V8 Engine swap

[Donovan]

I am looking at getting my power in my little MX5, as I am setting it up to be a track day car, and maybe even doing a Targa in it. I don't really want to do the turbo thing, and just looking a replacing the engine with something else with more power, but naturally aspirated. So my choices are most likely either a Rotary or a V8. I have seen a couple of you tube things with guys running Lexus V8's in their NZ MX5's but I haven't been able to find anyone around that has actually done a conversion. I don't want to be getting someone to do it that has to re-invent the wheel, and would rather deal with someone who has had previous experience in doing the change over. I have found someone that has done a rotary conversion, so as a last resort can go down that path, but for some reason have a preference for shoving a small V8 into it.

The Lexus seems to have decent HP, but I am worried about the weight of the engine over the front axle stuffing up the balance, and the size of it with the quad cams on it. The other suggestion has been the Rover V8, being a smaller lighter engine (some people have said that they weigh much the same as the 1600 engine already there), but not producing the same sort of power. But these motors don't seem to be around a lot, so my pickings are slim.

The Americans seem to go with the LS1,2 or 3 motors, and they reckon that it only adds about 60kg over the front axle with these (think that figure was using the LS3 out of the corvette)

Does anyone know of the guys that have the V8's in NZ in them, and where they got them done. I don't care if they aren't in Auckland, just the upper half of the North Island would be handy.

Then there is just the matter of what transmission to run. I have already bought a MazdaSpeed LSD, so hopefully can still use that, and going to be running the brakes with a set of 310mm rotors and Wilwoods 4 pots up front and a set of 273mm rotors and callipers out of a NB8B in the rear, so hopefully stopping power is sorted out as well for what ever ends up in the engine bay.

[petercristina]

One of the mechanics at Powerhaus is running an American V8 in his Mx5. I believe he did the conversion himself basing it on the Monster Miata setup.Cheers,
Peter

Powerhaus Wellington
160 Tinakori Road, Thorndon 6011(04) 499 8715
On Mon, Sep 6, 2010 at 9:58 PM, Donovan <horsepower@mx5forum.co.nz (horsepower@mx5forum.co.nz)> wrote:

I am looking at getting my power in my little MX5, as I am setting it up to be a track day car, and maybe even doing a Targa in it.  I don't really want to do the turbo thing, and just looking a replacing the engine with something else with more power, but naturally aspirated.  So my choices are most likely either a Rotary or a V8.  I have seen a couple of you tube things with guys running Lexus V8's in their NZ MX5's but I haven't been able to find anyone around that has actually done a conversion.  I don't want to be getting someone to do it that has to re-invent the wheel, and would rather deal with someone who has had previous experience in doing the change over.  I have found someone that has done a rotary conversion, so as a last resort can go down that path, but for some reason have a preference for shoving a small V8 into it.

The Lexus seems to have decent HP, but I am worried about the weight of the engine over the front axle stuffing up the balance, and the size of it with the quad cams on it.  The other suggestion has been the Rover V8, being a smaller lighter engine (some people have said that they weigh much the same as the 1600 engine already there), but not producing the same sort of power.  But these motors don't seem to be around a lot, so my pickings are slim.

The Americans seem to go with the LS1,2 or 3 motors, and they reckon that it only adds about 60kg over the front axle with these (think that figure was using the LS3 out of the corvette)

Does anyone know of the guys that have the V8's in NZ in them, and where they got them done.  I don't care if they aren't in Auckland, just the upper half of the North Island would be handy.

Then there is just the matter of what transmission to run.  I have already bought a MazdaSpeed LSD, so hopefully can still use that, and going to be running the brakes with a set of 310mm rotors and Wilwoods 4 pots up front and a set of 273mm rotors and callipers out of a NB8B in the rear, so hopefully stopping power is sorted out as well for what ever ends up in the engine bay.

