1987 Winnebago Lexus 1uz v8 swap

  

Motorhome Lexus v8 swap

Started 8/5/06
Status: in progress

Why the swap?

RV'ing is a great way to see the country, and what better way to do it in a Toyota RV, if you want something small. There are many different models of the Toyota RV, and there is even a website dedicated to them, www.toyotamotorhomes.com. Here you will find all sorts of information reguarding models, axle info and there is even a forum that you can join.

Now, these are great vehicles, but I think they all have one drawback, the engine. There are only 4 engines avaliable for these motorshomes, and in my opinion gutless. These motors are the 20R, 22R, 22RE and the 3VZE. Unfortuantly by the time the 3.4 5VZE, companies no loner did RV conversions on the Toyota truck chassis The 20R has something like 70hp, the 22R/22RE has between 90-110hp and the 3.0 3VZE has 150hp, but behind an automatic transmission, it usually gets terrible gas mileage for the power it puts out, although not too bad behind a manual. These engines actually do ok around town, but by the time you hit the highway for those long hauls, good luck. And then there are those pesky little hills, 45mph if you are lucky. So, now we look into solutions. You could always do a 3.4 conversion, but the engines are usually pretty expensive and you gain only 50hp over the 3.0. You will get better gas mileage with the 3.4. So really, the 3.4 option really isn't too bad. You could always go something with a chevy 350 or ford 351. Great power, but TERRIBLE gas mileage, so for cross country, not really te best option. You could always turbo the 22RE, this I believe to be a pretty good option as well, and will get you around 170hp.

Another really great swap, which I will have more information on later is the Volkswagon 1.9TDI swap. I have done one of these in a samurai, and it turned out great. This could also be done with the motorhome, and there are conversion kits already available. With the TDI, you will get upwards of 30 mpg and some decent torque. By uprading the injectors and sending in the ECU for an upgrade, you can increase your power, and usually improve gas mileage at the same time. The downside to the TDI conversion is the price of the engines. You will have a hard time finding the TDI engine for less than $3,000. That really adds to the price of doing a conversion.

The options available for these vehicles are limitless, but I have decided to go with the Lexus 4.0 V8. This way you get the reliabilty of Lexus/Toyota, and you get to keep the motor from one as well. The Lexus 4.0 V8, the 1UZ-FE engine is designed for a good mid-range power. It was is also designed with fuel economy in mind. In the lexus SC model, there is the SC300 and the SC400. The SC300 uses a 3.0 I6 where as the SC400 uses the 4.0 V8. The SC400 actually gets 2-3 MPG better than the SC300. The 1UZ engine gets 240bhp and 260 ft/lbs of torque. Using this engine will double the horsepower over the 22RE engine that is in most motorhomes. The 1UZ engines as of when this was written, could be purchased for less than $1,000. That would include the transmission/harness/ECU/accesories.

Now to begin the swap.

Checking clearence on swap

The v8 is quite a bit wider than the 22R and the 3.0 v6, so there will be some slight clearance issues. The problem is mainly in the exhaust manifolds, so some different or some custom low profile manifolds will be needed as they hit the frame rails. The length of the engine is only about an inch longer than the 22RE. This won't leave quite enough room for a mechanical fan, but there will be room for an electrical fan which will be better anyway. Custom engine mounts will be needed as well as a possible oil pan to clear the steering. Oil filter mount will also need some customization, either that or just a remote filter adapter. As for now, this is as far as I have gone, and I will keep this page updated.





Parts

1UZ engine
ECU
complete harness
If you can, get the other size of the harness that the engine harness plugs into from a parts car. igniter/s There are 2 of them, and they are usually bolted together on the drivers side fender.
AFM housing with electronics

Transmission
The transmission I will be using is the auto behind the 1UZ engine. This is a HUGE upgrade over the stock auto that is in the motorhomes.
Another bonus with using the Lexus transmission is how it shifts. It was designed for smooth shifting, which will be nice for the motorhome.

A side shot of a test fit

As you can see, the lexus tranny is an upgrade over the RV's

Cooling
The only think I know right now is that a bigger radiator will be needed. Possibly a v6 radiator will be a great bolt in replacement.

Exhaust

The 2 bolt flange welded on in place of the 3 bolt flange

When using an engine from an SC400, the exhaust manifolds are a little to wide at the 3 bolt flange. Fortunatly, they didn't use cast manifolds, so you can weld on these things. I cut off the 3 bolt flange and changed it for a 2 bolt flange.
Here is a quick clip of the motor running with open pipes. V8 sound.

Fuel

Power Steering

comming soon

Drivelines
The output flange on the 1UZ auto will not work with the motorhome driveline, as it uses a 3 finger flange. A 4 bolt flange will be used in its place. This will require cutting off a centering pin at the tail of the transmission. This pin is not needed with the 4 bolt flange. This will also require a different sized output seal. I will have to get measurements to find the right one. With the 4 bolt flange, you can take your driveline to any driveline shop and have it lengthend or shortened to your specification.

A/C
comming soon

Wiring
comming soon

Installation
comming soon

email me at robertj@linux4free.com for any comments or questions