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[seapotato]

deja vu? My 12HT Rebuild Journey... - https://forum.ih8mud.com/threads/my-12ht-rebuild-journey.1255276/

Looking good Ryan. Every old Toyota motor I've had apart has a sludged/coked up intake manifold and head intake ports. Sludge from crank case vent, some coked up if they have EGR. Makes for a nasty mix. PITA to clean, but worth the effort. The EGR mix is usually what is hardest to clean, so you're lucky you don't have to deal with that.

Your motor is looking pretty good so far in terms of wear though!

Looks like your intake ports have a bit of a swirl design to them? That's cool!

Haha, maybe with fewer selfies...


I'm hoping to avoid going nearly as far as he did. Not gonna call it a rebuild, unless I have to.

We'll see tho. I don't have any bearings as yet, was thinking I'd see what the big ends looked like before deciding on that.
I've kindof assembled a rebuild kit piece by piece. It's costing a lot less with (hopefully) better parts, but bearings are still the thing missing.
I've barely cracked 600 bucks at this point, so far so good I guess.

Hopefully I'll get the pistons out today or tomorrow and then I'll know more. I'm curious about the protrusion of the new ones too. I don't see any reason I couldn't just skim the tops on the lathe if needed.


Didn't accomplish much yesterday aside from some valve lapping.

That gets old fast.

 

[GTSSportCoupe]

Haha, maybe with fewer selfies...


I'm hoping to avoid going nearly as far as he did. Not gonna call it a rebuild, unless I have to.

We'll see tho. I don't have any bearings as yet, was thinking I'd see what the big ends looked like before deciding on that.
I've kindof assembled a rebuild kit piece by piece. It's costing a lot less with (hopefully) better parts, but bearings are still the thing missing.
I've barely cracked 600 bucks at this point, so far so good I guess.

Hopefully I'll get the pistons out today or tomorrow and then I'll know more. I'm curious about the protrusion of the new ones too. I don't see any reason I couldn't just skim the tops on the lathe if needed.


Didn't accomplish much yesterday aside from some valve lapping.

That gets old fast.

I didn't really read that other guy's thread, but I did think his bearings looked pretty rough from the pictures. Almost a 1HDT bearing look to them... Your block has that big ladder reinforcing piece at the bottom? Or is that just the 1HDT/1HZ? Can't remember. I could see that being a PITA to deal with in doing bearings. I think if it were me I'd do them though; now's the time.

Does the 12HT have a bunch of different headgasket thickness options to choose from based on piston protrusion? I was lazy on my 2LTE and just ordered the thickest gasket...haha.

Regarding lapping; at least it's only two valves per cylinder.... Just using a lapping compound and going at it by hand? When I've done them myself back in the day I used a piece of rubber hose to attach the valve stem to a cordless drill. Oiled the valve guide, applied a little pressure to the valve while spinning in alternating directions. Worked well....

 

[seapotato]

I didn't really read that other guy's thread, but I did think his bearings looked pretty rough from the pictures. Almost a 1HDT bearing look to them... Your block has that big ladder reinforcing piece at the bottom? Or is that just the 1HDT/1HZ? Can't remember. I could see that being a PITA to deal with in doing bearings. I think if it were me I'd do them though; now's the time.

Does the 12HT have a bunch of different headgasket thickness options to choose from based on piston protrusion? I was lazy on my 2LTE and just ordered the thickest gasket...haha.

Regarding lapping; at least it's only two valves per cylinder.... Just using a lapping compound and going at it by hand? When I've done them myself back in the day I used a piece of rubber hose to attach the valve stem to a cordless drill. Oiled the valve guide, applied a little pressure to the valve while spinning in alternating directions. Worked well....

A bit of both with the valves. Mostly the suction cup wank, but a couple exhaust valves had enough pits to make that too slow. So a bit of fuel line works pretty well to grab on.

Old Brit mechanic at the boat yard only ever used a drill.

I try to finish off with the suction cup at least.

I'll decide on bearings once I get that bit apart.

Wasn't planning on pulling the crank, but it'll depend on how the big ends look. If they look like that dude's, then yeah. Those ain't going back in.


That stiffening plate is a pain in the ass. Kindof a double layered s*** sandwich when you put it back in.

I'm taking a brake from wanking valves to clean the engine up a bit while the pan is still on.

They do look better when those aluminum castings are clean.

Good inside job, cuz sweet heyzoos is it raining

 

[stevebradford]

Funny I enjoy doing it by hand

I get set up real nice with a comfy chair, music and a line up of drinks, spend a couple hours enjoying myself in the shop. Spinning the shaft and rubbing the valve like I’m starting campfires. I find it relaxing.

