Bulletproofing/Strengthening 2H to run Turbo? (1 Viewer)

[Lucero1989]

Gday lads,

Im currently the proud owner of a 2H that i fear will soon go POP! She is running a Denco turbo kit at 8 pound and has healthy EGTs of 450 post. However, she is an old donk and is starting to develop a knock when cold at start up. Im not going down the road of a 12ht conversion and the headaches associated with it; I plan on rebuilding the engine to 'turbo spec' so i can push the boost a little higher and squeeze a few more ponies out. Now i know there's no oil squirters on the 2H, but i was hoping someone could weigh in on some suggested 'beefier' components i could replace the originals with. Ive tried the search and looked everywhere - but cannot find much info! Hopefully someone has done a similar build before??

Cheers!

 

[duncanrm]

If its a late 2H block I understand they were cast with provision for the Oil Squirters and that a good machine shop could drill out the spots and install them. I have no idea how accurate this information is though.

 

[Freewheel]

Alfin reinforced ring land pistons for sure- the engine will eat unreinforced pistons. I've heard of the oil squirter thing and don't know- probably a "2H oil squirter" search would turn up some information of interest.
Also make sure everything in your cooling system is top notch- new thermostat, radiator, water pump, fan clutch are all important since the turboed 2H does not shed heat as well as a 12HT. I have to be careful on long steep climbs to not overheat.

 

[Tapage]

I would not put that much $$ on a 2H with plans of turn it onto a powerhouse pushing lot's of boost ..

I've push mine to 20 PSI but the head heat issue will haunt you forever .. if you are good with it, ready to keep an eye on your EGT and multiple oil / water temp gauges .. ready for downshift and slow down when need it .. then go for it !

I'm a very happy and proud owner of a turbo 2H from 2006 or so .. we know what we can expect from each other at this point ..

 

[roscoFJ73]

I would do a 1HZ conversion.

 

[Garry]

Like Tapage said, treat her with a little respect and she'll go for years. I run my 2H at 10lb boost all day. When it starts getting warm, I ease back a little... easy

 

[mongoose2231]

Like Tapage said, treat her with a little respect and she'll go for years. I run my 2H at 10lb boost all day. When it starts getting warm, I ease back a little... easy

I do the same!! Runs like a champ

 

[KIRK83]

Any progress on strengthening the 2H?

I will be diving into my engine this spring to solve some oil/water leaks and am curious if there should be other improvements to make.

 

[gerg]

I agree with rosco. Improvements on the 2h I would say are not at all easy for the average guy to do. Putting Alfin pistons in is not a simple head gasket job unfortunately. I'd have to agree with the 1hz swap. By the time you consider the cost of parts and labor to beef up your 2h I'd say it would be pretty close to breaking even with a swap except your truck would have much more value with a 1hz.

 

[KIRK83]

For some people it may be better to switch to a different motor but I have no interest in a different motor than the 2H. I have not one, not two but THREE 2H motors. (1 in my DD HJ60 that leaks oil like a sieve, 1 pulled from the DD that runs but requires rebuild and 1 in pieces in a box).

So for myself to throw all three motors in the trash seems like a total waste. I am also an engineer that works at a steel fabrication shop with a full machine shop at my disposal, so it seems like a great opportunity to modify at least one of my motors into a great 2H engine.

So back to my original question, anyone have info on ways to improve the 2H or know of serious issues that need to be fixed?

A few items that I have been looking into:
- improved cooling (head cooling due to turbo an issue?)
- block/internals strengthening (piston rings not ideal? areas prone to cracking?)
- additional oil filtration and distribution (CCV oil separator, secondary oil filtration)
- injection (pump diaphragm, indirect injection improvement)

I am debating going all out and making a 3D model of the motor and really investigating the common problems that I have read on various threads.

 

[GTSSportCoupe]

2H Powah!

 

[Nostradamus]

For some people it may be better to switch to a different motor but I have no interest in a different motor than the 2H. I have not one, not two but THREE 2H motors. (1 in my DD HJ60 that leaks oil like a sieve, 1 pulled from the DD that runs but requires rebuild and 1 in pieces in a box).

So for myself to throw all three motors in the trash seems like a total waste. I am also an engineer that works at a steel fabrication shop with a full machine shop at my disposal, so it seems like a great opportunity to modify at least one of my motors into a great 2H engine.

So back to my original question, anyone have info on ways to improve the 2H or know of serious issues that need to be fixed?

A few items that I have been looking into:
- improved cooling (head cooling due to turbo an issue?)
- block/internals strengthening (piston rings not ideal? areas prone to cracking?)
- additional oil filtration and distribution (CCV oil separator, secondary oil filtration)
- injection (pump diaphragm, indirect injection improvement)

I am debating going all out and making a 3D model of the motor and really investigating the common problems that I have read on various threads.

I had done a bunch of research on this topic over the past few years, and found a few things that might be of interest. Full disclosure: (1) I'm a mechanical engineer by trade, and (2) I did not have 3 2H engines in my possession, just the 2F that's in my rig - therefore I elected to go the 1HZ route, and have one on a pallet in my garage. With that said, here's what I learned...