[Posted via external email]

[Ian]

With a V8, you will spend a fortune getting the car built, and probably spend more time in the pits than out on the track.
MX4000 from ChCh (races using a Lexus engine - Ruapuna mainly) on this forum, is a talented engineer and he may warn you off.
There are many ways to go quick in an MX5 on the circuit...a well set up and driven car with 200HP (modest turbo/supercharger) could be done way cheaper/easier than a V8 conversion.
Your choice of course...best of luck.
Ian

[sprsta]

http://forum.miata.net/vb/showthread.php?t=176998

you wont meed any more power in an mx5 than this on the track im sure

[ham]

Try Don at

Autoway Service Centre in Hamilton

I think he has done a few conversions of various types

[Donovan]

Try Don at

Autoway Service Centre in Hamilton

I think he has done a few conversions of various types

Yeah, have already talked to Don there. He hasn't done a V8 conversion. Has done one with a 13B rotary in it, so if I go down that track will get him to do the conversion. He said that he knew someone up in AKL that runs an white MX5 with a Lexus V8 in it, and was going to try and get me his number at some stage. Have in the mean time, was talking to a European Engine importer to see if he had a Rover V8 (he only has a 210KW 4.0 BMW V8 and a 280KW 6.0L AMG Merc V8, hhmmmm) and he said he had a mate that has done the Lexus V8 conversion, who works at Drury AutoServices. Have talked to him, and going to pop down there at some stage to have a look at his one. The only problem is he is running the Lexus auto tranny.

[Growler]

Dimensionally the Lexus is a wide motor. You could go with a small block Chev (Say 302). They are fairly compact and there are a lot of performance parts for them. You could also run a Supra box (Pretty expensive though) but you may have to source/fabricate a new bell housing. (I have also known of a BMW box being used as well.
I know a guy who could fabricate engine and gearbox mounts for you so all you have to do source the engine and box.
He recently did a conversion putting a turbocharged 302 into a MK1 Cortina!

[Gravelben]

The LS motors are much, much lighter than the old small blocks AFAIK as well as having quite compact dimensions for a V8 due to being pushrod instead of OHC. They seem to be the V8 of choice for pretty much everything these days.

I don't think it would be suited to the character of the MX5 at all though (a nice revvy 200+hp NA V6 on the other hand... KL-ZE anybody?), but thats down to personal taste. Mind you I can see the appeal of an LS-powered RX7...

Really the simple answer as said is to turbo or SC the original motor, standard internals are good for around 270hp, upgrade those bits as well (still much cheaper than an engine swap and avoids screwing round with weight distribution) and 3-400 should be easily attainable.

[Timmo]

has anyone retro fitted the new 2.0l MZR unit and 6 speed box into the NA chassis? Its probably not worth the cost at the momet but it could be something to consider as second hand engine prices come down.

Anyone know what would be involved?

[Euen]

has anyone retro fitted the new 2.0l MZR unit and 6 speed box into the NA chassis? Its probably not worth the cost at the momet but it could be something to consider as second hand engine prices come down.

Anyone know what would be involved?

There has been some discussion about it on the engine swap section of Miata.net's forum but the Americans discounted it because the MZR has the inlet and exhaust on the opposite sides and on a left hand drive car this was not practical. On a RHD car it may be possible. Probably of greater concern would be the electronics involved in the change.

I guess anything is possible if you have the time and dollars to throw at it.

[Donovan]

I know a guy who could fabricate engine and gearbox mounts for you so all you have to do source the engine and box.

Is this just of the 302 engine, or any engine that I end up getting. If the latter might take you up on that offer

[Donovan]

Just been told about this site below. Seems they do a complete kit for the LS engine conversion into a MX5, everything that you would ever need, already made up.

http://www.bossfrog.biz/Miata_V8_Swap.html

[sprsta]

you can get it all through flyin miata also

[Growler]

I know a guy who could fabricate engine and gearbox mounts for you so all you have to do source the engine and box.

Is this just of the 302 engine, or any engine that I end up getting. If the latter might take you up on that offer

Yep! He is a race car fabricator and can almost do anything!

[sprsta]

http://www.trademe.co.nz/Trade-Me-Motor ... 585458.htm

how about one of these?

[Donovan]

Yeah, have seen that engine up on trademe before. Just haven't seen on of these put in there, and don't know the size of it compared to the Lexus option (I know it has the dimensions on the site, but I don't know the dimensions of the Lexus 4.0L. Also the Lexus engines seem a bit cheaper, about $1400-$1500 for a font cut of the 190kw version with the ECU, or about $2K for the VVT 215kw motor.

The other option I have been knocking around is one of these

http://www.trademe.co.nz/Trade-Me-Motor ... 251426.htm

Have been talking to the sales guys at place selling this (he has a mate with a MX5 with a Lexus V8 in it) and said he should be able to do the motor and electrics from $1800 depending on the motor he has at the time. Good thing about these, is that you can get the manual geabox for them from Europe, where as the Lexus going to have to fluff around with Lexus to get something bolted onto to it. But again, I don't know the size and weight of one of these, plus if anything goes wrong with this motor, it would be mega expensive to get fixed.

