Pictures of my MazdaRX8 Slant project

[MazdaRX8/6]

I just joined the forum after lurking here a while. I was inspired by Uncle Tony to do this swap. I bought a 2004 RX8 in like new condition for $1,500. I bought a running 1984 Dodge D100 for $500. I made my own transmission and flywheel adapters. I took a truck flywheel and turned it down on my lathe to the dimensions of the Mazda flywheel so that I can use the Mazda clutch and pressure plate with the Mazda transmission. So Chrysler from the front of the flywheel forward and Mazda from the rear of the flywheel back. They were very close in size.

My goal is to have fun and learn. The slant will have Haltech ECU that plugs into the Mazda wiring harness. The crank trigger is in front of the flywheel and the cam position sensor runs off a modified fuel pump lobe. Here are a few pictures.

 

[RustyRatRod]

Well now. I never wouldda thought it'da fit.

 

[Ottmundr]

Dude! That's awesome! I love it.

What's the plywood in that final picture? A spacer for mock-up?

 

[junkyardhero]

entirely ridiculous.

i love everything about this.

 

[Dave999]

Yeah that's kinda stuff i like to read about...

trans should handle it looked at trying to use one of them behind my hemi 6 then decided my ambition was way greater than my skill...

Dave

 

[Kendog 170]

That fits surprisingly well. Like it!

 

[ec_co]

I love this one. I was just talking to somebody yesterday that wants to do a forced induction Slant six setup in his 240Z, I pointed him to a couple of resources so we'll see what happens. I had a 2004 RX8 and it was absolutely a love-hate relationship. I loved the car, loved the styling, lots of fun to drive with a perfect 50/50 weight ratio. But damn that engine sucked for reliability of any sort and you have to constantly check the oil like it's an air-cooled Volkswagen engine because it injects oil into the engine. These are race engines and if you have an automatic, it tends to keep the RPMs low around the 2500 range which allows carbon to build up on the Apex seals and eventually those snap off and then you've lost compression and the engine. You've got to run them like you stole them all the time, they love 6000 plus RPMs

 

[Ozyduster]

I love this one. I was just talking to somebody yesterday that wants to do a forced induction Slant six setup in his 240Z, I pointed him to a couple of resources so we'll see what happens. I had a 2004 RX8 and it was absolutely a love-hate relationship. I loved the car, loved the styling, lots of fun to drive with a perfect 50/50 weight ratio. But damn that engine sucked for reliability of any sort and you have to constantly check the oil like it's an air-cooled Volkswagen engine because it injects oil into the engine. These are race engines and if you have an automatic, it tends to keep the RPMs low around the 2500 range which allows carbon to build up on the Apex seals and eventually those snap off and then you've lost compression and the engine. You've got to run them like you stole them all the time, they love 6000 plus RPMs

given the 240z has a six that actually fits the car why would you put a slant six in it lol

 

[ec_co]

given the 240z has a six that actually fits the car why would you put a slant six in it lol

According to him, because rebuilding an original Z motor would cost more and he wants to do something different and unique that has more power potential

 

[Demonracer]

The car he is building is a "Mazda", not a "Nissan/Datsun". Very interesting build though.

 

[mbaird]

Will the Mopar starter mesh with the Mazda flywheel ?
What is the diameter of the flywheel?

 

[mbaird]

Or are you using the Mazda bell housing?

 

[ec_co]

The car he is building is a "Mazda", not a "Nissan/Datsun". Very interesting build though.

I was referring to my post a little higher up where I said I was talking to a guy thinking about doing a slant 6 conversion into a Nissan 240z. I know the original poster is talking about an rx8, I had a 2004.

 

[dano]

Interesting build. I thought of doing this with a 2.0 Ecoboost or 2.3/2.5 Duratec. Lots of nice RX8's out there with trashed rotary engines.

