2005 Prius engine into 1986 MR2: mk1 1nzfxe Prius swap (gas only)

[NH scrap]

Originally Posted by Sean.Heihn

NZ is the engine family.

1NZ-FE is the engine model for the 1.5L Otto cycle version, Echo, Yaris, xA, 1st Gen xB in US/Canada
1NZ-FXE is the engine model for the 1.5L Atkinson cycle version, 1st and 2nd gen Prius, Prius C (US)/Yaris Hybrid (Worldwide)
2NZ-FE is the engine model for the 1.3L Otto cycle version, this is an engine option for the Yaris in Europe/Worldwide.

Toyota NZ engine - Wikipedia, the free encyclopedia

mr, wouldn't it be hard to get a 2NZ here and to ship from Europe would be cost prohibitive. If I could afford it, I'd swap in a 1NR-FE, 1.3L, Dual VVT-i, Start-Stop, 99 HP/97.4 ft-lbs. Or a 1ND-TV 1.4L TDI.

i think i'll jump on in here
i have seen low mileage engines offered in this country direct from japan
i never understood how this could be
well come to find out people in japan will not drive a car that is more than 2 years old
yes there might be some guy in japan who is really poor with one that is 3 years old but that is about it.
the Gov. over there makes you pay MORE to register an older car so owning one that is 4 or more years old just isn't worth it
they just go get a new car
the old cars have their engines/ tranys removed
the rest of the car gets crushed for the most part

while in Manila (Philippines)
2 years ago i saw the following Toyota engines being used
2 liter engine
(only saw one) used in a newer corolla
1.8 liter
this is the standard engine that they use in the corolla taxi cabs over there. they are dam near bombproof
1.6 liter
i also saw these used in corolla's but but not in a taxi
i think i saw a few in what they call the Vios
which is a yaris only the tail lights were different
i also saw some 1.5 liter & 1.3 liter engines being used in the yaris look-alikes that they had.

[unheardofinstruments]

I am impressed with the level of tinkering and thinkering going on in this thread, and that the thing can be lifted without a crane too. With all the extra complexity these newer engines have the gains are fractional but still worthy. Myself I prefer the build quality, simplicity and aesthetic appeal of an old car as a project and abhor dealing with the modern loom and greatly admire the amount of know-how involved mapping the things.
As for the 2stroke small jap van diversion I am intending to replace my standard gearbox in my '86 Suzuki Carry (Holden Scurry, vauxhall rascal, maruti...) 1Litre van with a 4x4 one and use the front wheel drive and replace the rear diff with electric drive that just bolts up to the springs to hybridise the thing (although it already gets good mileage being only 800kg and a good candidate for electric conversion anyhow.) It can also carry 700kg so battery weight is not such an issue, in fact more weight on the rear wheels than when empty would be great.(!)
The rear output of the box could run a PMDC generator set from a wind turbine I have lying around. A few batteries would do and the rear axle/controller/gearbox/PMDC motor setup I was intending to import from china is under 55kg and $1000, at 40kW and 120kmph it could run electric mostly with generator + motive force when required. This is the little brother;

power - search result, Chongqing Wagner Auto Parts Company Limited

There is a lot of potential in optimizing combinations of drives and engines and doing a better job than oem's, on hybrids too there seems to be plenty of scope for some serious ecomodding... It seems to me they are not really trying.
I am most inspired to see some good thinking and doing, big up everyone, back pats all round!

[stillsearching]

It may seem slightly off topic but I wonder if the Atkins cycle is similar to what those "30mpg musclecar" type Crower Mile-A-More (or Isky or whoever did them) camshafts which basically took a 1960's hot rod type engine with up to 13:1 stock compression ratio yet would make it run on modern 92 octane pump gas while knocking down good mileage. By all accounts below 2500rpm they were absolute dogs without torque, and they basically worked by bleeding off intake cylinder pressure before closing so there would be less air-fuel charge in the cylinder and less effective compression on what was there since it only closed after the piston was on it's way back up. By all accounts it worked, a shoebox style 1933ish ford vicky tested by Hot Rod Magazine with a 5.7L V8 chevy, no overdrives, no fuel injection, got a solid 25mpg plus on the highway using one.

