2977cc B and 3431cc 3B parts interchangeability

[lostmarbles]

The B engine primer pump appears to be common with all the following Toyota diesel engines:

• 2B
• 3B
• 13BT
• H
• 2H
• 12HT

Here is a photo of my latest Bosch primer pump installed:



This primer pump is sold under any of the following Bosch part numbers:

• 2 447 010 033
• 2 447 010 038
• 2 447 222 125
• 2 447 222 126

When you install it, you should replace the little copper washer it seats on (Bosch supplied one with my new pump), and you need to be careful of the spring and check valve that sit beneath it:



Unlike the OEM primer pump, this type is easy to install/remove because it requires a smaller spanner (only 17mm) and the hex is long enough to allow that spanner to be moved around obstacles as you turn it:




PS. - The thread is M16 x 1.5 so if you have a primer pump with this thread (and the entry-hole looks like it's made to accomodate a spring and check-valve stem) - then it should fit your engine.

 

[svpawnco]

B motor going bad

My 79 bj40 with the B motor is getting very weak. Compression is 340, 325, 310, & 220. Squirt oil in the 220 cylinder it shoots up to 400 psi. I am not ready to put a swap motor in yet, my thought would be to re-ring it for now while I figure out weather I should put in a 3B, or isuzu or ? Where can I buy parts for this B engine, Not a complete rebuild, bearings, rings ect. I am just trying to buy some time here. I would eventually like it to be turbo'd. What would some of you do? Tried to do a search on parts houses on here but didn't get any results.

Thanks

 

[lostmarbles]

My 79 bj40 with the B motor is getting very weak. Compression is 340, 325, 310, & 220. Squirt oil in the 220 cylinder it shoots up to 400 psi. I am not ready to put a swap motor in yet, my thought would be to re-ring it for now while I figure out weather I should put in a 3B, or isuzu or ? Where can I buy parts for this B engine, Not a complete rebuild, bearings, rings ect. I am just trying to buy some time here. I would eventually like it to be turbo'd. What would some of you do? Tried to do a search on parts houses on here but didn't get any results.

Thanks

Depends on the history of your B engine. I know mine has never been cooked (overheated), has always had clean/treated coolant, and has had regular oil and filter changes. So those things are big factors in why I want to keep mine.

Engine Australia sold me a "ring set" for my engine so they are readily available.

Whether you can get away with just replacing the rings (and honing) will become evident only on inspection (head removed). Personally I would think it would be unlikely.

 

[albert rodrigues]

This is great information Tom. I will add the part numbers to my spread sheet when I have a chance.
Albert

 

[lostmarbles]

Here's a thread that has just surfaced that is of interest to people looking at the interchangeability of B and 3B engine parts.

https://forum.ih8mud.com/diesel-tech-24-volts-systems/239786-1977-bj40-engine-trouble-b.html


From this thread it appears that a 3B head will actually bolt to a B engine (despite the engines having a different bore sizing).

But my B-engine exhaust manifold has M8 nuts on all its studs (which I think is the same sizing as for a 3B). But I had heard it mentioned previously that some employ smaller diameter studs. (Perhaps some pre 1979 models?) Also my pipe flange is indeed a 2-bolt flange compared to the 3B engine's more robust 3-bolt flange. Anyway, here's a photo of my B engine exhaust manifold:

 

[pilotmike]

3B head on a B

On my 77 BJ40, the previous owner had bolted on a 3B head onto the B block.
He used a cheap 3B Head gasket.
The 3B head gasket will not fit tight around the liners. This caused carbon buildup in the space between the 2. Also, water jackets were blocked using this gasket.
If you used a B head gasket with the 3B head, there will still be water jacket blockage.
You never know what the prevoius owners have done.
My B motor had the correct B stickered valve cover bolted onto a 3B head, bolted onto the B block. Also the exhaust manifold that is on mine was a "B" 2 bolt head pipe flange that they drilled out to make the manifold bolts work. On visual inspection before the head came off, anyone would have bet that it was a B head. There is a casting on the 3B head that is "3B".
I am in the process of finding a new B head.
This is confusing to read, sorry.

 

[lostmarbles]

.....The 3B head gasket will not fit tight around the liners. This caused carbon buildup in the space between the 2. Also, water jackets were blocked using this gasket. ...If you used a B head gasket with the 3B head, there will still be water jacket blockage. ........My B motor had the correct B stickered valve cover bolted onto a 3B head, bolted onto the B block..... On visual inspection before the head came off, anyone would have bet that it was a B head. There is a casting on the 3B head that is "3B"......

Wow. Thanks for taking the time to place this info here Pilotmike. That's is EXACTLY the type of information I wanted to surface. (Very valuable to others who own a 3B or B, need a new head or exhaust manifold and have one from the other engine available to them.)

...... Also the exhaust manifold that is on mine was a "B" 2 bolt head pipe flange that they drilled out to make the manifold bolts work. ....

