atcfixer

iTrader: (1)

I just picked up two 2000 Tundras, one which has a brand new factory replaced frame that's rust free. I've already bought a 1994 Lexus LS400 with 140k miles for the 1UZ engine and was planning to install it in a southern T100, but the Tundra came up first lol.

From my understanding the 1UZ is a strong choice because it has similar power output, is quite a lot lighter, and is a high end built engine, extremely smooth and refined. The 2UZ is a bigger version of the 1UZ, I know the heads were changed a lot (can't remember which set were better flowing), the block is cast iron, but only 2 bolt main vs 6. Longevity seems so be great for both engines.

So pretty much this is my current plan/options.

1UZ route:
4.0 1UZ 140k miles runs great
2UZ Tundra 4x4 trans and torque converter (higher stall to wake up the engine some for the truck application)
ecu ??? Have both ecu's, just not sure which would be best to use. I don't mind wiring/switches to make the 4x4 stuff work.

2UZ route;
4.7L 2UZ 220k miles runs ok, idles low haven't checked into it
Have a spare 2uz I haven't heard run yet
Same transmission of course
2uz ecu would be the logical pick

I'm planning to use the truck for work/hauling, but when I'm empty I'd like fairly good MPG. It's not going to be a mudder, going to try to keep it in good shape and I have other trucks for that stuff. My current T100 4x4 extended cab gets around 20-22mpg with the 3.4L v6. The frame/cab are pretty rusty, so been trying to find something that would be more ideal to work with. My 86 2wd pickup I got 25-30mpg. As you can see, I'm pretty good with getting fairly good mpg out of stuff. Not sure which engine would give the better mpg, probably the one with less HP at cruising rpm I suspect.

Thanks for any input =)

I should also point out wiring doesn't scare me, I have EWD for all the machines related to the swaps. Just looking for some input mainly on the 1uz vs 2uz option.

atcfixer

iTrader: (1)

Here are some pics, dark but should show a bit of what I have. Yes, the new framed truck is a standard cab, the green access cab is the one I plan to use, and planning to build my own box since both are pretty bad. Lexus has no title or I'd be driving it (needs miner electronics to make got reliably).

Sadly the new frame truck has a lot of stuff missing, the last owner used it as a parts truck, and the other one with a rusty frame was the "good" truck which has a bad trans. New frame truck has and engine and trans, but is missing transfercase, rear axle, front axle, drive shaves, and heater control knobs of what I've seen so far. Front end is barely together, have to pull bolts and such from the other truck or buy new to make it right.

Also are windshields, doors and rear windows interchangeable for the tundras reg cab vs access cab? The reg cab will probably be parted out after I make sure all is well with the access cab (needs grill and windshield for sure). Driver's seat bottom in one of them was ripped, so I'll be using the best of the two. The access cab truck has the SR5 TRD off road package, so the rear axle should be limit slip. Other truck is just SR5 I think.

For the frame, I'm planning to take everything apart, and clean/anti seize all the bolts. Axles I'm planning to sand/paint and such too, pretty much the drive line I'm making the best I can without spending a ton of money. The cab isn't the greatest, Might cut out the bad sections and weld in some new sheet metal to try to stop the rust, but might be best to replace the cab in 3-5 years from now if/when I find one in good shape within my price range. My dad has a chain lift that works pretty well for pulling cabs and such.

Oh the truck should be 4.10 gear ratio based on the door sticker (both are A03A). even though I read 3.91 is the common ratio on these trucks.

Dennis140

I would definitely go 2UZ, and maybe swap connecting rods from 1uz into 2uz block. 2uz will have the torque you want in a Tundra and the 1uz loves to rev but doesn't have as much low end grunt

atcfixer

iTrader: (1)

Prefer not opening the engines up, I know the 1uz does have bigger rods, but I'm not getting a super charger or turbo on the engine, so stock strength should be fine. If I remember right, the 3uz has even smaller rods.

I can't say how reliable this source is, but I've seen plenty of claims of the 1uz is gutless on the bottom end but dyno numbers don't really show it. I suspect the "gutless" bottom end is due to the low stall torque converter the lexus cars come with stock. The truck torque converters allow the engine to rev a little higher before turning the transmission. 40-50 ft/lbs of torque at ~2000 rpm is a fair bit though. Based on the image, it suggests putting the 1uz heads on a 2uz would be the best overall for max power output.



The other thing I didn't think of was front diff interferance for the 1uz, not sure if it's a direct bolt in, or if I'd have to swap oil pans from one of the 2uz's (my dad has a blown up 2uz for parts).

Big question is, if I use a 2uz, what to do with the 1uz lol. I wouldn't mind a 1uz powered ~1977 Toyota Celica when funds/space permit the idea.

