DIY V6 MX5 conversion

[GR1FF]

Hi all - as per the title I'm looking at the feasibility of doing a V6 conversion to my MX5 - for all the right reasons!

I've seen the Rocketeer kit which seems great, but I can't afford it.

So I'm thinking of DIYing it and have a couple of questions from anyone with knowledge/experience of these things.

Firstly - I assume the original (Mk1) subframe can't easily be modified to take a (Jag) V6 unit - otherwise that would be the obvious route?

Second - Assuming the answer is no, how difficult would it be to modify an 'off the self' replacement subframe e.g. from crapengineering?

Thanks in advance!

Edited by GR1FF on Thursday 21st January 08:47

Edited by GR1FF on Thursday 21st January 15:45

[VladD]

Unless you can fabricate your own subframe, I'd say in the long run it would be cheaper to buy one that's already been created for the engine you want to use. Of course, if you copy someone else's conversion you'll also avoid all of the problems that they encountered when they developed their solution. There will be loom issues, component issues etc. to deal with, so unless you really want to go on a journey of exploration and problems it might be best just finding the cheapest solution out there that someone else has done like, as you say, crapengineering.

[GR1FF]

Thanks VladD - I've no ambition to make my own, the question was more about modifying the original v fitting a replacement engineered version. Trying to establish whether modifying the exisiting one is possible or not - perhaps there's simply not the clearance for an install of an engine the size/shape of the AJ30?

[GravelBen]

IIRC the Mazda KL-ZE V6 can fit with a modified original subframe, but it was a few years ago that I looked into it.

[GR1FF]

It would seem whatever V6 you want to put in, a replacement subframe is the way most people go...

The Mazda KLV6 doesn't appeal over the AJ30 engine - the latter seems pretty much the most powerful (in standard trim) and is fairly lightweight too.

[GravelBen]

Funny enough from some quick research it appears the AJV6 is actually a development of the KLZE anyway, so probably the same fitment issues either way.

[GR1FF]

Wasn’t aware of that - I’ve read about it’s Porsche and Cosworth connections though.

[Graham The Bruce]

GravelBen said:

Funny enough from some quick research it appears the AJV6 is actually a development of the KLZE anyway, so probably the same fitment issues either way.

The AJV6 is not related or derived from the KL ZE in any way shape or form.
The AJV6 was derived from a blank sheet Porsche project that was then sold to Ford, who with the help of Cosworth developed it into what it became.

You're right that the KL ZE was first though.

[GravelBen]

Interesting - I found a few websites saying that the AJ was developed from the Duratec V6, which Ford developed from the Mazda KL (a few other duratec engines are Mazda engines too, as well as car platforms that were sold under both brands). Maybe it was just people making assumptions because of the Ford link.

Edited by GravelBen on Friday 29th January 08:41

[Graham The Bruce]

GravelBen said:

Interesting - I found a few websites saying that the AJ was developed from the Duratec V6, which Ford developed from the Mazda KL (a few other duratec engines are Mazda engines too, as well as car platforms that were sold under both brands). Maybe it was just people making assumptions because of the Ford link.

Edited by GravelBen on Friday 29th January 08:41

I think so, as it's widely known that the AJV6 was a Porsche design that was sold to Ford. It was not a Porsche design taken from Mazda.
Ford then, with Cosworth, developed it into the AJV6 (with VVT) and the Duratec V6.
Re Mazda, the Duratec V6 replaced the KL, but they're unrelated.

As a side note and unrelated really, I recall that the Mondeo Super Touring BTCC cars from back in the day used the Mazda derived KL, and were allowed to do so as it was in their Probe so within the extended range of cars and within the rules. Mazda ran the same engines in the Xedos BTCC cars as well.

[GR1FF]

Yep - there's a lot of cross-pollination between Mazda and Ford with regard to engine use, but as has been pointed out, the AJ30 version of the Jaguar AJ-V6 engine is based on Ford's 'Duratec 30' 3.0 V6 - developed by Cosworth, which in turn was a Porsche design originally. So not related to the Mazda KL series of V6 engines...



BTTT - anyone got any experience in this kinda work?

Edited by GR1FF on Friday 29th January 13:46

[griffdude]

Take a look at https://crapengineering.weebly.com/

[GR1FF]

Thanks - I mentioned them at the top - looks like that might be the way to go.

[magpies]

Hi GRIFF
are you still NE based or have you moved?
I have fitted the AJ30 to my TVR S1 and have just started the same conversion to another.
We are located in Teesside if you wish to pop over and we can discuss.

[magpies]

You said----
Firstly - I assume the original (Mk1) subframe can't easily be modified to take a (Jag) V6 unit - otherwise that would be the obvious route?

Crapengineering sell their front subframes which take the V6 - They do them with or without the engine mounts too.

Jut to note: the Jag gearbox is a direct top (5th) so is like driving everywhere in 4th, but with a 7500 rev limit (some take it to 8k) still gives a reasonable top speed.