24valve 1hd rebuild (1 Viewer)

[Crazyknot2]

Rebuilding a 1hd
Where can i get good advice and bearings from here in U S and other parts
Motor is actually a yanmar 6lpa but looking for the toyota parts to save $

 

[ozcrusier]

Send beno a PM he should be able to help you source the parts needed.

 

[Locked79]

Taiho do good bearing for the 1hd.

 

[Crazyknot2]

Where im a little confused is my manual shows 5 different size bearings for my crank which varry in size .0005 from mar2 to mark6
The oil clearance required is .005 my crank has mark 3,4&5 bearings why did the manufacturer do this to change just a few ten thousandths if the oil clearance is much greater and is it nessary when i rebuild

 

[mudgudgeon]

Does the FSM give you a tolerance on the clearance?
If .0045 is too tight, and .0055 is too loose, you need something in between sizes to make up for differences in finished size of crank journals.
The crank will be machined within certain tolerances, different sizes bearings are used to compensate for the differences in machining, and to maintain correct clearance.
Best practice is to measure the crank journals with a micrometer and order bearings to suit, then check bearing clearance using plasti-gauge as you assemble it all.

Or assume that the original size bearing is still the correct size and take your chances that swapping same for same is ok

 

[roma042987]

if crank journals look good and crank hasn't be turned I would recommend putting in the same code bearings that came out. I'd polish the crank and double check with plastiguage.

 

[Jan-78FJ40]

The Yanmar 6LP series is actually the 1HDFT, not the 1HDT. That is important, as things like intake manifold, linkage, exhaust manifold...are very different (I did what you did and have that engine in my 80). So are the injector lines and pump settings-these are important, as the Yanmar equilibrated pump puts out a lot more fuel than the truck cooling system can handle.
Most of the stuff is still available, some is not (like the throttle linkage plate on the intake manifold). Beno is fantastic, but a lot of the things you will have to get from overseas. Akella and amayama will be your friends.
You'll also have to change the water jacket, as the angle is very different on the sea-water cooled engine as opposed to the truck engine.
About the bearings-toyota used lots of bearings for tiny differences. Chances are you won't find those. However, the tolerances are big enough that the aftermarket that come in 005 and 01 over will do just fine. The rebuild or gasket kit from engine australia for the 1hdft will have everything you need.
Note that the piston-top shape is also very different between Myanmar 6lp and 1hdft, likely to handle the increased fuel. I would not mess with that, if you are not dewing a full rebuild, but you will not be able to swap out a single piston.
Have fun with it, it is a great engine.

 

[Crazyknot2]

Thank u very much i wasnt sure what motor it was but thought it was the 1hdft
I am actually putting it back in my boat but trying to use toyota aftermarket parts due to yanmar wanting 1300 $ us for main bearings 850$ for big ends
And close to 1000? For a ring set
Will rings be the same as 1hdft also

 

[Jan-78FJ40]

Thank u very much i wasnt sure what motor it was but thought it was the 1hdft
I am actually putting it back in my boat but trying to use toyota aftermarket parts due to yanmar wanting 1300 $ us for main bearings 850$ for big ends
And close to 1000? For a ring set
Will rings be the same as 1hdft also

Ah, that makes it much easier.
Yes, rings are the same as 1HDFT.

 

[Gengis]

Toyota parts are cheaper than something else????

so it's true, pigs can fly!!

G

 

[half k cruiser]

Where im a little confused is my manual shows 5 different size bearings for my crank which varry in size .0005 from mar2 to mark6
The oil clearance required is .005 my crank has mark 3,4&5 bearings why did the manufacturer do this to change just a few ten thousandths if the oil clearance is much greater and is it nessary when i rebuild

The simple answer is Toyota did not tolerance stack the inline motors during the 90's. I don't know if it has changed now, probably with more US manufacture. But essentially they are accounting for the fact that machines wear over time and get slightly out of spec. Also that two machines of the same exact job may still do things just a little different. The 5 different sizes means you essentially get a balanced motor from the factory.

When I had my 1FZ apart I was amazed at the tolerances. Taking things to .0001 past the decimal is pretty intense ! It also means you will have a tough time getting an accurate reading without really good equipment. Just think, even if you had a caliper that would read it, and was for certain calibrated right, just the most infinitesimal movement of your hand would offset the accuracy. The same problem holds true with the plasti gauge, it simply doesn't read 4 places behind the decimal.

Here's what you can do. If you aren't concerned about it being true to .0001, just take it to .001 The difference between .0001 and .0009 is no more than the thickness of a film of oil. In case that analogy doesn't do it for you. The center wall thickness in the bearings of my 1FZ had a variance from 0.0981 - 0.0987 inches. Toyota has five different bearings with 5 different center wall thicknesses to cover that range ! Simply put, though nice, it is overkill. The 1FZ I rebuilt has over 30k miles on it and runs super smooth with 0 issues. People would probably be shocked to know that I put standard size Mahle bearings in it (spec'd to only .001). Interestingly enough those bearings were made in Japan.