I guess i'm just wondering if that was an early Atkinson cycle, or the Prius-engine is just the modern take on that idea which seemed to be almost abandoned after it's brief stint in the aftermarket in the early 1980's.


I hope that factoid was of use to someone or that someone who knows better could comment as I posted on this topic once before but didn't see the level of followup I hoped for.

[cRiPpLe_rOoStEr]

Originally Posted by stillsearching

I guess i'm just wondering if that was an early Atkinson cycle, or the Prius-engine is just the modern take on that idea which seemed to be almost abandoned after it's brief stint in the aftermarket in the early 1980's.

The original Atkinson cycle had an articulated crankshaft to provide a power stroke longer than the compression stroke, while the currently-called Atkinson cycle doesn't. It's basically closer to the Miller cycle, altough without the supercharger which is used in the Miller cycle to overcome the output reduction.

[serialk11r]

Originally Posted by danwat1234

Wait wait, I have never heard of the Prius engine (whether the 2nd gen 1.5L or the 3rd gen 1.8L) having an OTTO cycle mode! That is why the 1.5L is only rated at a peak of 76HP and the 1.8L 3rd gen Prius engine only has a peak of 98HP. Maybe it's because it does OTTO sometimes at low RPMs for power, but always Atkinson at high RPM (see post #43), hence the low peak HP.
Are you saying that it has an OTTO cycle mode? I have never heard of this, I thought it was strictly Atkinson cycle, hence why it needs an electric motor for assistance, especially at low RPMs.
I thought some of the new Honda/Acura "Earth Dreams" engines that are 2L and smaller will have on demand Atkinson/OTTO cycle behavior so it'll work well in a car that doesn't have an electric motor to help out at lower speeds and could get hybrid like economy on the highway.

If the Prius engine does have an OTTO cycle mode, then why isn't/wasn't it made for some Toyota cars that weren't hybrid, such as a Yaris?

Great innovative project

They don't. There is no clear distinction between Atkinson cycle and Otto cycle when used in modern engines. Atkinson cycle simply refers to a larger intake cam than usual that results in lower torque but increased efficiency. Guess what else has this kind of setup? A race engine, except the exhaust cam is typically way too big and destroys the efficiency at low rpm by allowing way too much hot exhaust into the mix and ruining combustion.

The VVTi range on the 1NZ will not allow you to advance the long intake cam enough to recover the full torque of the 1NZ-FE. The reason VVTi is continuous is so that the ECU can adjust it based on torque demand and rpm together. The OP IIRC has a Megasquirt running the engine; since it's a cable throttle setup you can't fine tune the VVTi as well for maximum efficiency since the VVTi can only follow the throttle rather than move independently, but I think he would still benefit from a proper VVTi map.

[mr220v]

Atkins cycle refers to a motor with a power stroke longer than it's intake stroke. Originally this was accomplished with weird crankshaft/engine designs, but can also be accomplished with offset cams and cam timing, which is what this motor does.

Offset cams are often used in race engines (or by cheap 4age modders who only want to buy an intake cam). But again, the object there is to increase intake and exhaust cam overlap (better efficiency at higher rpms), not to delay closing of the intake valve to actually waste a significant portion of the compression stroke. That would be counterproductive in a race engine.

[SpeedyCorky]

i've been thinking about swapping a fuel efficient motor (hybrid likely) into a MK1 MK2 for years now.... for sure a *long term* lifetime goal of mine. pics in your original post dont work!!! fix 'em please!

[deejaaa]

works for me.

[alex16]

not bad but I believe mr2's are pretty efficient right out of the box if driven like a ecomodder would. I regularly achieved 32mpg avg with my 1987, on a road trip I made 37-39mpg@65mph with the only mods being a free flowing exhaust. I'm sure if I aero modded a little and removed the wing I could easily break 40mpg with the stock 4age, even better if I could do 65mph without being at 3.5-4.0k rpm.

[mr220v]

4age's are not bad, but I did notice on the mpg ratings on this site, sitting at number one is a toyota echo. I'd say that would make the 1nzfe or 2nzfe two of your best choices for conventional ecomodding.

The echo isn't exactly super light. Well, it's light, but not as light as an older tercel. A 2nzfe in a late 80's tercel would be the ticket I think. Anybody want to try it?