Fitting the Commodore V6 S/C into the NA

[steverisingsun]

Hi Guys,
I am just starting to pull my NA out and fit up a L67, has anyone done it?
Any info would be great
Steve

[Old Dude]

Rod over in WA has a V8 but I don't know if anyone has ever done a V6
Cheers
Dale

[dazzvazz]

Bit of a crude engine to throw in an MX-5?

The only upside is that they would be cheap to buy and get parts for.

The many downsides include...

- Heavy
- Thirsty
- Bulky
- Poor power per displacement ratio
- Et cetera

Would be very interesting though...

[geofiz]

Bit of a crude engine to throw in an MX-5?

The only upside is that they would be cheap to buy and get parts for.

The many downsides include...

- Heavy
- Thirsty
- Bulky
- Poor power per displacement ratio
- Et cetera

Would be very interesting though...

I think there is not as much difference as you think, as I have thought quite hard about doing this transplant.

VZ V6 - 168 kgs vs NA6 - 155 kgs.
Fuel use would be fairly similiar
V6 will be shorter but wider.
kw / cc fairly similar

[sailaholic]

Is that really all they weigh? Apples to apples as such.

Oh wait.... Vz was the start of the "alloytech" engine was it? Ie aluminium block?

Sent from my GT-I9100 using Tapatalk 2

[zossy1]

In some states (and certainly in NSW), a forced induction 3L engine will exceed the maximum displacement permissible for engineering purposes. Normally aspirated would be OK.

Something less than 2.5L in forced induction is the maximum displacement permissible for engineering purposes in a NA MX5 in NSW. 2.5L might be possible in an NB as they are slightly heavier.

[NitroDann]

20b turbo here I come!

Dann

[Bizi]

Interesting project! Since this is based on a Buick V6, probably fairly commonly used in some US cars, have you found any examples as fitted in the US?
Obviously most US cars are FWD but it may have been used in RWD small trucks/utes etc. Perhaps even in Camaro/firebird cars while they were still made?

I mention it in case you find any additional info that would be helpful, such as ECU issues or how to mate up the engine with a suitable bellhousing.

[Beelzeboss]

From VSB-14



Rotary engines have their displacement doubled, sorry Dann

Taking an NA MX-5 as 950kg that means the biggest N/A engine is 3.8L and biggest F/I is 2.6125L (so a 13b turbo would be OK)

As someone doing a V6 swap which doesn't require a complete re-wire of the front end, custom driveshaft, diff support, PPF delete, gearbox mounts (all of which you'd need for a commodore V6), I'm going to say unless you have heaps of experience don't even think about it! It will take a lot longer than you think.
Having said that, I'll be keen to see how the car turns out if you go ahead. Good luck!

[NitroDann]

Google: georgia tech miata

Dann

[wozzah1975]

In my opinion....

Why would you bother? It's a truck load of work for an engine that technically is dinosaur, and really not that good.

I have built a few V6 engines for various conversions (gemini, WB ute) for obvious reasons (better than the original and easy to do becuase of conversion parts readily available).

I highly doubt that the engine weights quoted earlier in the thread are correct, I'd be keen to see the complete V6 (with supercharger fitted and all ancilleries) compared to say a BPT (with turbo and the same ancilleries fitted). I think you'll find the V6 is substancially heavier, as will the gearbox that you have to mate up to it. It will make the car drive like crap.

A standard supercharged V6 makes around 140rwkw on the dyno I use. With an overdrive pulley kit and extractors it takes them to around 155-160rwkw. With heads and cam it takes them to around 180-190rwkw. Thats the point where you reach the limit of flow on the factory type supercharger. They do make a reasonable amount of torque, but that will be wasted on a light car like an MX5. I have seen one of these engines with good internal work and the right hang ons make 260rwkw, BUT is was ALOT of work, and expensive and utilised very little of the original engine (crank, block and heads). These engines also have a very nasty habit of breaking crankshafts when pushed (if you've ever seen one you'll know why). You're also very limited on valve size and port size unless you buy aftermarket heads out of the states. I would think in an MX5 engine bay that the extractors will be limited by the room you have to work, so anything you make will be a compromise in relation to power unless you butcher the car.

My point is a decent BPT will make the same power figures with the right work, and be reliable.
If you're intending on putting a V6 in in standard form it only makes 140rwkw. My naturally aspirated BP makes that amount of power (granted, the torque is more but as stated earlier wasted in a light car like an mx5). A BPT will make much more than that with very little work, up to 200rwkw with a basic package, and plenty more if you want to spend the time and money. It will be a fraction of the time wasted fitting the V6, and half the price.

I'd almost go as far to say that well set up BPT in an MX5 would run rings around equivelant Buick V6 conversion around a race track. I'd almost bet my left nut on it

If you want to fit something a little out of the box, then at least look at something half decent an worth the time and money in converting. Don't get me wrong, the V6 has it's place, but it's not in an MX5.

Cheers
Woz

[cooper1896]

F20C (supercharged)!!!

[dazzvazz]

I think there is not as much difference as you think, as I have thought quite hard about doing this transplant.

VZ V6 - 168 kgs vs NA6 - 155 kgs.
Fuel use would be fairly similiar
V6 will be shorter but wider.
kw / cc fairly similar

I think you are thinking of the wrong engine. I presume you are talking about the Alloytec? The Alloytec would be a swap worth doing.

The L67 is the Buick V6. I am pretty sure it weights more like 200 kg.
The fuel consumption would be much greater (I use to own a non supercharge 3800 and it chewed).
kw / cc may be alright, but it's supercharged so it's a bit unfair.

Those Buick V6's are by no means performance engines. They are slouches. I use to love mine in my Commodore as a cruiser, but I wouldn't consider all that work for something that wouldn't really suit.

[wozzah1975]

I think there is not as much difference as you think, as I have thought quite hard about doing this transplant.

VZ V6 - 168 kgs vs NA6 - 155 kgs.
Fuel use would be fairly similiar
V6 will be shorter but wider.
kw / cc fairly similar

I think you are thinking of the wrong engine. I presume you are talking about the Alloytec? The Alloytec would be a swap worth doing.

The L67 is the Buick V6. I am pretty sure it weights more like 200 kg.
The fuel consumption would be much greater (I use to own a non supercharge 3800 and it chewed).
kw / cc may be alright, but it's supercharged so it's a bit unfair.

Those Buick V6's are by no means performance engines. They are slouches. I use to love mine in my Commodore as a cruiser, but I wouldn't consider all that work for something that wouldn't really suit.

I doubt that the alloytec is light either. There's an aweful lot of valves, cams, timing components etc. I'd be keen to see what one weighs, but I think you'll find it's heavier than you think.

The alloytec's also have problems with a few klms on them. Timing component failure and valve guide issues are common. Getting good power out of one of these is expensive too, still only about 150-160rwkw standard, so why bother?

Woz

[NitroDann]

f20c is the obvious answer, and its not that hard.

Dann