kickerfox

I originally started talking about it here. https://www.rx8club.com/major-horsep...needed-241176/

I decided to start a build thread for others to benefit from and share knowledge.

My 8 is dying so I started to consider engine swap options and decided on using a v6 engine. A v6 should fit the engine bay without major modifications to the engine bay and subframe and offer "manageable" weight distribution. I looked into the Toyota v6 as one options but it seems there's no RWD bellhousing for it. The starter location would likely require modifying the 8s firewall. I continued my search for bellhousing options and stumbled across this information on www.4x4wire.com

"The Jeep/Dodge AX15 5-speed, the Jeep NV3550 5-speed, the Toyota R150F & R151F, the 87-92 Toyota Supra Turbo R154 and the Isuzu AR5 5-speed all share the same case to bellhousing bolt pattern. As such there are a number of possibilities that can be had when a 5-speed is desired:

94-95 Dakota 2.5L bellhousing: Connects all to any K car based 2.2L-2.5L L4 in a RWD application.

94-99 Dakota 3.9L V6 Bellhousing: Connects all to any 3.9L V6 and any 273/318/340/360 V8.

96-99 Dakota 2.5L bellhousing: Connects all to any Jeep 2.5L L4. Because of it's GM inherited bolt pattern, also works with any Buick FWD V6 and supercharged V6, any Chevrolet 2.8/3.1/3.4 V6, any Cadillac 4.1/4.5/4.9 V8 and with a minor modification, any Olds Aurora DOHC V8 and Cadillac DOHC Northstar V8.

88-99 Jeep 4.0L L6 bellhousing: Connects all to any AMC 290/304/343/360/390/401 V8 and any 72 and later 232 L6 and 258 L6.

01-03 Jeep Liberty 3.7L V6 bellhousing: Connects all to any 3.7L V6, 4.7L V8 and 5.7L Hemi V8.

Isuzu Trooper 3.5 V6 AR5 bellhousing: Connects all to any Isuzu 3.2\3.5 V6

Aftermarket:

Advance Adapters: Bellhousing for AX15 to Chevrolet-Buick-Olds-Pontiac V8 and Buick V6. Connects all to same.

Advance Adapters: Adapter plate for AX15 to Ford bellhousing. Connects all to same. Also they have a plate for the NV3550 to do the same.

Novak Enterprises: Adapter plate for AX15 to GM 4-speed bellhousing. Connects all to same.

Further info: Jeep AX5, Toyota W55, W56, W57 and W58 5-speeds all share a common face pattern on the case. As such, any 88-99 Jeep 2.5L bellhousing (NOT Dakota) will bolt a Toyota W series transmission to a 60 degree GM bolt pattern.

Aftermarket: Advance Adapters makes a bellhousing to bolt a W series Toyota trans to a Chevy-Buick-Olds-Pontiac block.

NOTE: Input shafts lengths vary.

Pre 1995 R150\R151 = 6.5"
1995 up Toyota R series = 7.5"
AX15 = 7.5"
87-92 Turbo Supra R154 = 7.25"
AR5 = ?
NV3550 = 7.5"
AX5 = 7.5"
Toyota W series = 6.5"

Advance Adapters makes an extra long pilot bearing when using a shorter input shaft tranny with a bellhousing that had a longer one. Obviously you can't put the longer input trans into a bell that had a shorter one.

Front bearing covers are interchangeable between the R series, AX15 and AR5. NV3550, AX5 and W series are not interchangeable."

kickerfox

The information above shows various options of bellhousings that will bolt to AX15, R150F, R151F, R154F, AR5, and NV3550 transmissions.

What got my attention was this "Isuzu Trooper 3.5 V6 AR5 bellhousing: Connects all to any Isuzu 3.2\3.5 V6"

I started searching for info about the 6VD1 (Isuzu 3.2L) and 6VE1 (Isuzu 3.5L) v6 engines. Here's some info about those engines.

Found in the Honda Passport and Isuzu Rodeo and Trooper. Should be very easy to find and CHEAP.

