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Mk1 Eunos 1.6 Project

27K views 183 replies 39 participants last post by  Zed.  
#1 · (Edited by Moderator)
Hello, this is my third MX5 after a break of a few years whilst I restored an old Karmann Ghia. I've had a mk2 & a mk3 but always fancied a red mk1 :)

It's a '91 Eunos Roadster which I picked up as a project car for myself to tinker with this winter. I'm hoping there's not too much major to address the sills and arches all look really solid, ironically this is the fifth car I viewed all of them a lot more expensive than this but all had signs of rot or bad previous repairs to the sills.

The vendor was a nice chap but didn't have much of a clue about the car so hadn't advertised any of the extras that I found when I viewed it.

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So far I've found it has an ARC chamber, stainless steel exhaust manifold and I believe the whole system (although it was a bit hard to tell in the mud!) a quickshift is fitted (which I hate), plus some sort of adjustable suspension (you can see dials on the bottom of the shocks) Aircon seems to work but time will tell, interior is a bit dirty but not ripped or torn, plus the vendor threw in the hardtop which is a little rough round the edges but a bonus.

The car hasn't had much use (or love) over the last year that the previous owner had it, but seems that owners prior to that have looked after it well.

Initial tasks are:

- A tappety engine turned out to be low oil which seems to have gone away by it topping up with oil and giving it an Italian tune once warm ;-)

- A few of the belts seem to intermittently squeal - so will work my way through replacing those

- General oil change, plugs, service etc.

- Unknown age of cambelt - plan to change this along with water pump, various gaskets, camshaft & crank seals etc

- There's a suspension rattle (quite a lot) but the steering & suspension seems to be quite taut so I suspect it's the ARB droplinks or similar - investigate &repair where needed

- Replace quickshift with normal one

- Paint - give the whole car a good mop to get rid of the classic red paint oxidisation

- Hood - seems sound but the rear has a loose flap that needs attention - if it doesn't leak I will leave it alone until the weather gets warmer then I will have a go at replacing if necessary

- Drivers door has slightly sagged so needs adjustment, ordered some of the solid door bushings to go on at the same time

- Front number plate plinth is cracked - may replace or even move to below the grill

- Replace stereo with something that doesn't have buttons the size of grains of sand and that I can actually read without having to pull over and squint at it. (honestly who designs aftermarket stereos these days? Makes me wonder if they have ever driven a car)

- Replace the naff 15" wheels and ditchfinder tyres with a set of Panasport 8-spoke wheels I have squirrelled away in the garage

- Fit front & rear lower chassis braces (need to check it doesn't have them first)

No doubt after getting to know the car in the next couple of weeks there's be more…
 
#27 ·
Lots of bits & bobs being addressed over the winter, ended up changing the entire exhaust system for a new manifold (MX5parts) plus silenced decat & Cobalt exhaust. It's still bedding in so the noise keeps on changing. Definitely think the manifold is noisier than the RS*R one though.

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Had a some grief around lining up the exhaust tip but think I've managed it through the use of Jubilee clips on the exhaust box hanger.
 
#28 · (Edited by Moderator)
This week's job is replacing the old radiator (pretty sure it's the original one judging by the stickers) and various hoses. Some of them had started to weep, the bottom rad hose was bulging alarmingly! and I had a leak from either the drivers side of the radiator or one of the hose underneath the manifold.

This seems to have been the culprit for the leak under the manifold. A previous owner had been running the engine without antifreeze so the rusty water had eaten away at some of the hose barbs. I cleaned this one up enough to put a new hose on it with a tighter jubilee clip than the previous OEM spring clip.

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Also took the chance to replace the thermostat housing gasket which had been weeping for a while (the cardboard was saturated when I removed it!) replaced with a new gasket coated with silicon gasket compound each side to try and prevent the same happening again.

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#29 ·
Added a 25mm spacer for the steering wheel made from a solid alloy block. It's quite nice as it uses the same bolt holes (just longer) and is machined so that it accepts the Momo horn button without needing the flimsy metal insert the standard mx5 boss uses. I found it on line at a Ferrari specialist http://www.superformance.co.uk/mondial/steering.html

Very happy with the results as it's really helped the driving position because I can now get my knees under the wheel as opposed to each side of it :)

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#30 · (Edited by Moderator)
New rad & water pipes fitted, not sure about the thermostat to inlet manifold sensor pipe in silicon though as it's much thicker outside diameter and rubs on the ARC chamber. Will be swapping it for an OEM one I think.

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#31 · (Edited by Moderator)
Managed to find an OEM R package boot spoiler thanks to another Nutz member jenkt :thumb-up: been keeping an eye out for one of these for a while. I'll give it a fresh coat of paint when the weather gets warmer.

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#35 · (Edited by Moderator)
This has been lurking in the depths of my garage for a few years left over from my old mk2 project. It's a Rota RB 15 x 7 in sliver (they don't sell them in that size/colour in the UK) I imported 5 from the US a few years ago. Not sure what to do with it now but would quite like to see if I can scrape together a set as the dish is much nicer than the Panasports I have on now, who knows...

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#36 · (Edited by Moderator)
Exhausts... got a bit of conundrum at the moment and I don't know what to do...

I've recently changed all three main components on the exhaust system and it's now too loud for my liking (also has quite a drone at low speeds) Interestingly it seems to have got louder after bedding in and a few heat cycles.

I used to run: RS*R 4:1 JDM manifold with new flexi section + OEM Cat + standard exhaust (this ran well but was pretty quiet)

It now runs: MX5parts 4:2:1 manifold + silenced decat pipe + Cobalt catback exhaust (too loud)

The reason I changed was it was very quiet and I like a little bit of sportyness out of the exhaust, plus the new flexi section had been welded in slightly over to one side so the cat was rubbing on the frame. Interestingly if I had fitted a decat pipe this is a lot narrower so shouldn't be an issue.

