What Engine Could Replace the KLZE?

[wytbishop]

When you ask the question "What engine could replace the ZE?" you seem to be asking "What other engine could become the de-facto choice for MX-3/323/Probe/MX-6/626 owners who want to increase HP for a reasonable investment of time and money?" the answer is that there is no such engine.

If you were actually asking "What is the best alternative to the ZE to swap into the MX-3 (...et al) since the supply of reliable ZE's is dwindling and it's out dated anyway?" the answer is and always has been...whatever you can afford and are capable of.

I think you're actually asking a combination of those two questions...hoping that there is a more modern engine that, with a bit more effort than we're used to, could be made to work. The answer to that question depends on what you consider reasonable work.

I said this recently in another thread and I'll restate it here. You could take any car in the world, remove the engine and all the necessary control devices and make it run on your kitchen table.

The only difference between making an engine run on a stationary stand and making it drive your car is that you have to couple it to the drive wheels through a gearbox of some kind and physically secure it in the allotted space. things like an exhaust system and axels and shift linkages can be done but cost a lot of money if they aren't compatible. There is also the issue of gauges and ancilary systems like ABS, anti-theft, etc. but as stated that's mostly just wiring. Sure all those things can be done but they won't be...or rarely...because even if you could, you would probably not do it to an MX-3.

[Redline322]

As far as the drivetrain is concerned, someone could make an adapter plate to use our existing trans, allowing the steering, axles and suspension geometry to stay correct. That would also eliminate the issue of modifying most of the motor/trans mounts to work. If you break down the wiring harness from the donor car and the stock harness we have, there isnt much that needs to talk to the ecu from our own harness, it is mostly engine focused, just look at the MS harness setups. You could use the donor engine harness for most things and the stock chassis harness and fuse panel just mainly needs it's 12V and ground to power lights and any power accessory. Your main issue is your instrument panel which needs tach signal and speed sensor to work properly, but you could just switch to an early panel that uses a cable instead of a speed sensor and tap into the coil signal assuming the new engine has coil packs and figuring out the proper voltage you need so you dont burn out the tach. You could also go the standalone route for engine management. It may be more difficult to install another engine that is not a b or k series, but as long as it'll fit in the engine bay, nothing is impossible. It just comes down to price, power, parts availability and durability.

[MrMazda92]

You are correct... However, the main benefit to an alternative swap would be the transmission. Anybody can make big power by going FI, on nearly any engine...

Putting that power to the ground on the other hand, is a huge problem for these cars.

[Nd4SpdSe]

I agree and like everything Wyt said!

As far as the drivetrain is concerned, someone could make an adapter plate to use our existing trans, allowing the steering, axles and suspension geometry to stay correct. That would also eliminate the issue of modifying most of the motor/trans mounts to work.

You're undersimplying the process. Ya, that could work, but that may not put the motor where it needs to be, it could be too much in any direction (and the orginal trans to the motor smaller) and it could not fit because it's too far to the passengers side (plus the adapter adding as a spacer), towards the front (hitting the rad or for balance) and maybe the firewall might be in the way. It could sit too high where you would have to cut your hood, or too low. Look at those doing K-series swaps in older Civics, their clearance is very, very close from the rad to they use solid mounts. Balance wise they become front heavy, worse with those doing a V6 in a Civic, they become drag only cars. With everyone saying how much they love the handling of their Mx-3, you're seriously affecting this, especially forcing the motor in an unnatural position in the car's layout. Part of it's design in it's destined car is where it sits and balance. Taking more into account that is all that your focused about is torque and power and how fast she goes in a straight line. Hopefully your new V6 is aluminum and not cast...

However, the main benefit to an alternative swap would be the transmission. Anybody can make big power by going FI, on nearly any engine...Putting that power to the ground on the other hand, is a huge problem for these cars.

Another good point hit on the nose. Look at all the research going into modifying and alternative gearboxes for FI KL's, that's a weakpoint for those with 300hp+ goals that most would love to rid of...

What the new cars with cable shifters, more fab work and adaptation. That would actually be easier than linkages and trying to adapt the Mx-3 one to fit and move properly through on the new trans so you're not over-extending (an issue in the rx8 with people who are way too agressive and jam/shove the gears into place) or short-throwing and wearing out the forks or the gears themselves. Takes some R&D and some engineering time to make sure everything is precise to a few milimeters.