My B head has M8 (8 mm) exhaust manifold studs. Do I take it from this that your 3B head has M10 (10mm) studs? (If so I'll have to correct what I said earlier in this thread about that!) And if so, in your opinion, did drilling out the "B exhaust manifold" (to fit a 3B head) seriously weaken it (by leaving insufficient metal around the drilled-out holes in places)?



PS. Sounds likie you have a good reason to be very disgruntled about your previous owner! (I sympathise.)

 

[amaurer]

On my 77 BJ40, the previous owner had bolted on a 3B head onto the B block.
He used a cheap 3B Head gasket.
The 3B head gasket will not fit tight around the liners. This caused carbon buildup in the space between the 2. Also, water jackets were blocked using this gasket.
If you used a B head gasket with the 3B head, there will still be water jacket blockage.

The question I have, then, is if the heads are interchangeable, why aren't the head gaskets? I don't see how there can apparently be water jacket passages missing in the gasket that aren't also missing in the head??

 

[pilotmike]

Water

Does someone have a picture of a new 3B head gasket? I can post a new B gasket pic so we can compare. The 3B head will bolt onto the B block, but whichever gasket you use is going to block water. Mine was running this way, so they will run. I just dont want to put another 3B head on a B block and end up with the same problem a few months from now
Mike​

 

[amaurer]

Does someone have a picture of a new 3B head gasket? I can post a new B gasket pic so we can compare. The 3B head will bolt onto the B block, but whichever gasket you use is going to block water. Mine was running this way, so they will run. I just dont want to put another 3B head on a B block and end up with the same problem a few months from now
Mike​

My 3B head gasket matches the head exactly, so if the B gasket doesn't then the heads shouldn't be swapped - it may work, but not as its supposed to.

Here are pictures of the 3B gasket, block, and head:

 

[amaurer]

and the rest of the head:

 

[lostmarbles]

Just been having some private discussions about oil coolers so I thought I'd add what we've found to this thread.

The B engine in my 1979 BJ40RV-KCQ has a sealed-unit oil cooler (not designed to be opened-up) that is secured to the block with just two bolts. (And these bolts are hollow to carry the oil flow.)

Whereas the oil cooler in a 3B in a 1981 BJ42RV-KC has a big removeable cast-alloy cover secured to the block with many bolts (and sandwiching a gasket inbetween). Inside this oil-filled housing is a separate (removeable) plate-type heat exchanger through which the coolant passes.

---- So the 3B employs a much more sophisticated unit that is more serviceable.


Edit 23 Dec 008 : This thread here shows a 1983 European BJ40 where the 2977cc B diesel is actually fitted with the 3B-type alloy oil cooler:
https://forum.ih8mud.com/40-55-series-tech/257796-1983-bj40-uk.html
So it looks like BJ40 production continued on past 1980 for certain markets (but not for the Australian/NZ market where I am) and those B-engines got some of the 3B features (like an alloy oil cooler and 3-bolt exhaust-pipe flange).

I suspect the reason for the continued production of the B-engined BJ40 past 1980 would have been connected with "marketing" and "Government Regulations". What I'm thinking is ........ Perhaps in certain countries a vehicle with an engine capacity over 3 litre may have incurred an increased tax/duty penalty. In such a case, Toyota may have stuck with the lower engine capacity in that market to make its vehicles more affordable.

 

[lostmarbles]

This thread here suggests that the following may be interchangeable between a B-diesel and a 3B":

https://forum.ih8mud.com/diesel-tech-24-volts-systems/257662-b-motor.html#post3981330

• Entire camshaft
• oil pan
• alternator
• rocker arms

PS. If you have an early-production B diesel (probably pre-dating those installed in Australian/NZ-market BJ40s - which would be pre-1977 I think) - you may not experience the parts interchangeability discussed in this thread. Because from what I'm getting now, it looks to me like the B-diesel evolved gradually to become more and more similar to what was to become the 3B. And astonishingly, it appears that for about 3 years, both the B and 3B engines were even being produced concurrently by Toyota/Diahatsu. What you got depended on what model vehicle you bought (Dyna, Landcruiser etc), and even then, on which market you were in (Australian, European, etc ).

PPS. And then, as if that wasn't complicated enough, during the B/3B production-overlap period, Toyota produced another diesel with an intermediate cc-rating and called it the 2B engine which they fitted to BJ41 cruisers (amongst others). But I believe the 2B-powered vehicles were mainly restricted to the "Japanese Domestic Market". However, with the surge in exports of second-hand vehicles, the 2B is now found in many different countries too.

