Diesel Demise

[peter_j_g]

Hi,

Well done! That's a neat trick with the zip ties to hold the belt in place - must remember that if I have ever to do a roadside injector pump swap!

[hiho]

Thanks guys,
i couldnt have done it without my lovely wife, or my father in laws lovely hilux. Luckily she was asleep during the last leg when the battery went flat!! "Honey" she said, "why arent the lights on?", "they are darlin now go back to sleep". I installed a spare set of brushes and charged the battery and all seems well. Next thing to fix is the speedo which is most likely a broken cable.

The zip tie thing i learned when working on old chain driven twin cam motors. I also zip tied the pump pulley to the pump bracket to prevent any slack in the belt allowing the belt to come off the crank pulley.

The reason the cam locking plate and pump pin would be handy are:

Tightening the cam pully bolt will cause the cam to turn unless you oppose the force with something. I used vice grips on the camshaft. This still may result in the shaft turning and also it also requires eyeballin of the slot in the end of the camshaft to be aligned with the machined cam cover surface. The cam plate does both of these things.

The pump pin would help because at TDC, the spring inside the pump acts to turn the shaft of the pump away from its TDC position. Without a pully on the shaft it is not easy to turn (its not easy to turn WITH a pully on the shaft). This means that one must turn the whole motor to align the key on the pump shaft with the slot on the pump pully. This only applies when doing it on the side of the road and using the zip ties etc.

Hope this makes some sense.
Matt

[brackie]

Yeah.. You really do need the locking pin and camshaft lock. Easy to make up and I'm sure with your capabilities a breeze.

[Golf Loon]

What a brilliant description of an epic saga.
Thanks for sharing, good to see another nut out there going the extra mile for an old golf
You have a very patient wife.

[hiho]

Took the head off today to discover the short motor to be in good shape.

The Pistons.....









Note the "valve prints". An interesting point is that the valves on No. 3 cylinder are not bent and are closed but there is still valve print. Any ideas?

[hiho]

All cylinders have cracks between the valves.
Note the impression on the valves from the cutouts in the pistons. Is this from normal running? If it is then GET THE RIGHT THICKNESS HEAD GASKET!!!









Note: No.s 3 and 4 were taken without flash.

[hiho]

The Shim.....



The head....



Let this be a warning to you....

[hiho]

Just a note regarding the carbon deposits (or lack thereof) on the piston crowns and in the combustion chambers in the preceeding photos, the car was run on straight biodiesel for 500kms immediatly prior to death and on mostly biodiesel (70%+) for 5000 kms before that. Biodiesel has been ruled out as a cause of death.

Im not sure what a diesel combustion chamber should look like with regards to carbon buildup. I assume that as diesels run lean most of the time there should be less carbon deposited as it gets burned off again during lean running when compared to petrol motors. This motor is much "cleaner" in the combustion chamber than petrol motors that i have stripped after less than 10,000 kms (carburettored) but how does it rate compared to GLD's running dinodiesel?

Any ideas???

[gldgti]

the biodiesel tends not to be worse than dino diesel for carbon buildup, but may not be better either.

those cracks between the valve seats are a usual thing in these engines, ...unfortunate but usual...

[brackie]

The amount of carbon build up in diesels is a direct result of fueling, however cylinder head design plays it's part in removing carbon on the exhaust stroke. Well designed exhaust ports and system will improve the removal speed of gas and particulates so reducing build up. VW got it pretty right and most of the heads and pistons that I've seen have been very clean. Pay attention to the "smoke screw" (max.fuel at the govenor) as if this is allowing too much fuel to enter the combustion space as well as being blown out of the exhaust carbon will build up.
I've seen plenty of diesels with large amounts of carbon in the head but never to the point where performance has been affected.
The "ghosts" of the valves or combustion space seen in the pics are common and probably nothing to worry about, although if the motor has been apart before I would be checking the piston protrusion above the block and making sure I fitted the correct thickness gasket.