Dennis140

The 1uz isn't gutless at all on low end even with stall...maybe in a Tundra lol The 2uz has the extra torque to move your Tundra easier which will increase economy, the 1uz isn't going to be so easily worked

Dennis140

According to your graph yes 2uz block 1uz heads but you will run into a few issues .... the 2uz has a better intake manifold than early 1uz so its going to be more work, easiest just to slap in 2uz and enjoy

Dennis140

And just to clarify I own both engines.. 07 4runner v8 and 95 with 1uz swap

atcfixer

iTrader: (1)

Good info . I've went from the 22r to 3.4L 5vz and since I have the V8s figured I'd move up the power bracket lol. Generally the 4cyl (was a 2wd pickup) gets me by, the v6 does 99% just fine with respectable mpg. Hauling home the Tundras with the T100 defo showed the v6 was struggling a little. I kept speeds around 45-50mph and probably got around 17mpg.

I see your 1uz 4runner wouldn't be a MPG setup, but what kind of mpg does your 07 4runner get? VVTi probably makes a huge difference and the right foot I'm sure effects a v8 so much more than the i4/v6. I'm hoping with my driving habbits I can get atleast 18mpg empty on country roads (55mph) with fair distances (20 miles or so) per trip.

Based on that chart I found, it seems to suggest the 1uz has the better heads. I didn't research it myself, but my dad mentioned the heads + intake can be swapped as a set between the blocks. Not sure how accurate it is though. I probably wouldn't bother with it myself but would be interesting to know just for the sake of it.

Dennis140

The newer style 1uz heads and intake are identical to the 2uz. The earlier style will require full head and intake swap.
Depending on how I drive 18 is possible and more if it's hwy and you keep it at 65-70. The 07 is also Awd so that doesnt jelp much with economy. Best I ever got to a tank is 19mpg

Dennis140

My 95 gets around 15mpg if I baby it..needs bigger tires lol

atcfixer

iTrader: (1)

Interesting details, I drive ~60mph on the express way since I'm generally in no hurry and enjoy going further on fuel, so if you're getting ~18 going 65-70, it should be possible to hit 20mpg at around 60. 5mph difference at those speeds is a fairly large effect on mpg. Also I do drive in the slow lane, and I'm out in the country, traffic jams basically don't exist here unless a tractor is taking up the whole road lol.

Just for the sake of guessing and assuming your 95 runner is street legal/driven, I'd guess you run around 15mpg with the 4.88s and 33's?

Dennis140

Will be going to 35s soon that will correct my Speedo and match wheel speed of factory LS400

Dennis140

Trust me on the 2uz ..Toyota designed it as a truck engine for a reason, if the 1uz could easily have done the job they would have never used a 2uz in a Tundra ...as far as reliability I suggest replacing starter before installing either engine along with timing kit, water pump, and seal kit

Dennis140

1 more thing 1uz = premium gas all the time...

atcfixer

iTrader: (1)

I've read 1uz can run on reg, but performance will be lower assuming everything else is in good working order (knock sensors etc), but fuel cost difference is a thing to remember for sure.

My 15mpg guess wasn't half bad =), at ~18mpg and assuming 4.10 gearing with ~31-32in tires vs 4.88 gearing with 33's, it's around 20% difference + extra effort for the lift/weight. Bigger tires should give a tiny bit better mpg if you're adjusting the distance correctly for the tire size/ratio. Same logic works for cars trying to get better mpg, +10% higher gearing normally nets close to that in better fuel econ if driven similarly.

Yea the starter job is a real pain, the 1UZ my dad's planning to use needs the starter, it acts up during the winter and has ~220k miles. I'll defo be checking the timing belt (maint history unknown), water pump makes sense while I'd be in the area. What's the seal kit for? I don't know a crazy lot about the UZ engines, but based on camry 4cyl engines, "rebuilding" the oil pump is common and cheap/simple to do. They are similar to a 22r/re oil pump in design.

While on the subject of reliability, have you ever had any issues with the trans cooler not being large enough for the stock tundra? Not sure if the 4runner came with it stock or not, but both Tundras I have, have the external trans cooler. It's something like 9x12in.

I'm most likely going with the 2uz, since it would be the easiest to use and of course gives more power. The spare engine is probably a fair reason too just encase something major did happen.

As for the 2uz with low idle, sounds like it's a simple clean the tb and clean the iac. If it still acts up, clean out the mass airflow sensor with the correct cleaner.

atcfixer

iTrader: (1)

Ignore double post

Dennis140

You shouldn't have much trouble with a/t temp unless your towing an rv...i have identical trans cooler no issues so far ...and I thought the same about regular unleaded and the 1UZ but it doesn't like it at all misses and pings to much

Dennis140

07 4runner actually has 3.73 gearing and pulls amazing can literally drive everywhere under 2000 rpm at 3000rpm it's pulling hard actually faster than a vortec max Silverado that says a lot power wise 6.0 vs 4.7

Dennis140

The seal kit is kinda a maintenance bonus while is out of vehicle change front and rear seals, valve cover gaskets, exhaust manifold gaskets, and oil pan gaskets nothing like knowing it's all new once installed