[SLYDIT]

you can get adaptor plates made up or ordered from places like dellow automotive. I'm sure you could get a T5 5 speed in there with the 1UZ.
the problem with the 1UZ is that they are pretty limited in the head flow... i would get a non vvti one and have the heads ported out to maximise flow.

[broomfish]

JE-DE 3.0 DOHC V6 from a Sentia is my pick
Already RWD, but only came in auto

[brownie]

If you like the 1UZ,i suggest you maybe PM MX4000 ,ask for any pitfalls.
They are not a light motor,Quad cam,36 valves and 6 bolt bottom end,Damn Strong though.
Mazda JE,Too big and heavy with Quad cam motor,JE SOHC is getting a bit long in the tooth,Manuel gearbox not too hard to sort.
Ford 302 is a good fit,Seen a custy with a 302/T5 box and jag diff,recons it owed him $6000.00 all up,The 302 was a carby set up so no expensive ECU to set up.
The other end of the scale,Another Customer i have spent $60,000 doing the Ford setup,But would be the best MX5 in NZ ,bar none.
Ford 302 is a common as conversion ,But at least there is plenty of info around to do it.

Hit the net and google MX5 V8 conversions,I'm sure you will get plenty of info to make your own choice.

[LS3V8MX5]

Check out: 6.2L Alloy V8 2005 NC
440HP
Total car weight 1150kg (only 30kg over std)

[Euen]

Congratulations on a brilliant looking conversion.

[Stevo]

Check out: 6.2L Alloy V8 2005 NC
440HP
Total car weight 1150kg (only 30kg over std)

Outstanding conversion. Makes me drool lol
Cheers Stevo

[Donovan]

At last, someone else that has done it in NZ that I can pick their brains about.

Who did you get to do the conversion? What gearbox, diff did you use?

I have been looking at various kits from the US for doing it, that they reckon with them, it is a pretty straight forward change over, from Bossfrog, their Venom V8 kit, and then have to find an LS series engine, a Tremac T56 gearbox, and a diff from a Ford Thunderbird, and then they say it is a pretty simple conversion from there.

The other little problem I have, is whether to get an LS1 or 2 engine out of a Holden, or bring the whole lot in from the US. I have been told by someone that the oil pans on the Holden's are totally different from the US sourced engines, and so the kit might not work with the Aussie V8.

So many questions, and so jealous.

Have you ever stuck it on a set of car scales to see how much of a weight gain it is over the front axles?

[LS3V8MX5]

Car has lost- (Yes Lost!) weight on front axle, I've had to lower the front by 20mm to restore standard ride height.

This is first NC conversion in the World- Boss Frog Kit is for NA/NB

Gearbox is Tremac T56, GM front half to suit engine and AC Cobra tailshaft housing. The GM (Holden) tailshaft is way too long and results in hopeless gear lever location.
Gear shifter is loosly based on Ford Mustang but modified to my own design to allow use of standard internal console trims.


Sump is Holden, but reduced in depth by about 22mm and internal baffles and oil pick-up redesigned to suit. Still holds 7 litres including filter.

Headers built to suit and ceramic coated inside and out to reduce heat build up.

Diff is standard with Redline "Heavy" gear oil, has done 10,500 kilometres so far, including a track session at Taupo- no noises or leaks (yet).

I 'm sure if the car was raced regularly a stronger diff would be required, but at the moment it's just a road car.

I wouldn't use ford thunderbird diff- I'd use RX8 with FD crownwheel and pinion, because the design and mountings are identical to series III MX5; but for me the "factory" look is more important than ultimate strength. Once again- this is not intended to be a race car...

[Donovan]

Did you do the work yourself, or someone local down in Hamilton.

I am going to have to go down the strength path, since the car is mostly going to see track work and driven in anger. I have been contemplating just using the Mazdaspeed race diff that I have with the engine, but suspect the half shafts would let go with the torque of the motor.

How in the world do you get the power down, 325KW and a mountain of torque (580NM?). You must have tyres on the back of that thing that need their own post code


I know someone with a NA turbo race car that was running 300kw, and he had to pull it back to 275kw to get around the track, ended up being quicker with less power. Mind you, the NA is a lot lighter and being a turbo, all came in one wack at the end of the rev range. Would imagine your power is more liner, which is why I want to do the same to mine, rather than going down the turbo path.

Did you bring the engine in yourself?