B head saga- Not a good weekend

[Gengis]

I had to pull the engine, just to fix a g/box leak and replace the oil pump housing. While I was at it I thought I would lift the head for a quick peep and replace the stretch bolts which I reused the last time.

Now, mine is a late model B, with no liners and a built in vacuum pump and rotary IP.
Stay with me now:

When I first got the motor, about 10 years back she was in a sorry state and the rebuilders fitted liners. (Can’t remember why, possible because of availability of piston or max oversize exceeded, whatever).

So, I had a good look, pulled a piston and checked rings bearing etc., all good, so I fitted the new gasket and tightened down to the torque recommended on the tappet cover label.

What I did not even check, was that the gasket fitted properly!!! In this case, being a late model gasket, the piston holes are the size of the pistons and make no allowance for the fire rings of the liners. I did not see this, don’t ask me why, but I did not.
So now on tightening up, the gasket now on top of the liners (fire rings) tries to reseat the liner, and 3 liners crack, in a perfect circle about 5 mm down.

I found this out because, thankfully a piece of the squashed gasket folded into the piston bore and prevented me from turning the motor over. I cursed, checked everything else and pulled the head again to find 3 nice giant sized bangles as a present for my stupidity.

I now have a stripped down engine block, ready to go in for new liners tomorrow.
A new gasket, the correct one this time
A new set of head bolts
May as well chuck in new rings

Question:: If you are still prepared to deal with a fool.

I must fit the old model gasket (To clear the fire rings). Did these gaskets come in different thicknesses?

10 years ago, when I rebuilt her the first time, I just asked for a B gasket and fitted what I got and it worked. Not from an official Toyota dealer.

Advice appreciated, and kick my behind if you want, I am man enough to take the punishment.

George

 

[lostmarbles]

I had to pull the engine, just to fix a g/box leak and replace the oil pump housing. While I was at it I thought I would lift the head for a quick peep and replace the stretch bolts which I reused the last time.

Now, mine is a late model B, with no liners and a built in vacuum pump and rotary IP.
Stay with me now:

When I first got the motor, about 10 years back she was in a sorry state and the rebuilders fitted liners. (Can’t remember why, possible because of availability of piston or max oversize exceeded, whatever).

So, I had a good look, pulled a piston and checked rings bearing etc., all good, so I fitted the new gasket and tightened down to the torque recommended on the tappet cover label.

What I did not even check, was that the gasket fitted properly!!! In this case, being a late model gasket, the piston holes are the size of the pistons and make no allowance for the fire rings of the liners. I did not see this, don’t ask me why, but I did not.
So now on tightening up, the gasket now on top of the liners (fire rings) tries to reseat the liner, and 3 liners crack, in a perfect circle about 5 mm down.

I found this out because, thankfully a piece of the squashed gasket folded into the piston bore and prevented me from turning the motor over. I cursed, checked everything else and pulled the head again to find 3 nice giant sized bangles as a present for my stupidity.

I now have a stripped down engine block, ready to go in for new liners tomorrow.
A new gasket, the correct one this time
A new set of head bolts
May as well chuck in new rings

Question:: If you are still prepared to deal with a fool.

I must fit the old model gasket (To clear the fire rings). Did these gaskets come in different thicknesses?

10 years ago, when I rebuilt her the first time, I just asked for a B gasket and fitted what I got and it worked. Not from an official Toyota dealer.

Advice appreciated, and kick my behind if you want, I am man enough to take the punishment.

George

Sorry to hear about your engine trouble George.

Re-aquaint me with the engine's history ....(production year and vehicle model it came in) and I'll try and search the info for you.

PS. - If you don't have this info ... then I don't think I can help.

 

[amaurer]

Sorry to hear about your engine trouble George.

Re-aquaint me with the engine's history ....(production year and vehicle model it came in) and I'll try and search the info for you.

PS. - If you don't have this info ... then I don't think I can help.

x2, specifically what vintage were the liners you had fitted? The mix and match of part makes it tough to say what wrong vs right, but I bet someone here can sort you out.

Also, however, I'm shocked you could crack a liner, much less three! by torquing down the head!!!

 

[Gengis]

OK, from the top then.

I got this engine about 10 years ago from a junk yard, it has a big B stamped on the right side, and it cause lots of problems initially when looking for spares because it did not look like the engines in the manuals.
It turns out, much to a lot of surprise (Even on this site) that Toyota modernised their old B, probably in the early 90's. Mine has a vacuum pump, oil squirters, rotary IP and a fancy stepped tappet cover ( Like the 14B), and no cam follower inspection plate on the side of the engine, 5 bearing cam.
I have found the exact match on Toy. DIY on a 1994 Dyna truck,

Now, when I sent it to the engineers, all those years back, they inserted liners, and there definitely were no liners before then. I am not sure if they were Toyota liners or not, but we got liners anyway. They were also very proud of the fact that thy left the "fire rings" standing proud, telling me that some machine shops deck them flush with the block.
I did not know much about diesels then, and when I got it all back, I fitted a head gasket to match the one that came off. Probably an original B head gasket because the bores were wide enough to clear the fire rings. (As I mentioned identifying the engine was a problem and the PO probably also struggled).

