Mx5 Rocketeer V6 Conversion Project

[Lewis's Friend]

shirt said:

Any progress on the engine? I’m considering the aj30 to power my race car but finding info and parts suppliers is proving difficult. Just wondered if you had a line on where to buy a full recon kit - all the seals etc?

No progress so far - I've concentrating on getting the car driving. But with that done, I should be able to turn my attention to it. So soon I hope.

[Lewis's Friend]

threespires said:

How much is needed for 2 doors?

I used a few offcuts and some new sheets, but I would say four of the 375x270 sheets would do it. Remembering you don't have to cover every inch of a panel.

[Lewis's Friend]

Another fairly minor update as I'm trying to get some miles on the car, get the brakes bedded in etc.

I had a very good chat with a guy at Wheels in Motion in Chesham about the steering/handling of the car as I'm not too happy with it. He was very informative and gave me a few things to check, mainly centred around ensuring the suspension bushes have not been caught and effectively preloading the bushes. This seems fine, so next will be a trip up to Chesham to let him have a look over it, though he suspects the suspension setup is very wrong for a lowered car. We shall see!

In other news, I managed to get my rear wheel centres sorted. Tarmac Sportz were very helpful in sourcing new ones (this post seems to be plugging companies, but praise where it us due!). Previously the rear drive shafts sat almost flush with the wheel centre opening, which I realised too late. So the new ones I hole-sawed before sticking the centre plate down.

Before (excuse the picture quality - this is a crop):

1 by Jon Fellows, on Flickr

Centre cut up:

IMG_20180622_060056 by Jon Fellows, on Flickr

And fitted with the centre plate in place (though not clean):

IMG_20180622_094211 by Jon Fellows, on Flickr

I'm much happier now - little details slowly getting done!

In other news I started stripping ancillaries off of the V6. This went surprisingly easily, even the exhaust manifold studs, which looked horribly crusty.

As it stood:

IMG_20180611_165910 by Jon Fellows, on Flickr

And after judicious application of a rattle gun and WD40...

IMG_20180614_170656 by Jon Fellows, on Flickr

IMG_20180614_170704 by Jon Fellows, on Flickr

And that's it for now. I'm not going any further with the engine until I get the kit instructions so I know exactly what bits I need to keep and what I can bin off... Getting there though!

[Lewis's Friend]

Updates have slowed for this somewhat now, but that's a good thing because I'm actually using it! So I'm happy about that, even if it makes for a boring thread.

I have been making some incremental improvements though. First up was to try and address the dodgy gear shift. Some of this will have to wait until I pull the gear box out as I suspect some of it is due to clutch issues and slave/master cylinder problems. However, the shifter often requires rebuilding, and can help with the feel of changing gears, so I bought a Moss rebuild kit.

Transmission tunnel trim removed revealed that I was correct in thinking a rebuild was required...!

IMG_20180625_111407 by Jon Fellows, on Flickr

There are not meant to be holes in the upper boot. Not visible in this photo is the fact that the lower boot had also disintegrated, meaning there was nothing stopping the (filthy) turret oil from slopping out of the top of the gearbox!

I removed the shifter, cleaned all the accumulated grot of ages off of it, and tapped a new nylon end cup onto it. It promptly cracked and so I had to order another. What an idiot...

IMG_20180625_123026 by Jon Fellows, on Flickr

I then gently pressed the new cup on, and all was well. Here is a rather unglamorous picture of some of the replaced parts, to try and give an idea of the sad state of the shifter before this work.

IMG_20180625_123033 by Jon Fellows, on Flickr

And back together, with new turret oil all topped up.

IMG_20180628_101847 by Jon Fellows, on Flickr

This has made a reasonable difference to the shift of the gearbox, but is still not ideal (probably for the reasons outlined above). So work to be done still, but pleased with the difference made.

When I ordered the new nylon cup, I also ordered some new matts for the car (because a restoration is not complete until new matts have been bought). Now I feel it is almost complete!

IMG_20180628_103027 by Jon Fellows, on Flickr

[Lewis's Friend]

Drew106 said:

You're lucky you didn't have this thread over on the Nutz forum, as it has just wiped all it's old threads! Still waiting to see if it's permanent. Lost my own Eunos project thread, after nearly 2 years of updates...

Wow, that sucks. I suppose that is a danger to all of these threads though - -either image hosting or the home website...

[Lewis's Friend]

Thanks for the kind comments, they're always appreciated.

The kit should be arriving very soon which is exciting. Pictures will be posted when it gets here!

[Lewis's Friend]

M4CK 1 said:

It looks like a great conversion. The guy on car throttle is doing the same conversion, although your mx5 is looking in much better condition. He went to Rocketeer on his you tube channel. https://youtu.be/pzc2eF-Dhvw.
How much is this conversion??

I very much enjoyed driving the demo car, and I'm getting there with sorting the handling on my car so I'm very excited to get a load more power in it now I'm starting to enjoy corners in it!

