Compound Turbos on a 2nd Edition B Engine (1 Viewer)

[bsweaty]

Like the title states, I am considering adding a set of compound turbos to a 2nd gen B motor(naturally aspirated, some people refer to this as the BII and shares a block with a 11B) in a 1993 Toyota Dyna 200. The notable reason why? First, why not? I have a spare CCT Stage 1 CT12B from a KZN130 Surf project that never came to fruition. Secondly I am in the process of converting to 4x4 via solid axle swap, bumping up gears from 5.30 to 4.10 with 35" tires and will need more HP, this thing currently has around 96 according to info I can find. Some thoughts and questions here, especially for anyone who's compounded ANY B series engine... Or even any Toyota engine, I know Cummins folks compound stock engines all the time.

First, the CT12B is just a little guy with a lightweight billet wheel. I feel like it'll spool up ultra quick and be a great addition to the bigger CT26 behind it. Thoughts on this? Or will it be too much overlap in the power band? Both have adjustable wastegates, and often the wastegate on the smaller turbo feeds into the bigger turbo to help with spool. It's implied that I will be adding a front mounted intercooler during this project.

Second, internals on this engine. My goal will be max boost somewhere in the 25psi range. If I needed too, I think this CT26 could hit 30(or at least their documentation says it will with the right spring). I have a feeling the mechanical injection pump will supply enough fuel. However I have little to no experience with the internals on this engine. From what I can tell, it seems robust. Robust enough to handle 25 psi? I am not sure. Looks like ARP makes a set of head studs that will fit. Anything else to consider? Cam? Valve springs? Connecting rods? Notably this engine compression tested 415 psi across the board, seems to be super solid with a true 35k miles on it.

Third, is it worth the effort? The 14BT exhaust manifold bolts right up, and the CT26 mounts perfectly right there. I am having to add oil supply/return lines, coolant supply/return lines, new intake pipes and a new dump pipe already. Adding the CT26 is a given, but will the addition of the CT12B be worth it for the low end spool? I think so. Opinions? There's plenty of space for activities, especially with a 13" lift for the solid axle.

Am I smoking crack here? Will my engine implode upon first pull or will this be something that lasts for a while?

Thanks!

 

[MauricioR]

Hey, I like your idea! I have some opinions and questions about this...
1. I currently run a CT12B on an old B engine but I feel is really laggy, these engines lack power on low RPMs so I believe a CT20 would be a better fit to improve low RPM response (dont mind me if you don't care about low rpm power).
2. Your engine is a 2nd gen B (?) what's the difference from a regular B? Is it the injection?
3. I had the experience of blowing up few gaskets on my Cummins few times throwing 30-35psi, I solved the issue by using ARP studs. Originally these Cummins have a Torque spec for the OEM head bolts of 115ft/lbs, with the ARP I went to 135ft/lbs and now it holds 50PSI. You can do the same thing and have an insurance on your gasket, have a chat with the ARP folks.
4. The internals on these engines are fenomenal, I really don't think you will bend a rod or brake a piston, however I will highly recommend to use a Pre-Turbo Pyrometer so you can measure engine temps and avoid melting down a piston or anything.

I have few colleagues that currently run 22-25psi on 13&14B engines with no issues with overtorque head bolts, but there is always a risk of braking the bolts.
Thank you for sharing your amazing project

 

[bsweaty]

Hey, I like your idea! I have some opinions and questions about this...
1. I currently run a CT12B on an old B engine but I feel is really laggy, these engines lack power on low RPMs so I believe a CT20 would be a better fit to improve low RPM response (dont mind me if you don't care about low rpm power).
2. Your engine is a 2nd gen B (?) what's the difference from a regular B? Is it the injection?
3. I had the experience of blowing up few gaskets on my Cummins few times throwing 30-35psi, I solved the issue by using ARP studs. Originally these Cummins have a Torque spec for the OEM head bolts of 115ft/lbs, with the ARP I went to 135ft/lbs and now it holds 50PSI. You can do the same thing and have an insurance on your gasket, have a chat with the ARP folks.
4. The internals on these engines are fenomenal, I really don't think you will bend a rod or brake a piston, however I will highly recommend to use a Pre-Turbo Pyrometer so you can measure engine temps and avoid melting down a piston or anything.