Anyway, it all went together and gave me 10 happy years of service, all be it with not too much millage, 15 or 20 thousand KM's.

So, a week or so back, I had to pulled the engine to replace the oil pump housing and put a new seal in the gear box and I thought I would just take a look under the head, and check all those things I knew nothing about 10 years back. I was also worried about the head bolts, because they appear to be stretch bolts (with a star shaped 17mm head) and I had unwittingly re used them all those years back.

So I checked the head inserted new cups, pulled just one piston, mainly to see if they had alfin inserts and check ring condition. (No inserts and rings still serviceable, so I called them all good, and slapped on the head gasket and tightened the head down.

Now I had gone out and got a brand new TOYOTA gasket kit, at one hell of a price, but I justified it by just wanting to close the engine up for another 10 years. BUT, I ordered the gasket kit for the NEW B, (1994 dyna toyo.DIY) because that’s what my engine is. Obvious now, these engines have no liners or fire rings, so the gasket bores are close to the cylinder bores.
As mentioned I did not even notice that the gasket now lay on top of the fire rings, instead of surrounding them, and I put the head on and torqued up.
I used the sequence on the tappet cover label, 36 Ft/lbs+90+90. After fitting the tappet assembly, I turned the engine over to align and fit the IP, and it stopped dead at the top of the stroke. A piece of the gasket had been squashed by the fire ring and protruded into the bore and stopped the piston. If this had not happened I would have completed assembly and tried to start and drive her like this.

On pulling the head off, I noticed my mistake, used words like "gosh" golly" gee wizz" drat , and then planned to pop in to the spares shop and get a gasket just like the old one. But when I lifted the gasket, the top of the liner came away with it, and 2 others had also cracked and came away easily.
I can only assume that the pressure on top of the fire rings tried to push the liners down further, but they have a lip (flange) which prevents them being pushed too far in, but probably not designed for the extra pressure once seated, and they registered their protest by cracking in a neat circle, about 5 or 6mm into the bore.

So the questions again;
Did the "old" B's have liners with Fire Rings???? If so then I guess that this would be the gasket to go for???
Is there a gasket selection in case the block needs decking????
Any other recommendations or things to look out for.
Regards
George

 

[amaurer]

So the questions again;
Did the "old" B's have liners with Fire Rings???? If so then I guess that this would be the gasket to go for???
Is there a gasket selection in case the block needs decking????
Any other recommendations or things to look out for.
Regards
George

I think most B's prior to 1988 had liners. I don't know for sure if they all had fire rings or not, but fire-ringed liners seems to be the standard Toyota design, so I assume so. All the B's and 3B's I've seen have had them.

There are no options for gasket thickness.

The 1986-1988 B gasket (for an engine WITH liners) is 11115‑56050 but its no longer available from Mr. T.

 

[gerg]

Unless it was MLS, without a fire ring I doubt that gasket would last more then a few hours before buring through. Maybe a 35hp VW motor can run without them, but I cant see a diesel lasting long.

 

[Gengis]

Cheers Amaurer

Looking back at the "OLD" B gaskets they started at 11115-56020 in 1984 and seemed to go up in the last digit on a regular basis.
What do you think is the difference and which ones are still available,
My last gasket was a no name brand, and although it kept the compression and oil in control, it did seep a bit of water near 3 and 4 on the inlet side. Never was a problem and just presented as a rusty sweat between head and block, and I never “caught it in the act" so to speak. And the head was skimmed and the block decked, prior to fitting.
Back then I did not even know about piston clearance, petrol heads don't ever seem to encounter this. Anyway, the block was decked then, and I am worried that if they have to do it again, after pressing in new liners, that I may have a problem.
I'll wait and see, and ask the engineering company to measure the Piston Protrusion, before I collect,

What is the piston protrusion limit on this engine?? (I guess on the older B's.)

My manuals, are all for the old B’s, anyone got an online manual for the late model B's???


Regards
George
Ps

Oh dear, the engineering company can’t do this, I did not supply the crank!!!

 

[Gengis]

Cheers Greg
Your reply came in while I was typing.
The whole world of fire rings and protrusions are new to me, and still a bit hazy.
I see the need for the fire rings, but it's certainly a fine line between gasket compression and fire ring to head clearance and I don’t have any of the maths on these?

