[Ethanissan]

Thought I'd start a seperate thread for the engine rebuild instead of doubling the size of the car's build thread.

Blank first post so I can edit it later to summarise.

 

[Ethanissan]

Engine is on a stand, head is off, and everything is accessible to inspect:

The big head bolts on the passenger side and under the rockers were very tight, as they should be, and needed me swinging off the breaker bar to get them undone, and the smaller set of bolts up the drivers side weren't as tight, but probably by design, I haven't looked at the torque specs or pattern for them yet.

I'll do this in lots of smaller posts, as it'll be reeeeaally long otherwise

 

[Ethanissan]

On first inspection of the head, already extremely happy, no visible cracks in sight, looks like I might be in luck after all:

I then got the head over to a bench and cleaned it up some, still no cracks in sight, not looking too bad for just rubbing with some rags:

I'm not sure why, but all of the exhaust valves have white build-up on them. It can be scratched off and looks powdery once it's broken off. I've taken photos of each individual cylinder to show how good they are, this is why I'm doing it in more than one post:

 

[Ethanissan]

Plenty of carbon build-up, as to be expected in an old sooty diesel.

On first inspection of the block it's pretty clear to see that the oil coming out the sides of the head gasket was everywhere in-between the gasket and block:

After a wipe down though, it's looking even better than the head:

the old N/A sitting sadly in the background. Maybe it'll get a chance to roar back into life for a while as I'm building the turbo motor.

This piece of garbage can go in the bin:

 

[Ethanissan]

So to recap so far, top end looks great, Dad's pretty certain they've put a new head on this thing the last time it was apart, which is awesome news, I'm genuinely really happy about that, means almost no matter what else happens, this engine is going back in the MK 😁
Valves look great, probably replaced when the head was, all the rocker assembly looks awesome, I'm hoping that maybe the injectors were done at the same time, but I'm thinking of getting them tested anyway just to be sure none are dribbling; that would spell the end of the engine, as Landy would testify to if he was still active.

 

[Ethanissan]

Now onto the not so great news. It might've seemed above that I can just buy all new genuine gaskets for the engine, give it a good clean inside, put it all back together, and have a recently rebuilt engine all well and good, but that's probably not the case.

While the top end has clearly been rebuilt, Dad's suspecting that the bottom end hasn't been touched, or has been touched but put back together the way it was.
Basically, there's a lot of play in the pistons inside the bore, and the thing that worries him most is that there's a small amount of rotational play as well; as in, you can rotate the pistons slightly either way.

The other thing too is that it looks like the bores have been honed, but probably not much. Problem is you can also see some pretty significant scratch marks up the sides of each cylinder too, perpendicular to the crank and gudgeon pins. So it seems that the bottom end bearings, and/or the gudgeon pins, have some play in them. It also seems like after the bore was honed they either didn't replace the rings, or replaced them with standard size, not oversized ones to suit the hone, which could be contributing to the piston play.

If you rock the pistons side-to-side in the cylinders they knock against each side of the wall as well, not sure if this is normal but dad suspects this is where my engine had a noisier, knockier, and generally slightly rougher idle than the farm ute we've got.

Pics of the cylinder bores, and a video of the piston movement, to come.

 

[geeyoutoo]

Now onto the not so great news. It might've seemed above that I can just buy all new genuine gaskets for the engine, give it a good clean inside, put it all back together, and have a recently rebuilt engine all well and good, but that's probably not the case.

While the top end has clearly been rebuilt, Dad's suspecting that the bottom end hasn't been touched, or has been touched but put back together the way it was.
Basically, there's a lot of play in the pistons inside the bore, and the thing that worries him most is that there's a small amount of rotational play as well; as in, you can rotate the pistons slightly either way.

The other thing too is that it looks like the bores have been honed, but probably not much, as you can still see the honing marks all around the cylinder. Problem is you can also see some pretty significant scratch marks up the sides of each cylinder too, perpendicular to the crank and gudgeon pins. So it seems that the bottom end bearings, and/or the gudgeon pins, have some play in them. It also seems like after the bore was honed they either didn't replace the rings, or replaced them with standard size, not oversized ones to suit the hone, which could be contributing to the piston play.