I have few colleagues that currently run 22-25psi on 13&14B engines with no issues with overtorque head bolts, but there is always a risk of braking the bolts.
Thank you for sharing your amazing project

@MauricioR thanks so much for getting back and the info you provided!
1. When you did your CT12B turbo install, did you advance your timing? Did you turn up the fuel as well? Do you know at what RPM you begin to boost at? It would be pointless for me to compound two turbos close together in size. The whole point of compounds is to cover as much powerband as possible. The CT26 is the turbo that came on the 14BT, a 3.7L. I have a feeling you are right about the CT20 being the correct turbo for the bottom end!
2. From my understanding, and I have never ripped a I or a II gen B engine apart... After 1988 the B engine is considered second gen, sharing a block with the 11B. I believe it has large camshaft bearing journals, updates to the pushrods, flywheel bolt pattern, and piston oil squirters. I do not believe my B engine is direct injected,
3. I like your style! I am building a new VE pumped 24v Cummins motor for my '92 Dodge W250 at the moment... and I have a set of ARP studs waiting to go in! What truck is your Cummins in? I can't remember the part number right now, but ARP made head studs for another vehicle that are within 2mm of the head studs for my motor. I figure it'll be a great way to go regardless!
4. This is what I keep hearing, which is why I am not afraid to compound turbo this engine. Again, not shooting for the most boost on the planet, just trying to benefit from boost across the powerband. This van is SO slow. It currently tops out around 60mph.

Thanks again!

 

[mudgudgeon]

Pass the crack pipe!

30psi through a ct26 with Toyota internals will not end well. They are concidered to be at their limit around 15psi.
I blew one up at around 22psi.

I love the idea of compounds, and when i was younger and slightly stupider liked at doing it.
These days, i think there's better aftermarket options that would achieve most of what you want with a single turbo.
Compounds are multiple extra layers of complication. Lots to work out that could derail a project, depending on your persistence and willingness to screw stuff up, and try again. If keeping it simple with a single makes it more achievable to get the project kicking sooner, there's merit in that.

From memory, the smaller turbo needs to be big enough to handle the full volume of intake/ exhaust.
You say the ct12b is "a little guy". It needs to match the engine volume. The large turbo is a bonus on top.
Small turbo can be tuned for spool characteristics you want etc, but should not rely on wastegating exhaust to maintain flow through the system. Wastegate is to control turbo speed.

 

[mudgudgeon]

I shoulda looked at the shiny stuff better. I see you have a mambatek ct26. So the 15psi limit is not valid.

 

[bsweaty]

Pass the crack pipe!

30psi through a ct26 with Toyota internals will not end well. They are concidered to be at their limit around 15psi.
I blew one up at around 22psi.

I love the idea of compounds, and when i was younger and slightly stupider liked at doing it.
These days, i think there's better aftermarket options that would achieve most of what you want with a single turbo.
Compounds are multiple extra layers of complication. Lots to work out that could derail a project, depending on your persistence and willingness to screw stuff up, and try again. If keeping it simple with a single makes it more achievable to get the project kicking sooner, there's merit in that.

From memory, the smaller turbo needs to be big enough to handle the full volume of intake/ exhaust.
You say the ct12b is "a little guy". It needs to match the engine volume. The large turbo is a bonus on top.
Small turbo can be tuned for spool characteristics you want etc, but should not rely on wastegating exhaust to maintain flow through the system. Wastegate is to control turbo speed.

@mudgudgeon consider it passed and thanks for the voice of reason here.

Which engine did you blow up?! And what exactly did you blow up? Maybe I'll wastegate around 20psi to start.

The B engine is a 3.0L just like the 1KZT-E(actually not much else is the same minus displacement). I have a feeling that the CT12B is actually the right turbo for the job, and might be a bit much for the little guy.

The CT26 bolts up to the manifold that bolts up to my motor, both designed for the 3.7L 14BT engine. This is a very simple install, but I fear it may be too much. The CT26 is likely a little big for the job here, but the one I ordered from Mamba does come with a fancy lightweight wheel to help.

I may not be able to properly run the CT26 without a smaller turbo... It may not start spooling until it's too far down the powerband to be effective. I feel like the CT20 would be the better small turbo. My goal here is power across the band as effectively as possible.

So I suppose the question now is:
1. Modify my exhaust manifold to take a CT12B and run it as a single, as it's the turbo designed for the closest displacement. But may have some lag.
2. Sell the CT12B and compound a CT20 with the CT26 and FAAFO until it works.

How does this sound?

 

[Eurasiaoverland]

Heavily boosted indirect injection B engines don't usually last long (plenty of turbo 3B threads here). So then you'll be after a new engine for that very nice looking Dyna.

So... why not just buy a decent new engine now. A 14B would be perfect, and is a perfect platform for turbocharging.