It's probably better to go on the rocketeer website for prices, as they do a couple of levels of kit, or a whole build. Mine is the full kit which is (almost) everything you need barring the base car and the V6, which is £7k. Not cheap, but I'm hoping (and expecting) it to be worth it. The kit seems properly engineered, whereas any of my efforts would be horribly amateur at best!

[Lewis's Friend]

A small general update. No pictures, but progress nevertheless.

I rolled my front arches, as I was catching the tyre occasionally up sudden compression. The same process as the rears, and now I have clearance.

I also took the car to Wheels in Motion to try and see why the handling felt rubbish. Essentially it comes down to the place I used to do the initial alignment being very poor at their jobs. Admittedly they said they would only align to factory settings, rather than the fast-road settings it's on now. But they didnt even do that right, with negative camber on one side and positive on the other. Total rip off, but at least it's done now and corners are fun again, rather than things to be tiptoed round wondering what was broken!

Little steps!

[Lewis's Friend]

Smokin Donut said:

Great read, thanks. I had one of these years ago, I cannot recommend enough a gearbox oil change to Redline MT90 (if not already done). This made a noticeable difference to the gear change which if in good nick should be one of the slickest of any car................period.

Enjoy, I loved mine and missed it................till I got the Elise!

Cheers for the feedback.

At the moment it has some Fuchs cheapest in it, as it'll all be coming out (probably over the drive) when I pull the gearbox for the engine swap.

After that I'll look at putting decent stuff in, probably Redline.

[Lewis's Friend]

A small but exciting update (for me at least)... The conversion kit has arrived. Most of it anyway - I'm still waiting for the exhaust manifolds and flywheel as there have been supplier issues, but I have the rest which will mean I can crack on with engine prep with a bit more purpose.

But first a random picture from out and about, just in case people forget what she looks like...

5 by Jon Fellows, on Flickr

But now, more interestingly perhaps, a living room full of bits

4 by Jon Fellows, on Flickr

I've been very impressed with the build quality of the bits so far. Obviously the proof is in the fitting/working, but first impressions are very good. A couple of pics of some parts for your delectation:

One inlet manifold.

3 by Jon Fellows, on Flickr

New cast sump.

2 by Jon Fellows, on Flickr

And finally the adaptor plate for engine and gearbox.

1 by Jon Fellows, on Flickr

I am most excited, and need to crack on. Now I need to drill the snapped exhaust stud out...

[Lewis's Friend]

AndrewEH1 said:

jumare said:

I've got a (rusty) MK1 and this would be very appealing but so does making the most of what there is a standard. I do wonder if using the rocketeer subframe with a standard engine would lose a lot of weight.

Good luck with the build.

You'd have to adjust the Rocketeer engine mounting points because they're designed for the Jag V6

You can buy tube subframes for a standard engine which lose a great deal of weight I understand, plus are meant to be stiffer.

I'm hoping to do a good job on the kit! Time will tell!

Edited by Lewis's Friend on Sunday 5th August 12:56

[Lewis's Friend]

V8RX7 said:

Lewis's Friend said:

You can buy tube subframes for a standard engine which lose a great deal of weight I understand, plus are meant to be stiffer.

They are certainly lighter weight.

It was some time ago but I seem to remember an engineer analysed them and pronounced them "crap"

Fair enough! Not something I've ever looked into I confess.

[Lewis's Friend]

shalmaneser said:

The quality of the parts does look excellent.

I'm amazed they're casting their own sumps - the investment that Rocketeer must have made in tooling will have been significant - I wouldn't have thought they'd have the sales volume to make the numbers work at first glance.

I think the original run of sumps were fabricated (might be wrong though). They seem to have a lot of interest in the kits still, so I guess investment is worth it.

As I say, so far I'm very impressed, and they seem to be trying to improve bits with each run as well.

[Lewis's Friend]

We'll, when it's done if anyone is itching to get in a V6 powered mx5, I might be persuaded to sell. I'm not an established speed shop, so won't ask top dollar. I might go as low as £35k to the right buyer...!

[Lewis's Friend]

Sway said:

Perhaps a little more work needed to get to that figure!

However, in principle I think it's a fair view - there's a huge amount of goodwill regarding the little miata, and a full ground up restoration and enhancement tailored to the UK market I think would do well - or at least well enough to make it worthwhile for a time.

If Flyin Miata can have 2 or 3 $50k+ v8 conversions in at any given time, then a UK designed variant (jag v6, Ohlins piggybacks, 4pot brakes, nice interior, modern infotainment, etc.) should be able to find some buyers as a luxury Caterham for an equivalent cost.

Back on topic though - any updates OP?

I could see it too, but it would have to be a very good restoration as you say, and I suspect they need to get a bit older before they fall into a more classic band in people's mind.

Working against them is that even now they are very common. Vast swathes have been lost to rust and other factors, but there are still huge amounts out there. But over time, excellent condition ones will start to command a premium (though how much that might be I have no idea)!

