Lexus to R32 GTR... Wish me luck!

[Shuey]

Ok, time to come out of the closet!

I've been contemplating this conversion for some time. Why? Simply because my RB26 is feeling a bit average and because the mere thought of a twin turbo Lex V8, 4wd is a bug that I haven't been able to cure.

The check list so far:

R32 GTR...Check
Spare GTR gearbox... Check
Spare GTR Sump with integral front diff... Check
Spare 1UZFE... Check.
Enuff crazy thoughts that this may even work...check
Enuff engineering know-how to get this to happen in reality... errrrrrr... time will tell!

 

[Shuey]

The next check list is the inherent issues with such a transplant given that the mission is to have it in full attessa 4wd mode.

1. Adapting the Lex engine to the GTR gearbox and having a flywheel/clutch combo that will work
2. Adapting the Lex engine (basically 4 cylinders long) to a GTR Sump/Diff (basically 6 cylinders long)
3. Fabricating engine mounts that will line up with the factory GTR chassis mount points... issue being that the RB mounts are forward on the engine and Lex is about mid engine.
4. Clearing all the firewall paraphilalia on the GTR such as brake booster, clutch and its booster, ABS unit etc.
5. Bonnet clearance... a measuring stick tells me clearly this will be a problem.
6. Finding enough room for turbo manifolds etc.
7. Selecting the right engine management system and then finding the right person to tune it.
8. Getting it engineered.

Seems easy enough to me... what do you recon... gotta be crazy!!!


I'll provide an update where and when I can and I'm infact part way through solving or have solve some of these issues already. For those that I have not yet solved, its more a case of taking the time to get the conceptual solution out of my head or off the AutoCad drawings and into the shed and made then tested.

Cheers,

Shuey

 

[Lextreme II]

As far as I know... you will be the first Skyline with Lexus V8. Best of luck bro... keep us updated.

 

[Shuey]

Ok, so part one of the conversion was to get the GTR gearbox to fit up to the 1UZ Engine and for those of you who have had to buy a new bellhousing you will know that there only a few suppliers around the traps that can supply such an item.

In this instance it is a new item/conversion and not readily available off the shelf... but throw enough money at at one of these companies and they will make one for you. Me on the other hand, I opted to make my own.

So out with the Vernier Calipers a straight edge and a pencil and paper and I drew up both the gearbox template and the engine template. I had an old bellhousing off an auto box that I had left over from my Hilux conversion, so that helped with gaining accurate dimensions, particularly the dowel holes.

The trick to getting this right is all about the location of the dowel holes in relation to the dead centre of the crank shaft for the engine and the dowel holes and the dead centre of the gearbox input shaft. Without this being spot on you will have a gearbox input shaft that will not run true to the crank, then wind up with premature wear of bearings etc.

With the dimesions in hand, AutoCad makes life easy.... See screen shot attachement.Green holes are skyline gearbox holes and pink are the engine holes.

 

[Shuey]

Once done on AutoCAd, I sort out the local laser cutting shop and emailed them the file... 3 days later I had the adapter in my hot little hand and keen to see if my handy work was accurate or not!

A keen eye will see the dowels in the adapter plate in the photo of the gearbox with the adapter plate bolted on. These are crucial to the alignment of the Box to the Engine.

One point to make is that the bellhousing on a GTR gearbox is not removeable like the ones on Toyota engines... R150, R154, W55 etc..

 

[Shuey]

And then... will the adapter then align with the engine???

On a technical note, the gearbox input shaft on a GTR gearbox protudes past the face of the Gearbox by 15mm and from memory the pilot bearing seat in the crankshaft of the engine sits proud of the engine by about 25mm, so the adapter plate does not hinder the input shaft from seating on a bearing in the crank.

For the record the pilot/spigot bearing is 32mm OD and 5/8" ID.

 

[Shuey]

So... I gotta say... seeing the gearbox line up the input shaft into the crank spigot bearing then seeing the adpater slot straight into the dowel holes was a very satisfying moment... my single biggest engineering feet to date...

You may notice that I haven't pulled the Gearbox hard up against the engine as the starter motor fouls on the gearbox... nothing a die grinder won't fix.

Another interesting thing is that the engine/gearbox bolts on the Lex are 12x1.25mm. You'd think that countersink socket hexcap screws would be easy to get hold of, but there are no such thing!!! You can get HexCap and nomal hex bolts off the shelf, but countersink ones are a special order and at about $35 each custom made items, I've opted to drill out the thread and Helicoil the threads to 1.75mm pitch to solve the problem. Countersink bolts are a must for this application so that the adapter plate is flush on both sides for the right fit.

Not bad for a financial planner, huh???

The next part of this section is the Flywheel and clutch. At this stage I figure that I'll probably just buy one from Dellow Auto and get the clutch bolt patten drilled to Skyline specs. I have a lathe that I can spin one up in, but time is not something that I have alot of at the moment, so...

 

[Shuey]

The next part is adapting the Sump to the Engine.

Now... this may seem pretty easy on first inspection, but when you get into it, its a F'in major!

Issues and notes:

1.GTR Sump is 683mm long and 270mm wide while the Lexus sump is 547mm long and 268mm wide. So a close match in width (which creates a problem) and mile out in length (which believe it or not is less of and issue than the width being an issue).