There is nothing worse than turning the engine over after fitting the head and feeling that sudden stop at the top of the stroke!!

George

 

[amaurer]

Looking back at the "OLD" B gaskets they started at 11115-56020 in 1984 and seemed to go up in the last digit on a regular basis.
What do you think is the difference and which ones are still available,
My last gasket was a no name brand, and although it kept the compression and oil in control, it did seep a bit of water near 3 and 4 on the inlet side.

I only have 3B experience, but the only substantial difference between early- and late-80's gaskets is that the later ones are MLS instead of composite. My assumption would be that they made the same change for the B.

I doubt there the shape/location of the water jackets was changed, but I'd definitely test fit the gasket first to make sure.

 

[lostmarbles]

Hi George.

Toytota says a 1994 B from a Dyna has gasket 11115-56090 which is 1.5mm thick.

But I guess that's irrelevant for your modified engine now anyway.

I believe this gasket here is still available to fit my liner-equipped 1979 B:



Do you want me to take some measurements off it?

And what exactly are you guys referring to as "fire rings" on these engines? Can someone perhaps arrow them in a pic and explain the theory behind them?



Edit:

The Aug 1988 RM132E FSM says to select the appropriate thickness (between 1.5, 1.6, and 1.7mm) head gasket depending on piston protrusion only for the direct injection engines (11B and 14B).

Piston protrusion figures are not discussed for the indirect injection engines (B and 3B) from what I can see.

 

[amaurer]

And what exactly are you guys referring to as "fire rings" on these engines? Can someone perhaps arrow them in a pic and explain the theory behind them?

The "fire ring" is equivalent to the "liner protrusion" mentioned in the FSM... its just the lip of the liner that sticks up above the block surface.

I believe when properly installed the head is intended to make contact with the liners such that the head gasket is not directly exposed to the combustion zone.

 

[lostmarbles]

The "fire ring" is equivalent to the "liner protrusion" mentioned in the FSM... its just the lip of the liner that sticks up above the block surface.

I believe when properly installed the head is intended to make contact with the liners such that the head gasket is not directly exposed to the combustion zone.

Thanks Drew.

And on that basis George, I guess (since you're going to use liners and an older head gasket) you should keep to the protrusion spec for my engine which is 0.01mm to 0.10mm.

Hmmm. But that limited protrusion must surely be designed to crush the head gasket a bit more around the bores rather than shield the gasket completely from combustion pressures.. No?

 

[amaurer]

Thanks Drew.

And on that basis George, I guess (since you're going to use liners and an older head gasket) you should keep to the protrusion spec for my engine which is 0.01mm to 0.10mm.

Hmmm. But that limited protrusion must surely be designed to crush the head gasket a bit more around the bores rather than shield the gasket completely from combustion pressures.. No?

That depends on your definition of "the protrusion"...

The top end of the liner has a flange of sorts that sits into the block and keeps the liner from being pressed too far down. The protrusion spec you refer to is for that flange protruding from the block's surface - it should be flush, essentially.

The fire ring is a small length of the liner that sticks up past that flange. There's no spec for that, but its only the order of a 2-3mm,from memory.

FSM pic, showing the cross section of the liner. The "fire ring" is the bit sticking up directly under the "10" in "0.10mm"

 

[Gengis]

Thank you all for the replies

I am still waiting on word from the engineers, but need to have all my ducks in a row, because time is running out, I need this baby done and tested by December.

Tom; your liner clearance is spot on, but as AM says, we still have 2 or 3 mm of what I have come to know as fire rings. I see no evidence of these having contacted the head, but it must be close, hence my worry about gasket thickness.

Concerning the measurements, then not to worry, they are all the same for water and oil ways, just that my last "no name brand" seemed a little short of packing around the water ways in one area. That's why I want the real Toyota deal.

I can also only guess that the later model engines, without fire rings and liners must have really good gaskets. The one I have (which caused all the damage) is the real deal and weighs about twice what the no name brand weighs, and is multi-layer.

 

[lostmarbles]

That depends on your definition of "the protrusion"...

The top end of the liner has a flange of sorts that sits into the block and keeps the liner from being pressed too far down. The protrusion spec you refer to is for that flange protruding from the block's surface - it should be flush, essentially.

The fire ring is a small length of the liner that sticks up past that flange. There's no spec for that, but its only the order of a 2-3mm,from memory.

FSM pic, showing the cross section of the liner. The "fire ring" is the bit sticking up directly under the "10" in "0.10mm"

Fixed it for you Drew... ("Fire ring" filled with red ink)

(I couldn't view the image.)



Thanks Drew. I love being educated about cruisers (and of course "diesel 40-series cruisers" in particular").

