v6 swap options
 

Hey guys. It's been awhile since I've had much to say in Miata-land since I sold my turbo'd Miata...which was since driven into a brick wall. :(

I now own an '04 RX-8. LOVE the car. HATE the engine. (Sorry rotory guys) I've been considering v6 options and it dawned on me, don't alot of Miata guys yern for a v6? Well...I found one with bolt-on RWD options. It's VERY similar to the KL but by golly there's a transmission that fits it. :D

Who's interested? Should I start a thread on it here or are there enough swap threads going?

There are not that many v6 miatas. Most don't beat around the bush and go straight for 8

Same thing goes for the RX8. They do LSx or xUZ swaps.

I'd imagine there isn't alot of v6 Miatas because there arn't alot of good v6s out there with RWD options ...until now. mwahaha

TurboTimmah is building a KL beast. Check out his thread

https://www.miataturbo.net/cars-sale...2412500-67451/

CodingParadox has a KL Miata as well, no idea if it sold or not.

Quad turbos? :giggle: I remember his twin turbo build.

Engine in question... Isuzu 6VD1 (3.2) and 6VE1 (3.4). Aluminum block, DOHC, 75deg V (short height), forged rods, cast crank, open deck, and COP ignition. Built by Honda. They can be found everywhere. Troopers, Amigos, Rodeos, and Honda Passport as well as various Isuzu and Holden trucks. Good news is, there's bolt-on options to bolt a Toyota Supra (r154 ect) transmission to it. It has the GM 60-deg bolt pattern. Hello options.

Check out the 6-bolt mains and main bearing support plate with the oil rail in it. The forged rods have oil squirters also (like the SR20).

very interesting. cast crank kinda sucks if you wanna make a ton of torque. but it will still probably be a beast.

has anything else like this been done or will you be the 1st?

I'll be the first. I didn't jump in thinking "hey lets put a Isuzu truck engine in an RX-8". I did want a v6 though. I was looking for transmission options for the Toyota 1MZ-FE when I stumbled across pics of the Isuzu v6. There was a supercharger kit available for it and another company (I spoke to the builder) did over 800hp on the cast crankshaft. The widest part of the engine (valvecover to valvecover) is 24". Having spent countless hours in my Miata's engine bay, I think it'll fit. Obviously that honking intake will have to go unless stump pulling torque is what you want. It looks larger then it is for some reason. If you reference it's size off things like the cam pullys and water inlet and outlet you get a better feeling for it. Oh that's another thing, could it get any easier to plumb a radiator to it? Here's some dimensions.

https://www.miataturbo.net/attachmen...1&d=1356749045

https://www.miataturbo.net/attachmen...1&d=1356749054

what do you plan to control it with?
Im sure MS can do it (and many others) but won't you be completely alone in setting it up and tuning it?

Yes I would be. I'll use the electronics that ran that engine before. The problem I'll have is getting the RX-8s canbus cluster working. There are chip swaps available for it so it's unlikely it can be reflashed through the OBDII port. Nothing a piggyback can't solve. Depending on the year ('92-95 and '96-04) I can get cable or drive-by-wire electronics.

I really wish I had an MX-5 now. This would be a cakewalk.

Another interesting tid-bit. The image below is a production powerplant for a plane using the Isuzu v6. It's supercharged and rated at 350hp. Weight (INCLUDING the prop reduction, supercharger, and alternator) is stated at 352.74lb. The reduction itself is stated 66.14lb. That leaves 286.6lb leaf for an impressively light 350hp supercharged v6.

https://www.miataturbo.net/attachmen...1&d=1356750021

Lets put one in my Fiat if I get bored next year.

Hey what's up Split. How you been? Hell yeah lets do eeet! You hold the hood open and I'll kick it off the roof. Seriously though. If I get this nailed down you guys are golden for v6 swaps. The Dodge Dakota 2.5L bell housing has a GM 60 on the engine side and a Toyota on the transmission side. Here's just a few transmissions that will bolt up. Including a 6-speed from the Supra. :bowrofl: Here's 13 transmission options for it.

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

But wait there's more!

