- Thread starter
- #21
Demolished 3B Piston Sleeves- what caused this?
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
- Thread starter
- #22
I just want to mention how much I value this forum and appreciate everyone's input.
I've been watching @Beno 3B rebuild and wondering if I am able to match his efforts. My biggest challenge seems to be getting the right parts for the engine version(s) I own and not really realizing there were as many subtleties between model years.
This broken engine happens to be the 5 bearing Cam model which is upside over my original engine. I have no idea how many cam bearings are in the currently running engine I have, which by the way is also a bit of a dog. I'm testing compression tomorrow with a hopefully more useful gauge than the POS harbor freight garbo I was using... These 3b's keep me busy!
I've been watching @Beno 3B rebuild and wondering if I am able to match his efforts. My biggest challenge seems to be getting the right parts for the engine version(s) I own and not really realizing there were as many subtleties between model years.
This broken engine happens to be the 5 bearing Cam model which is upside over my original engine. I have no idea how many cam bearings are in the currently running engine I have, which by the way is also a bit of a dog. I'm testing compression tomorrow with a hopefully more useful gauge than the POS harbor freight garbo I was using... These 3b's keep me busy!
- Thread starter
- #23
I used the spray Copper Gasket per your recommendation to help with sealing the MLS gasket on this refresh, AFAIK there were no leaks. Again no machining of either block or head.
Reading this I have questions. In no particular order. Do you have service specs for the engine? Plasitgage ?
1. The bearings look like crap. Was everything clean ? Are the journals square and not tapered ? Thrust clearance checked ?
2. Is the piston to liner clearance within spec ? Ring end gaps ? Set these per hole and keep them together
3. does Toyota or the aftermarket make liner shims? Some big trucks have liner shims so they can be matched. Will swapping liners help? Ie buy an extra liner or swap them between holes until they are within spec,
4. Was the head gasket correct ?
5. If the rods don't match have the big ends been resized ?
6. Have you ever used Plastigage on the rod bearings ?
I will have more later
1. The bearings look like crap. Was everything clean ? Are the journals square and not tapered ? Thrust clearance checked ?
2. Is the piston to liner clearance within spec ? Ring end gaps ? Set these per hole and keep them together
3. does Toyota or the aftermarket make liner shims? Some big trucks have liner shims so they can be matched. Will swapping liners help? Ie buy an extra liner or swap them between holes until they are within spec,
4. Was the head gasket correct ?
5. If the rods don't match have the big ends been resized ?
6. Have you ever used Plastigage on the rod bearings ?
I will have more later
Im not familiar with installing an inline pump , or is it a rotary pump? I was wondering about the timing specifically.
Pumps also get small amounts of diesel left in them which dries into a fine powder, but that takes a few years.
Last edited:
- Thread starter
- #26
Ahh these are great questions! And I have some of the answers because I measured some of these things. This is the first time I've been this deep in a motor, in hindsight it is way more detailed than I treated it.
1. Clean - mostly, I certainly could have been cleaner and now I see why.
Journal Shape - no idea, didn't measure.
Thrust clearance - didn't measure
2. Piston to liner clearance - didn't measure
Ring-end gaps - all in spec kept together
3. Not sure if there area shims aftermarket or OEM. I made no changes to the liners, they were only lightly honed.
4. HG correct - I need to verify. AFAIK it was correct
5. The engine appeared to have been rebuilt before - and there were 2 different sets of stamp marks on the rods. I guess to keep the rods/cap together? No idea if the big ends were resized.
6. I was lazy and didn't plastic gauge the rod bearings. This crossed my mind the second it failed, engine building is obviously highly precise and I certainly could have done better.
Whats the theory behind this?
- Thread starter
- #28
I defer to Gerg on the topic of timing retard, but the idea was to achieve lower cylinder temps, to account for increased stress of turbocharging. The fuel adjustments were the typical - increase to maximize power with EGT'S in tolerable limits.
Retarding timing mechanically is to compensate for increased intake temps from a turbo which has the effect of thermally advancing timing I believe by reducing ignition delay, combustion duration or more likely a combination of both.
Last edited:
FJBen
SILVER Star
Can confirm this "new" diesel doesn't last very long at all just sitting. My tank, Injectors were completely varnished. The IP needed fully rebuilt. It sat for almost 4 years before I bought it and rebuilt it and it was fully messed up.
As to the engine being "rebuilt" before, you might find your issue right there.
Just talked with my machine shop, expert in diesel small/large/industrial. I explained what happened and he said cracked liners/shattered liners is almost always from wrong liner protrusion. his words: someone got in there, messed up the bore, slapped the liners back in and the moved/slapped around breaking/cracking the liners. Also if protrusion is wrong andDidn't measure it, thats what happening.. Saw it all the time on Ford 8n/9n tractors, He said isn't the headgasket, or anything you did if you just light honed, valves new headgasket. He said he always uses liner sealer when installing dry liners to make sure they don't move.
Hope that helps?
as for the bearings, that could from the lack of oil pressure of just bad install as we already know the bearing caps are mixed.
On a bearing and bearing cap, they are a pair. you don't change those as they are chamfered (beveled) as a pair for clearance around the crankshaft. Without that or mixing caps, That means there is no smooth surface on the chamfer which leads to spun bearings on the Big End to start. If these bearings/caps are installed wrong you risk spinning a bearing, bad heat transfer or bearing issues.
This is a very precise measurement across the bearing. It's possible when installed, they used the wrong tool. In my case, By using the wrong tool, or tool wrong, the other shop had 1&1/2 thousands of variance machined across the big end of the con rod. Again, bearing issues, spun bearing, heat transfer would have happened. By the time my machinist was done, it was at 1/8th of a thousandths out from straight.
