1 HD-T v 1 HD-FT engines

[93cruiser6.5GMTD]

Gidday,
Can anyone tell me what the main difference is between the 1 HD-T and the 1 HD-FT is? I understand that the physical appearance of the 1 HD-T looks very much like a 1HZ engine but I would hope that it is marginaly stronger to cope with the factory turbo application. The 1 HD-FT looks somewhat different, I've been looking for a 1 HD-FT auto in an 80 series wagon but they seem to be as rare as hens teeth. All opinions greatly appreciated.

[old lux]

A 1 HDT IS JUST A 1HZ with a turbo slapped on the side. A 1HD-FT is the 24 valve multivalve head. Actual turbo motor. So much better. Match up with the auto and they are sweet as. If you buy a 1HDT. miss well buy a 1HZ and turbo it yourself sane result basically bar the boost compensated pump and injection timing

. Go 1HD-FT

[MADSHORT]

sorry old lux a 1hdt is nothing like a 1hz please get facts right two totally different engines
cheers
Gordon

[Northside 4x4]

The 1HD-T is actually a direct injected engine, 1hZ in indirect.

Block and crank are the same. Rods and pistons very different.
The 1hd will last alot longer running at higher power levels due to its thicker pistons.

[MADSHORT]

and the rest of the engine is heaps stronger in construction than a 1hz

[93cruiser6.5GMTD]

Thanks a lot for all your input, makes more sense now. I figured the factory TD may be stronger than the std 1HZ, but certainly didn't know about the 1HD-T being direct injection....very interesting.

[SIMMO84]

1hdt is direct injection, has oil squirters to cool pistons, has a bigger injector pump that has a boost compensator, a much better engine than a 1hz will ever be with a turbo bolted on.

[93cruiser6.5GMTD]

Guys, In summary to this topic, would it be fair to say that both 1HDt and 1HD-FT engines are as good as one another in terms of strength and longevity?

[NCpaj]

Guys, In summary to this topic, would it be fair to say that both 1HDt and 1HD-FT engines are as good as one another in terms of strength and longevity?

Strength-Yes as they were both designed as dedicated turbo motors with all the nessesary bits being stronger than the 1hz

Longevity-Yes, but you might find that the 1hdt motors get worked harder compared to the 1hdft(as it has more power) but that grabbing at straws.

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

[80's_delirious]

Guys, In summary to this topic, would it be fair to say that both 1HDt and 1HD-FT engines are as good as one another in terms of strength and longevity?

Yes, 1HD-FT is the pick if you can find one, performance is a bit better, and I think the BEB problem that played the 1HD-T isn't a problem in 1HD-FT

[Z()LTAN]

1hdt is direct injection, has oil squirters to cool pistons, has a bigger injector pump that has a boost compensator, a much better engine than a 1hz will ever be with a turbo bolted on.

1hz's have oil squirters too bro

[MJ80]

A 1 HDT IS JUST A 1HZ with a turbo slapped on the side. A 1HD-FT is the 24 valve multivalve head. Actual turbo motor. So much better. Match up with the auto and they are sweet as. If you buy a 1HDT. miss well buy a 1HZ and turbo it yourself sane result basically bar the boost compensated pump and injection timing

. Go 1HD-FT

bahahahahha ! im seriously considering quoting this in my sig its solid gold.

You are so misinformed ! thats totally incorrect and the 1HDT is miles ahead of the 1HZ inside, your comparison could not be further from the truth.

The 1HDT is totally built for a turbo and is very different inside to the 1HZ, its basically the same as the FT except the FT is a 24v !

Personally i think the difference in power is to minimal to worry about and i don't think its worth the premium some think it is over the 1HDT.

[South]

On paper the differences in power are minimal, in the real world its chalk and cheese

Hardware wise they again are different kettles of fish

Not worth the premium to those that can't afford them, definitely worth the premium for those that can.

[bad_religion_au]

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

had a mate who was a service manager at toyota when these things came out (he left the trade before i met him). he claims, and i believe him, that there was one bad batch of engines with wrongly specified big end bearings, and that these would have shown up by now if it was going to be a problem. sure, if you can be stuffed to do it, why not, but i do believe that by now, if there were going to be problems, they would have surfaced by now.