Jeep AX15 and NV3550
Isuzu AR5 (originally bolted to the Isuzu 3.2L and 3.5L v6s)
Jeep AX5
Toyota W55, W56, W57 and W58
The W-series Toyota 5-speeds share a common face pattern on the case. Any '88-99 Jeep 2.5L bellhousing (NOT Dakota) will bolt a Toyota W series transmission to a 60 degree GM bolt pattern.

I'm interested to see your results. I've always wanted to do V6 but most suck or are unpractical right now (Ford's new 3.5L ecoboost engine:drool:). I looked a little bit at Isuzu engines as I think the mazda KL is very similar or something, don't quote me though. I like all the transmission options too. That's another annoying thing about the KL swap.

Here's some interesting figures I calculated. I'm pretty sure I didn't screw this up. :)

Calculated rear wheel lb-ft torque.

Gear----Isuzu v6 w/ Toyota R154 (4.10 r&p)----Stock '95 Miata (4.10 r&p)
1-------------3607---------------------------------------1505
2-------------2170---------------------------------------868
3-------------1455---------------------------------------635
4-------------1110---------------------------------------475.6
5-------------835----------------------------------------387


205/60/15. 5th gear.

Equal 65mph@2850rpm

Red is Miata, Blue is v6+R154 (4th gear is equal). It should feel very close to the stock Miata gears. Shift points are very close to the same except for that nice .753 overdrive. :)

https://www.miataturbo.net/attachmen...1&d=1356758942

The Isuzu v6 in question is actually a Honda engine. It was built under contract by Honda of Japan for Isuzu. I REALLY like the 75deg V. I measured 13" from the crank to the tops of the valve covers. This could help quite a bit with manifold issues. There's one fitment issue though. Check out the goofy oil filter "bracket" (or whatever it is) at the front of the engine. If it fits, great. If it doesnt fit, check out that second photo. I'm thinking banjo bolts (or ANs) might thread right in there for a remote filter. The water outlets (from the heads) also have ports in the rear. If the stock front outlets are used, this engine may run into the same issue Miatas have with the rear cylinders running hotter. I think that's only an issue with boosted Miatas.

https://www.miataturbo.net/attachmen...1&d=1356759442

https://www.miataturbo.net/attachmen...1&d=1356759476

V8 > V6

If you're doing a swap like that. Why not go all the way...

Weight. The v6 is more then 100lbs lighter then an LS1 for example. It's also more manageable. There's horsepower, then there's usable horsepower. Race you through the turns! :D

I wouldn't be mentioning weight as an advantage until you see the engine, with the necessary ancillaries on a scale.

The supercharger is another 25lbs, which would imply the engine itself is lighter then the alloy Honda 4-bangers. I dunno, but general physics tells me that 2 extra con-rods and pistons + 4 added valves + 2 extra intake and exhaust manifold runners etc do not usually add up to a nett weight saving.

I like the noise V6's make more. Really though it's all personal preference. Why do people use superchargers instead of turbo's?

Because the US went off the gold standard, and granted the Federal Reserve bank monopoly control over the fiat currency which replaced it.

Seriously, though...

The idea of a V6 swap is intriguing. I can't quite explain why, but at some basic emotional level, it's always seemed like the powerplant that the Miata ought to have.

I know little of Toyota and GM in this regard, but if the engine has a common GM bolt pattern, would not also many GM transmissions fit onto it, without having to hunt down a Supra as a donor? (I'm thinking 80/90s F-body, S-10, etc.)

Subscribed. I love my KL/T5z combo even without the compressed installed. With a proper NA intake & headers it probably would be quick enough. Now if you could add more cubes.... i think 3.5 or so would be nice. The 2GR-FE in our RAV4 is surprising. I never heard of this engine. Hard to believe there are that many trans options. Good research lazzer! Again!

Yeah, why can't you use the T5 S10 bell housing with a T5 with better ratios?

Do you still have your KL buggy?

GM made a tiny 2.5 V6 for Saab back in '94. All aluminum IIRC, 170hp, 168 ft/lbs. Someone should spend the massive amount of money to adapt that to the miata. It was a 35 degree V6, so very thin.

