ACL rod bearings after 150k kms.

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This gets into the debate on which oil is best.
I found at least through my oil analysis tests that my levels were better running Dino 15w/40 opposed to 10w/30 Dino.
Currently running 5/40 synth and will do a test at 5000km.
 
I'm sure the issue has a permanent fix but it would be a cost vs benefit game that not everyone is willing to play.
Improving pump flow and oil gallery flow would help significantly and would have the same effect as changing to lower viscosity oil. Also improving oil filtration may help as well, maybe a bypass system with synthetic oil.
 
I though posting about the best oil would open a can. No pun intended. I look forward to your oil analysis on the 5-40. Is that the t6? Oil is a tuff topic as most if not all rarely give actual hard data as far as viscosity and film strength and stuff. I'm more trying to identify problems and develop a theoretical plan on how to deal with it. My only though was if the bearing is getting starved, the better flowing oil is somewhat a logical step.

I have read about chamfering the oil journals as well as tear dropping them to borrow main bearing oil flow and direct a small portion to the rods. I honestly have no clue on the effect of that but will run it past my machinist. I don't think I'd ever open a crank and start drilling passages personally. Good stuff to discuss though.
 
powermad said:
Cavitational erosion is the result of air in the system exploding and making craters.
Little micro bursts that will remove material.

It will do it to a piston liner if the coolant DCA is not correct.
It's not heat related, it's harmonics.

The BEB I posted earlier on the Volvo engine were the only ones showing that type of wear.
The mains all looked great.
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That's one form.
But the problem here isn't bubbles exploding. It's bubbles imploding.

Basically if you pull a very low pressure in a part of the system (near vacuum) then fluids like oil stretch out to gas. It's basically boiling through low pressure rather than high temperature.
When the low pressure suddenly disappears the bubbles collapse rapidly, sending shockwaves through the nearly incompressible oil.
It's the shockwaves that do the damage. They literally fatigue the surface off metal.
Badly designed or operated pump impellers and boat propellors have the same issue.

So how do you stop bubbles forming and imploding? Well in shocks the system pressure is increased to stop it. This is why gas shocks can run hundreds of psi of gas pressure. To prevent the lowest pressure parts of the system getting low enough to cavitate.
Koni shocks for an LC80 front end run ~500psi.

Raising the oil pressure in that part of the system will help. But the big question is how?
I'd think putting an HD-T and HD-FT bottom end side by side would yield some interesting differences.
 
gerg said:
I though posting about the best oil would open a can. No pun intended. I look forward to your oil analysis on the 5-40. Is that the t6? Oil is a tuff topic as most if not all rarely give actual hard data as far as viscosity and film strength and stuff. I'm more trying to identify problems and develop a theoretical plan on how to deal with it. My only though was if the bearing is getting starved, the better flowing oil is somewhat a logical step.

I have read about chamfering the oil journals as well as tear dropping them to borrow main bearing oil flow and direct a small portion to the rods. I honestly have no clue on the effect of that but will run it past my machinist. I don't think I'd ever open a crank and start drilling passages personally. Good stuff to discuss though.
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Yup T6. Curious to see how it works. It starts nice in cold weather with it. I would guess that its going to do better than my 15-40 test. I think regardless I am going to run a synth from now on for winters :meh:
I have only ran Rotella in my trucks.
 
I've checked mine every 50-60km still good run mine hard pulling 5gr revs daily, played the hypo turbo game , only probs I've had are ring land and transmission shutter. Greg I wouldn't be scaredoff by the beb's ,if you want to mock up a compound on mine ,I've come to the conclusion that these motors need two turbos period
 
It would be cool to meet up and see how much room you have wrong way. I think it's pretty tight with the booster there, but usually there is a solution. That's one reason I'm getting a lhd 80. And... I'm not scared of the bearing....sheesh. I am scared of my wife's wrath though!
 
gerg said:
I also found these folks that use a totally different surface feature to increase fluid film strength as well as combat cavitation.

http://www.taihonet.co.jp/e/mgb_01.html
I'll email them guys tonight.

