Advice on the condition of this turbo? Thanks.

[lynchmob]

I'd also say it happened to #1 because that cylinder is getting the least air of all 6. #6 will be getting similar amounts of air, how does it look?

.

In a turbo engine why would one expect to have less air flowing into any cylinder?

 

[kevinmrowland]

So I've never been in a 1HZ either. But that's the exhaust port adjacent to your scorch mark on the top of the piston?
I see thermal damage, the hottest part in the cylinder is the wall by the exhaust port and this is where you have damage.

In a nutshell, you've melted a piston. I suspect this softening and localized melting is accompanied by the ring-lands softening, your rings breaking and then the chunk coming out lower.
I'd also say it happened to #1 because that cylinder is getting the least air of all 6. #6 will be getting similar amounts of air, how does it look?

How hot was your EGT gauge reading? If it never reads hot then I'd say for some reason it's not reading the hottest part of the gas flow.

That's near the exhaust port, but there are two deformations 180* opposite each other.
I mentioned earlier in the thread that I run 11.5 psi boost and as a rule have never gone over 950* (900 actually) egt.
The motor did have a life before me though so I am thinking that this might be some residual damage.
All the other cylinders look perfect, #6 included.

Subscribed.

I came to this thread to ask where you are getting the parts.

I think my 1HZ is going to need at least a top end refurb...it will probably get opened this week...

Aren't you out here on a motorbike trip? Bring the engine with you, we'll do both at the same time.

 

[yooper]

Aren't you out here on a motorbike trip? Bring the engine with you, we'll do both at the same time.

In a few weeks, the weekend of the 15th. Wanna come? We were thinking of stopping by, maybe on Sunday on the way home, if we aren't still on the coast.

 

[Dougal]

In a turbo engine why would one expect to have less air flowing into any cylinder?

Shape of the intake manifold

That's near the exhaust port, but there are two deformations 180* opposite each other.
I mentioned earlier in the thread that I run 11.5 psi boost and as a rule have never gone over 950* (900 actually) egt.
The motor did have a life before me though so I am thinking that this might be some residual damage.
All the other cylinders look perfect, #6 included.

If those are degrees F, then 900 and 950 as true readings aren't enough to reach 70mph. I'd be concerned about the accuracy of your EGT setup.
In non turbo stock form these engines run very rich. You would exceed 900F by fitting a turbo and not adjusting the fuel.

Any chance the opposite damage is from the piston being pushed across the bore?

 

[mudgudgeon]

I haven't addressed anything else with it, I am going to remove the hose and take a guess at the fluid level, but my thinking is that it's been fine for 7 years, if the line placement were an issue I would think it would have cropped up already, and I also think that is a factory 1HD-T oil pan.

I know this is kind if irrelevant as you have found your problem, but for interest sake, 1HD-T engines have the turbo oil return line drilled and tapped through the side of the crank main cap/cradle, not through the oil pan. The 1hz crank cradle/lower crank case will have a boss cast in it where the 1HD-T has the oil return.

Cheers



I would rebore those cylinders, the scoring may not look deep, but it is enough to see you doing another rebuild prematurely.

 

[kevinmrowland]

In a few weeks, the weekend of the 15th. Wanna come? We were thinking of stopping by, maybe on Sunday on the way home, if we aren't still on the coast.

That would be awesome....
I posted in the other tread that with the way my luck has been going this year I've not been riding my motorbike at all.
I should really sell it to fund all this other stuff, I can always build another.
Stop by though, and bring my number in case you run into any trouble.

If those are degrees F, then 900 and 950 as true readings aren't enough to reach 70mph. I'd be concerned about the accuracy of your EGT setup.
In non turbo stock form these engines run very rich. You would exceed 900F by fitting a turbo and not adjusting the fuel.
Any chance the opposite damage is from the piston being pushed across the bore?

I drive like a granny...
Farenhieght, 900-950, but right after the turbo, VDO gauge, I cap my hill driving at 900 to account for a bit of temperature drop in the turbo impeller.
Now that the manifold is out for awhile I'll set it up to read both pre and post turbo temps for comparison.

But yeah, I run fairly cool, don't push the motor, fuel is turned down and my injection pump has the boost compensator which I have also tuned for economy as well.

As for the 180* score mark, the piston has the same kind of deformation on the top, just not as severe.
Could have been pushed over by the other deformation and heated up due to friction, then deformed itself as well....

I know this is kind if irrelevant as you have found your problem, but for interest sake, 1HD-T engines have the turbo oil return line drilled and tapped through the side of the crank main cap/cradle, not through the oil pan. The 1hz crank cradle/lower crank case will have a boss cast in it where the 1HD-T has the oil return.

Cheers

I would rebore those cylinders, the scoring may not look deep, but it is enough to see you doing another rebuild prematurely.

Nothing is irrelevant!
Even if for no other reason that I like info.
Good to know about the HD pan, the EPC lists a different pan for the HD than the HZ, so the drain was just my assumption in the difference.

For reference, this is an oil level comparison with where the dipstick sits, oil level should be right at the lower end of the drain tube when at rest, so should be good for a running motor.

As to the cylinders, once I had the piston out a full re-bore was apparent, they could not be felt at the top, but down lower you can feel a ridge, probably 0.0015" at it's worst. Think I'll need to step up to the 0.050" oversize pistons to be safe since these are #2 spec, if they were #1 spec I'll bet a #3 would fix it though.

