Builds 1985 JDM 3B Engine Rebuild and Other Stories (1 Viewer)

3B REBUILD BJ70 JDM

Onur

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Well, since crap hit the fan, figure it is time to do this correctly.

I was planning on a head rebuild only but when I pulled head and cleaned up pistons, all 4 were cracked unfortunately.

So off to the races we go.

This thread will document the head and block rebuild. IP has already been rebuilt and will not be addressed here.
Injectors are also rebuilt and will not be addressed here. They will just be bolted on once the build is complete.

Vehicle specifics:

1985 BJ70-MR model. BJ70-0004000 frame number (10/1985 build).

JDM vehicle. Rotary injection pump. 215K KMs. I bought it with about 47K KMs and I have hammered on it in the 5 years I have owned it.

This first picture was taken on my ride home to Atlanta from Springfield, MO. 2015

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Flopped it in Death Valley heading out of North Pass.... 2017

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Southern Utah.... 2016

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The Rincon....

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Hole-in-the-Rock Trail in Southern Utah.

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So, it has seen a lot of action in the past 5 years. :)

I am hoping this thread will be useful for people as reference for parts as well as mechanical data. Hopefully everything will make sense.

Furthur....

Best.
-onur
 
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gilmorneau

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Bummer about the pistons. I'll be watching with interest.

Curious about one thing...

Rotary injection pump.
I'm certainly open to learning something new, but I thought the rotary pump debuted on the 3BII around 1988/1989-ish. Is it a JDM thing? I'm not all that up on RHD market particulars.
 

Onur

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Bummer about the pistons. I'll be watching with interest.

Curious about one thing...



I'm certainly open to learning something new, but I thought the rotary pump debuted on the 3BII around 1988/1989-ish. Is it a JDM thing? I'm not all that up on RHD market particulars.
Injection pumps are market and specification based.
 

mongoose2231

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I scoured the forum for a build thread! No wonder I couldn’t find it, it was just started! Looking forward to this. She’s a sexy beast! Glad to have had the privilege to get behind the wheel!
Cheers Onur!
 

Onur

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Looking forward to this as well. You think turbo had anything to do with cracks? I bet you've had some unobtanium stashed away for this day.

Quite possibly Roma. :meh: I started the turbo at about 8-10psi and then pushed it a bit to about 15psi about 1 year ago or so.

Yes, tons of unobtanium will be posted here. :)
 
B series historical information.

Onur

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We'll start at the top and make sure we have some documentation correct.

The B series engines from Toyota have been around for a very long time. It was originally a gas engine until 1947 and then became the designation for a diesel engine. To my knowledge, one of the only times Toyota has ever changed an engine family designation from gas to diesel and still kept the same engine family name.

The earliest usage of the B series family engines in a Land Cruiser was in February 1974. That indicates the manufacture of the engine series began in late 1973 for MY 1974.

Another thing to consider historically is that Toyota bought a 16.7% share in Daihatsu in 1967. Daihatsu was originally an engine manufacturer with very advanced machining abilities... they eventually branched into vehicle manufacture as well... especially mini-cars and utility vehicles.

Toyota then consigned Daihatsu to build the B series engines for Toyota vehicles as well as for Daihatsu vehicles. The engineering was done by Toyota, castings were manufactured by Toyoda Industries, and the engines were then assembled together by Daihatsu. Daihatsu also used B series engines in their own smaller 4x4 trucks and utility vehicles for SE Asia, Africa, and the ME.

This type of engineering transfer and protocols for technical cooperation are one of the hallmarks of the Toyota keiretsu system. Toyota slowly acquired more and more of Daihatsu over the years until it became a wholly owned subsidiary in 2016.

You can see here the evidence of this engineering/procurement partnership:

1. Underneath the valve cover both the Toyota and Daihatsu emblems:

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2. And again on the timing case cover:

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Many of the standard and semi-standard part numbers used in the B series engines also indicate Daihatsu procurement— any part numbers starting off with a 90040-49 in the prefix 5 digits indicated Daihatsu Motor Co.
 
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B Series information

Onur

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As with all things Toyota, the B series engine family has consistently been developed in small incremental ways throughout the years by both Toyota engineers and Daihatsu engineers.