Nice to know there are some in the box solutions to this problem. It might not solve it, but might greatly increase the life of the bearings.
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I had a set of these fitted today to my 1hd-fte after reading all the horror stories. They came highly recommend by my local mechanic. He has fitted dozens of these 1hz and 1hd-t's and by all reports they are holding up fine.
On a side note, my original bearings were fine. No signs of delamination or damage anywhere. Over 200000kms on the engine and Gturbo @ 30psi for the last 40000kms.

ForumRunner_20140211_152449.webp
 
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gerg said:
Nice bearings locked. Good to hear some positive feedback from your mechanic on the taiho bearings. How many KMs on that set? What oil do you run by the way? Thanks g
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200k he said.

One thing to remember is that he has a iteration of the engine that is not as hard on the BEB's as the 1HD-T. So his life span results for his BEB's is really only relevant to his generation of engine.

Im a bit skeptical that its the oil causing the issues. It looks like this engine (1HD-T) has a design issue that can really only be maintained by replacement at a 100k interval.

No point gambling on the loss of a engine for a $150 set of bearing and 2-3hours of work every 100k kms.
 
Forgive me guys. I've only scanned this thread between other projects today but I'm not sure all of these points/ theories have been covered.

I suspect that...

The problem has to do with the forces/ resonance/ frequency transiting the con rod under certain load/rpm conditions.

A truck which spends a lot of time at the evil 2000 RPM will destroy bearings much sooner than one which cruises at 2200 RPM.

The problem is likely due to the swirl chamber design which is why , by and large, the problem doesn't exist in the 1HZ.

Toyota changed the piston design at some point to try to fix the problem.

The forces on the main bearings are completely different than the rod bearings.(rotation rather than oscillation)

I just plan on doing the BEB bearings, timing belt, water pump, cam seal all on a 160,000km schedule but if I ever have the head off I'll swap the pistons for some from Mahle and never do bearings again <<<the last five words are meant to be a joke
 
gerg said:
What oil do you run by the way?
Thanks
g
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I run Fuchs cargo 15w40 changed every 10k.
Wheelingnoob is correct. The 1hdft/fte aren't known for doing beb's like the 1hdt's but considering the share the same block design and the same crank, I wonder what makes the 1hdt harder on the beb's
 
Locked79 said:
I run Fuchs cargo 15w40 changed every 10k.
Wheelingnoob is correct. The 1hdft/fte aren't known for doing beb's like the 1hdt's but considering the share the same block design and the same crank, I wonder what makes the 1hdt harder on the beb's
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Different piston and also two stage injection. The problem only manifests itself in the bearings. It doesn’t originate there.
 
lowenbrau said:
Different piston and also two stage injection. The problem only manifests itself in the bearings. It doesn’t originate there.
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All the engines mentioned above (1hdt/ft/fte) are direct injection and have two stage injectors. Yet the problem only manifests itself in the 1hdt. If we bring the 1hz into the equation we could argue about different pistons/indirect injection and so forth.
I'm just wondering why in one and not the other two.
 
serenity said:
2 stage injection?
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Copied this off a diesel site.

SINGLE STAGE: original old technology where rotary distribution pump delivers fuel to injectors one at a time using relatively low pressures(120-130 bar)still fuel efficient but noisy and smoky

TWO STAGE: The first stage of injection remains the same but it has been joined by a higher pressure second stage (300-400 bar) this allows more power and a more efficient burn.
 
Locked79 said:
All the engines mentioned above (1hdt/ft/fte) are direct injection and have two stage injectors. Yet the problem only manifests itself in the 1hdt. If we bring the 1hz into the equation we could argue about different pistons/indirect injection and so forth.
I'm just wondering why in one and not the other two.
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I think it is the swirlchamber/piston design.

1990 1HD-T used Piston PN 13101-17020
1995 1HD-T used Piston PN 13101-17040
1995 1HD-FT used Piston PN 13101-17080
1997 1HD-FTE used Piston PN 13101-17080
All used the same rod, I think

I dont think the problem exists to the same extent in any engine with a piston other than 13101-17020
 
Just looking at pics of the 1hdt piston and the 1hdft and fte pistons, the 1hdt has its piston dish feature offset to one side where as the ft and fte have the dish centered. I wonder if it being offset causes some sort of harmonics? I think it differs because the 1hdt injector fires from the side where as the ft and fte fire down inbetween all of the valves.
 
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