Build 15B-FT Shoehorned into a Canadian Spec 1986 BJ70

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just other forum posts and their experience with these smaller air to water cores....

something to consider is the intercooler is only taking out the heat of turbo air compression, not the heat of fuel burn, the only way to take the heat out of the fuel burn is less fuel (less power and counter productive to improving driveability) or more air (higher boost), and then the intercooler will really be doing the job its there for ( reduction of heat of turbo air compression above 12psi)
lower than 12psi and the heat of compression is low enough to not be a real major contributing factor in the egt temp

Im sure you know most of this but its just worth considering tuning your truck to 12psi or so, then just upping your boost to 18-20 psi to take some heat out of it.
this is safe to do in a diesel (vs gasoline) as there is no lean detonation considerations, and if you arent adding fuel you arent really adding unsafe power levels with the extra boost
 
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I'd be more worried about the H55F pushing 120+ km/h up hills in (presumably) 5th gear.
 
A bunch of similar diesel engines dont even use an intercooler, plus the factory intercooler for these engines are tiny. If I was really concerned about it (which I wouldn't be amd dont think you are either) I would just temporarily install a couple of air temp gauges before and after the intercooler to see what it does while under load.
I think turning the boost up is a terrible idea personally, leaving it in as stock form as possible will yield the most longevity and reliability just like Toyota intended.
 
roma042987 said:
A bunch of similar diesel engines dont even use an intercooler, plus the factory intercooler for these engines are tiny. If I was really concerned about it (which I wouldn't be amd dont think you are either) I would just temporarily install a couple of air temp gauges before and after the intercooler to see what it does while under load.
I think turning the boost up is a terrible idea personally, leaving it in as stock form as possible will yield the most longevity and reliability just like Toyota intended.
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its not the boost.... its the fuel that is the culprit of decreased longevity if you understand the particulars of what is actually occurring, this isnt a gasoline engine, they are fundamentally different and act opposite regarding heat load under boost ( all fuel being equal and removing heat of turbo air compression)
lean conditions in a gaspot create detonation and knock and reduced engine life (lean makes it hot, fuel cools it (simplified))
you cannot run a diesel to an unsafe lean condition (within reason) (lean makes it cool, fuel adds heat (simplified))
 
Eurasiaoverland said:
I'd be more worried about the H55F pushing 120+ km/h up hills in (presumably) 5th gear.
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In Europe we pushed the H55's far above that with the HJ61's often while towing heavy equipment . The H55 should be able to handle the weight of the BJ70 with upgraded power just fine . Back in the day my HJ61 was cruising on the highways at night at 140 kph frequently , this was before all off Europe was covered with speeding cameras of course
 
LDowney said:
[continue of basic reconfiguation]

Upper Thermostat Housing – need to source the upper thermostat housing from a 3B to enable direct re-use of the existing radiator (i.e., housing lines up with the upper hose connection on the radiator). No longer available from Toyota, but I had a used one that I could use.

3B Bellhousing – need to source from the 3B to enable mounting the H55 to the 15B-FT. The bellhousing bolted up directly to the 15B-FT. Again here to I had these parts from my 3B. A complication did emerge. The 3B support bracket on the righthand side (i.e., exhaust side), between the block and the bellhousing, bolted up directly to the 15B-FT. However, the 3B support bracket on the lefthand side (i.e., intake and starter side) did not bolt up correctly. The bolt holes on the 15B-FT block had been moved such the 3B bracket would bolt up to the bellhousing but only with one (of two) bolts holes in the 15B-FT block. I was reasonably confident that 3 bolts for such a robust bracket should suffice, but why chance it when a new replacement bracket could be fabricated that would fit properly. With the help of my friend Mike, we fabricated components out of steel to build the new bracket. The replacement bracket could be readily fabricated using the 15B-FT engine/3B bellhousing as a fixture. But out of concern for fire and introduction of unnecessary heat (via welding) into the block and bellhousing, we used the original 3B and 15B-FT brackets to jig up the steel components on the welding table. Our jig enabled positioning/holding the components in correct orientation during welding. Then we cut and shaped a piece of 3/8 inch flat stock to fit between the jigged components and welded the components together. Out of concern for warpage in the final part, the welding was completed through a series of small welds with ample cooling periods between welds. The new part bolted to the 15B-FT block and the 3B bellhousing as needed, so we were successful.
View attachment 4075871
View attachment 4075872


Flywheel and Clutch- the 3B flywheel utilized the older 6-bolt configuration with a nominal diameter of 12.75 inches. While the 15B-FT flywheel utilized the newer 8-bolt configuration with a nominal diameter of 14.15 inches. => The 15B-FT flywheel would not fit in the 3B bellhousing, so an 8-Bolt flywheel with the 3B diameter was needed. The 13B-T flywheel was known to meet this criteria, but I didn’t have one and the 13B-T flywheel was no longer available from Toyota or aftermarket sources.

I contacted Dave Stedman at Japan4x4 with the details and he was able to source a new flywheel and clutch that was a direct replacement.

Alternate Parts identified and sourced by Dave Stedman were

Part Description Part Number​
Disc Assy, Clutch 31250-60432​
Cover Assy, Clutch 31210-36330​
Flywheel Sub-Assy 13405-56041​
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After reviewing my post about fabricating the left-hand side support between the block and the bellhousing, Roma (@Roma) investigated the geometry of these supports on two project engines that he has in his shop. One engine is a 15B from MegaCruiser and the other is a 3B-II from a BJ75. He removed these supports and confirmed that they would correctly connect between the 15B-FT block and a 3B aluminum bellhousing.