[NCpaj]

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

had a mate who was a service manager at toyota when these things came out (he left the trade before i met him). he claims, and i believe him, that there was one bad batch of engines with wrongly specified big end bearings, and that these would have shown up by now if it was going to be a problem. sure, if you can be stuffed to do it, why not, but i do believe that by now, if there were going to be problems, they would have surfaced by now.

Thanks for the info mate, that makes more sense than my info that i heard through a mate through a mate at toyota (toyota chinese whispers). Does anyone know if they had the same BEB problems with the 1HDFT as in the 1HDT??
Cheers...

[bad_religion_au]

Thanks for the info mate, that makes more sense than my info that i heard through a mate through a mate at toyota (toyota chinese whispers). Does anyone know if they had the same BEB problems with the 1HDFT as in the 1HDT??
Cheers...

same source said that 1hdft's had less BEB warranty work done than the 1hz's.

[CRUZAAMAD]

i worked across from a mechanics shop, one of his customers who was a mate of his had, dont know if he still got it.
the 80series had 600,000 kms and has gone through 3 1HDT motors, and at 600 was up for a new one, it let go in bathurst.

[chunks]

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

had a mate who was a service manager at toyota when these things came out (he left the trade before i met him). he claims, and i believe him, that there was one bad batch of engines with wrongly specified big end bearings, and that these would have shown up by now if it was going to be a problem. sure, if you can be stuffed to do it, why not, but i do believe that by now, if there were going to be problems, they would have surfaced by now.

My elderly neighbour has an 1HD-T 80 that has done big end bearings twice...it's currently at the shop getting a rebuild right now!

[Hamo]

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

had a mate who was a service manager at toyota when these things came out (he left the trade before i met him). he claims, and i believe him, that there was one bad batch of engines with wrongly specified big end bearings, and that these would have shown up by now if it was going to be a problem. sure, if you can be stuffed to do it, why not, but i do believe that by now, if there were going to be problems, they would have surfaced by now.

My elderly neighbour has an 1HD-T 80 that has done big end bearings twice...it's currently at the shop getting a rebuild right now!

Just like any motor they need to be service'd properly & at a geuss your " elderly neighbour" isnt up to 5000 km oil changes yet.

[KiwiBacon]

Toyotas engineers have co-authored a paper on cavitation on bearings in 6 cylinder diesel engines.
Bad batch of bearings? Don't think so and 5,000km oil changes aren't going to stop that either.

[80's_delirious]

Toyotas engineers have co-authored a paper on cavitation on bearings in 6 cylinder diesel engines.
Bad batch of bearings? Don't think so and 5,000km oil changes aren't going to stop that either.

I read a very technical article about harmonic vibrations in the 1HD-T being the cause of failed big end bearings, 1HZ, 1HD-FT,FTE are apparently different enough to be not have the same troubles. My head hurt after reading a few paragraphs though

[NCpaj]

Toyotas engineers have co-authored a paper on cavitation on bearings in 6 cylinder diesel engines.
Bad batch of bearings? Don't think so and 5,000km oil changes aren't going to stop that either.

I read a very technical article about harmonic vibrations in the 1HD-T being the cause of failed big end bearings, 1HZ, 1HD-FT,FTE are apparently different enough to be not have the same troubles. My head hurt after reading a few paragraphs though

Could you post a link? would be interesting to read.Cheers

[MJ80]

Change BEB every 100K costs $500, problem solved, not an issue.

[KiwiBacon]

Toyotas engineers have co-authored a paper on cavitation on bearings in 6 cylinder diesel engines.
Bad batch of bearings? Don't think so and 5,000km oil changes aren't going to stop that either.

I read a very technical article about harmonic vibrations in the 1HD-T being the cause of failed big end bearings, 1HZ, 1HD-FT,FTE are apparently different enough to be not have the same troubles. My head hurt after reading a few paragraphs though

Could you post a link? would be interesting to read.Cheers

It's linked on this board somewhere.

[Northside 4x4]

Most of the problems with very early on BEB with the 1HDT were not related to the bearings at all.
It was one bad run of rods machined incorrectly.

