Outer Limits 4x4 Board

Hey There

All i want to know is what are the pro's and cons on both motors (12HT Vs 1HDT), and if you had the choice of either or, which one would you go for???

Reason im asking is dad is thinking of ordering a 6.5L V8 Turbo Diesel for mums 80series cruiser, which means i have the option of fitting the old 1HDT (4.2 TDi) into my 89 Sahara which will replace the existing 4.0L Tdi). How much effort is it to do the conversion, what needs to be changed so everything goes to plan. At the end of the day would it be worth it???

Mums motor was fully rebuilt at 208 000kms and the car has now got 340 000kms so the motor has done 132 000kms since the full rebuild. My 12HT has just clicked over 339 000kms and is still going strong.

So if i could have peoples feedback it would be much appreciated.

Cheers Troy.

i know the 1hdt has heeps more torque down low but probly wont last as long as a 12ht u can't kill a 2h iknow someone who ran a 12th with 24 pound of boost for over 100 000k's

Don't bother fitting the 1HDT. If he's givinig it to you then take it and flog it for a coupla grand.. hahaha.
Seriously the 12HT is a much better engine. Maybe not as much low down but the trouble isn't worth it. If you gave me the option of replacing my 2H with either i'd take the 12HT.

vSAHARAx wrote:Hey There

All i want to know is what are the pro's and cons on both motors (12HT Vs 1HDT), and if you had the choice of either or, which one would you go for???

Reason im asking is dad is thinking of ordering a 6.5L V8 Turbo Diesel for mums 80series cruiser, which means i have the option of fitting the old 1HDT (4.2 TDi) into my 89 Sahara which will replace the existing 4.0L Tdi). How much effort is it to do the conversion, what needs to be changed so everything goes to plan. At the end of the day would it be worth it???

Mums motor was fully rebuilt at 208 000kms and the car has now got 340 000kms so the motor has done 132 000kms since the full rebuild. My 12HT has just clicked over 339 000kms and is still going strong.

So if i could have peoples feedback it would be much appreciated.

Cheers Troy.

Sorry to say dude but your old man's not thinking straight .... the 1HDT Direct Injection motor is a gem .. why replace it with an antique 6.5 Chev .... It'll cost him well over $15,000 (if he has someone like Linquip do the job) and ultimately will make the car a pig to drive. I guess he may want to tow something huge around but I've had a couple of factory turbo 80 series and they tow fine particularly with a little "tuning" of the pump by someone who knows what he is doing (ie not me) . Besides they can only tow 2.5 or 3.5 ton depending on which model I recall and the std direct injection motor will do that easily.

Has he looked into spending a fraction of what it will cost him for the chev conversion on upping the power output of the 1HDT? He could probably spend 4-5K and be far happier with the outcome and have less problems in the future.

Anyway, if he does go ahead with the swap and you end up scoring the motor, you would be better off selling it (should get $3k easily if it's complete) and spending the rest on yourself or your ride (lockers maybe?). There would be a fair amount of work to fit the 1HDT into your cruiser including changing the gearbox, exhaust, radiator, plumbing, wiring etc etc. I have seen it done into a HJ47 ute and also a early HJ75 Troopy so it can be done but it wasn't a simple bolt in job in either case. The other thing to consider is that your 12HT is a good motor in it's own right. I've also had a VX Sahara before until it was stolen and it was a great truck .. the motor was reasonably powerful (although not as powerful as a 1HDT), dead reliable and reasonably economical.