If you rock the pistons side-to-side in the cylinders they knock against each side of the wall as well, not sure if this is normal but dad suspects this is where my engine had a noisier, knockier, and generally slightly rougher idle than the farm ute we've got.

Pics of the cylinder bores, and a video of the piston movement, to come.

A rule of thumb is 0.001" play per inch of bore and bearing diameter, give or take a little depending on how it will be driven.

 

[Ethanissan]

A rule of thumb is 0.001" play per inch of bore and bearing diameter, give or take a little depending on how it will be driven.

Does that include rotational play? That's the bit that Dad said concerns him as that's to do with bearings, not bore, rings, or pistons.

 

[geeyoutoo]

Does that include rotational play? That's the bit that Dad said concerns him as that's to do with bearings, not bore, rings, or pistons.

If you only have 0.001" play per inch of bearing diam you will get 2 tenths of bugga all rotational play out of that.

 

[Ethanissan]

If you only have 0.001" play per inch of bearing diam you will get 2 tenths of bugga all rotational play out of that.

Righto, I’ll get these photos of the bores soon and a video of the play, and measure it while I’m out there. But first, dinner 😁

 

[rgren2]

Great write up.

 

[Ethanissan]

Photos first, video in a sec.
I know there's some dust and stuff down in the cylinders at the moment, but everything's coming apart anyway so I haven't been as careful as I probably should be.
Piston #1

The piston is clearly rotating on the gudgeon pin here and contacting the cylinder wall, also taking away the carbon buildup at the top of the cylinder ^

Piston #6

Piston #5

Again, piston is contacting the wall near the top (bottom of image) ^

Piston #3

Piston #4

 

[Ethanissan]

The thing with all of the images above is that all of the scratches line up with how the piston twists on the gudgeon pin. There's no score marks inline with the pin, in a way that suggests the pin is loose side-to-side at all, so I'm wondering if perhaps the rings are standard size, not oversized, and just too small for the cylinder after it's been honed; or even the original (worn out) rings and just need replacing.

Anyway here's a video of how much movement there is in piston #3 (similar for all):

they're noisy when they hit the cylinder wall, which is what I was referring to earlier when talking about the noisier idle than the ute

 

[rgren2]

A lot will be revealed when you pop a piston out.

 

[Ethanissan]

A lot will be revealed when you pop a piston out.

Yep, sump will come off tomorrow, I might start poking around the timing system as well to see how that all goes together and comes apart (worst case I forget how to put it back together and I look it up, the internet is a good thing), so hopefully then all the bolt-ons will be off tomorrow and it’ll just be a blank block with the crank, cam, and pistons in it, and oil cooler on the side. Then I’ll be able to see if the main bearings have much side-side movement with it all still assembled, and pistons out to inspect the gudgeon pins.

I tell you what, this is going to be a good thing to have around too:

Sent from my iPhone using Tapatalk

 

[rgren2]

Don’t believe everything you see in those books. Be prepared to question things. They are a good guide, mostly.

 

[Ethanissan]

Don’t believe everything you see in those books. Be prepared to question things. They are a good guide, mostly.

Oh yeah, I’m well and truly aware of that,
Here at home alone I’ve got diffs that don’t conform to it’s listed ratios and other little things it gets wrong that I can’t recall off the top of my head. I’m hoping at least it’s diagrams of the engine assembly are close enough for me to figure out from, if not take some torque specs from as well.

 

[rgren2]

As in all things, measure twice, cut once. Always look for conflicting information. Sorting out the correct bits is where you have to utilise your brain. Bit like people who blindly follow their GPS and end up lost.

 

[Foo]

Take pics of everything before you pull it apart and you won't forget how it goes together and load all stages to a portable hard drive.

Foo

 

[geeyoutoo]

Take pics of everything before you pull it apart and you won't forget how it goes together and load all stages to a portable hard drive.

Foo

Ed Zackery, can't have to many pics when your pulling things apart or making adjustments.