Stroke & bore of a 3BII

[Rickycruiser]

Has anyone ever took a 3BII apart and measured the bore and the stroke????

In Belgium The 3BII was only mounted in the 1989 BJ70 for a very short time.

I have one in a BJ43 and I think it is actually 4B

I'm preatty sure the bore is correct, but I have no mesurements of the stroke

for this I need to measure the exact bore and stroke, i've got the orriginal servicemanual for the 3BII/14B and here it looks exacly the same

So, if anyone out there ever has to replace a cilindergasket, cilinderhead, or anything of that sort, PLEASE measure de stroke of the cilinder and let me know
you can reply or send a PM

for those ho do not know what a 3BII lools like, see pick

 

[roscoFJ73]

If it was a 4B ,why would it have 3B molded on the side?
From what I can see ,the 4B was in production from 99-04,long after the BJ73 went out of production in 1990.
The 4B shares the same part number with a 14B/15B for the crankshaft,but no 3B

 

[amaurer]

I don't know why you're so determined to find a difference here... there is not a single bit of evidence to suggest that its a 4B, but its application and the fact that it says "3B" are pretty big clues that it is, in fact, a 3B (II).

3B-II's have the same stroke and bore as the 3B. The piston part number is the same and those parts interchange. In fact ALL 3B's (I's, II's, whatever) after 11 '84 use the same piston p/n.

EDIT: incidentally the only external difference I can find between a 3B and a 4B (apart from the casting on the block itself, that is) is on the injector pump - the 3B fuel input is on the top of the pump, while the 4B's input banjo is on the rear of the pump (same face as the injector lines). From your previous pics you definitely have a 3B style pump.

 

[lostmarbles]

Bore x stroke (mm) = 102.0 x 105.0

(102 = standard pistons as opposed to oversize)

 

[Rickycruiser]

I don't know why you're so determined to find a difference here... there is not a single bit of evidence to suggest that its a 4B, but its application and the fact that it says "3B" are pretty big clues that it is, in fact, a 3B (II).

3B-II's have the same stroke and bore as the 3B. The piston part number is the same and those parts interchange. In fact ALL 3B's (I's, II's, whatever) after 11 '84 use the same piston p/n.

EDIT: incidentally the only external difference I can find between a 3B and a 4B (apart from the casting on the block itself, that is) is on the injector pump - the 3B fuel input is on the top of the pump, while the 4B's input banjo is on the rear of the pump (same face as the injector lines). From your previous pics you definitely have a 3B style pump.

I Know I must sound annoying, but I find the differance between a 3B and a 3BII much greater than the pour 6extra hp and no extra tork.

Since I don't know the productiondate of the 4B it wouldn't sound that strange if they just upgraded the engine with a longer stroke

the 3BII is also a directbore whitout sleves, and the service manual giver 4 differant sizes for diameter and an extra 4 oversize pistons if you have to remachine the block.

the reason I pressing this, is because I just really want to know, if you ever drove an engine as this one, you would find it strange as well.

 

[roscoFJ73]

I Know I must sound annoying, but I find the differance between a 3B and a 3BII much greater than the pour 6extra hp and no extra tork.

This could be many things including the condition of the engine and fuel systems and also because one has an inline pump and the other a rotary pump.

Since I don't know the productiondate of the 4B it wouldn't sound that strange if they just upgraded the engine with a longer stroke

Toyodiy only lists it as being in production from 99-04.This is the part number for the partial engine assembly, 11400-58240

the 3BII is also a directbore whitout sleves, and the service manual giver 4 differant sizes for diameter and an extra 4 oversize pistons if you have to remachine the block.

I dont see how that would make a difference,all the sleeveless engines toyota made had at least 3 oversize piston sizes.
Ive heard that when engines are assembled,they choose the piston that fits best.
It was in the B and H engines that toyota converted from sleeved and non sleeved. It is an evolutionary change in design to save money.All engines after that became non sleeved AFAIK

the reason I pressing this, is because I just really want to know, if you ever drove an engine as this one, you would find it strange as well.

I cant think of ANY toyota engine that shares the same engine number prefix with another engine of a different cc.

It may also be possible to fit a 4B crank into a 3B engine with the correct rods,but if toyota did it they would have added 4B to the engine molding

 

[amaurer]

the 3BII is also a directbore whitout sleves, and the service manual giver 4 differant sizes for diameter and an extra 4 oversize pistons if you have to remachine the block.

the reason I pressing this, is because I just really want to know, if you ever drove an engine as this one, you would find it strange as well.

All later 3B are sleeveless, not just the 3B-II.

I have 3Bs with both the inline and the rotary pump and I agree, the rotary pump version feels stronger. This forum has agreed several times on that point, in fact. But thats a characteristic of the pump, as far as we know - I certainly don't suspect my 3B is really a 4B.

I dont see how that would make a difference,all the sleeveless engines toyota made had at least 3 oversize piston sizes.
Ive heard that when engines are assembled,they choose the piston that fits best.
It was in the B and H engines that toyota converted from sleeved and non sleeved. It is an evolutionary change in design to save money.All engines after that became non sleeved AFAIK

Yep, both late 3B's and 3B-II's list ALL the same piston part numbers, including all three oversize pistons AND the "mark-1" and "mark-2" pistons which were selected to fit the blocks.

 

[Rickycruiser]

Ok, I give in.

Would have been great do

condition of my engine?? 300000KM and more, I know the former owner. only had to replace the O-ring on the trottle valve on the pump

 

[roscoFJ73]

Any guesses on fitting a 4B crank into a 3B?

 

[Rickycruiser]

Any guesses on fitting a 4B crank into a 3B?

I guess this would be " plug and play", when the cilinderwall is remachined, or brand new

 

[roscoFJ73]

If a 4B would fit,then you could also turn the 3B into a 5B by boring it out. I thiink the 5B/15B uses the same crank as a 4B.

 

[leonelcanut]

I have exactly the same idea for my BJ42 from 1984 with a 3B engine. As I need to overhaul the engine was wondering if with minor modifications you could put a 14B or 14BT head on top of the stock 3B block...is that crazy? scuse my ignorance.