The great thing about the technical cooperation between Toyota and their suppliers is that they end up utilizing each other's technical specialties in a symbiotic manner. Most of the time, engineers from Toyota will be embedded in the Technical development departments at its respective suppliers. This is the case with about 100 different Toyota suppliers. In reciprocation, Toyota allows engineers from suppliers and subsidiary companies to spend time in Toyota factories and technical departments learning the methods and philosophies of the Toyota system... Toyota has consistently created specialist suppliers-- NipponDenso was spun off from Toyota in 1949 to manufacture electrical parts and motors, Aisin Seiki was spun off from Toyota in the 1940's, Arakawa Auto Body was spun off from Toyota in 1945, etc. Toyota invested in Daihatsu and in return they received out-sourced engine machining and building expertise.

There have been many different iterations in the B family of engines:

B
2B
3B
3Bii (this is technically not a different engine but a sub-classification of 3B development-- mainly engine architecture and control systems)
4B
11B
13B/13B-T
14B/14B-T
15B/15B-F/FT/FTE

The number in front of the B indicates generation.

The 1 in front of the 2nd number will indicate that the engine is direct injection.

So, for example, the 13B-T is the 3rd generation of the B engine, it is direct injected and it is turbocharged (T).

In my 70, we have a 3B from the 1980's. There were a few different variants of this engine but overall it basically stayed the same from about 1981-1990 in the Land Cruiser form (it continued on in other platforms like the Dyna, the Coaster bus, etc.)

My truck was manufactured in 10/1985. In fact, it was the first frame manufactured that month. Kinda cool.

9C7CA0B4-2AA2-430D-8D6D-A75CA03A3300_1_201_a.jpeg


The engine serial number is a bit more amorphous in terms of dating it.... I've wanted to do a B engine serial number database but just have never gotten around to it.

B114114B-1890-49B1-A4E8-3AA6BA6ADE56_1_201_a.jpeg
 
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Onur

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In any event, what started as a bit of a cleaning project while I was grounded at home from work has taken a bit more of a larger scope structure....Mainly at the egging on of my wife @CatskillsRunner who understands (a bit I think) my Toyota mania... Though she does question my sanity often ... especially when I am staring at part numbers and reciting them while I sleep (true story).

I started with wanting to clean up the engine bay harnesses as well as some surface corrosion on the inner fenders...

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Well, that escalated quickly as I looked at entire shelves of parts I had bought for my 70 over the years... Let's just say I do have a thing for Toyota OEM parts....

And, well, after discussing with my understanding wife the situation with the head and cooling system, I decided to swap the head gasket to the upgraded MLS 11115-58110 from a 13B-T and also address building a new head because I knew the precups at a minimum were toast.

My hunch was correct.....
 
Engine Control System Specifics

Onur

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So let's get some understanding of the B engine family technical data. I'll let Toyota technical writers and engineers take over at this point:

Basic engine descriptions (notice it's different engines in different platforms):

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Oiling System:

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Cooling system:

Screen Shot 2020-04-01 at 00.29.18.png
 
Rotary Injection Pump Operation

Onur

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And we have the remainder of the fuel system (a real nice and simple description of basically the Bosch VE injection pump. NipponDenso took the pump, re-engineered it, added their own control system and branded it as theirs. Rather common in the automotive supplier world at Tier 1):

Screen Shot 2020-04-01 at 00.31.06.png


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Is that Moose's old landcruiser? He was a member here donkeys years ago and owned a low klm white soft top BJ70.
Jeep owners must go nuts when they see one for the first time.:smokin:

There have been many different iterations in the B family of engines:
Did you leave out the 4B and 5B for a reason? I know they are not common.
 

Onur

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Is that Moose's old landcruiser? He was a member here donkeys years ago and owned a low klm white soft top BJ70.
Jeep owners must go nuts when they see one for the first time.:smokin:



Did you leave out the 4B and 5B for a reason? I know they are not common.
Forgot 4B. Thanks.

Never heard of a 5B. News to me. :)

Truck is not from a forum member or anything like that. Imported by @SteveJackson from Land Cruisers Direct, an importation company here in the States.
 

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