2. The RB26 sits on an angle in the engine bay of GTR's... I have yet to determine the exact angle but my inclinometer suggest that it is about 12.5 degrees...the Lex engine on the other hand sits level in the engine bay... prefer not to have it on an angle... but it may end up on an angle if my plans for the adpater plate don't work out!!! So, the issue is, how do you adapt a sump that is level on the bottom of the sump but the engine/sump face is at 12.5 degrees to the bottom???

3. The sump is sculpted to fit around engine bay structures such as cross members, steering racks etc, so a cut and shut may not be an option;

4. The sump's natural position is approx 20mm above the front cross member and is located in such a postion (latitude and longitude) that the front drive shafts/axles are in a particular alignment... something that I don't wanna mess with... some nerdy *** guy prolly spent a few years getting this geometry right and I don't wanna go there. Plus as the engine torques over under load the axles are configured to allow for movement in that direction in that plane of movement... do I need to go on here... sh!t... must be getting late starting to cr@p on way to much now... Is anyone still reading this... time for a picture I think...

See attachement

Anyhow... I think I have it sussed... the green part is the GTR sump Flange with the Red one is the Engine side flange... with a bit of creative thought, picture these two flanges welded together with plate to form a wedge type adapter... make sense??

 

[Shuey]

I'll be double checking these two flanges over the next day or so and make sure they are precisely measured up then I'll have them laser cut out of 10mm mild steel then get the TIG out and tack it all in to place.

Wish me luck...

 

[Anaema]

wow. if i new anything about engineering i would say that you are doing a good job... but. im not really an engineer.

one thing i am wondering is how tall the adaptor for the sump is going to be. if its too tall you will need a new hood, but if its too short the crank throws might hit the driveshaft. i understand that the block design is very similar to Fords old Y-block in that the block extends well below the crank centerline, but i have no idea how far the crank throws extend below the block. thats the only major problem(if its major at all) that i can see.

 

[autronic]

Shuey:

Nice work mate ! The only thing I'd be concerned about is the overall height of the engine/sump combo.
Where is the centerline of the 1UZFE crankshaft compared to the RB26 crankshaft ?
Do they line up, or is the deep skirt on the 1UZFE block moving it upwards alot ? If it moves upwards
to much the handling of the car can be affected, the centre of gravity will move up.

Is it possible to do the sump to block adapter as one piece ?

Good luck !

 

[Lextreme II]

Very nice and innovative....

 

[turboandrew]

Shuey, this is amazing work. About the sump: have you thought about just doing a dry sump, in hopes that you could pretty much eliminate a traditional oil pan, and just work on securing the differential to the block?

 

[urtwhistle]

wowwww nice work mate, u have gone to this much effort u gotta go the whole way and make this work. this when done will supprise many alot of other skyline owners.

 

[Pro]

awesome conversion - love your work.

how do you plan to get around the valley mounted starter motor on the 1UZ adapting to the GTR gearbox?

 

[Shuey]

Thanks for the feedback guys.

Amaema. Great point about the height of the adapter plate. I'm concerned about the overall height of the engine/sump combo as well. The sump to crossmember clearance doesn't leave anything to play with considering there must be some space left to allow for the engine to torque over under load.

Autronic.... I have yet to take accurate dimensions of the crank to block skirt on both the RB set up and the Lexus set up, but it isn't so large that it makes the conversion impossible (I hope I won't be eating those words).
As far as the centre of gravity is concerned, yes I figure it will shift the centreline of the crank upward (hopefully not so far that the gearbox bellhousing will touch the tunnel), but not so much that I'd expect handling issues. I figure that an alloy block set back in the engine bay (relatively speaking) will counter any minor crank centre line height adjustment.
Yes, it is possible to make the sump adapter one piece...Billet aluminium. I considered it and may still do it. But right now it's a case of seeing if the combo will actually fit in the engine bay. I'll knock it up out of mild steel to start with then sit the whole thing in the engine bay then make some decisions.

TurboAndrew. Good question too... To be honest with you, I've looked at those systems and asked myself the question... How the hell do those things work? They look way cool! I'm figuring that IF I can secure the sump/diff to the Lex engine, then it'll hold oil to, so...

The build up so far has been met with some great challenges and the gearbox adapter is the first prototype. I have all the bolt holes and dowells in the right place and it now needs to be recut to cater for the sump to bilt up. I left some extra meat on the bottom section, but it could do with more.

I have a few photo's below that show the sump in position and you will get a better idea of the adapter in the CAD shots I put up earlier in the thread. Also see the clearance on the crank to front driveshaft.

Cheers,

Shuey

 

[Shuey]

For an extra taste of things... I've put in a full shot of the engine, sump in position and the gearbox bolted up... makes you horny right???

 

[KazeSupra]

Me personally, I would've done the VK45 or VH45 to keep everything Nissan...

Irregardless of that, awesome project. I can't wait to see it finished and driving.

 

[turboandrew]

KazeSupra, I would probably agree, although I think this project is very cool anyway. Shuey, are you aware the Nissan already has their AWD system with a V8 (The FX45)? Is uses a auto tranny, but I would think that might be easier to swap out (with a GTR manual) then adapt a different engine. Nevertheless, keep up the good work.

 

[Anaema]

what will you do for the front seal? or does the 1UZ crank even seal against the oil pan?