 

[bsweaty]

Heavily boosted indirect injection B engines don't usually last long (plenty of turbo 3B threads here). So then you'll be after a new engine for that very nice looking Dyna.

So... why not just buy a decent new engine now. A 14B would be perfect, and is a perfect platform for turbocharging.

If I could find a 13BT or a 14BT in the USA for a reasonable price on a reasonable timeline, I would. They are few and far between here.

An intercooled, tuned, moderately boosted B engine should hold up for a little while. Right? Note that this is a B II engine. Piston oil coolers, more robust cam bearings, removal of lifter window in the block. The 2LT-E and 1KZT-E are two other Toyota engines that come factory indirect injection with a turbo... I am aware that they both have head cracking issues when over heated. Just need to keep the heat down!

 

[Eurasiaoverland]

If I could find a 13BT or a 14BT in the USA for a reasonable price on a reasonable timeline, I would. They are few and far between here.

An intercooled, tuned, moderately boosted B engine should hold up for a little while. Right? Note that this is a B II engine. Piston oil coolers, more robust cam bearings, removal of lifter window in the block. The 2LT-E and 1KZT-E are two other Toyota engines that come factory indirect injection with a turbo... I am aware that they both have head cracking issues when over heated. Just need to keep the heat down!

None of those improvements (I am not sure that earlier B engines lacked oil squirters - early 3Bs had them) get around the real issue which is IDI engines having more heat concentrated in a weaker head. Indeed, with moderate boost you might not reduce its life too much, but 25 psi is very, very far from moderation.

 

[AussieHJCruza]

The B ain't gonna like a turbo, let alone compounds at 20+ lbs of boost...sorry to be the party pooper but you'd be better off spending the money on a DI engine that can shed the heat and make decent power.

 

[mudgudgeon]

I had a hdj81. Blew up the compressor wheel on a stock ct26. The engine munched the shrapnel.

The CT26 bolts up to the manifold that bolts up to my motor

With compounds, the smaller turbo bolts to the manifold, then the larger turbo. So exhaust gas goes from manifold, through small turbo, it gets driven first, and spools first, then through the larger turbo.
The larger turbo will spool a bit slower.

 

[MauricioR]

I had the same thinking as you did when I used the CT26b on my B, it was originally from a 1KZ and matched the CCs, but no... It ended being too laggy as I said (I suppose the 1KZ moves more air ?).
On my B engine, all I did was the turbo and a little bit more fuel, I then was able to use a higher gear on any hill.
Something that stopped me from going further was the clutch, there was a point of power where the clutch started to slip, so I had to reduce fuel.
Motor has around 8 years with the turbo and zero complains.
Check it out: Turbo on a B engine (1978 BJ40) (With Intercooler) - https://forum.ih8mud.com/threads/turbo-on-a-b-engine-1978-bj40-with-intercooler.930152/page-2

I really don't think you would explode the engine to be honest if this is done properly, look at the 1hz guys throwing more boost that most of the 1HDT. The main concern about IDI is cracking the heads. HOWEVER! I will advise you, if you have the chance to invest on a 13B-T or 14B-T would be a better idea, you will get better results with these engines. Not mentioning if you could fit a 15BT-FTE there, that would be the holy grail.

If I were you I would do that... Just do it single turbo for now with a CT26b or CT20 and set it to 6-10PSI so you can have a little bit more power then save money to get a 13,14 or 15B. Would be easier, less riskier and you'll get more power.

Regarding my Cummins... I have it on an 80 series LC, quite a big project I am on right now... Just a regular 12 valve with a p7100 with all the possible mods, 64mm turbo, fully manual 47RE, and some other toys, hopefully will be able to share it on July when I finish.

 

[bsweaty]

I had the same thinking as you did when I used the CT26b on my B, it was originally from a 1KZ and matched the CCs, but no... It ended being too laggy as I said (I suppose the 1KZ moves more air ?).
On my B engine, all I did was the turbo and a little bit more fuel, I then was able to use a higher gear on any hill.
Something that stopped me from going further was the clutch, there was a point of power where the clutch started to slip, so I had to reduce fuel.
Motor has around 8 years with the turbo and zero complains.
Check it out: Turbo on a B engine (1978 BJ40) (With Intercooler) - https://forum.ih8mud.com/threads/turbo-on-a-b-engine-1978-bj40-with-intercooler.930152/page-2

I really don't think you would explode the engine to be honest if this is done properly, look at the 1hz guys throwing more boost that most of the 1HDT. The main concern about IDI is cracking the heads. HOWEVER! I will advise you, if you have the chance to invest on a 13B-T or 14B-T would be a better idea, you will get better results with these engines. Not mentioning if you could fit a 15BT-FTE there, that would be the holy grail.

