HDJ81V 1HD-T Vs. 1HD-FT

[SteelHunterFJ80]

Does anyone know what the differences are between the 1HDFTE head vs the 1HDFT? Is flow significantly better?

 

[TheBussman]

Reading this topic I"ve noticed a lot of misunderstanding. So, I would like to give you some ideas, hope it helps a bit:

1. Cylinder block and crankshaft are the same for both motors.
2. VE pump almost the same - any diesel workshop can assemble FT pump from T and vice verse. All parts are available. Main injection difference is in the cam-plate, however, a lot of other parts also differs. FT pump with its cam-plate delivers more fuel to the nozzles at the correct timing.
3. The 1HD-T has a factory problem with main crankshaft bearrings and with rod bearings. You can easily see that from Toyotaparts catatlog andreplacing the parts numbres.
4. Almost all 1HD-T at this time have problem wih exhaust valve seats in cylinder head. It can not be normaly fixed for considarable budget.
5. Almost all 1HD-FT with EGR system have problem with valvetrain and the cylinder head need to be rebuilded with new parts.
6. Now important: all parts from FTE head fit to FT. Moreover, the FTE head itself much better, than FT head. So, it is better to install FTE head with its cover - everyting is available. I have done this and it works perfectly. FTE camshaft also better for most of us, since it has more low-end and mid-range characteristic, as the intake valve closing timing is retarded by 8 degrees compared to the FT cam (24° ATDC for FTE vs. 32° ATDC for FT).
7. You can easily install pistons from FTE to FT - it works good - my friend just finish doing that. Over words, you can use almost all hardware parts from FTE for FT, except timing gears from restyle FTE, but this is different story.
8. Regarding engine construction - 1HD-FT(FTE) is much better than 1HD-T, because two simple things: Ingection nozzle FT (FTE) sits exactly in the center of the cylinder and exactly orthogonal towards pistol. Combustion chamber inside the FT (FTE) pistol is fully symmetrical. However, because of large valve plates of 1HD-T, its nozzle installed with inclination towards pistol, so, the combustion chamber inside the T pistol is shifted to the edge, and the pistol is not symmetrical.
9. Of course, 24 valve is much better, if you really want to boost this engine over 200HP. And it is works already after 1500 rpms. Toyota fixed all junior diseases in FTE cylinder head.
10. Exhaust outlets inside 1HD-T cylinder head are the same SMALL sized, as an HZ ones. So, their size will be not enough for hi torque and hi HP output. From over hand, you may use twinscroll Safary manifold for easy twinscroll swap. As for me – this is not a benefit - when you know, that there is a much more efficient solution.
11. It is important to understand, that most of 1HD (T,FT and even yangest FTE) engines being offered now, are the subject for rebuilding (if you really want to receive a reliable and mighty one).

#4 do you have any more info on this? I haven't seen much in the way of examples to support this and I've had several apart, all the valve seats were fine. however I do see how this could be a problem if it was driven a long time without valve adjustments and the 1hdt does take a little more effort to adjust the valves then then others.

 

[John Young]

#4 do you have any more info on this? I haven't seen much in the way of examples to support this and I've had several apart, all the valve seats were fine. however I do see how this could be a problem if it was driven a long time without valve adjustments and the 1hdt does take a little more effort to adjust the valves then then others.

My valves and valve seats were toast on the current 1HD-T project. Not surprising as I was told it was run on kerosene in Afghanistan. On the positive side it was not that big a drama to install new seats from Engine Australia.

 

[TheBussman]

My valves and valve seats were toast on the current 1HD-T project. Not surprising as I was told it was run on kerosene in Afghanistan. On the positive side it was not that big a drama to install new seats from Engine Australia.
View attachment 4032044

glad you got it fixed. at-least it wasn't cracked like mine. you didn't check the valve lash before you took it apart did you?

 

[John Young]

glad you got it fixed. at-least it wasn't cracked like mine. you didn't check the valve lash before you took it apart did you?

I did, actually, out of simple curiosity. As I recall the clearances were all very small, the valves having gotten very badly worn. 0.08 to about 0.13mm as best as I can recall. The poor old abused thing had other problems too:

Bore Running size 94 mm need 1 mm over size piston
Crankshaft running standard main and big end
But main need size 0.50 mm bearing and connecting need 0.25 mm bearing under size
Crankshaft has bend also upto 0.15 mm

 

[VADUS]

I've read in a couple of places about folks substituting a mechanical fuel pump. Do you have any views on that idea?

Well, it can be done, but it is not bolt-on. First of all, you will need to make new orifice in front wall for mechanical pump. Secondly, you'll need to make the transfer bush between mechanical VE pump shaft and FTE timing gear (from electronic pump). Because in most cases it doesn't fit mech. pump. Everything is to be done with HI fidelity and precision, otherwise the pump will die quickly.

 

[VADUS]

Does anyone know what the differences are between the 1HDFTE head vs the 1HDFT? Is flow significantly better?

Flow is the same. The difference is hear: (quote from official Toyota);

1. The cooling performance has been improved by enlarging the water jacket around the exhaust valves and the injection nozzles, thus improving the reliability of the engine.
2. The exhaust valve seats have been changed to a type made of sintered alloy that excels in wear resistance.

So, this head doesn't have a problems with valve seats and local overheating

 

[VADUS]

#4 do you have any more info on this?

Just what I have seen in our Cruiser club in Moscow, and what I've heard form the forum-mates. We also have a big TLC community in Russia: land-cruiser.ru.
The seats are being worn-out and valves go up, killing the valve clearance. Also it increases the volume of combustion chamber, that in its turn, reduces the compression ratio.

 

[VADUS]

Secondly, you'll need to make the transfer bush between mechanical VE pump shaft and FTE timing gear (from electronic pump). Because in most cases it doesn't fit mech. pump.

Here I made a mistake. Bushing to be done for gear bearing for a front FTE cover, because it has a different sizes. The conical part of pump shaft is the same and doesn't require bushing.
FTE bearing 91mm, FT bearing 85mm. Here are the photos of my forum-mate Antonik:

 

[Dougal]

Does anyone have simple aftermarket computers to control the VP37 style pumps yet? The electronic control is quite simple and they were used in a large range of vehicles.

 

[TheBussman]

Does anyone have simple aftermarket computers to control the VP37 style pumps yet? The electronic control is quite simple and they were used in a large range of vehicles.

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