 

[gerg]

Notice how it exclaims that the liner must be shimmed to protrude off the deck of the block. If it does not protrude enough the head gasket will not be compressed properly and the gasket will fail prematurely. Ensure that this measurement is done correctly, as it is often overlooked. When I had my liners pressed in, I did not check this and mine sit flush. When I replace my head I will be adding an aftermarket shim specifically designed to increase pressure on the gasket there. Coincidentally, I also have blown 2 HGs in 2 years.

 

[Gengis]

OK then
the engineers pulled the old liners and can get new ones, so I am now assuming that I can go ahead and buy things again

Tom, Greg and Am, help me think this one through please:

I can get the same gasket as Tom indicated, so I now have an early model B setup (liners and gasket), do I

1. Get normal head bolts and torque up the same way as the early manuals suggest (87Ft-lb ????? )

2. Get another set of stretch bolts and torque up according to the label on my tappit cover (36Ft.lbs +90+90)

Cheaper to go with early model ones which can be reused ????

WHAT IS THE " STRETCH" BOLT STORY ANYWAY


May as well do some houskeeping while i am at it so, what else to do before bolting back down. ( and rebuilding the engine).

Head only has max 20000km on the valves and now has new cup inserts and has had a skim, they put a vacuum on the ports when the skimmed and all the valves held, so I'm calling it good.

Bearing and cam shells still look good ( as well they should)

My Toyota gasket kit (with the offending head gasket) contained crank oil seals, but the old ones do not leak a drop and I hate messing with things that work. ( Then why did you lift the head as...ho...e). but they look OK in quality so i guess i'll replace them.

Such a simple motor, guess thats why we love them

George

 

[amaurer]

OK then
the engineers pulled the old liners and can get new ones, so I am now assuming that I can go ahead and buy things again

Tom, Greg and Am, help me think this one through please:

I can get the same gasket as Tom indicated, so I now have an early model B setup (liners and gasket), do I

1. Get normal head bolts and torque up the same way as the early manuals suggest (87Ft-lb ????? )

2. Get another set of stretch bolts and torque up according to the label on my tappit cover (36Ft.lbs +90+90)

Cheaper to go with early model ones which can be reused ????

WHAT IS THE " STRETCH" BOLT STORY ANYWAY


May as well do some houskeeping while i am at it so, what else to do before bolting back down. ( and rebuilding the engine).

Head only has max 20000km on the valves and now has new cup inserts and has had a skim, they put a vacuum on the ports when the skimmed and all the valves held, so I'm calling it good.

Bearing and cam shells still look good ( as well they should)

My Toyota gasket kit (with the offending head gasket) contained crank oil seals, but the old ones do not leak a drop and I hate messing with things that work. ( Then why did you lift the head as...ho...e). but they look OK in quality so i guess i'll replace them.

Such a simple motor, guess thats why we love them

George

Hmm, those questions are good ones, I think.

One school of thought would be to use head bolts that match the vintage of gasket you're using - that basically means TTY (stretch) bolts with MLS gaskets.

... However... I am personally using an MLS gasket with standard (non-stretch) bolts on one of my 3Bs and have no issues.

One potential datapoint is that I think both MLS gaskets and stretch bolts were innovations developed to handle the CTE mismatch between modern aluminum heads and cast iron blocks. This isn't an issue for the B series (w/ iron block and head), so it may have simply been an issue of "following the herd" for Toyota rather than an upgrade borne out of necessity.

Thats a guess, mind you. I do think the MLS gasket is superior, regardless, so there goes half my logic.

 

[Gengis]

I think I'll go for price and availability concerning the head bolts
Any idea of what TTY stand for???

Also, it seems that you can only get MLS gaskets from Toyota these days ( ?? ), so there must be hundreds of engines working away with MLS and regular head bolts!!??

George

 

[gerg]

I agree the TTY bolts are for alum head stuff. I if you do use stock bolts, meticulously clean the block threads and the threads on the bolts or go and buy new ones. They are not that expensive. In the past i have used a fine triangle shaped file for the bolt threads (only on the damaged areas) and a brass brush for the block holes. You can use ARP bolts, but it will run you 250$ and 5 bolts need to be cut down to fit under your rocker arms. I dont think its necessary for a stockish motor.

Also, buy thread lube for when you install and torque them down. I recommend ARP ultra torque assembly lube. Torque in 20lbs increments. I would re torque after initial warm up to temp (let it cool completely through) and a few weeks later. I retorqued mine once a week for over a month as they loosened up tons. I was blown away by it. I was actually curious to see how long it too for them to plateau.

Here is a link for when I did my ARP/MLS gasket redo.
https://forum.ih8mud.com/diesel-tech-24-volts-systems/488209-3b-arp-studs-vendors.html