First ever diesel engine rebuild and snags already

[Blackrubberducky]

First Tractor Rebuild and Running into Major snags-photo-3-.jpgFirst Tractor Rebuild and Running into Major snags-photo-5-.jpg

Recently Ive pull the 2 cylinder diesel engine from my old 1300 yanmar tractor to weld up a cracked block. It did run before I pulled the motor and ran good with plenty of power, before it sat for a couple of years. Well anyways as I was pulling off the valve cover I noticed no lifters on one cylinder, and a snaped head bolt that kept the rockers to the valves . Could this tractor have ran on 1 cylinder for 8 years? Im extremely confused how it could even run with the amount of compression that one cylinder was making not letting gases through. Also any tricks yall have for removing the snaped head bolt:confused2:

 

[Blackrubberducky]

Pics

 

[Baby Grand]

Drill & Easy-out should get that bolt shank out without much cussing.
Theer's no bolt preload, now that the bolt head's gone, and it's unlikely there's much corrosion, so thread friction should be very low.

 

[jaotguy]

sounds strange but .... any piston in the other cylinder ? no piston = direct route to intake , exhaust and crank case ... maybe reason for no rockers?....

seen an old gasser that ran rough.... pulled the plugs to change them , one plug had no gap .... put the new plugs in and fired it up ... blew the oil filler/ breather right off the motor .... turns out there was a holed piston in that cylinder and the new plug ignited the gas fumes in the crankcase.

 

[kenmac]

You may have more on your hands than a cracked block

 

[normde2001]

This brings back memories of horror stories from a few years back of these small tractors destroying the valve train on the rear cylinder. Turned out to be a twisted cam shaft, caused by seizing in the rear of the block, (no oil groove for bearing surface). This allowed rear piston to hit valves, bending push rods, breaking parts, etc. Are the push rods in the crankcase?

 

[Blackrubberducky]

I sure I hope don't have more than a cracked block. Pulled the head and it looked like I had a head gasket failure with oil every were opposite side of the crack. It did have both pistons the pistons with lifters have more carbon and soot on the head of the piston. The crack does seem to go deeper like I feared, and comes within a 1/4in of the bore

 

[Blackrubberducky]

 

[Blackrubberducky]

 

[normde2001]

Yep, you have the clear imprint of piston hitting valve, especially in rear cylinder. Could also be some badly worn rod bearings.