If I were you I would do that... Just do it single turbo for now with a CT26b or CT20 and set it to 6-10PSI so you can have a little bit more power then save money to get a 13,14 or 15B. Would be easier, less riskier and you'll get more power.

Regarding my Cummins... I have it on an 80 series LC, quite a big project I am on right now... Just a regular 12 valve with a p7100 with all the possible mods, 64mm turbo, fully manual 47RE, and some other toys, hopefully will be able to share it on July when I finish.

If I could get my hands on a 13, 14, or 15BT in the states for a reasonable rate I would. They pop up every once in a while and are fleeting. I'll like run the CT26 to start as it fully bolts up. I'll keep the boost low and intercooled for sure.

6BT in an 80 series is the dream! How are you supporting that kind of weight?

 

[bsweaty]

None of those improvements (I am not sure that earlier B engines lacked oil squirters - early 3Bs had them) get around the real issue which is IDI engines having more heat concentrated in a weaker head. Indeed, with moderate boost you might not reduce its life too much, but 25 psi is very, very far from moderation.

Wild idea here. My engine shares a block with the 11B which is direct injected. Having looked at both the head and pistons… I can rebuild my motor with 11B parts and either drill out my current head for direct injection or find a 11B head. Then I could boost at my hearts content… right? Maybe sleeve the block?

 

[Eurasiaoverland]

Wild idea here. My engine shares a block with the 11B which is direct injected. Having looked at both the head and pistons… I can rebuild my motor with 11B parts and either drill out my current head for direct injection or find a 11B head. Then I could boost at my hearts content… right? Maybe sleeve the block?

An 11B head, pistons, injection pump and injectors would be needed.

 

[bsweaty]

An 11B head, pistons, injection pump and injectors would be needed.

View attachment 3569497

View attachment 3569503

Do you happen to know the difference between injectors and injection pump? Pop pressure? Both part numbers between the two are one digit off…

22100-56440 vs 22100-56430.

 

[Eurasiaoverland]

Do you happen to know the difference between injectors and injection pump? Pop pressure? Both part numbers between the two are one digit off…

22100-56440 vs 22100-56430.

Totally different injector design - compare the above to yours. And yes, higher injector opening pressure.

Injection pump has lager plunger bore (most likely 11 mm vs 9 mm) so greater delivery pressure.

BTW when it comes to part numbers, if the last digit is one off another part, there's a good chance (but not always) that the parts are very similar and interchangeable. Any other digit has nothing to do with interchangeability.

 

[Eurasiaoverland]

I had the same thinking as you did when I used the CT26b on my B, it was originally from a 1KZ and matched the CCs, but no... It ended being too laggy as I said (I suppose the 1KZ moves more air ?).

I thought all 1KZs had the CT12B? CT26 was on the 14B-T, 15B-T (not -FT), 1HD-T/FT so would seem to be oversized for a 1KZ.

 

[AirheadNut]

Paging @theglobb! I wonder what, if any, the differences are between the bottom end of the 3B vs the DI turbo B engines. Broken cranks on turbo 3B's seem to be a trend.

You might get away with boosting a 3B in a lighter vehicle, but in a heavy platform like a 4WD Dyna with big tires it will be highly overstressed and prone to overheating and causing engine damage, like cracked precups, cracked head, broken crank, etc.

I would highly recommend looking at getting one of the DI B engines, preferably a turbo version, to swap in. Would save lots of headache and possibly be cheaper in the long run vs trying to build out a 3B.

 

[Eurasiaoverland]

Paging @theglobb! I wonder what, if any, the differences are between the bottom end of the 3B vs the DI turbo B engines. Broken cranks on turbo 3B's seem to be a trend.

You might get away with boosting a 3B in a lighter vehicle, but in a heavy platform like a 4WD Dyna with big tires it will be highly overstressed and prone to overheating and causing engine damage, like cracked precups, cracked head, broken crank, etc.

I would highly recommend looking at getting one of the DI B engines, preferably a turbo version, to swap in. Would save lots of headache and possibly be cheaper in the long run vs trying to build out a 3B.

The block of the 3Bii is identical to the block of a 14B and 14B-T. The 3Bii crank is shared with the 1988 and 1989 13B-T. Rods are beefed up on turbo engines. Seems odd if it's the crank that lets go on turbocharged 3Bs. Turbocharged 14B and 15B engines have a different (I think higher volume) oil pump, which might have something to do with it.