Good luck.
Simo

putting the 1HDT into your cruiser will mean a new gearbox aswell unless your dads getting rid of that too.

the 1HDT has everything on the opposite side to a 12HT, which isnt a major pain but will mean more time and money to do the swap.

if i was you i would spend the money you were gonna spend on swapping the 1hdt in on beefing up the 12HT (intercooler etc)

Hi
Guy on here has a 1hdt in a 89 60 series, not too hard to fit, heaps of grunt...especially if you intercool it.....but that can be also said about your 12ht.... down side is the hdt has big end problems and u will have to fiddle with the fuel delivery system, a hj75 belhousing will fix the bolting up problem.
Funny thing is your 12ht is probably worth as much as the hdt secondhand.
Andrew

Simo63 wrote: Sorry to say dude but your old man's not thinking straight .... the 1HDT Direct Injection motor is a gem .. why replace it with an antique 6.5 Chev .... It'll cost him well over $15,000 (if he has someone like Linquip do the job) and ultimately will make the car a pig to drive. I guess he may want to tow something huge around but I've had a couple of factory turbo 80 series and they tow fine particularly with a little "tuning" of the pump by someone who knows what he is doing (ie not me) . Besides they can only tow 2.5 or 3.5 ton depending on which model I recall and the std direct injection motor will do that easily.

Good luck.
Simo

Says the guy who owns a 6.2 chevy

I had the option and went for the 1HDT into an '89 model. In terms of performance, the DT leaves the HT for dead, especially when you intercool it.
There's a lot more in the fitting as EVERYTHING is on the other side, and the 90-91 75 series bellhousing mates it together with the original box with a little adjustment on the input shaft spiggot bearing. If you can get the engine for free, you're a long way in front, but it will still cost a bit to get evrything else connected (electrical, exhaust, engine mounts, radiator in/out) It depends on your budget.
I'm with Simo63, your dad's mad, tell him to put a safari intercooler on the 80 and get it tuned properly, it'll get up and go then. I have a Safari core on mine and it absolutely hammers even with 35's and an 8% overdrive in high range.
While you're at it, throw an intercooler and bigger exhaust + dump pipe on yours, it will be cheaper than putting the DT in and give you roughly the same power and torque. Call Beaudesert exhaust for the dump pipe (about $200)
PM me if you want more detail on the conversion.

what does it cost roughly & whats involved in fitting the safari intercooler to the 1HDT?

Why do you need a new gearbox? Cant you use a 7x series bellhousing like with the 1hz conversion?

Mad Cruiser wrote:

Simo63 wrote: Sorry to say dude but your old man's not thinking straight .... the 1HDT Direct Injection motor is a gem .. why replace it with an antique 6.5 Chev .... It'll cost him well over $15,000 (if he has someone like Linquip do the job) and ultimately will make the car a pig to drive. I guess he may want to tow something huge around but I've had a couple of factory turbo 80 series and they tow fine particularly with a little "tuning" of the pump by someone who knows what he is doing (ie not me) . Besides they can only tow 2.5 or 3.5 ton depending on which model I recall and the std direct injection motor will do that easily.

Good luck.
Simo

Says the guy who owns a 6.2 chevy

Your right .. so I've got a little bit of an idea ... although I would expect the 6.5 turbo to be better than the 6.2 Jeepster. I've also driven a later model Rangie fitted with a 6.5 turbo and it wasn't as nice to drive as a standard one .... rough as guts, slow as buggery and uncomfortable because the gearing was all wrong.

I bought the jeep with the 6.2 fitted .. i wouldn't convert it myself. It's just a cheap tow vehicle. Just trying to help the guy out with some advice

Cheers
Simo

Gonna keep the HT, too much buggerising around, and for dad well he is lookin at a 100 series now. so what would be the best exhaust for my HT? 3-3.5" dump pipe into a 3" exhaust with high flow cat and muffler? thats what i was told in another post.

cheers
Troy

vSAHARAx wrote: so what would be the best exhaust for my HT?

Probably 2 1/2" unless you intercool it, then 3"

Joombi wrote:what does it cost roughly & whats involved in fitting the safari intercooler to the 1HDT?

The fit is relatively simple, and from memory the complete bolt on kit was $1825. I got a second hand core only as I don't have an 80, so it was a lot cheaper than that, but then there was the plumbing costs. You would need someone to retune the engine after that too which would be around $200 I guess, however Safari are very particular about their fuel settings, and won't warrant a thing unless you go through one of their agents.