Super-scribed!

I happen to be parting an 88 Supra and have a 154 for you if you want it. Cheep

I'm going off of what the aircraft manufacturer states.

Yes they do. T-5. T56, etc. can all be bolted up. I have no verification as to which ones are a "direct" bolt-on as far as the flywheel, clutch disk, pilot bearing, throwout bearing, and input-shaft are concerned.

Nope. I sold it this summer. :( I didn't have anywhere to store it because I moved the computer shop out of the warehouse and into a retail store. :) I had to sell my Turbo SR20 Sentra too. Now I just have the X90, recent RX-8, and I bought a Honda Superhawk motorcycle to fix up. The Hawk cured my adrenaline needs for last summer.

Are you donating it for research? :) I have to look into what years to use. I think Toyota has two different versions of it. I remember reading that somewhere.

In terms of cost, I think the cheapest and easiest v6 swap in a miata would be the k series using one of clairetoo's kits. That lets you use the miata trans, starter, PPF, most of the clutch stuff, etc. she has a tubular subframe but you can get away with using the factory subframe if you are crafty. You are on your own for intake, exhaust & oil pan.

If you wanted a stronger trans then I see any v6 swap costing all about the same. The only difference being the cost of one engine & trans combo compared to another. And that cost difference would be minimal compared to the cost of the entire swap. If you can find a v6 & trans that fits the factory subframe with a good capacity oil pan and an intake that fits under the hood, a starter location that allows a header & exhaust on both sides, then you would be way ahead of the game. If you can also have A/C & P/S too (like the LS swaps), then awesome. Assume a trans mount, ppf/diff mount, shifter, speedo, & engine management solution regardless.

IMHO the trans issue with the K series is very minor in the grand scheme of the swap.

None of this applies to an rx8, but this is a miata forum :)

And the aditional 1000cc of displacement is nice.

I've read alot about the KL in RWD applications. The bell housing was the biggest nightmare in my eyes. Engine mounts - easy. Wiring - easy. Plumbing - easy. Fabricating a bellhousing is a nightmare imo.

The reason I'd be going with the r154 is it's strength. The cost is higher then say a T5 but if I ever boosted the v6, I'd need it. So I might as well start with one.

Who's got a kit? Link?

Not sure if clairetoo has a website. Crap engineering is her business. Here is the m.net link.

KL mazda v6 swap thread. - MX-5 Miata Forum

I didn't make a bell housing. I made an adapter plate for it and the flywheel. I am running all fox body stang stuff aft of the crankshaft. Clutch & trans has more than enough capacity for the application.

all this V6 talk makes me want to see the new ford V6 twin-turbo ecoboost engine experimented with... but im poor and cant do that.

I didn't realise anyone had found a solution for a v6 Miata yet. I read of many people trying though. I'm in a little different situation with the RX8. I'm trying to maintain alot of the systems the car has like traction control. The Isuzu has a DBW throttle on newer models.

These measurements may be of more use to you guys then me. Here's a r154 trans I measured today. That is a Supra turbo bellhousing which will not bolt to the Isuzu engine. I haven't got my hands on a Dodge 2.5 bellhousing yet to see how long it is but with the input shaft length of this particular transmission, one would need a bellhousing that's close in length to the one shown. There are SO many versions of bolt-on transmissions available it may take some time but more then likely one of them will put the shifter where you need it.

Anyone have a Miata trans laying around to measure the distance from the bellhousing to the shifter? Get me that number and I'll keep an eye out for you.

https://www.miataturbo.net/attachmen...1&d=1356912236

I have that dimension at work. I have most of the critical features in my cad model. Hit me up tomorrow.

I have that transmission.

Bell housings are simple to adapt to it.

miata 5speed bellhousing to:

Shifter centerline 32"

tail shaft seal face 32.625"

Front most face of the input shaft: 0.41"

I think for my use in the RX-8, the W58 puts the shifter where I need it. I'm not sure which GM60 bellhousing will maintain that shifter position.