Manufactured by Honda of Japan.
Aluminum open-deck v6 24v
Pentroof combustion chamber
SOHC ('96-97 SOHC only) and DOHC (98-04 DOHC only) variants
6VD1 and 6VE1 share the same block
6VE1 uses a stroked crank, different pistons, 8-deg longer cam duration (same lift as 6VD1), same rods as 6VD1
4-bolt mains with 2 additional bolts per main through the sides of the block
Cast crank
Forged rods with squirters
Coil-over-plug ignition
Supercharger kit available (Alpine)
6VD1 Bore x Stroke: 93.4 mm x 77 mm
6VE1 Bore x Stroke: 93.4 mm x 85 mm
'92-97 uses shorter con rod. 146mm
'98+ uses longer con rod. 152mm
Pre-'97 crankshaft CAS rings different then '98+
Oil pressure 57-80psi @ 3000rpm
Firing order 1-2-3-4-5-6
2000+ Drive-by-wire throttle

Approximate dimensions.
Height: Crank center to valvecover - 13"
Height: Crank to plenum - 18"
Width: Valvecover to valvecover - 24.5"
Depth: Timing cover to rear - 19.5"
Depth: Crank pully to rear - 22"

Compression Ratios:
'92 3.2L 9.3:1 DOHC&SOHC
'93-'96 3.2L 9.8:1 DOHC, 9.3:1 SOHC
'97-2000 3.2L 9.0:1 DOHC, 3.5L 9.1:1 DOHC
2001-2003 3.5L 9.1:1 DOHC
2004 3.2L 9.1:1 DOHC, 3.5L(GDI) 10.3:1 DOHC

Block info:
'92-97
Shorter deck.
146mm rod.
Crank has 6.937" reluctor.

'98-04
Taller deck.
152mm rod.
Crank has 7.25" reluctor.

Connecting rod info:
'92-97
Length 5.748" (146mm) length
BE 2.244" (57mm)
BE width 0.858 (21.8mm)
SE .866 (22mm)
SE width 0.858 (21.8mm)

'98-04
Length 5.984" (152mm)
BE 2.244" (57mm)
BE width 0.858 (21.8mm)
SE .866 (22mm)
SE width 0.858 (21.8mm)

Piston info:
3.2&3.5L Bore 3.677" (93.4mm)
3.2L Compression Height 1.327" (33.7058mm)
3.5L Compression Height 1.169" (29.6926mm)
Pin 22mm

Crankshaft info:

Pilot bearing 40mm

'92-95
CAS forged into center of crank. 6-notch reluctor.

'96-97
CAS pressed onto center of crank. fully-notched 6.937" reluctor.

98-04
CAS pressed onto center of crank. fully-notched 7.250" reluctor.

Head Info:
92-95 SOHC and DOHC
Mechanical bucket .6685-.6690" diameter.
DOHC - Single pully for drive belt. Internal chain to interconnect the cams.
Intake valve 1.34" (34mm)
Exhaust valve 1.142" (29mm)

'96-97 SOHC only
Mechanical bucket
Belt drive cam.

'98-04 SOHC and DOHC
Mechanical bucket
DOHC - Single pully for drive belt. Gear driven to cams.

Stock Power Limits (from HPheaven)
Pistons 400~450HP
Rods 600~650HP
Crank ~800HP
Race build (forged crank, rods, pistons, close deck, ARP, etc.) 1500+HP

This intake has got to go but look at those ports on the heads! Also note the coolant inlet and outlet. The first and third engine shows different heads. Not sure what years of what used those. It has a belt driven cam pully which drives a shaft that's gear'd to the cams. The last picture shows the other head variant I've seen.













...more to come

kickerfox

More engine pics. Check out that bottom end. Looks like the main girdle contains the oil rail.

The 3th and 4th images show two versions of DOHC heads. '92-95 used chain inside the head to connect the cams. '98-04 used gear drive to interconnect the cams. ('96-97 SOHC only)











Some Toyota transmission info...

R150 - A 2WD transmission found in many Toyota trucks.

Ratios:

* First Gear: 3.830:1
* Second Gear: 2.062:1
* Third Gear: 1.436:1
* Fourth Gear: 1.00:1
* Fifth Gear: 0.838:1

R150F - A 4WD transmission found in many Toyota trucks.