 

[MazdaRX8/6]

Thanks for your questions. The wood you see was the original fitment adapter model I made. I made the bottom of it flat to keep the engine and transmission square, using the Mazda crossmember as a guide. I made it out of three pieces of 3/4 plywood. One piece bolted to the transmission and two pieces bolted to the engine. So 2.2" total. ( 3/4 plywood is not quite 3/4). I had to use a larger spacer than I wanted to keep from cutting itno my firewall. I found the center of the crankshaft and the center of the transmission (using the back plate of the rotary engine case) then bolted the two together. Sorry about the bad pictures. Eventually I made the engine to tranny adapter out of billet aluminum I bought as drop on Ebay. 2.2 inches think. I was very careful to get the exact centers correct. They are within .002. The Mazda clutch is 240 mm which is 9.45". I cut down a 12" cast flywheel to make it have the same dimensions as the Mazda rotary flywheel. The ring gear, pilot bushing and clutch dowels and bolts are Mazda. The starter on the Mazda is mounted in the transmission so I had to fit the Mazda ring gear to the back of the Chrysler (now Mazda) flywheel. So the car thinks everything is Mazda. Clutch release and everything is Mazda. Everything from the face of the flywheel back is all stock Mazda. With the Haltech ECU it all plugs and plays. I cut the second v belt groove in the harmonic balancer so that both grooves were the same. For whatever reason they were two different sizes. I can now use a two groove Delco alternator and two groove PS pump and a two groove small block Chevy water pump pulley (modified). The PS pump is from a Miata. Two belts for the alternator, water pump, and PS pump. The AC compressor will be a Sanden run by one belt.

You may ask "Why would anyone do this?". I like to tinker and make things that are unusual. I wanted a modern car with electric windows and airbags. The slant fits right under the hood. It has about the same horsepower as the Mazda. The weight is near the same (late model slant is pretty light) so I won't need to change any suspension or driveline. I did change the transmission from a 6 speed to a 5 speed to get a better overdrive. I may have to change the rear end gears eventually. I calculated that I will be running 2704 RPM at 75 mph. I want to take it to the car show and people not know that it isn't factory. Thre are plenty of people making drifters from the RX8's. I don't care anything about that.

I'll keep you guys posted as I move along.

Kenny

 

[MidnightSwinger]

Real hot rodding at its finest!

 

[MazdaRX8/6]

Its taken a lot longer than I anticipated. A LOT longer.

 

[mbaird]

Really ? A slant is the same weight as a rotary ? I wouldn’t have guessed that.

 

[TT5.9mag]

Really ? A slant is the same weight as a rotary ? I wouldn’t have guessed that.

And makes the same power? I’ve seen 13b turbo rotarys make 400 pretty easily.

 

[TT5.9mag]

At least from the pictures posted the quality of work is leaps and bounds above what Tony did to that Miata.

 

[71GSSDemon]

Really intteresting build. I dig it

 

[Ottmundr]

At least from the pictures posted the quality of work is leaps and bounds above what Tony did to that Miata.

Yeah, shoulda done a 318. RRR I seen your tagline.
All you clowns hating on the 318 are wrong.

 

[MazdaRX8/6]

As far as weight goes, when you remove the oil coolers, all kinds of things specific to the rotary, (I have a crate full of plastic and other parts no longer needed) move the battery to the trunk, and replace an electric rack with a hydraulic rack it is nearly a wash. The late model slant is considerably lighter than the earlier models. Remember, the starter is no longer on the engine, but on the transmission. The Dutra Duals weigh the same as the stock manifold.

 

[NC Engine Builder]

I believe your math is off. A iron slant is not light by any means, and if it's a stock slant, it will have about 105 hp.

 

[mbaird]

As far as weight goes, when you remove the oil coolers, all kinds of things specific to the rotary, (I have a crate full of plastic and other parts no longer needed) move the battery to the trunk, and replace an electric rack with a hydraulic rack it is nearly a wash. The late model slant is considerably lighter than the earlier models. Remember, the starter is no longer on the engine, but on the transmission. The Dutra Duals weigh the same as the stock manifold.

Interesting