But because they make and machine them in batches of literally hundreds or thousands of number 1 rods, then so on for number 2 etc...
They didnt know which motors these bad rods went into, thus the recall.

Crank whip accounts for most of the very old age 1hdt bearing failures these days though. I have seen literally dozzens of 1hz/1hdt cranks crack near the thrust washers over the years even in standard motors.
Most of them develop a rough idle and slight knock when running, because they dont just break clean, they crack. Some of them run for thousands of km's with slight symptoms before it gets bad.

Of all the engines I have built, 1hdt and TD42 cranks are the most unbalanced. And not by a little bit, by ALOT.
Something like 15grams out of balance equals about 30kg of force @3800rpm.
Imagine 30kg of force hitting something 63 times per second. Its a wonder the things last more than a few minutes. Its truly a testament to how tough they are built.

[KiwiBacon]

Most of the problems with very early on BEB with the 1HDT were not related to the bearings at all.
It was one bad run of rods machined incorrectly.

But because they make and machine them in batches of literally hundreds or thousands of number 1 rods, then so on for number 2 etc...
They didnt know which motors these bad rods went into, thus the recall.

That is the "company line", but there are a few choice bits of evidence that it doesn't explain. My theory is either an oiling problem (which was fixed by the time the 4 valves were out) or an oiling problem caused by crank harmonics.

If I owned an HD-T I'd be doing the shells every time I did a cam-belt. Accept they have a limited life and deal with it.

[TheBigBoy]

My 1hdt engine had 550 000k's and had never been rebuilt. And still ran like a dream before a full rebuild 180 000k ago. It doesnt happen to all the 1HDT's. Just a few.

[80's_delirious]

Most of the problems with very early on BEB with the 1HDT were not related to the bearings at all.
It was one bad run of rods machined incorrectly.

But because they make and machine them in batches of literally hundreds or thousands of number 1 rods, then so on for number 2 etc...
They didnt know which motors these bad rods went into, thus the recall.

That is the "company line", but there are a few choice bits of evidence that it doesn't explain. My theory is either an oiling problem (which was fixed by the time the 4 valves were out) or an oiling problem caused by crank
harmonics.

If I owned an HD-T I'd be doing the shells every time I did a cam-belt. Accept they have a limited life and deal with it.

It also doesn't explain why people have checked BEBs early on the engines life, and found them on the verge of failure, then instigate regular 100k km replacement without recurring imminent failures

[chunks]

If you get one make sure you take the sump off and change the big end bearings, originally these engines used to spin big end bearings and stuff the crank.... Cheap insurance to change them.

Great engines though!

had a mate who was a service manager at toyota when these things came out (he left the trade before i met him). he claims, and i believe him, that there was one bad batch of engines with wrongly specified big end bearings, and that these would have shown up by now if it was going to be a problem. sure, if you can be stuffed to do it, why not, but i do believe that by now, if there were going to be problems, they would have surfaced by now.

My elderly neighbour has an 1HD-T 80 that has done big end bearings twice...it's currently at the shop getting a rebuild right now!

Just like any motor they need to be service'd properly & at a geuss your " elderly neighbour" isnt up to 5000 km oil changes yet.

He is actually very pedantic with maintenance, no expense spared.

[bad_religion_au]

Most of the problems with very early on BEB with the 1HDT were not related to the bearings at all.
It was one bad run of rods machined incorrectly.

But because they make and machine them in batches of literally hundreds or thousands of number 1 rods, then so on for number 2 etc...
They didnt know which motors these bad rods went into, thus the recall.

That is the "company line", but there are a few choice bits of evidence that it doesn't explain. My theory is either an oiling problem (which was fixed by the time the 4 valves were out) or an oiling problem caused by crank
harmonics.

If I owned an HD-T I'd be doing the shells every time I did a cam-belt. Accept they have a limited life and deal with it.

It also doesn't explain why people have checked BEBs early on the engines life, and found them on the verge of failure, then instigate regular 100k km replacement without recurring imminent failures

but if it were an inherent oiling problem, wouldn't you expect the bearing wear rate to be approximately the same every 100 000k's?