The shop I worked in was a bit of a hack but we also did it by hand.

Most or just about all of the gassers I worked on the valves were caked with carboned oil to the point you would wonder how it was breathing. None of the 3B’s I worked on had any build up at all despite original valve seals and 500,000k. The difference must be venting the crank vapour to the atmosphere versus intake and or leaking turbo seals sending oil down the intake.

 

[seapotato]

Funny I enjoy doing it by hand

I get set up real nice with a comfy chair, music and a line up of drinks, spend a couple hours enjoying myself in the shop. Spinning the shaft and rubbing the valve like I’m starting campfires. I find it relaxing.

The shop I worked in was a bit of a hack but we also did it by hand.

Most or just about all of the gassers I worked on the valves were caked with carboned oil to the point you would wonder how it was breathing. None of the 3B’s I worked on had any build up at all despite original valve seals and 500,000k. The difference must be venting the crank vapour to the atmosphere versus intake and or leaking turbo seals sending oil down the intake.

Temperature too. 12ht runs pretty cold.

I can hit 800 pre turbo if I drive like an a******, but it's usually 600.

3b it's more like just shy of melting pistons, so oil doesn't stand a chance haha

 

[seapotato]

I think the lapping is over now. Thank ****.

Feel like I need one of these.

Not much else of note. More cleaning.

Wasted time waiting for a firewood delivery, but of course the guy flaked, because firewood guys are all flakes. (otherwise they wouldn't be firewood guys)
There was a sob story about worker having to go to er, sick kid wife and goat etc, but I suspect it was just because it was raining.



Ordered some standard size big end bearings from 4wheel auto. Figured I may as well get them headed this way. Didn't order mains.

Kinda funny, because I haven't had one of these apart this far before ( or any toyota diesel for that matter) I wasn't 100% clear on how the lifters were accessed.

I can see now that the first couple that were kinda stuck to the pushrods are laying loose inside the holes if I peer down with a light.

Soo, that means turbo comes off tomorrow so I can remove those two side covers. Still trying to douche all the crap off before I open anything down below. Still pretty gross, but it is what it is. Once the turbos out of the way I'll be able to get at it a bit better.

In a perfect world I'd have got the lump blasted off before going this far, but carwashes seem to get upset about that these days.

 

[Rigpig]

Let's hope for a sober reassembly!

 

[seapotato]

Let's hope for a sober reassembly!

Fear of ****ing up is very sobering


Got the turbo off yesterday, which was fun...couple of charming little inaccessible bolts.

Managed to uncover some more blue paint. Not used to seeing that...I don't remember the blocks being painted on any other of my cruisers.


Anyways, got one of these out. Ring land isn't flogged out so that's good. 5 to go tho.

Everything looks ok, I'm starting to think my exhaust stank was largely due to gummed up valves.




But if I'm this far and already have the new pistons....

 

[GTSSportCoupe]

Fear of f***ing up is very sobering


Got the turbo off yesterday, which was fun...couple of charming little inaccessible bolts.

Managed to uncover some more blue paint. Not used to seeing that...I don't remember the blocks being painted on any other of my cruisers.


Anyways, got one of these out. Ring land isn't flogged out so that's good. 5 to go tho.

Everything looks ok, I'm starting to think my exhaust stank was largely due to gummed up valves.




But if I'm this far and already have the new pistons....

Nice to see the pistons looking good so far.

When were the injectors last rebuilt? If ever? Might be part cause of exhaust stank? Poor spray quality/pattern making for incomplete burn?

 

[seapotato]

Nice to see the pistons looking good so far.

When were the injectors last rebuilt? If ever? Might be part cause of exhaust stank? Poor spray quality/pattern making for incomplete burn?

Not that long ago actually. I did them while I was doing the lhd conversion or thereabouts.

I couldn't tell the difference afterwards

 

[GTSSportCoupe]

Not that long ago actually. I did them while I was doing the lhd conversion or thereabouts.

I couldn't tell the difference afterwards

Well, so much for that theory...

 

[seapotato]

Well, so much for that theory...

Combo of rebreather pipe and soupy turbo maybe? Although the turbo feels pretty good. Not much play to speak of.

 

[GTSSportCoupe]

Combo of rebreather pipe and soupy turbo maybe? Although the turbo feels pretty good. Not much play to speak of.

Did you ever try smelling it to see if it was oil burning smell or diesel smell? Seems a lot of Toyota's early DI motors have a bit of a blue cloud behind them; but it's usually produced by diesel not oil (80 series are notorious for it at idle). I saw it behind Jon's 60 last time we were out also. His was definitely not oil burning but was diesel smell.

Although those inline pumps usually outlast the motors, maybe they just become a little less precise over time.

