Chevy V8 MX5

[V8'sOnly]

Has anyone on the forum built a Small Block Chevy powered MX5 in the UK ? Just trying to get some answers for questions about my project . I know this is a "standard" swop in the USA along with the Ford V8's which I know has been done here .

[Oldandslow]

Philistine!!
:P

[skinny]

not quite a chevy...
http://www.mx5nutz.com/forum/index.php?showtopic=9...



but i think his next project is a chevy into a mk2.

http://www.mx5nutz.com/forum/index.php?showtopic=1...

[V8'sOnly]

Quite impressive ! Got mine listed on Ebay at the moment , huge amount of interest and 98 watchers in just two days . .

ETA

Please don't plug your wares on the forums it's not allowed.

TYIA

Edited by Big Al. on Wednesday 10th October 13:34

[V8'sOnly]

Sorry , I'll remember that .

[triplerotorracer]

If you want a nutter mx5 I would put a triple rotor in it. Non turbo so a two litre car and sounds like an F1 car and a light engine like the original one fitted to car so you don't spoil the handling. Being non turbo the power won't spit you off road. Is 530hp enough?

[Richyvrlimited]

triplerotorracer said:

If you want a nutter mx5 I would put a triple rotor in it. Non turbo so a two litre car and sounds like an F1 car and a light engine like the original one fitted to car so you don't spoil the handling. Being non turbo the power won't spit you off road. Is 530hp enough?

You'll probably have to move the rack though, which will ruin the handling.

[groupcracer]

Not sure if you will need to move the rack but the weight of a V8 will have a major effect on the cars balance. These are prone to understeer and then you balance it with your foot but much more weight up front won't help that. Sure more power will help kick the back out but do you want to drive like a rally driver everywhere.

[Richyvrlimited]

groupcracer said:

Not sure if you will need to move the rack but the weight of a V8 will have a major effect on the cars balance.

Except the LS series of V8's are pretty comparable in weight to the cast iron block the MX5 has.

Add in the heavier differential you also need and the weight balance is actually barely effected.

See:

http://www.flyinmiata.com/projects/LS1/index.php?U...

Edited by Richyvrlimited on Friday 7th December 15:32

[Munter]

groupcracer said:

but do you want to drive like a rally driver everywhere.

...

[MX-5 Lazza]

As my car has oodles of power I have it set up to have a touch of natural understeer which I can balance or turn into oversteer using the throttle. It makes for a very safe yet very rapid car.

Also, I've had to move a 1.6 Mk1 engine and I can tell you it's a bloody heavy thing for its size & power!

[lastmin8264]

I can see the appeal of combining the two. But i have a v8 (monaro) and recently a eunos. I love the characteristics of both cars but not sure if I would want them together.

Other engine transplants would jump to mind first. The T56 gearbox is average and the transplant would require huge fabrication I guess to transmission tunnel, drive shafts etc.

If you want a v8 I would buy a v8 car or one with a known conversion if you want a rapid mx5 look at forced induction of std block imo

[MX-5 Lazza]

I've had MX5s for 14 years. 1st a standard Mk1 1.8 for 5 years and the current, very rapid Mk2.5 1.8 supercharged for the last 9 years. While I do love driving them, particularly the SC Mk2.5 I do find having to thrash them tiring. The SC means the Mk2.5 doesn't have to be thrashed to make good progress on the road which makes it a much more relaxing place to be. However, I can see a lot of the attraction of a big V8 in one of these cars. In fact, if my engine dies, that might be a future project for me

[lastmin8264]

5.7, 6.0 or 6.2 LS engines in a crate are not cheap though you could try and find a crashed monaro or vxr8.

Imo I like to keep transplants in house, Mazda 3 mps lump?

[MX-5 Lazza]

My MP62 + Intercooler + injectors was around £4k (it was more expensive back then) and after spending that I still have an MX5 engine. An LS engine isn't much more than that.

[lastmin8264]

It would make a great combo hence the AC Cobra being an icon but if you wanted to put even a basic LS1 5.7 with fuel injection alloy heads circa 350bhp £6k matching manual gearbox is £3k these are new prices of course i bet you could pick up a documented donor engine, ancillaries and gearbox for £6k and would then just need fabrication costs.

it would make a very interesting but expensive mx5, seen a few people though recently transplanting these lumps into a bmw 3 series and also an rx7 but i think they are doing the labour and fabrication themselves, much respect.

mine was rr at 340bhp at the wheels i couldn't imagine how good that would sound in a convertible and with the weight of an mx5 especially an early one it would be a real weapon. probably more car than i could handle if im honest. there is a limit on what bhp you actually need for a road car, i guess 200-250bhp is enough if you have that in an mx5 i think thats just perfect.

[V8RX7]

MX-5 Lazza said:

My MP62 + Intercooler + injectors was around £4k (it was more expensive back then) and after spending that I still have an MX5 engine. An LS engine isn't much more than that.

Except you still have to install it and you'll need a gearbox, custom exhaust etc

If you pay someone to fit it I wouldn't expect much change from £5k plus probably £7k parts bill but that will get you a reliable 400bhp 400lbs BUT having that in my RX7 I can tell you that it's too much for the road.

300bhp would be better IMO which the far cheaper 1UZ engine will give you.

[dblack1]

Many people put the 5.3 liter from trucks (and other GM products) rather than actual LS motors. The 5.3 liter motors are cheaper, more common, and usually in better condition than a LS motor. The 5.3 liter motor follows in the tracks of the LS motors (because it pretty much is one) and can make big power easy. If you want 300+ hp out of your car reliably, a motor swap is a must, the 1.6 and 1.8 motors just were not designed to handle big power, and everything in the LS family makes 345+ (and the non-LS labeled motors in the family produce 270+). Putting one of these in a mx is a lot of work (maybe more than meets the eye because most of this is done in america where they drive on the other side).

[V8RX7]

But the 1UZ is available for circa £200 mated with a Supra box and the conversion kit probably £1500 all in which is less than half the cost of even the 5.3 with a suitable clutch and box.

Admittedly the LS is far cheaper to modify - particularly cams with only one, against the 1UZ's 4

[Kozy]

I know it's a hell of a lot smaller, but have you thought about the Mazda KL series V6 engines? They mate up the standard gearbox with an adapter plate. The usual 2.5 litre engines come with 165bhp, the top spec JDM ones 199bhp, so a fair way short of a V8 especially on torque, however being a short stroke (~74mm) I should imagine they could be tuned for about 200lbft and 260bhp NASP. It should be able to take plenty of revs too, possibly up to 10k if you feel the need! An ITB'd, 9000rpm V6 isn't going to sound all that bad even compared to a V8... IMO of course.

The engine itself is (IIRC) lighter than the standard engine and sits further back, improving handling. Cheap to buy also (compared to an LS anyway)

Would definitely be my choice for a transplant MX5. I can't imagine 400lbft in an MX5 would be all that usable...

Edited by Kozy on Monday 4th February 12:04