If you break down the wiring harness from the donor car and the stock harness we have, there isnt much that needs to talk to the ecu from our own harness, it is mostly engine focused, just look at the MS harness setups. You could use the donor engine harness for most things and the stock chassis harness and fuse panel just mainly needs it's 12V and ground to power lights and any power accessory. Your main issue is your instrument panel which needs tach signal and speed sensor to work properly, but you could just switch to an early panel that uses a cable instead of a speed sensor and tap into the coil signal assuming the new engine has coil packs and figuring out the proper voltage you need so you dont burn out the tach. You could also go the standalone route for engine management..

Thats not so much of an issue, as those simplest swaps that have been done in the past: OBDII>OBDI, 4cyl>V6, V6>4cyl, DOHC>BP. It's doable, but it also adds extra work and cost comparative to the simplicity of a KLZE swap which doesn't require anyone to touch their harness. Some of the stereo wiring here scares me, never mind people that aren't experienced in it touching the engine wiring harness. Most will twist and poorly tape their connections (no solder or shrink wrap) and use only crimp connectors will start to complain after some time that the car doesn't right right or misfires or at all because the connectors came lose from engine vibration/movement or corroded from rain or humitity. MS, sure you can do that, but than again, if you survived the installation despite you did the radio installation with marettes, ideally you should get the car dyno tuned, again more money. The truck is suppose to get Megasquirted this year. I have no references because it's never been done, ever, or any EMS on those trucks. I'm only attempting this once the Rx8 hits the road, but once that's done, the truck will get towed (out of my pocket, or cheat and use CAA) to a shop and get dyno tuned.

It may be more difficult to install another engine that is not a b or k series, but as long as it'll fit in the engine bay, nothing is impossible. It just comes down to price, power, parts availability and durability.

Tools, fabrication skills, time, a place to work. How many people here own a welder or know how to weld? Very few. My dad's an awesome welder, but we don't even own one (been on the to-buy list for many years). It is impossible to do any non-conventional swap without a welder on hand, or a good friend with fab skills and a portable welder, cause you'll have to mock-up the mounts while the engine and trans is "sitting" in the engine bay, with the hypothetical axles and any other linkages/supports lined up.

[wytbishop]

I think this is a very important discussion. This is the exact thought process I went through at the start of my custom car design journey...

Me: "I want monster power for my MX-3..."

Smart me: "But even if you could make huge power, you can't put it on the ground."

Me: "I could do a tubular front clip and basically do anything I want!!"

Smart me: "If you're going to do that why not just design and build a tube chassis custom and do a whole new car?"

Me: "I could put the MX-3 body on a C6 conversion chassis." (I actually considered this...)

Smart me: "That's crazy...for that money you could design a whole car!"

...and it went on from there.

I want my MX-3 to be awe inspiring, but the fact is that for the money and time it would take I could design and build something better. The fact that what I am actually designing is way way off the charts of anything practical or sane is another issue entirely.

[MrMazda92]

Another good point hit on the nose. Look at all the research going into modifying and alternative gearboxes for FI KL's, that's a weakpoint for those with 300hp+ goals that most would love to rid of...

What the new cars with cable shifters, more fab work and adaptation. That would actually be easier than linkages and trying to adapt the Mx-3 one to fit and move properly through on the new trans so you're not over-extending (an issue in the rx8 with people who are way too agressive and jam/shove the gears into place) or short-throwing and wearing out the forks or the gears themselves. Takes some R&D and some engineering time to make sure everything is precise to a few milimeters.

You're right, and it bums me out... 50% of the reason I am not building a KL for boost is the FWD limitations... The other 50% is that I don't want to keep a garage full of transmissions for when I lose one.

Tools, fabrication skills, time, a place to work. How many people here own a welder or know how to weld? Very few. My dad's an awesome welder, but we don't even own one (been on the to-buy list for many years). It is impossible to do any non-conventional swap without a welder on hand, or a good friend with fab skills and a portable welder, cause you'll have to mock-up the mounts while the engine and trans is "sitting" in the engine bay, with the hypothetical axles and any other linkages/supports lined up.

I have Tools, time, and a place to work... I can weld both steel and aluminum(still practicing this one, definitely harder for me )

Too bad I lack the fabrication skill and money to make anything truly awe-inspiring, because I sure as hell want to...

You've got a lot of insight on this topic, I'm glad that you are part of this discussion. I can tell from the way you bring things up, that you have thought a lot on this subject yourself... Probably measured a few engines/gearboxes as well, huh?

My MX-3 wetdream would be a RWD LSX conversion.

If I had $50,000 that needed to be spent, and nowhere else to spend it, the things I would attempt.