 

[seapotato]

Did you ever try smelling it to see if it was oil burning smell or diesel smell? Seems a lot of Toyota's early DI motors have a bit of a blue cloud behind them; but it's usually produced by diesel not oil (80 series are notorious for it at idle). I saw it behind Jon's 60 last time we were out also. His was definitely not oil burning but was diesel smell.

Although those inline pumps usually outlast the motors, maybe they just become a little less precise over time.

It was a little of everything. Good haze off idle that mostly cleared up when warm.

I know these aren't the cleanest of toyotas diesels, but leaving work in the morning going up that hill I tended to get the bird fairly often.

Not really a ton of either blue or grey smoke, but the stank was strong.

Back when I left work at the same time as all the other guys, it was a race to get to their cars before me


Between that and the noise I figured it was time to go in and have a look. Noise could still be a bit of tin completely unrelated to the engine, but at least after this I'll know what the noise ISN'T.

I messed around with adjusting the timing a few months ago to see it it made any appreciable difference, and not really.

I figure, ****it. After this, it is what it is.

 

[GTSSportCoupe]

It was a little of everything. Good haze off idle that mostly cleared up when warm.

I know these aren't the cleanest of toyotas diesels, but leaving work in the morning going up that hill I tended to get the bird fairly often.

Not really a ton of either blue or grey smoke, but the stank was strong.

Back when I left work at the same time as all the other guys, it was a race to get to their cars before me


Between that and the noise I figured it was time to go in and have a look. Noise could still be a bit of tin completely unrelated to the engine, but at least after this I'll know what the noise ISN'T.

I messed around with adjusting the timing a few months ago to see it it made any appreciable difference, and not really.

I figure, f***it. After this, it is what it is.

Maybe you should switch to fry oil and make them hungry at the end of the day.....

Oddly mine actually does run and smell a bit different depending on where I get my diesel. Esso seems to run best. Shell runs like s*** for example.

 

[seapotato]

Got them all out. Top ring definitely has a bit of wiggle to it on most. Not as bad as some I've seen pictures of, where you could pretty much fit a second ring in.

See that little line in there? I think that represents how much the gap has widened.

The ridge isn't as deep as the rest of the ring groove, so I think it's a wear mark.

All things considered, I'm starting to think my odometer reading 235k is accurate.

I've read that you tend to hear a ring noise on acceleration, but I really doubt this would make enough noise to be heard over a cruiser in full voice.

Now it's pretty much hurry up and wait for some stuff to show up, so a good clean up, and maybe I'll paint and reassemble the head over the weekend. See if the ghetto spring compressor will survive long enough to put them back in.

and now a shower before someone sees me and accuses me of going blackface...

 

[GTSSportCoupe]

Got them all out. Top ring definitely has a bit of wiggle to it on most. Not as bad as some I've seen pictures of, where you could pretty much fit a second ring in.

See that little line in there? I think that represents how much the gap has widened.

The ridge isn't as deep as the rest of the ring groove, so I think it's a wear mark.

All things considered, I'm starting to think my odometer reading 235k is accurate.

I've read that you tend to hear a ring noise on acceleration, but I really doubt this would make enough noise to be heard over a cruiser in full voice.
View attachment 2706641

Now it's pretty much hurry up and wait for some stuff to show up, so a good clean up, and maybe I'll paint and reassemble the head over the weekend. See if the ghetto spring compressor will survive long enough to put them back in.

and now a shower before someone sees me and accuses me of going blackface...

Well, I'd say well worth the effort based on what you've found there.

 

[seapotato]

Well, I'd say well worth the effort based on what you've found there.

Yep. It was worth getting into. I needed a project to get the mind off the bull**** anyways.

As ring land wear on one of these engines go, it's not that much. I've seen pictures of some with 300k on them that were waaaayy worse.

Nice to get it sorted out so I never have to think about it again tho.


Catch 22. I'd probably have driven this thing for another 5 years and not given the main bearings any thought, and here I'm thinking about getting an engine stand and going full on.

 

[Diesel Cruiserman]

Where are the pistons from and are the upgraded (alfin) ones with much stronger lands?

 

[bikersmurf]

Yep. It was worth getting into. I needed a project to get the mind off the bulls*** anyways.

As ring land wear on one of these engines go, it's not that much. I've seen pictures of some with 300k on them that were waaaayy worse.

Nice to get it sorted out so I never have to think about it again tho.


Catch 22. I'd probably have driven this thing for another 5 years and not given the main bearings any thought, and here I'm thinking about getting an engine stand and going full on.

In for a penny… in for a pound.

Doing the main bearings now will be 100x easier than tearing into it later to do them.