Ratios:

* First Gear: 3.830:1
* Second Gear: 2.062:1
* Third Gear: 1.436:1
* Fourth Gear: 1.00:1
* Fifth Gear: 0.838:1

R151F - A 4WD transmission found in many Toyota trucks.

Ratios:

* First Gear: 4.313:1
* Second Gear: 2.330:1
* Third Gear: 1.436:1
* Fourth Gear: 1.00:1
* Fifth Gear: 0.838:1

R154 - This transmission is a robust 5-speed transmission found in the 1987-1992 MKIII Supra Turbo.

Ratios:

* First Gear: 3.250:1
* Second Gear: 1.955:1
* Third Gear: 1.310:1
* Fourth Gear: 1.00:1
* Fifth Gear: 0.753:1

V160 - Toyota MKIV Supra 6-speed

1- 3.827
2- 2.360
3- 1.685
4- 1.312
5- 1.000
6- 0.793

NOTE: Input shafts lengths vary.

Pre 1995 R150\R151 = 6.5"
1995 up Toyota R series = 7.5"
AX15 = 7.5"
87-92 Turbo Supra R154 = 7.25"
AR5 = ?
NV3550 = 7.5"
AX5 = 7.5"
Toyota W series = 6.5"
V160 = ?

If you take a close look at the back of the Isuzu block you'll notice quite a few holes for mounting a bellhousing. That's because both the 3.2L and 3.5L have two bolt patterns. One is Isuzu and the other is the GM 60deg pattern. Transmission options for this engine are almost endless.

...more to come

Slidin8

lol just pick an engine already

dznutzuk

That's a pretty tall engine-you better think about that detail when picking an engine...

kickerfox

One doesn't just throw a dart at the board and "pick" an engine. There are too many variables to simple "pick one". Is it a good engine? Will it fit the car? Is is cheap and easy to find? Are parts available? Can you find them in the future? Is there an available RWD transmission? Will it handle future upgrades like FI? Is it too heavy for the chassis? Just to name a few.

It's actually a 75deg cylinder spread. It may lay a bit lower then the 60deg engines and not as wide as the 90deg v6s and v8s from GM and Toyota. Pay attention to the center of the crank to the tops of the valve covers (ignore the pan and intake as they will likely need to be custom fab'd) then look at a complete Renesis. The 13b is pretty tall when it's dressed in RX-8 intake plumbing.

Mawnee

Wow...you managed to pick one of the few engines that actually makes LESS power than the renesis.

bse50

... and it also weighs more and is by no means intended to be a sporty engine.
Just do a REW swap if you really have to take the renny out.

kickerfox

Horsepower: 215hp @ 5,400 rpm (230hp for '04 GDI)
Torque: 230 ft-lbs @ 3,000 rpm

230ft-lbs vs. the 8s 159ft-lbs? Right off the bat the v6 is going to pull out of the hole like mad. It'll probably light up the rears from a 2k rpm roll. My transmission choice will play the roll after the holeshot.

The 6VE1 has been built to 813hp so it has potential. I don't have that high of a goal for it though. As a daily driver the v6 will be great. Good torque, twice the mileage, and much easier to handle in stop and go traffic.

If you guys can think of a better (read: inexpensive and common) v6, let me know. I havent made any final decisions. Until then I'll be updating the thread as I learn more about this engine.

godesshunter

Good luck finding one of those Rodeo engines that doesn't burn oil. At this stage in their lives, they all run like a 2 stroke. You're going to have to do a rebuild.

Don't they only make like 200 hp anyway? I comment you for your research, but it seems like a lot of work for zero gain.

godesshunter

Why are you stuck on the v6 idea? just to be unique?

kickerfox

Yes I'll be rebuilding anything I buy used.

That, the torque, fuel savings, and future HP potential. I have a love/hate relationship for the Rotary engine. If I could tip in the throttle at 2k, and fill the space between me and the car in front of me in stop and go traffic before someone merges into it, I'd keep the rotary. Otherwise I have to press in the clutch, rev it up, and feather the clutch, over and over. It gets old quick. Other then that it's a blast to drive but that rotary does not like going slow. If I lived in the country I'd be rebuilding the Renesis.