Thanks Tim. That is a long one isn't it? The RX-8 is about 27" from the firewall to the shifter. After looking at quite a few photos, the Pontiac Solstice has a pretty long trans. There was another R-series trans that has a "tripod" mounted shifter like the Solstice but I don't know what it was from. The mount was aluminum vs. the Solstice's steel shifter mount. Ring a bell?

Found it. SC300 shifter.

https://www.miataturbo.net/attachmen...1&d=1356976682

It has begun... kinda. I still need to figure out the elusive transmission combination.

https://www.miataturbo.net/attachmen...1&d=1365751285

https://www.miataturbo.net/attachmen...1&d=1365751276

Subscribed to this shit!

Subscribed

More trans info.

I bought a '98+ Trooper bell housing today. I'll be picking it up tomorrow. Here's a Solstice trans. It should bolt to the Isuzu bell since it's an AR5 and that's what the Trooper had. Note the PPF mount. :bowrofl: This is very close to a bolt-in solution IF the Solstice input shaft is long enough.

https://www.miataturbo.net/attachmen...1&d=1365814910

https://www.miataturbo.net/attachmen...1&d=1365876782

I'm going to copy this from my thread on the 8 forum so you guys can grab the dimensions and see how they translate to the Miata platform.


Oh I'm loving this. Long story long...

The 8's trans is 29" from the motor to the shifter.
The Solstice is 34" from the motor to the shifter.
Solstice bell housing is 7.25" long.
Isuzu bell housing is 7.75" long.
Solstice trans on the Isuzu bell housing is 34.5" long.

Subtract the 8's trans from 34.5" and that puts the front of the Isuzu/Solstice combo 5.5" further forward. I estimated the front of the 8's trans to be about ~4" behind the firewall. The Isuzu/Sol will be 1.5" in front of the firewall. PERFECT!! This gives me 1.5" of clearance!

EDIT - A little more good news... CLUTCHES... Trooper 10.5"OD 1"x24t spline. Solstice 9"OD 1"x23t spline. Dodge Ram/Duster/Challanger/Etc 10.5"OD 1"x23t spline. It has the OD of the Trooper with the spline of the Solstice. WIN! SACHS BBD4163 Meaty disc. Oreilly has it for $68.99 and it's a 6-spring. http://www.oreillyauto.com/site/c/de...1344&ppt=C0015 Aftermarket available also.

Here's a pic of the RX-8 trans and the new Solstice trans on the Isuzu bell housing.

This suits my needs in my RX-8 swap but may be of interest to anyone doing an engine swaps. There's many bell housings that will bolt to the Solstice AR5 transmission. If the Isuzu engine doesn't work out, a Dodge Dakota bell housing will allow me to bolt it to a GM60 engine.

https://www.miataturbo.net/attachmen...1&d=1366734631

Before i read the rest of this old thread, i'm going to say you're talking about the Suzuki 2.5 or 2.7.

It's very similar to the KL because it's based on the KL.

And wow.... i was wrong.

That's an interesting choice. o_O

Isuzu? Yeh. I wouldn't have thought anything Isuzu had would be worth the effort but after seeing how the engine is designed it seemed like a decent engine. Apparently Honda built it and it's used in planes with a supercharger. How bad could it be? My first choice was the Toyota 1MZ but it didn't have any RWD options.

Similarities can be found in all these aluminum v6s but what sold me on this engine were the many bolt-on transmissions options, the head design, and 6-bolt mains. The cams are mechanical bucket over valve and close together and driven by a geared shaft mounted low on the head. The shaft is belt driven. This keeps the engine narrow and the belt covers low. Should be a fairly light valve train and capable of higher RPM. It's also non-interference. The 3.5L of displacement and resistance to detonation is also a nice thing. Guys run 10psi non-intercooled on it's 9.5:1 compression ratio. Not bad. It does have a cast iron crank though.

That intake manifold has got to go but check out that intake port.

https://www.miataturbo.net/attachmen...1&d=1366737843

Buy my two CA18DET turbos!