Not sure if they did they grudeon pin either. On mine: By using a brake hone hand tool, the whole bearing was out of round and the piston wrist pin was loose and wobbled slightly. It measured differently all the way across. It also was sticky/binding in spots as well. This can result in a spun bearing again, along with bad heat transfer that can destroy a bearing, piston and score the walls.
Anyway you look at it, you are in for a full rebuild. I'd do liners, alfin pistons, and a full kit. Engine Australia makes a good kit with quality bearings, however I would use OEM toyota MLS headgasket, intake/exhaust seals for sure. Feel free to look at my build as well to see how I handled the 13BT rebuild.
- Thread starter
- #31
FJBen,
Thank you for the explanation of this. I'm by no means a mechanic, just a guy who loves his old Land Cruiser and wants to try and keep it running forever. I've paid a mechanic to rebuild my original 3B fully once before, it's clear that he wasn't up to the task as that engine survived less than 2 years - an expensive problem for me that the shop was unwilling to admit to and therefore unwilling to fix. I compromised with them by accepting replacement engine installation as "payment for the problem", though I paid for the replacement engine. That's the engine that I tried to refresh after the install, that immediately failed that we're talking about now. If nothing, I'm learning lots and gaining the confidence to work on these, pull them, reinstall them etc.
I want to make this rebuild to be the one that lasts and be able to say I did it right.
I'll take a look at your 13BT (sweet motor by the way) rebuild thread
-Cheers,
Ryan
Thank you for the explanation of this. I'm by no means a mechanic, just a guy who loves his old Land Cruiser and wants to try and keep it running forever. I've paid a mechanic to rebuild my original 3B fully once before, it's clear that he wasn't up to the task as that engine survived less than 2 years - an expensive problem for me that the shop was unwilling to admit to and therefore unwilling to fix. I compromised with them by accepting replacement engine installation as "payment for the problem", though I paid for the replacement engine. That's the engine that I tried to refresh after the install, that immediately failed that we're talking about now. If nothing, I'm learning lots and gaining the confidence to work on these, pull them, reinstall them etc.
I want to make this rebuild to be the one that lasts and be able to say I did it right.
I'll take a look at your 13BT (sweet motor by the way) rebuild thread
-Cheers,
Ryan
John in Utah
SILVER Star
Faster burn basically. Calling it thermal advance is kind of a misnomer since intake air temp obviously doesn’t affect when fuel enters the cylinder.
Your very right in saying Thermal advancing is an incorrect term but if it were put in the corrrct terms then most folks wouldn’t understand the implication and would probably dismiss it.
I too have rebuilt an engine in the past and had liner protrusion issues other people have experienced the exact same thing so it has come to really speak to me about how delicate it is to rebuild Engine with liners and now rather than pressing new liners and pressing out liners like it’s no big deal I do a rebuild and hone the liners and leave them in place as long as they are within spec
Last edited:
FJBen
SILVER Star
- Thread starter
- #36
I haven't started yet. Been focusing on the existing motor that's in the truck and looking for a 100 series 
. Just added an water/air ic to the system because I can't seem to get my EGTs to stay in the sub 1100 range when climbing a slight hill and trying to hold 65mph. I'm also chasing a rough start issue involving white smoke and a misfire that goes away when warm. In know my compression is 395 on #1 and 425 on the others....I think it's a head issue rather than rings, leakdown test points to air coming through the head, but I'm not sure if there is also a pump/injector issue. Injectors were rebuilt in March.....
. Just added an water/air ic to the system because I can't seem to get my EGTs to stay in the sub 1100 range when climbing a slight hill and trying to hold 65mph. I'm also chasing a rough start issue involving white smoke and a misfire that goes away when warm. In know my compression is 395 on #1 and 425 on the others....I think it's a head issue rather than rings, leakdown test points to air coming through the head, but I'm not sure if there is also a pump/injector issue. Injectors were rebuilt in March.....
Any fuel weeping around injector lines/pump? Fuel leaking out, even a tiny bit, means air going in. I had a loose injector line gave me the sane symptoms but would self prime in like 30 seconds and clear up. Took me a long time to figure it out. I was looking at it the whole time but never thought such a tiny leak could cause such grief.
- Thread starter
- #38
I'll have to re-inspect.
Do you guys know what a leaking valve sounds like through the air intake and the engine is running?
FJBen
SILVER Star
I haven't started yet. Been focusing on the existing motor that's in the truck and looking for a 100 series
Nice, has the intercooler helped a bunch? How did you set that up? Any pictures of that?
You can do the crack a fuel line test when it's stumbling one line at a time at the injector to see if it changes idle. When you find the one that doesn't change the idle sound, you know you've found the injectors/cylinder that causing issues. As @gerg said, even a tiny amount can cause issues.
Loose fitting?
Possibly crack in injector line?
- Thread starter
- #40
I'll throw some pictures up tonight. So far it's a helped drop EGTs maybe 100deg. The unit is a small one from Frozen Boost (Type 116) I believe, I have a 1 quart reservoir, and approx 10×10×2 radiator, Bosch 12v pump to move full coolant. I'm going to hook up my remote barbecue probe to the radiator and test temps in different conditions to get an idea of how cool it's keeping the coolant, and the i/c.
So I've bled air out of the system before using the crack a line method and this misfire feels more like a stumble like partial or incomplete combustion. I'm loathe to pull the head because I just got this engine installed in April...
I'll keep diagnosing until head pulling is imminent. I'm also still playing with fuel settings to find the happy egt vs power zone. I'm pretty happy with 10psi max boost, and I get to 10 psi and hold it almost instantly with this little turbo. Even on the flat road cruising at 65, it is pegged at 10 psi and 1000 -1100 EGTs. I think I have a bit more room to increase fuel, it's not spewing black smoke yet