 

[Dougal]

First job is to shift that EGT probe. Post turbo is useless. Put it pre-turbo and make sure the probe reaches the middle of the gas-stream.

 

[kevinmrowland]

I will now direct you to post #86:

Now that the manifold is out for awhile I'll set it up to read both pre and post turbo temps for comparison.

 

[mudgudgeon]

Later model 1hz have an oil level sensor on the side of the sump, It's at roughly the height of your dipstick in the photo.

 

[kevinmrowland]

Yup, pretty much right in the center of the pan height.
I've got no problem with where the drain is, plan to leave it intact unless I buy a new oil pan.


For parts I've been talking to a nice fellow from Engines Australia.
They have a full rebuild kit for 825, that is all gaskets and seals, HG, head bolts new pistons and rings, etc.

They then have a "turbo" rebuild kit that is the same thing but includes ceramic coated turbo pistons, unfortunately they have a larger 33mm pin though so the kit also has all new con-rods. That one comes out to $1872.

The pistons are tempting and if money where no object I would give that one a shot, but an extra $1k is out of the question at the moment.
The price breakdown for the parts is reasonable tough, it just adds up quick:

Turbo pistons, non-ceramic coated are $45, ceramic coated are $114.
They both have the 33mm pin though so new connecting rods are needed at $132 each.
I would go for the pistons, but can't do the pistons and rods.



According to my guy there, the bearings for this kit are all made by Taiho, who in turns makes the ACL and Genuine brand bearings, no idea if they are built to the same standards though, anyone have any insight there?




KR

 

[mudgudgeon]

The increase in gudgeon pin size for the turbo pistons, brings the rods, pins and pistons up to the equivalent of 1HD-T parts. What's your chances of sourcing rods from a 1HD-T?

 

[kevinmrowland]

I would say.... slim to none.

 

[Pacer]

Does anyone have insight on your cracked pre-cups in the head?
Have you got them removed yet?

 

[kevinmrowland]

Well I've been taking the head around to shop for machine work and for the most part the response has been "those look fine, they all do that." Only one shop said they should come out. The cracks are quite fine and if you look at the head gasket it actually looks like it has a compression seal around the perimeter of the cups as a backup seal anyway.
The way it stands right now is they should stay in unless the head needs to be milled. In that case they are apparently very hard metal that can not be cut, would have to be surface ground, and that can only be done to a point.

For now they are still in place.

 

[amaurer]

Well I've been taking the head around to shop for machine work and for the most part the response has been "those look fine, they all do that." Only one shop said they should come out. The cracks are quite fine and if you look at the head gasket it actually looks like it has a compression seal around the perimeter of the cups as a backup seal anyway.
The way it stands right now is they should stay in unless the head needs to be milled. In that case they are apparently very hard metal that can not be cut, would have to be surface ground, and that can only be done to a point.

For now they are still in place.

You've gotten terrible advice.

While yes, cracking is typical, this forum is littered with engines destroyed by dropping precups.

The lip on the block/HG does hold the cup in place... but the issue is with the cup cracking and pieces falling out, which certainly happens.

Also - its very possible to mill the head with the precups in. I had mine done that way.

 

[Pacer]

Glad I asked... Kevin is probably not...
How to get them out?

 

[kevinmrowland]

You've gotten terrible advice.
While yes, cracking is typical, this forum is littered with engines destroyed by dropping precups.
The lip on the block/HG does hold the cup in place... but the issue is with the cup cracking and pieces falling out, which certainly happens.
Also - its very possible to mill the head with the precups in. I had mine done that way.

As mentioned, that part of the equation is still up in the air. If we were talking about the 3B then yes, but the pre-cups on the HZ as a bit different design with less of them hanging over the cylinder wall.

There is a lot of conflicting info on the interwebs about the 1HZ cups, some say to just replace, many others comment that as long as they are very fine radial cracks, a new set will simply crack the same exact way after installation.

As for the milling, are you sure your head was cut and not ground? (or sanded)
Once again this could be part of the difference between the B and HZ, on the HZ every shop said to mill (with a cutter) they would need to come out, we did a basic scratch test on their base and the metal is MUCH harder than the surrounding steel.

It's not a huge deal either way, the difference of $100 to replace or not, that is not huge in the scale of the rest of the project, but I still like to make sure it would be funds well spent.

Glad I asked... Kevin is probably not...
How to get them out?

The FSM shows a nice little puller for the application, but that's a special one. I've been told that you can usually pound them out from the injector hole, but that is once again not HZ specific info.
The injector is at quite an angle on these and does not point you in an ideal direction to pound them out. (that is another part of the B-HZ difference, they pushed the cups much further off the edge of the piston wall, presumably for more strength, but that makes things a bit more angled as well)

 

[Dougal]

Why are you surfacing the head anyway?

 

[kevinmrowland]

Not.
Unless it happens to need it. (my luck...... )

That's what I mentioned as the only definitive reason I would have to pull the pre-cups so far. Cracks are still an up in the air issue....

 

[fjbj40]

Replace the precups if they are cracked, period.

Precups cracking is the nature of the beast, 3b's anyways. I am use to the 3b, they mill them with the precups installed, nor grind.

I guess the hz is a different beast than the 3b if they say to leave them and they need to be ground if newly installed.

If it is only a $100 then why not?