I have a pair of T25s from a 300zx but I'm always keeping an eye out for good deals. What's the price? Wouldn't those be well suited for boosting BPs? Have you tried selling them here?

A bit small for BP. Brain said good for 150-160 whp on Miata. They are T25 but .48/.49 AR. Would still spool good with 1,250 cc per turbo!

Thinking $300 for the pair.

The Isuzu engine is a 3.5L or 1.75L per bank. They might be similar to the T25s I have. Send pics and any identification numbers.

Oh, yeah, I was thinking you were doing a 2.5 KL.

Pictars in links below.

Turbo #1 acquired last week. CA18 DET turbo, .49 AR hot side, .48 AR cold side. No shaft play.

https://www.miataturbo.net/diy-turbo...1/#post1003583

Turbo #2 acquired two months ago. Was told it was an SR20 T25 when I bought it, never opened the box until this week. It's another CA18 DET turbo. Same specs, .49 hot side, .48 cold side. It is a fresh rebuild. Unfortunately for me, I paid $225 as I was led to believe it was a SR20 T25.

https://www.miataturbo.net/meet-gree...9/#post1004248

I figured $150 each was fair.

That's reasonable. I got mine from a friend who bought a 300zx engine from his friend who hydro-locked the engine. Paid $100 for both. Every once and awhile I get really lucky like that but I'll pay in the long run because ever since I got them I've got v6 on the brain.

I don't know what happened lately but I can't even give away Miata parts these days. I just junked B6 and BP turbo manifolds because no one wanted them. Junked a pile of BP flywheels, blocks, heads, and B6 shortblock, crank, bla bla bla.

How bad could it be? Pretty bloody bad, quite a common motor in a rodeo work utes here on this side of the planet. 3.5 ltrs where the biggest pile of poo!
Most turn into 2 strokes by about 100kms. Chew fuel and oil.

Holden/GM have a Allotec 3.6 ltr motor which the rodeo, work utes, now use. I'm pretty sure you guys run that motor in Cadiliac CTS, Buick LaCrosse plus a couple of others. But these motors also/can have a few problems as well, timing chains sensors etc.
I.M.O. this would be the motor I would pick.

It's built with the same materials as any other engine so I'll give it a shot. :) The oil burning is caused by a stuck oil ring. There's an updated piston for it. Don't use shit oil it'll be fine.


https://www.miataturbo.net/attachmen...ine=1367415627

^^^
Fair play
Game on then!

Game on indeed. I forgot to mention. The engine/bellhousing/solstice combo was a bullseye.

https://www.miataturbo.net/attachmen...ine=1367510785

https://www.miataturbo.net/attachmen...ine=1367510785

Speaker wire. The equivalent of baling wire for townies.:dealwithit:

#12 solid copper actually. The RX8 has a power plant frame like the Miata and it's not there. I'm still in mock-up stage. :)

Too easy.

https://www.miataturbo.net/attachmen...ine=1367609097

https://www.miataturbo.net/attachmen...ine=1367609097

A little update on the Isuzu 3.2L engine's potential from the 1680hp record holder, Dynomotive.

Stock internals = 450hp (10psi gets it) (piston and valve spring limit)
Pistons+valvesprings = 650hp (connecting rod limit)
Pistons+springs+rods+cams = 700~800hp (crankshaft limit)

I'll be happy with 8~10psi while maintaining the low end/fast spool of T25s on 9.8:1 pistons.

Here's a shot of the Isuzu rod on the left vs. Miata on the right. I tweaked the Miata rod with a programing error on my anti-lag settings. -doh!- If Miata rods are good for ~75hp each I can easily see those Isuzu rods handling 75hp ea.. 75*6=450hp. Supposedly they're good for 650hp which is 108hp a rod.

https://www.miataturbo.net/attachmen...ine=1368855182

Exciting swap! Can you explain what it will take to get the wiring working properly?

:bowrofl:

Old-school computer geeks may recognize the analogy here to the fabled (and occasionally true) legend of the Killer Poke.


related reading, equally humorous:

Halt and Catch Fire - Wikipedia, the free encyclopedia
lp0 on fire - Wikipedia, the free encyclopedia