Oh, the other thing is the v6 may require less modification to the 8's front subframe and steering rack. It also keeps the weight down and back compared to the v8 or i6 swaps. I don't want to completely ruin the handling. I know any swap will compromise the 50/50 weight distribution but I'll manage. I have read the weight of the 6VD1 is 354lbs fully dressed. That's probably including that monstrous intake mani that's probably ~20lbs. What's the weight of the Renesis fully dressed?

kickerfox

Here's a piston from the Isuzu engine that I found on the web. As godesshunter mentioned, it burned oil heavily. The thing to notice here is the size of the ring land for the top ring. Nice and fat. No wonder people are supercharging these engines without blowing them up. CR is 9:1 which is fine for FI.



Here's the crank that's used in the engine. I keep an eye out for certain things that would indicate it's strength like the width of the journals. The rod journals look as wide as the mains. That goofy ring in the middle is the reluctor for measuring crank angle.



Here's the engine's connecting rods. Things to note are the oil squirter (arrow) and the thickness of the big-end near the beam. It looks alot like a Nissan SR20 rod. My Miata rods look about as thick and I managed 15psi on the stock BP internals for years. The Isuzu rod's beam almost looks disproportionately small compared to it's BE. SE uses a nice 22mm pin.

bse50

Alfa Romeo V6 engine - Wikipedia, the free encyclopedia
The 3.2 is a bit heavy but has potential even in NA form...
Check its bore and stroke
The 5 cylinder 220hp engine is also nice. Intake, exhaust, tuning and you're up to 260hp with a relatively lightweight unit.

godesshunter

When I hear the word torque, first thing I think of is an inline design. BSE may be onto something with the 5 cyl thing.

Have you considered an Audi inline5?

If I remember correctly, The turbo 5cyl was getting close to 300hp out of the box and had torque for days. And I know them vw fanboys have gotten into the 400hp range pretty regularly. That would be a build worth showing off!

kickerfox

bore/stroke
93/78mm 3.2L Alpha
93.4/77mm 3.2L Isuzu
93.4/85mm 3.5L Isuzu


The Alpha or Audi motors would be hard for me to find. The Audi would be the easier of the two but I have yet to see any at the yard. The 8's engine bay doesnt have alot of room between the firewall and powersteering motor to accompany an inline. I don't think an i4 would fit let alone the i5. That's part of the reason I'm sticking with the v6. They're short.

The VW VR-6 was one engine I looked into. I love the sound of those and you can get quite a bit of power out of them. I still run into the length issue plus it's an iron block, something I'm trying to stay away from. This Isuzu v6 would probably make closer to 250~275hp with some pistons. The stock ones are only 9.1:1.

bse50

Contact fastlaneracing, a member here.
He was able to fit one of the engines you think couldn't be fitted

olddragger

iTrader: (3)

Thank YOU! I have asked why not a good v6 swap in this car for some years now and you seem to know what you are doing!
One option not mentioned is the 4 cyl in the S2000. Supposedly it will fit the RX8 trans? Just a thought.
But I love v6 engines--the sound they make is more like the personality of this car, it seems like a better overall "fit".
I would love to see a GM v/6 swap, but the one you have chosen is smart.
I choose to sc this engine and that gave it the characteristics you mentioned that you wanted. Just touch the throttle and close the distance.
Now how are you going to handle the electronics?

kickerfox

The s2000's engine is a great engine but if your going to make the RX-8 into an s2000 you might as well just buy an s2000. The v6 on the other hand should provide better "boostless" power then the s2000's i4. The s2000 is still only 150~160ft-lbs of torque. It'll take supercharging to get stump-pulling low out of it. The other thing you pointed out is the exhaust note. A v6 with a good exhaust can sound very agressive yet smooth ans silky at low rpm. Correct me if I'm wrong but a v6 should be firing as many times at 6000rpm that the Renesis is firing at 9000rpm. Finally there's the uniqueness of it. Think about this... If the s2000 came with a v6 option, which do you think would sell? The i4 or the v6?

I'd have to use the ECU from whatever v6 I choose. The v6 harness will be wired into the 8's systems for various power, ground, and "analog" signals such as turning the fuel pump relay on and off. This will get the v6 running at least. The hardest part will be driving the 8's instrument cluster and center display. I haven't looked yet to see how the center display works. There are aftermarket canbus interfaces available that allow you to convert analog signals into whatever your cluster needs but I haven't looked into those yet. What I would probably do is gut the 8's cluster and drive the analog gauges with the PCB from the v6's cluster. I can probably make that work but I'll have to do more research into both cars' clusters.