• it appears that the later 2H blocks have a boss that can be drilled and tapped for the piston oil squirters as they sit above an oil passage (there are claims that the 2H blocks with the bosses are the same as the 2HT block - YMMV). Further, it appears that the 12HT oil squirters are suitable for this mod
• pistons can be sourced that have the alfin inserts and a thicker crown which will allow the ring lands and piston tops to hold up to the turbo pressures
• 2Hs (and 1HZs) are indirect injection engines, meaning that the head has a couple of design elements that limit what can be done with turbocharging. (1) the IDI design has pre-cups, which are prone to cracking and can drop into the cylinder should they come apart, and (2) the combustion cycle starts in the head, not the cylinder like a DI engine which puts a ton of heat into the cylinder head.
• Handling the high heat load in the head appears to be one of the two challenges limiting the 2H (or other IDIs) top end with respect to turbocharging - the other being fueling from the stock IP. Based on what I read, the DI engines tend to have IPs that can be wound up more than the IDI IPs
• For heat load on the head, the appear to be three paths to pursue. Intake air temp post turbo can be brought down via intercooling. The cooling system can be improved with high capacity radiator, and finally, getting hot exhaust gasses away from the head ASAP via a large diameter exhaust system.

OK, that's all I've got. I came very close to going the 2H route, but ultimately decided on the 1HZ primarily due to the fact it's been in production since 1995 to present day, hence parts availability is pretty good. Also, did a safari in Africa a few years ago in 1HZ powered LCs and was really impressed.

 

[coldtaco]

gun runner 5's mechanic rebuilt the engine before I bought his truck, don't really know the details but they tried to build it with intent of installing a turbo. You could find his HJ-75 thread can't remember what exactly he labeled it. When I picked it up in Georgia I think the boost was set around 8psi. The factory water temp gauge would get hot on long climbs at hwy speeds, I usually drove at 62mph. When I got home I installed a extra water temp and verified that it was running quite warm, especially hitting long climbs at 65mph. I worked on the cooling issue all last summer, ended up using Evans Waterless Coolant due to it not prone to creating steam with is a bad thing. Then this spring after switching to Evans the rad top part sprung a leak again, so I was fed up with removing the rad so many times to get all these recurring pin hole leaks fixed. So I got a custom Aluminum Rad from PWR in Australia built. I had it lengthend 2" and the intake pipe to dump inside the header at mid point. Before at 65mph it would run around 205F and hit any significant hills and it would go to 215F in a hurry, Now it sits at 180/182F all day long at 65mph and climbing the one long hill in the area it only got to 192F creasting the top. I have the boost set at 12psi. Looks like I finally have the heat beat. You can also check my thread AKHJ-75.
I would also recommend an HZ or 1HD for the money you will spend, but it's your money and we all enjoy other peoples successes with their cruisers.

 

[KIRK83]

All excellent info, I will definitely be taking these into account once I dive into the motor.

 

[Dougal]

A couple of points.

Direct injection engines have flatter heads and bowls in the pistons. That puts more heat into the pistons and less into the head. Which is why they don't overheat easily but run piston oil squirters when factory turbocharged.

Indirect injection engines have flatter pistons and bowls in the heads. That puts more heat into the head and less into the pistons. Which is why they heat and crack heads and don't need piston squirters as much.

Alfin pistons are about piston strength under boost. Reducing compression ratio will help that too. But will make starting harder (which is why IDI engines have such high compression ratios). Retarding injection timing also reduces peak combustion pressure.

My suggestions are everything you can do to the cooling system and to improve airflow into the engine. Drop compression ratio to reduce stress on everything. Install alfin pistons. Back the injection timing off a few degrees or so.

Then, most importantly, make sure it runs lean and cool at full load. Like 20:1 AFR max. 22:1 would be better. Boost is not the enemy, boost drives airflow which is your internal cooling.

 

[dare]

2Hs don't have conventional oil squirters but they do have a hole drilled up the centre of the conrod, a groove in the little end bush and a hole in the top of the conrod. Obviously this squirts oil at the underside of the piston. I think it's interesting Toyota didn't use conventional oil squirters when the block was obviously set up to take them.

I don't think the oil squirters are worth worrying about, I've never seen or heard of cracked pistons (as you'd expect from high egt damage) in a 2h but flogged ring lands are common in high km engines.

2Hs have quite a low compression ratio for an IDI, 20.7:1.

In Australia turbocharged 2Hs are very common, their numbers would probably run into the tens of thousands. Unfortunately the best source of information is the various landcruiser facebook pages. As with all facebook pages 95% of posts are BS from people with no clue and no experience but there are gems to be found. Something that surprised me is the number of people who have had turbo 2Hs from new/near new, I've seen a number of posts from these sorts of owners claiming 300'000-500'000kms trouble free. I've also seen about half a dozen compound turbo setups (a few of those outside of facebook) and many many people are running 20+psi single turbo with adapted VE injector pumps or modified A types/12H-T pumps.

Personally I'd want alfin pistons and new precups before turboing. That said, precups don't seem to be anywhere near the problem on 2Hs that they are on 3Bs. HJ4x and HJ75 Landcruisers have small radiators as standard so I'd move to a HDJ79 radiator (120mm taller) or similar.

 

[Neil826]

Unopened 2h that was pulled out of a 60 series with 400,000km, VE td42 pump bolted on with a way too big t04e. Thing has been absolutely raped and all that has happened is the blow by has improved.
It does push water over 25psi but thats to be expected with a headgasket made of cardboard.

They are 37's