In terms of my car, holidays and a new boiler at home have stopped progress for a while. Hopefully there will be some updates fairly soon. I'm about to start painting the engine, because I'm a tart, which will then mean I can start to dress it up ready for fitting; though that won't be in the immediate future.

Thanks for the continued interest in it though!

[Lewis's Friend]

Another update on the MX5. Not V6 related yet sadly, but that will be coming soon now I hope.

Since I've had the car, the steering has felt rubbish. I have had suspension alignments done and it helped the overall handling and feel of the car, but the steering itself still felt odd. The best way I can describe it is that when going round a large roundabout as you began to accelerate and the steering wheel loaded up it would almost feel as though it was pulsing in your hands. Not enough to deflect you from your driving line, but disconcerting and not conducive to quick or fun driving.

So I thought I would try depowering the steering. This is a slightly controversial mod as some people swear by the increased steering feel and say it is not too heavy while others think you are mad for deleting PAS. I read around the subject and came to no definite conclusions, so thought I would give it a go. The reason for trying it is that I wanted to make sure it was the PAS causing the strange steering feel, and so by deleting it completely I could eliminate it as a cause, and because my TVR was non-assisted and I loved it.

I bought a second hand rack, and stripped it. There are various ways of depowering, such as looping the fluid lines, but this tends to make the steering heavier than it needs to be as you are still moving hydraulic fluid around. A more complete (but irreversible method) is something like the 'Flyin Miata' guide.

After stripping the rack, there are basically two things that need to be done. Firstly, the internal piston needs to be turned down so that when the fluid lines a plugged, the piston is not trying to compress any air. Thus:

IMG_20180815_082158 by Jon Fellows, on Flickr

The next step is to take the pinion shaft, and weld a spline up. If this is not done, the spline can introduce to play into the steering (normally the high pressure fluid takes up this movement if I have understood it correctly). So a buddy at work who is good at such things welded it for me:

IMG_20180817_132438 by Jon Fellows, on Flickr

The rack is then reassembled with suitable lubricant, the fluid lines plugged and the pre-load on the pinion set up.

IMG_20180901_103523 by Jon Fellows, on Flickr

Until the rack is done. The tart in me also insisted on painting and cleaning the rack, and I took the opportunity to put new boots on as well.

IMG_20180901_121536 by Jon Fellows, on Flickr

IMG_20180901_121523 by Jon Fellows, on Flickr

Obviously you then have to remove the old rack. This was a filthy job, but I got there eventually, and I didn't even cut the hoses; tempted though I was at various stages throughout the removal!

IMG_20180827_130930 by Jon Fellows, on Flickr

It was then a case of fitting the new rack, having measured track rod end positions etc to get the steering near where it should be in terms of geo. I also centred the steering wheel using the very newest technology...!

IMG_20180901_125803 by Jon Fellows, on Flickr

And fitted:

IMG_20180901_135805 by Jon Fellows, on Flickr

So, was this a massive success? Does much glory accrue to me?
Having driven it, the steering is too heavy for me for road use. I can see how it would be great for a more track focussed car, but for (almost) everyday use it has a little too much heft. This is not helped by the fact that my physique suggests more of a poisoner than a fighter... However, success was had in that the weird pulsing was gone. So definitely an issue with the PAS (if I had to guess from the depths of my ignorance I would say the gating valves for the PAS fluid in the rack are letting by), which I wanted to diagnose before carrying out the V6 swap. So a successful diagnosis, and I've never taken a steering rack apart before so I learned too!

Next step, back to the V6...!

[Lewis's Friend]

TwoStrokeNut said:

Try it on 185 section front tyres, as were fitted to the car originally. MX5s steer the best on original sized rubber which still has plenty of grip with modern compounds. With much wider front wheels / tyres, manual steering is going to be a chore.

You're quite right, that has probably not helped. I'm happy enough to use the PAS though, as long as it's working ok. I'm happy enough to have identified the problem area, and I've spoken to a rebuild company who I may get to look at it (second hand racks are cheap enough, but I'd be very sad to fit one and find it has a similar issue. Hence debating a rebuild).

The perform with smaller wheels at the front is finding staggered wheels and tyres in the right sizes. Particularly as I want a bit more rubber at the back to handle the additional power.

[Lewis's Friend]

WinstonWolf said:

That's bloody genius, I'll pinch that when I replace the rack on the TVR

It got it near enough, but would still need tracking doing!

[Lewis's Friend]

WinstonWolf said:

Lewis's Friend said:

WinstonWolf said:

That's bloody genius, I'll pinch that when I replace the rack on the TVR

It got it near enough, but would still need tracking doing!

Mine went to Centre of Gravity, cost about £400 but worth every penny. Then the rack started leaking again

If it makes you feel better, I spent £300 at a local place, who totally messed it up. So then I spent another £120 getting it done right by competent people!

[Lewis's Friend]

Most places I've seen charge by the amount of adjustments needed. When you set your whole suspension to the middle settings, it tends to take a while to get it right!