The electrical system will probably take longer then getting the engine in the engine bay.

kickerfox

I've been searching for interchange parts for the Isuzu engine. The Toyota 1UZ-FE (v8) uses a very similar rod. Ford Duratec 2.0L also.

Engine_______BE_______Pin________Length
6VD1________57mm____22mm______146mm
1UZ-FE_______55mm_____22mm______146mm
Ford2.0______49.91mm__20mm______146mm
Various BMW__52mm_____22mm______144/146mm

The 1/2/3UZ-FE Toyota v8 has an aftermarket following. Crower makes rods for it. It's not that difficult to have the BE opened up 2mm. The BMW rod might not open up 5mm but combined with turning the crank, it would allow you to choose what deck height you wanted. Maybe drop it .5mm to bump down the CR.

Steel Billet Crower Connecting Rod Toyota Landcruiser Uz1 Uz2 Uz3 5.748 C To C - Connecting Rods

I'll keep hunting...

olddragger

iTrader: (3)

I understand what you are saying about the S2000 engine and agree.
electronics will be a puzzle and going with analog gauges would be a easier and more trouble free way of dealing with it.
Who needs traction/stability control anyway? ABS and the power steering should be ok?
Following with great interest.

kickerfox

On the topic of electrical/ECU systems. I will not delete my cruise control! lol

The 2002 Honda Passport, like the RX-8, uses a fly-by-wire throttle with the cruise-control logic built into the ECU (like more fbw cars). The Passport looks to have the cruise control buttons mounted on the steering column levers. It shows individual switches. The RX-8's steering wheel mounted buttons are resistive. The 8's ECU measures the resistance (probably by return voltage*) for each button to determine it's function. This may sound like it'll never work together but one could use a pic/mcu to monitor the 8's buttons and signal the Passport cruise functions.

*The resistive buttons, common on steering wheel controls, work by the ECU providing a voltage (at a fixed current) to all the buttons using a single wire. Each button is then connected to ground through varying resistors. The lower the value of resistor, the lower the 5v signal will drop when the button is pressed. It's like a two resistor voltage divider with each button varying the value of one resistor. "SET" may drop the voltage to 4v. "Res" might drop the voltage to 3v ect. The ECU can then determine which button was pressed.

Here are the Passport and RX-8 cruise button schematics.

kickerfox

The biggest issue with any swap will be the canbus systems. The engine control won't be an issue as long as you have all the wiring and components from the donor car. The most difficult part is getting the cluster to work. One option may be to drive the 8's analog gauges themselfs with the logic board from the donor cluster. Another option is to replace the 8's cluster with the cluster from the donor car. A third option, and likely the easiest, is to run the v6 using electronics from another car that has a cluster you like that will fit the 8. The cam/crank trigger pulses must match (use trigger wheels if you have to) and the ignition systems must be similar (wasted or COP). Use the correct maf, injector size, and fuel pressure for the ECU your using and you can get just about any v6 ecu to run any v6 engine. The only thing you may need to account for is timing and VE differences between engines. This can easily be overcome using a piggyback like an AEM FIC.

The Kia Soul uses a cluster similar to the RX-8's design but using all analog gauges. It may have some use. Just thought I'd mention it.

Below that, the Passport cluster which is VERY boring.

stickmantijuana

There's yet another, possibly the better option. Run the engine with the donor hardware. Run the gauge with the RX8 computer. Only input you'll need is the RX8 reluctor ring and splicing some select sensors which aren't hard. Besides, this is the only way to keep the stock e-power steering functional.

I like V6's, but am puzzled by your specific choice. There are some great V6 engines to choose from.

Mawnee

I get the feeling you have never been in a fast car. You seem to have some very low standards for "pull out of the hole like mad" and "light up the rears"

If I were going to spend all the time, money, sweat and blood for a swap...I would want it to be a significant performance upgrade, not a step sideways. Spending thousands on a swap to save hundreds in fuel a year is not a good enough reason.