lighter pistons in 1HZ - what to do?

[rockcrawler31]

i have an 01 1HZ and someone mentioned to me that turbo'ing it might be a bad idea due to lighter pistons in later models. Sooooo, that puts a bit of a dampener on things.

It looks like i have two options, blow cash on putting heavier pistons in the atmo motor i have so i can turbo it,

or

try and do a 1HDT swap.

I'm trying to work out what is the economically and practically better way to go. Any ideas what is involved with swapping out the pistons on the 1hz and at what cost if i do it myself? Adding this of course to the cost of turboing it.

or

how hard would the 1hdt swap be, and costwise where can i get a decent motor. I was thinking buying a wreck or an older 80. I imagine i'd still be up for a reco, but then i would only be up for a turbo upgrade and intercooler.

can some folks bounce some dollars and ideas off me??

[rockcrawler31]

As the motor i have now is in pretty good shape, i was also considering buying a runner 80 series with a turbo and swapping the motor and re-selling the whole lot on again. that way i don't have a motorless 80 and a 1hz lying around. I know that i wouldn't get as much for an 80 that's been downgraded to an atmo motor, but it might offset the price of the swap a bit

[dow50r]

If your after bush torque down low, turbo the z, if your fter legs on the road towing, hdft it...same block on both, bolts straight in. If you do your sums, after selling the z, it wont cost any more than a turbo kit installed...and if you buy that wreck, after you sell the parts, it will probably cost you time only.

[rockcrawler31]

it's not a question of whether or not to turbo a 1hz, it's a question of turbo'ing THIS 1hz. it's a later model motor with lighter pistons that some have told me will lunch themselves with a turbo on it. The earlier motors had heavier pistons and love a turbo. Plus some quick sums indicate that after selling a hz for 4 grand, i'll still have to fork out 8 grand for a second hand runner hdt, plus money for an intercooler, better turbo (like ANY other turbo than a ct26), new bottom end bearings etc. So that would be about 5 and a half k, after sale of old engine.

I'm sure this has been covered before, can i put a hdt head on my hz block? that might be a cheaper option. 1.5k for head, 500 bucks for pistons (guessing), another grand and a bit for a turbo and about 500 bucks for an intercooler.

[rabmail]

it's not a question of whether or not to turbo a 1hz, it's a question of turbo'ing THIS 1hz. it's a later model motor with lighter pistons that some have told me will lunch themselves with a turbo on it. The earlier motors had heavier pistons and love a turbo.

Where did you get the info that the later model 1Hz's have lighter pistons and can't be effectively turbo'd. I have a much later engine (2006) I am about to fit a turbo to and I don't expect to have any problems. There are a lot of late model 1Hz's running turbo's.

Dick

[rockcrawler31]

From a chap on here, and i found it mentioned in some of the threads regarding turbo's on 1hz's. If you do a search and limit it to the toyota index you'll find some.

[Tapage]

Honestly after driving in diferent situtations 1HZ with aftermarket turbo and 1HD-T factory turbo .. I would say the DI it's a hole diferent ..

The IDI engines are great and run fine .. but the direct engines ( turbo course ) do the hole way far faster and you really feel the push .. but the turbo.

Don't get me wrong .. the 1HZ with a well fitted turbo do perfect .. just if you have the chance . . go for 1HD-T

[rabmail]

From a chap on here, and i found it mentioned in some of the threads regarding turbo's on 1hz's.

I do not think this information is correct. Unless somebody can come up with specific information that the Piston is lighter/weaker I would not be worried about it.

The only Piston change that I know if is this one,

"LandCruiser's 1HZ engine was upgraded in May 1998 to meet European emissions standards. Improvements at that time included a new piston and combustion chamber design, large injector nozzle holes, new injection timing, a new glow-plug system, increased oil pan capacity and the adoption of an hydraulic cam chain tensioner"

There are hundreds, maybe thousands of later 1Hz engines running with Turbo's on them. Check with the people who install Turbo's as to how many installations they have done. One installer in Cairns has done a large number for the Freeport mine in Indonesia.