[marcdh]

The transmissions are OK really. There's not much point for more than 300bhp in a fwd mx3 streetcar IMO. At 290+ it was hilarious fun but traction was a problem! Agree if you're going crazy may as well take the gearbox with it as per 3sgte

[MrMazda92]

That's about the consensus that I have seen everywhere... 300 is where they start going boom all across the boards.

300 BHP is great for a car of this weight on the street... High power track builds are severely limited though, unfortunately. One or two drag runs with 500+ HP at the crank and you are in tranny swap territory...

[Nd4SpdSe]

You've got a lot of insight on this topic, I'm glad that you are part of this discussion. I can tell from the way you bring things up, that you have thought a lot on this subject yourself... Probably measured a few engines/gearboxes as well, huh?

Depends. I've been around for a while, and of course questions about non-conventional swaps came up even before I was on here, but was much, MUCH less frequent, and typically was about people wanting to put in a rotary, cause apparently because it's a Mazda rotaries are automatically bolt-in....

When I was in the midst of getting my swap done (driving the 626 in the meantime. Swap took about a week), my boss at the time said I should of put in a 350. Now I knew that the KLZE was a simple swap, but of course in the back of your head your thinking "why didn't I". I never really understood how much more complicated of a non-ZE swap would of been, and with that, you do a bit of research. You read about projects like the 351 Focus and the Civette LS1 Civic and you start to see what's really involved for the RWD. As you're exposed around cars, and own a few different ones, you see motors that look similar. When I first started to drive and my one friend got his Mx-3, and to me at the time, the SOHC B6 and the F2 in the 626 looked identical, sitting side by side too. I recent years doing installs on cars, there's a few motors that has a striking resemblence to a KL. Pop the hood of a Duretec 3.0L and don't tell me that's not the first think you think:

(I did contemplate about the plastic intake manifold for it's lightweight and much lessened heat transfer/absorbtion abilities)

But you start to look and do research, you start to add up the little jobs that you need to do, especially the ones you (or I) can't do, like welding, which is a BIG deal. Than the costs of custom parts than you just can't fab (like axles), and the list gets longer, and longer, and the budget goes up and up, and reality sets in. My buddy wanted to BP his Festiva, it never got done. Despite it being a relatively easyish swap, the passenger framerail needed to be notched and one mounts fabricated, and with that little bit of work needed, that swap never got done.

I've been on the forum a long time (obviously) and as time went on and I gained experienced, knowledge and seniority, newbies come in and start asking questions, and just giving simple answers like "because you can't" and "it's expensive and requires a lot of work" just don't cut it. They don't know better, their mints are so caught up with the idea and they lack the knowledge/experience that it wouldn't compute in their heads, so you search for the answers, the real, hard, unadulterated truth on exactly what is involved. You show people the laundry list on what's needed to get the job done, and some of the on-the-fly engineering that you need to do, and most see it after for what it is. Than you get the ones that say "well you just have to do this...", well if it was JUST that, it would happen much more frequent, and it's not that easy. Perfect example is the recent mention of the adapter plate to use the OEM trans. That's just a small piece of the whole puzzle in fitament of the engine, and look how long it took Cody (Tehbrookzorz) to make his own adatper to fix an Rx7 trans on a KL for his RWD Celica project. Some projects you see on the net look easy, but people who do them have the ability, engineering and most important, the tooks to do projects that 99% of us can't. The RWD KL Miata is especially inspiring, but he didn't do it all himself, going to companies like Progressive Automotive and
D&D Fabricating for his project, as as subnoted under "D&D Fabricating" he puts "(lots!)", including the ITBS manifold, exhaust, trans adapter and custom oil pan to say the least.

Than you get to stuff like balance. I almost cried for a while when we did the swap and we couldn't put my CS strut bar back on. I loved the power, but wanted to shed a tear every time I took a corner, I felt like I took one step forward and one step back. Yay I could go faster, but what's faster if I had to take corners slower? This just a bar, never mind shifting 500lbs of motor in a direction that would negatively affect the balance and handling performance of the car.

[Redline322]

I have access to 2 220v mig welders, a plasma cutter that will cut up to 7/8" plate and 2 licensed mechanics that both have 20+ yrs of experience and fab work before if I need extra help. The 2.5L makes practically the same power as the KL but it has a cast iron block, so you can rule that out. The 3.0L is aluminum, including accessories it weighs roughly 350lbs and the same outer dimensions as the 2.5L and since ford borrowed alot of the tech from mazda, I'm going to guess that it is close to the same size as the KL. With accessories, the KL is around 310-315lbs, not much of a difference. When you factor in a low boost turbo or s/c setup for a KL and intercooler piping, etc., the weight is pretty equal. Instead of making an adapter plate, I could probably try to find a manual transmission from a mazda 6, but that would require moving mounts and new axles. For extra clearance, I could notch the passenger side frame rail if needed and both cars have low hood lines so it might clear. Next time I hit the junk yard, I'll take some measurements. If i can find a wrecked 6 for cheap, I might take this on next summer.

