1HD-FT Head and Rebuild Questions (1 Viewer)

[SteelHunterFJ80]

Hello all,

I am a relatively new owner of a 1HD-FT motor and and in the process of doing a swap. I come from the 1fz-fe side of things so diesel engines are a new experience for me.

Couple questions for all the diesel guys:

1. Is it a good idea to have a spare head on stand by? I don't need a new one now but I have a line on a reasonably priced brand new head.

2. Is it better to save the $ on the new head and look for another complete 1HD-FT down the road?

3. The engine is out and I'm replacing all the usual parts. I don't think the head gasket has been done. Would you all do this?

4. Other than the usual culprits what would you replace? Should I get new injector lines? That's pretty much the only thing I haven't bought yet.

5. What would you make sure to replace?

Would certainly appreciate the input of @chapel gate @SNLC @OGBeno @Tapage @AussieHJCruza @orangefj45 @Indestructible 47

Thank you all

 

[AussieHJCruza]

@SteelHunterFJ80 we don't see the 1HD-# with head problems unless they have been badly overheated or abused. I personally wouldn't see the need for a new head, but if the price was right, genuine parts are always nice

Parts are still fairly available over here, so my perspective might be a bit different, but it would take a catastrophic failure to not have a usable engine block. If you can get hold of a spare engine and have somewhere to properly store it, it wouldn't be a bad thing, but the 1HD-# is no less reliable than a 1HZ if it's looked after, Inc BEB replacement.

If it was my Engine, I wouldn't do the head gasket unless I was having a head job done and getting the block checked for squareness. The HG is an MLS gasket so I'd want to be sure that the head and block are clean and square to get a decent seal. Personally, I'd do as many external gaskets as possible Inc front and rear main seals, sump etc, timing belt, water pump, injectors, have a look at the big ends while the sump is off. If it's done a few km, now is the time to to the fuel pump as well, given you'll have timing belt etc. Off.

It probably goes without saying, but when you do timing belt and water pump, only use genuine parts and replace the tensioner etc.as well. Lastly, if it still has the Dowell pins in the front of the block, I'd pull them out or make sure they're very firmly still pressed in. They occasionally fall out and kick off the timing belt or make it skip a few teeth which isn't pretty.

Cheers

 

[SteelHunterFJ80]

@SteelHunterFJ80 we don't see the 1HD-# with head problems unless they have been badly overheated or abused. I personally wouldn't see the need for a new head, but if the price was right, genuine parts are always nice

Parts are still fairly available over here, so my perspective might be a bit different, but it would take a catastrophic failure to not have a usable engine block. If you can get hold of a spare engine and have somewhere to properly store it, it wouldn't be a bad thing, but the 1HD-# is no less reliable than a 1HZ if it's looked after, Inc BEB replacement.

If it was my Engine, I wouldn't do the head gasket unless I was having a head job done and getting the block checked for squareness. The HG is an MLS gasket so I'd want to be sure that the head and block are clean and square to get a decent seal. Personally, I'd do as many external gaskets as possible Inc front and rear main seals, sump etc, timing belt, water pump, injectors, have a look at the big ends while the sump is off. If it's done a few km, now is the time to to the fuel pump as well, given you'll have timing belt etc. Off.

It probably goes without saying, but when you do timing belt and water pump, only use genuine parts and replace the tensioner etc.as well. Lastly, if it still has the Dowell pins in the front of the block, I'd pull them out or make sure they're very firmly still pressed in. They occasionally fall out and kick off the timing belt or make it skip a few teeth which isn't pretty.

Cheers

Thanks @AussieHJCruza

I had done quite a bit of research before posting and couldn't find any head issues but wanted to be sure before buying a new head.

The Dowell pins is new information to me. I'll search more about that. It reminds me of some Dowell pin issues for Cummins I once read about.

Good news that I already have most of these parts including all the OEM timing belt parts. I think I will start working on it this weekend and I'll make sure to start a new build thread on it. I'm pretty much a 2 mechanic so I'll definitely need guidance. Thanks again!

 

[CycloSteve]

The thread that @Rock40 put together for his 1HD-FT conversion is very thorough. Let me know if you have any specific questions, as I have heaps of documentation, including FZJ to HDJ wiring/harness pinouts, part-number references and sources in spreadsheet format. Makes life a bit easier than trying to figure it out on your own.

 

[chapel gate]

i think aussie pretty much has it covered.
ive personally never heard of a head gasket failure in the uk.
you wont need it, but if funds allow, a new head at the right price is worth banking. must be stored correctly though.

 

[Indestructible 47]

A couple of questions I'd be asking myself are what kind of kms are on the engine? Do you have any idea if the engines history? If it is a high km engine, I would suggest compression testing it when you can to get an idea of the condition of the internals. If you are going to do the valve cover gasket, check valves with a feeler gauge. These engines are actually meant to have that checked every 100,000kms iirc. Otherwise @AussieHJCruza has it covered. Good luck

 

[SteelHunterFJ80]

The thread that @Rock40 put together for his 1HD-FT conversion is very thorough. Let me know if you have any specific questions, as I have heaps of documentation, including FZJ to HDJ wiring/harness pinouts, part-number references and sources in spreadsheet format. Makes life a bit easier than trying to figure it out on your own.