With the fitment confirmed, Roma was able to identify the part numbers for these support brackets which are included here

Dyna BU162 and MegaCruiser

33119-36042 Plate, Stiffener, Lh(Mtm) [10.1996- BXD20]​

BJ7# equipped with 3B-II engines

33119-36040 Plate, Stiffener, Lh(Mtm) [08.1988-01.1990 BJ7# ..MTM]​


Thank you Roma, no fabrication of the bracket required.

Looks like I need to purchase one of these so I can replace my fabricated part with a correct Toyota bracket (at a time that works for me).
 
LDowney said:
After reviewing my post about fabricating the left-hand side support between the block and the bellhousing, Roma (@Roma) investigated the geometry of these supports on two project engines that he has in his shop. One engine is a 15B from MegaCruiser and the other is a 3B-II from a BJ75. He removed these supports and confirmed that they would correctly connect between the 15B-FT block and a 3B aluminum bellhousing.

With the fitment confirmed, Roma was able to identify the part numbers for these support brackets which are included here

Dyna BU162 and MegaCruiser

33119-36042 Plate, Stiffener, Lh(Mtm) [10.1996- BXD20]​

BJ7# equipped with 3B-II engines

33119-36040 Plate, Stiffener, Lh(Mtm) [08.1988-01.1990 BJ7# ..MTM]​


Thank you Roma, no fabrication of the bracket required.

Looks like I need to purchase one of these so I can replace my fabricated part with a correct Toyota bracket (at a time that works for me).
Click to expand...
FYI, the brackets -36040, -36041 and -36042 are all interchangeable. I've never set eyes on the -36041 type, but -36042 has been beefed up compared to the Land Cruiser 3BII -36040.
 
3640 and 3642
The 3bii and 15bf brackets here for comparison.

20230603_102940.webp
 
OGBeno said:
Engine swaps are so easy! Every one should do one! It’s plug and play! No issues at all!
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1hdt-fte i guess then..... full shiitstorm
 
:hillbilly:
 
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The 15B-FT is larger and more powerful than a 3B.
The 15B-FT is mounted up with 3B motor mounts.
No risk here ...

The motor mounts failed and I didn't notice. Or at least I didn't notice a failure event. I did notice cuts in the edges of the fan blades from contact with the fan shroud and they were getting deeper.

I went to order replacement 3B mounts (12361-58060) and they were not available. Pivoted to 13B mounts (12361-58061) and they were not available either. So I started with an ebay search and immediately got hits for aftermarket mounts from a German manufacturer (Motorlagerung vorne) and the listings were in German (with no translation option in ebay). From the pictures, it was clear that the aftermarket mounts differed from Toyota configuration. Specifically, the isolator was not bonded to the upper steel cover. The upper mounting stud and locator pin extended through the loose upper steel cover. I was concerned with these unknowns.
I contacted Ralf (@Felde ) for help and insight. He demonstrated the best of this Cruiser community. This was a cold contact requested his help. He immediately reviewed the ad and confirmed that the product/manufacturer/ebay lister were legit. He suggested I contact the company directly so I could ask questions / inquire about pricing and shipping directly from them. Ralf thank you very much for your help.
When I searched for the Motorlagerung, City Racer showed because they listed these motor mounts as stocked and available. This made the choice easy so I placed the order and had the motor mounts in 3 days. However, the mounts that I received were manufactured by Nakamoto (P/N same as 13B mounts, 12361-58061) and appeared to be the same as the Motorlagerung mounts. Time to install them.
20260327_143333.webp

The larger size of the 15B-FT over the 3B quickly became a consideration. I could not jack the engine high enough to disengage the mounts from engine bracket or the frame bracket. The 15B-FT was snug against the firewall. The frame brackets are welded to the frame, so I had to remove the engine brackets. Clearance to the right side bracket was sufficient that removal/replacement was not too challenging. Clearance to the left side was tight. The injection pump and return fuel line were just inches away with the steering shaft reducing access space too. This resulted in a much more challenging removal/reinstallation task. As a result, the left side required several additional hours to complete compared to the right side.
20260327_143326.webp

20260327_143707.webp

Got it done and working great again. Once I got the new mounts in / everything buttoned back up and running, I realized that the 15B-FT makes the entire Cruiser vibrate at idle. I recall this being the case last year when I first completed the 15B-FT install, and it is back due to the new motor mounts. So in the future; I will know that if the Cruiser is not noticeably shaking at idle, then I need to be looking at replacing the motor mounts again. Now to see how well these aftermarket mounts last ...
 
As you have found out, the later B engine mounts with the integrated metal cover are no longer available.

The earlier, open type, 12361-56021, should still be available. Partsouq have them:

INSULATOR, ENGINE 1236156021 | Toyota Parts | PartSouq

Quality parts for Toyota auto with fast ✈ delivery! Best prices on market for 1236156021 - INSULATOR, ENGINE!
partsouq.com partsouq.com

Also on ebay, 12361-56021 GENUINE TOYOTA LAND CRUISER FRONT ENGINE MOUNTING BJ40 | eBay - https://www.ebay.com/itm/296067455219

The issue with the more powerful B engines is the increased torque reaction which shears the LH engine mount. The workaround is to make some sort of limiting strap/chain to stop the mount over-extending. Some people recommend increasing the idle speed to 800 rpm or above, to reduce the low speed vibration.
 
You are very welcome. Thank you for pointing me to this European source, as I was also loosely looking for some but couldn't find any.
(Will get myself a pair once back from my recent African mission).

My 3B used to shake the rig at idle, too. I found this to be resonance vibrations. A bit of fine-tuning of the idle revs fixed it.

Cheers from Malawi Ralf
 
Great write up that will surely be handy if I ever start the same swap.

Check intake temperature AND boost drop across the intercooler core. That will show you if it’s an issue. This book has the calculations and other info you need for the intercooler. http://www.volkspage.net/technik/04/maximum_boost.pdf
 
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