If you keep the boost to 7 to 9 PSI and the EGT to below 500 I do not think you will have any problems. There is a lot on this subject on the ExploreOz Forum

I do agree that an aftermarket Turbo on a 1Hz is not as good as the Direct Injection factory Turbo, but the 1Hz with a good turbo installation, driven sensibly will probably do all you need.

Dick

[dow50r]

yep agree, the problem lies where you fit the turbo, am not happy and boost it further...it will make the 1hz a pleasure to drive.

[rockcrawler31]

looks like there's only one way to find out for sure. I'm planning on running a pyro and decent intercooler set up and about 12 pound.

does anyone here have any opinions on running a small scoop on the front left hand side of the bonnet for the water to air radiator? particularly regarding interfering with airflow through the main radiator by introducing a positive pressure in the engine bay. I'd prefer to avoid putting another radiator infront of the existing one if i can.

[Tapage]

particularly regarding interfering with airflow through the main radiator by introducing a positive pressure in the engine bay.

I'm interested in know more about that .. I have this issue ..

[80diesel4play]

Running a T3 with front mounted VL 60MM intercooler on my 1HZ.

The cooling becomes an issue thermos which I've been running.

Going to add some GU scoops to draw the hot out. My original 1HZ lunched a bearing so now have costed the same deal out and compromised between teh 1dt goodies and 1hz.
Bowled 1HDt pistons and 1HDT rods on a tougher crank. should be able to dial a whole lot more into it than 13psi I had.

1HDT heads are more fragile and prone to cracking than 1hz. The above was my engine builders way of meeting my intended output requirements. Do yourself a favour - spend coin on the pump - that controls everything!

[rockcrawler31]

so are you going to face the scoops forward or rearward. I think the idea some people have is that if you face them forwards it pressurises the engine bay which decreases the air going past the rad, but if you reverse them then they produce a venturi effect sucking air out of the engine bay which increases flow past the rads.

So let me get this straight - You're running hdt rods and pistons with hz head and bottom end, with a T3.

are you intercooled and with what kind of boost?

[Ruggers]

mate you realize that the 1hdt piston are direct injection while the 1hz is indirect with precombutsion chambers in the head so you will be losing compression by running this combination, plus the disruption of fuel being injected. i would consider a 1hdt head or the later mutlivalve head as it will flow a lot more and put out a lot better power

[balzackracing]

hey Milo,

Ruggers is correct, the difference between the 1hdt and 1hz is quite a bit. swirl pot design is different from the direct to the indirect injection. Also the gudgen pin is larger in diameter on the 1hdt so you would also have to use 1hdt conrods. You could by a new set of pistons and have them ceramic coated.
Another Issue to keep an eye out for is the precombustion chambers cracking.

Hows the chop coming along?? Did you end up using creative conversions?

[rockcrawler31]

I'm pretty sure that if i did have to do a rebuild i would just use aftermarket heavier 1hz pistons or yes, have them coated.

i have finally had the truck chopped properly. The first attempt was um, disappointing at best and dangerouse at worst. The creative job is spot on and worth every cent, particularly when you consider it was only 1000 bucks more than the first job. The blokes there have done a bang up job, with new steel on all work, proper bracing, very little bog needed (only a thin skim in some spots) and properly rust protected. All i need to do now is find some time to actually be at home to get some work done to it.

[80's_delirious]

if you are considering a rebuild, wouldnt it be worth pricing a brand new 1hd-t?

There is a brand new bare long 1hd-t listed on ebay by a toyota dealer at hte moment for just over $7k, surely cheaper than rebuilding 1hz with 1hd-t parts as you have suggested?

[rockcrawler31]

It's all just throwing ideas around at the moment. I'm pretty sure i'm just going to turbo this motor (it's only done 130k), and when it dies, i'll go up to a 1hdt, and buy the motor outright.