And here's a thread which says the B-engine from a 1977 BJ40 has longer flywheel teeth and smaller-diameter flywheel-to-crankshaft bolts than a 3B engine from a 1988 BJ73:

https://forum.ih8mud.com/diesel-tec...-b-3b-turbo-intercooler-last.html#post4152919

 

[roalco]

Just a bit further on the B/3B head and head gasket issue. I have a spare B engine that I bought years ago, had all 12volt accessories (glowplugs, alt, starter and edic) and a 3 bolt exhaust manifold. It also had a spun main bearing and a nearly new (less than 1000km) commercially rebuilt head (no cracks, new precups, Injectors, et al).
My thought was to use the head as a temporary spare on my daily driver when I pull the original 3B head for a leisurely rebuild this summer.
I just pulled the head (the part number cast in is 11111-56020) (I think it's a 1980) and compared the head gasket that was fitted (marked B-2B) with a new 3B gasket. A slightly different outline (different manufacturers) and the 3B has a 107mm cylinder hole with the B-2B having a 102mm cylinder hole. Overlaying them, all the holes (coolant, oil, bolt) seem to match spot on and the cylinder bores are concentric. I would think a 3B gasket could be used on a B in a pinch, it would only very slightly lower the compression ratio (until it builds up a carbon block).
It seems the heads should swap well, the exhaust ports seem smaller than the 3B gasket, and possibly the valves are a bit smaller, does anyone have the inlet and exhaust valve outside diameters for the 3B?
Any thoughts?

 

[lostmarbles]

Useful stuff as contributed by Wedg3 in this thread:

https://forum.ih8mud.com/diesel-tech-24-volts-systems/439485-b-3b-difference.html

engine B 1979

engine 3B 1984

I rebuild a B engine and trying to do the same on a 3B...

I know that a post show the pieces that is the same on the two engine but I have some trouble finding it. I'll tell you some difference between those engine.

B engine ... 3 bearing camshaft, really small compare to 3B 4 bearing camshaft with bigger hole for oil.

B engine ... smaller crankshaft.. smaller bearing and smaller bolt that retain all that.

B engine ... Big timming gear and less teeth but same diameter so a complet set of 3b timming gear fit but have a different numbert of tooth.

The head of a 3B fit on B engine.

The oil pump is the same. But the timming cover of a 3B doesn't fit on B engine.

The rocker is identical.. but the bolt that retain the rocker is smaller on B engine.

The Fuel pump,injector pipe, injector, intake is the same on each engine.

The oiling system on 3B engine is oversize compare to B engine. Bigger hole, piston oil squirter, and bigger passage on every part.

the liners and piston is bigger on 3B, and connecting rod can't be exchange.

The oil pan and the strainer is the same.

The flywheel and clutch of a 3B can be modifie to fit on 3 finger clucth of the B engine.

the belthousing of 3B fit but need to change the transmission mount. The 3B belhousing have a RPM sensor mount on it.

The fuel filter is the same.. the mount is different.

the alternator is identical, but mount is different.

The mount for the engine is identical and at the same place.

The exaust of a 3B fit on B but the B doesn't fit on 3B.. smaller bolt size. Same exaust flow by the way, same diameter

all sensor are the same on both engine.

I think it's all !

 

[YardPig]

I wonder how this translates into the newer B engines. I have a B engine in a 1991 Dyna. I was considering installing a 3B in it for a bit more jam (hahaha, I know), and because I have it sitting in the shop already. I'm curious if Toyota bothered to start updating in the newer years, besides the nicer valve cover...


Shawn

 

[lostmarbles]

I wonder how this translates into the newer B engines. I have a B engine in a 1991 Dyna. I was considering installing a 3B in it for a bit more jam (hahaha, I know), and because I have it sitting in the shop already. I'm curious if Toyota bothered to start updating in the newer years, besides the nicer valve cover...


Shawn

They certainly did keep changing things Shawn.. So a 1991 B would be "more advanced" than a 1984 3B.

That's why my thread became so difficult!

In other words, a negative aspect in my 1979 B-engine may have been "improved upon" in a 1982 3B and then improved again in a 1988 B-engine.

So you can never say a 3B is more advanced than a B without knowing the "years of manufacture".

And this is complicated further by the fact that not all changes were "changes for the better". (I believe some were done just to save manufacturing costs.)

But there's no substitute for "increased cubes" in the power stakes. So I guess on that basis you could indeed say "any 3B is better than any B".

 

[YardPig]

I do know from searching the EPC that 08/88-up cam bearings, camshaft and rear knock out expansion plug are different than earlier models, although 3B and B new style (08/88+)are the same. So Toyoace, Dyna, Coaster, BJ73, BJ70, BJ75 3B and B same deal. Doesn't really help much for North American people, as this year of 3B was only available JDM, but they are being imported and wrecked, so this will only confuse the parts even more so to the unsuspecting.

Also in the EPC it appears the early 3B were 6 bolt and the 88+ B engine are 8 bolt crank.

Shawn

 

[Wes]

Thanks for this info! Although the thread is about interchangeability between B and 3B engines, you have provided useful info that applies to my 2B as well. It looks like your sources may still provide some of this stuff. Guess it's time for me to start stockpiling.

 

[Henry Schofield]

Very Cool, I was hoping to rebuild my engine but now that I found a hairline crack on the block I am searching for an overhauled long block to replace my B, not sure if to go with 2B or 3B. If I can get a B I would be happy with that. Your engine bay looks AMAZING mine is the dirty version of that with the Brake servo on the other side and no fan blower.....and as you said my Power Steering way up high
Thanks for the thread!