Yes thanks for the offer, I'm sure I'll have questions for you as I go through it. I was in contact with @Rock40 last year to start ordering parts. Turns out we live about an hour apart.

I think I'll use his build thread as a general guide for me. I'm a solid 2 banana mechanic so I'm going to need all the help I can get. My biggest fear us to screw up the timing and damage a valve or piston.

 

[SteelHunterFJ80]

i think aussie pretty much has it covered.
ive personally never heard of a head gasket failure in the uk.
you wont need it, but if funds allow, a new head at the right price is worth banking. must be stored correctly though.

Well I might just do that. It's roughly $2,900 shipped direct to me and from a reputable parts distributor. That's price includes everything, taxes duties etc. Not sure if its a must have or an eventually have at this point in the build. My main concern is really investing a lot of time and energy in it and then down the road needing a hard to find part and having to pay through the nose to get it.

 

[bottombracket]

Consider a pump rebuild and new vs rebuilt injectors while you’re in there. I use Pacific Diesel Injection in Portland, OR for my IP and turbo rebuild needs.

 

[bottombracket]

Check play on turbo and have it rebuilt too if out of spec.

 

[SteelHunterFJ80]

Check play on turbo and have it rebuilt too if out of spec.

Or even get a new turbo....

 

[bottombracket]

Yeah yeah yeah! Now we’re talking.

 

[Rock40]

Yes thanks for the offer, I'm sure I'll have questions for you as I go through it. I was in contact with @Rock40 last year to start ordering parts. Turns out we live about an hour apart.

I think I'll use his build thread as a general guide for me. I'm a solid 2 banana mechanic so I'm going to need all the help I can get. My biggest fear us to screw up the timing and damage a valve or piston.

Yeah let me know if you need assistance, I have the time

 

[SteelHunterFJ80]

Yeah let me know if you need assistance, I have the time

Hey thanks I might take you up on that!

 

[Rock40]

Hey thanks I might take you up on that!

I have the correct plunger type timing tool also just FYI. No way to screw anything up if it's all in spec

 

[SteelHunterFJ80]

I have the correct plunger type timing tool also just FYI. No way to screw anything up if it's all in spec

Oh nice, that would be for the injection pump I'm assuming?

My next item to review on the FSM is timing belt, water pump and gears. That's the part I bit nervous.

How did you clean out the intake and exhaust ports on the block? If I recall, you did not pull the head correct?

 

[Rock40]

Oh nice, that would be for the injection pump I'm assuming?

My next item to review on the FSM is timing belt, water pump and gears. That's the part I bit nervous.

How did you clean out the intake and exhaust ports on the block? If I recall, you did not pull the head correct?

Yes, I have the timing tool for the injection pump timing.

The timing belt and timing gears aren't too bad, just follow the FSM and remember that everything is set at Bottom Dead Center, there are timing marks on all the gears too. After I do the belt, I always rotate the crank by hand to to absolutely verify that nothing is bound up.

Unless they are really plugged up, I'd leave the intake and exhaust ports alone. You don't want a bunch of carbon falling down into the cylinder and potentially scoring the cylinder walls. If I recall, mine were just sooted up like normal.

I did take all my intake and turbo tubes in to have them hot tanked. With the EGR, they were really, really badly gunked up. And no, I didn't pull the head. I did replace all the head bolts, one at a time and torqued to spec because the exterior ones were ridiculously rusty. In fact, one was so rusty that the socket just spun on it. Had to carefully weld a nut on that one and finally got if off. Rusty bolts like that are not something I want to deal with when the engine is in the truck. Nearly 70,000 now on the swap and the oil analysis keeps coming back perfect so there is nothing wrong with the head or head gasket.

 

[SteelHunterFJ80]

Yes, I have the timing tool for the injection pump timing.

The timing belt and timing gears aren't too bad, just follow the FSM and remember that everything is set at Bottom Dead Center, there are timing marks on all the gears too. After I do the belt, I always rotate the crank by hand to to absolutely verify that nothing is bound up.

Unless they are really plugged up, I'd leave the intake and exhaust ports alone. You don't want a bunch of carbon falling down into the cylinder and potentially scoring the cylinder walls. If I recall, mine were just sooted up like normal.

I did take all my intake and turbo tubes in to have them hot tanked. With the EGR, they were really, really badly gunked up. And no, I didn't pull the head. I did replace all the head bolts, one at a time and torqued to spec because the exterior ones were ridiculously rusty. In fact, one was so rusty that the socket just spun on it. Had to carefully weld a nut on that one and finally got if off. Rusty bolts like that are not something I want to deal with when the engine is in the truck. Nearly 70,000 now on the swap and the oil analysis keeps coming back perfect so there is nothing wrong with the head or head gasket.

Excellent information, really helpful. I have an 1HD-FT paper copy that I can go step by step with. And the tip about rotating the engine crank afterwards was going to be a follow up question of mine. For the carbon, I have heard that running a biodiesel blend will clean a lot of that gunk out but just make sure to have extra fuel filters on hand.

I recall that your motor had some rust that made some of the fasteners a bit tough (exhaust manifold, crank bolt etc). Glad to hear that after a thorough run through that your motor is running so well. I will send in some oil analysis too when the time comes.