[Nd4SpdSe]

Well, your only a small percentage of people here with that it would theorietically take to pull off the swap.

Anything is doable with a plasma cutter and welder

Here's a good one searching on PT

I have been a member of PT for many years now and if I only had a dollar for every time I have seen this same exact subject come up.... People keep seeing that the engine looks somewhat the same because of a similar shaped intake manifold and that it has the same displacement. I have even seen newbies arguing with knowledgeable members that the engines and parts are interchangeable. But this obviously shows a complete lack of knowledge about engines or cars. And in my opinion -someone who knows so very little or neglects to do the required research is also the type that would not be doing major swaps or fabrication for such swaps. So why do the people ask in the first place?

To answer you question as a few others have tried - the engine is in no way related. It is only slightly similar looking because of "borrowed" technology/design. So that being said -you should also be able to swap out a Dodge slant-6 for a Ford slant-6 because they are both slanted. And as another member said - why? The horsepower is very similar. If you were to do a LS7 swap into a MG Midget then you would realize how much fabrication work is involved and would then understand why swapping similar hp engines is not a very bright idea!

Also, in researching I found reference to the SHO motor, the reason why it works in an Mx-6/626/Probe is because if the nature of events. The Gen1 Probe came with a Vulcan 3.0l V6, the Mx-6/626 on that platform would be naturally compatible with that setup. The SHO motor bolts up to the Vulcan trans.

[Josh]

and look how long it took Cody (Tehbrookzorz) to make his own adatper to fix an Rx7 trans on a KL for his RWD Celica project.

Should have looked on RX7 club, you can do it without an adapter, and using stock Mazda parts Frankensteined together. TurboII trans with a B2200 Bell housing and center shaft will get it to directly bolt up


You know to be honest I had very little fab abilities until I did my AWD swap. Hell I had only used a welder a couple times up until then. It took me a year to save the parts up and only 30 days to do in my spare time after work. Went a lot easier than I had expected. spent some time grinding welds and rewelding though. The Duratec would be a sweet swap and would not be hard especially if you had a donor car.

[MrMazda92]

Also, in researching I found reference to the SHO motor, the reason why it works in an Mx-6/626/Probe is because if the nature of events. The Gen1 Probe came with a Vulcan 3.0l V6, the Mx-6/626 on that platform would be naturally compatible with that setup. The SHO motor bolts up to the Vulcan trans.

This is exactly why I was so thrilled to see that SHO in the MX-6. If the SHO works, there's a chance in hell that the Duratec would be doable as well.

I honestly believe the Duratec engines are the best V6 candidate out there for a non-conventional swap... It won't ever be easy, but we will never know until we put honest effort in to try and make it work.

Josh... I had a cosmetic totaled 2000 Ford Taurus SES in my driveway for a year and a half, rotting. You have no idea how tempting it was... Ex girlfriend didn't want me to tear into it. When she moved out, she had it scrapped!!! Just to spite me... She didn't get any money out of it.

I had a Ford Taurus SES with 101,000 miles on it sitting in the driveway. The wheels and tires alone would have sold for $200 within a week of posting them. -.- The body was 90% perfect, from the passenger doors back it was immaculate.

My mood just turned sour...

[fowljesse]

Here's a sort of related idea, without starting a new thread; It seems to me that the transmission will hold up to 500HP, if you don't hammer on it. I don't drag race much, if at all. It's kind of fun, but I prefer autocross. Of course AutoX isn't easy on the tranny, either, but I think it would hold up. I would use the power smoothly, while in gear. I think it's the shock of inertia that causes problems. The only tranny I ruined was when I was 15, and would neutral drop an auto Tempo, to do burn-outs Most of my acceleration is in 2nd, and 3rd gear, without much, if any flat shifting. I don't know if it can be proven, since most guys that want that kind of power use it in ways that are bad for the tranny.

[MrMazda92]

Honestly, if people got involved in a MASSIVE bulkbuy for PAR gears... I mean massive, more than 100 dedicated buyers, we might be able to get something usable for less than a kidney and both legs.