Legally converting na6 to 1.8 in Victoria?

[93_Clubman]

FWIW, I understand Disco's old NA6, which was converted to 1.8 & SC'd by Daniel Sadique when Sue Ransom owned it, was engineered & registed in Vic.

[bruce]

But I think it dodgily engineered for the supercharger (ie. VicRoads may not accept the original engineers report anymore).

[93_Clubman]

yeah, I understood Disco wasn't certain about the currency of the engineers report, but it might provide a lead in terms of going from 1.6=>1.8

[Fatty]

guys, i have been reading this thread with interest and i really thank you all for your thoughts and advice. some of you have gone to a lot of trouble to look into the issues for me, so thanks a lot. sorry it's taken me so long to respond, but i've had a million things going on in the last week or so.

matty i will definately consider the nb motor option.... you've got my brain ticking over there.

[corners]

Personally if it was me I would look at improving the 1600 engine.

When changing to the 1800 and running off 1600 electrics your gonna run into different problems as coils & injectors are different to begin with along with Throttle body and other stuff.

Then comes the more interesting part when you wanna go aftermarket ecu or anything like that.

My car has the bigger brakes, diff etc but I still went a 1600 simply for ease of swap and any aftermarket troubles....

Shoot me a PM if you want any more info as I did heaps of research

Cheers
Jaron

[fastfreddygassit]

*pokes head up*
Have you thought about turbocharging the 1.6??
I heard its a good mod to do....

[Stu]

*pokes head up*
Have you thought about turbocharging the 1.6??
I heard its a good mod to do....

Damn, someone left your cage unlocked again

[davo5]

This thought has probably gone through every 1.6ltr MX5 owners mind at some stage - one of the "books" (partially available on google books) even has a chapter on the conversion, one of the solutions was to weld an addition to the 1.6 inlet manifold flange to make it fit the 1.8 head. (they had a photo of this)

Personally for me I'm not going to do the change, i have dríven a 1.8 and a 1.6 and there is nothing between them, certainly not enough to justify the level of work required to do the swap.

Also 1.6 bits and pieces seem to always be much cheaper.

[mx52nv]

This thought has probably gone through every 1.6ltr MX5 owners mind at some stage - one of the "books" (partially available on google books) even has a chapter on the conversion, one of the solutions was to weld an addition to the 1.6 inlet manifold flange to make it fit the 1.8 head. (they had a photo of this)

Personally for me I'm not going to do the change, i have dríven a 1.8 and a 1.6 and there is nothing between them, certainly not enough to justify the level of work required to do the swap.

Also 1.6 bits and pieces seem to always be much cheaper.

Why would you want a 1.6 inlet manifold on your BP head? Or did you mean the 1.6 throttle body?

I would have thought most people use the FM 1.8 Conversion Kit?

Kit includes:
* EGR plate kit
* throttle cable bracket
* coil bracket
* motor mount brackets
* throttle body adaptor kit
* electrical parts needed to extend your CAS wiring

And the instructions are here -> clicky
If you are using a NA8 BP then this would be the easiest to drop into an NA6CE.

Les @ MX5 Shop

[davo5]

Why would you want a 1.6 inlet manifold on your BP head? Or did you mean the 1.6 throttle body?

Hmm I apologize, i swear i was browsing a book on google books where they swapped the whole manifold, but now i can only find books that suggest the throttle body adaptor. I must be on drugs.

So for ECU / fuel metering the 1.8 will just flow more air through the 1.6 AFM and the 1.6 ECU will compensate accordingly?

[mx52nv]

From page 1:

Regarding 1.8 BP conversions, I have some intimate knowledge regarding these. So let us say you bought the FM conversion kit, a low kilometre BP motor & was doing the work yourself - the only issue would be if your OEM ECM (factory computer) will be able to run the 1.8 injectors after 5,000 rpm.

A little more info discussed here -> clicky.

In short, it works for some but not for others.

Les @ MX5 Shop

[93_Clubman]

Hmm I apologize, i swear i was browsing a book on google books where they swapped the whole manifold, but now i can only find books that suggest the throttle body adaptor. I must be on drugs.

So for ECU / fuel metering the 1.8 will just flow more air through the 1.6 AFM and the 1.6 ECU will compensate accordingly?

you need to weld a bar across the bottom of the NA8 manifold to widen it pick up the studs if you want to use it on an NB8 head - it's the pic of this in Tanner's book that you're probably thinking of. the 1.6 manifold & head are shorter in length than the 1.8

[Matty]

The pic in Tanner's book is an NA8 manifold being adapted to fit on an NB8A head.

Bore spacing on the 1.6 vs 1.8 will prevent you from doing this (plus the injector mounts are different, etc)