I still have all the parts, so I'm thinking of swapping a few around to see what difference it makes to the noise. The new manifold is definitely thinner than the RS*R and you can hear it has a slightly tinny sound in the engine bay when you rev the engine. If I fit the RS*R manifold back on will the flexi section make that much of a difference quietening the engine down over the current rigid 4:2:1 ?

My options I think are:

1) MX5parts 4:2:1 manifold + silenced decat pipe + Cobalt catback exhaust (current setup too loud & drones)

2) Just change the manifold to RS*R 4:1 manifold + silenced decat pipe + Cobalt catback exhaust

3) Add the old cat back on using: MX5parts 4:2:1 manifold + OEM cat + Cobalt catback exhaust

4) Use the RS*R manifold + decat pipe + with standard exhaust

Not sure what to try first but suspect I'll end up spending a lot of time on my back under the car :-(
 
#38 ·
Option #2 and then take a video :whistle:

Certainly use the RS-R manifold if you can.

Love the Rota's, good amount of dish.
The RS*R manifold seems to be made of a lot thicker steel than the MX5parts one! I never tried it with a silenced decat when it was on the car. Think I'm leaning towards substituting the silenced decat for the old cat first, if that doesn't work then option 4 - RS*R + decat + standard exhaust

And yes I love the Rota's - problem is I only have one of them!
 
#39 ·
Option #2 and then take a video :whistle:

Certainly use the RS-R manifold if you can.

Love the Rota's, good amount of dish.
The RS*R manifold seems to be made of a lot thicker steel than the MX5parts one! I never tried it with a silenced decat when it was on the car. Think I'm leaning towards substituting the silenced decat for the old cat first, if that doesn't work then option 4 - RS*R + decat + standard exhaust

And yes I love the Rota's - problem is I only have one of them!
Ah miss read that, I thought you had the whole set.

Well I've an RSR 4-1, standard cat and cobalt exhaust fitted at the minute, but I've not driven it yet as it's on ramps still. Doesn't seem too loud, could be a good place to start at least?
 
#40 ·
Unfortunately the RS*R has had the flexi section replaced in slightly the wrong angle which means it works with a narrow silenced decat but not a wider standard cat without rubbing on the powerplant frame.
 
#41 ·
4-1 manifold didn't really make any difference to the noise on mine. I'd say the biggest cause would be the decat, swap that out for a cat and keep the rest as is.
 
#42 ·
My setup is:

Standard manifold, Silenced de-cat (MX5parts), Cobalt cat-back.

It's hard to determine someone's idea of too loud, but for me this setup is pretty ideal. It is loud, but I don't think it's excessive. I didn't notice a huge difference to the volume after 'de-cating'.

I've been thinking of upgrading the manifold, but I'm not sure. If I do decide to go turbo I'd need to replace it again.
 
#43 ·
I replaced the cat last night and drove to work today, the volume has definitely gone down. The sound is great with the roof down but still drones a bit with the roof up so I'm going to keep it for a while like this and see if it mellows or grows on me. If it doesn't then the RS*R, decat & standard exhaust will go back on. Good job I hadn't got round to selling any of the parts!
 
#44 · (Edited by Moderator)
Today was good weather (ish) so I tackled machine polishing the bonnet for a second time to get rid of the dull finish & scratches that were still there after the last attempt about a year ago. Seems to have done the trick this time :)

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And after...

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Then onto the wheels, I managed to source some more suitable centre caps than the modern ones I had fitted to the Panasports. Moss sell them for their mini wheels, they are about 1/2mm too big where they clip in but with a bit of fettling with a file they seem to fit nicely. Got the vintage Mazda stickers from eBay rather than the modern Mazda logos.

These are the old ones:

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and the new ones...

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#45 · (Edited by Moderator)
Continuing a weekend of cosmetic work, I replaced the old Mazda badge on the back of the car, it was quite loose as it came off by just prizing it with my fingernails revealing two holes behind where I presume the old Eunos badge went. It looks like a previous owner wanted to remove any traces of it being an import as I swapped the modern Mazda badge on the front of the car for an original Eunos round 'V' one a while ago.

Anyway, I quite like the smooth look of the back of the car without badges on both sides so I decided to cover up the holes with a Roadster badge rather than a Eunos one (yes I know it should go on the left but there weren't any holes that needed covering on the left!) and I much prefer the script Roadster badge over the block writing 'EUNOS' one.

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Continuing the cosmetic theme I dug out some JDM car mats (that were lurking in the boot when I bought the car) from the depths of the garage gave them a thorough cleaning and they've come out quite nicely. They're not perfect but quite acceptable and I love the patina on the metal 'Roadster' badges on the mats.

Bit of a before & after, top mat before cleaning, bottom one after cleaning!

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#48 · (Edited by Moderator)
The car is looking very nice, the red came up a treat with the machine polish!
Cheers, the trick seems to be not to go too heavy, do it a couple of times cleaning the panel each time to check how it's going, then lay a couple of coats of wax down to protect it. And I remembered to mask off the windscreen , so all the black trim this time so it didn't get pink spots!

I've been looking for some eunos car mats...bit pricey on EBay...good work looking good! I'm get excited to get mine back and build it back up

Sent from my SM-N950F using Tapatalk
Considering they must be 20+ years old they seem to be very good quality thick mats so I suspect they were expensive when new
 
#49 ·
it's the coldest month of the year so what else to do but to try and sort out the non-working aircon! Not quite as daft as it sounds, the undertray is still off from replacing the radiator and the aircon people are not exactly busy in February so were more than happy to do a home visit at short notice & hopefully reasonable cost. Fingers crossed it's just a re-gas or a minor leak rather than something major...