a D restoration

I've run it for about 2-3 hours since the work was done. Obviously I didn't do a very good job, because I seem to have extra vibration in the engine, and I'm leaking coolant into the oil.

On the vibration, I've checked to make sure that the flywheel is on right. It is splined, and there is one tall spline that fits over a pin on the crank, so I think it's on correctly. I also rechecked the clutch drive disk. It is keyed to the flywheel, so can only go on one way. So I'm not sure what to check next.

On the coolant in the oil, it's leaking pretty slowly. I don't think coolant is getting into the cylinders. The shop that did the valve job checked the head for cracks and it appeared OK. So that leaves the possibility of a cracked block that I didn't see while I was honing, or a leaking head gasket or lead washers around the head studs. Any other possibilities that I may have overlooked?

I'm letting the engine drain overnight, then I'm going to fill the radiator with water and see if I can locate the leak by looking behind the valve cover.

After all this work it's really got me bummed. I'm open to any suggestions right now.

Dale

Dale

The D104R crank was used with 6 1/2" pistons. I wonder if the stroke was changed when they went to 6 3/4" pistons? Both cranks take the same connecting rods, but it's possible that the wrist pin location changed when they changed pistons. As I turn the motor over, the piston skirt comes out of the cylinder bore. At BDC, I can just see the lower oil ring. Is this normal, or are the pistons coming down too far?

When I bought the tractor, #1 piston had the lower skirt broken off up to the oil ring, although it still ran. That's why I bought two used pistons. Now that I've had time to think about it, I wonder if there was enough wear in the old bearings and wrist pins to allow the oil ring to pop out under the cylinder bore at BDC, then snapping off the piston skirt on the up stroke?

Dale

All I can find is the stroke for the D was 7". I'm not finding anything about the stroke being changed and don't have any old cranks to check and see. Maybe someone else can tell us for sure?

No Glen, the block is std, and has never been bored or sleeved. There's really not much wear in the bore. It does have some pitting in #1 cylinder bore, but decided to live with the pits rather than bore/hone it out too much.

Dale

Good luck on your pull!

Dale

One thought I had on the vibration last night; maybe it's only running on one cylinder? I'll check the mag timing again after I figure out the coolant leak and get her up and running again. Another thought; maybe the crankshaft is bent? Not sure how to check it without removing the crank and taking it somewhere.

I did replace the rod bearings and reshimmed them. I did not remove the crank nor the camshaft, so it's possible that those bearings could have some wear. I did leave .010 endplay on the flywheel. The splines on the flywheel are worn, so I torqued the flywheel bolts pretty good. I do have a slight wobble in the flywheel. Don't know if this is normal or not.

Thanks for your input!

Dale

Did you have the head or block surfaced or check it for flatness? I had to redo a 35 D 3 times before finally getting the head and block to seal and finally went with another head I had surfaced again. It doesn't hurt to take the cylinder studs out and have some surfaced off the block too. We had both sides surfaced on D blocks before to help raise the compression some too.

I was thinking your '27 would have a keyed flywheel but a splined clutch with dowel pin on clutch side too. The '27 & 28 we did had the cranks changed before to later ones. You said flywheel was wobbling now but loose before. I've never had much noticeable wobble in the flywheels before and thinking you shouldn't have much if any. Make sure it's not coming loose again. You may need to change flywheels or have worn crank splines too. Would try that before replacing crank. I have some extra splined flywheels but none of the early crankshafts.

I've never seen a bent crank in a D but seen bent rods from someone trying to pull start one that was stuck. But I suppose a crank could be bent some too. Would think mains would be really worn if ran long with a bent crank. They did have some bad cranks in some of the 28 Ds for a while but never heard of any in 27s. We had a 28 that the crank was broke in half between the throws when we got it and the guy we bought it from said they had ran it hard for 2 years and just parked it when crank broke and it had sat all that time. No other damage and we put a motor in it from a 29 and it ran great. Seen a few 28s that when crank broke it ruined the whole case. We have changed engine parts around before on several Ds and never had a balance problem with them. Good luck with the leak problem. Let us know what else you figure out.

Yesterday I refilled the radiator with water and pressurized the system to about 12psi. When I looked in the crankcase, I started seeing water trickle out of one of the pushrod openings. I looked into the valve cover, and it was difficult to see where it was coming from, but I could see water dripping from under #2 cylinder. About a drop per second. I don't believe any water is getting into the cylinders. (I'm leaving the water in it overnight to see.) And it doesn't look like it's leaking around the head gasket, so I think I must have a cracked block between the water jacket and the pushrod openings. I suspect at some point water froze in there and cracked the water jacket. I'm not sure how to fix this one without replacing the block. Any thoughts?

Thanks for the tip on the magneto drive. I will mark it once it's running again, and keep an eye on it. If I can't figure out a simple way to seal the leak, it looks like teardown time, and it may be awhile before she's running again.

Dale

Link

It would give me more confidence to hear from others who have tried it. Has anyone else ever used this stuff?

Dale