Jason Exocet type G build thread

[jason82]

I decided to rebuild my clutch master cylinder while its off the car as its easier to do it now, rather than take the car apart at a later date. I have also replaced the clutch slave cylinder with a complete new unit & a shiny BF Goodridge stainless flexible clutch line.

So I purchased a genuine Mazda clutch master cylinder rebuild kit from Autolink on ebay, item number 160596754730 for £20.77 including vat & delivery (I will be rebuilding the brake master cylinder at some point in the next week or two aswell as its quite easy). My clutch master cylinder was really grotty, so I got a wire wheel in the cordless drill & gave it a good clean up. Before you strip the master cylinder, get some old rags, cotton wool buds & some new clutch fluid (just a tiny bit to lubricate the new seals prior to installation), this does get a little messy.

Firstly you need to remove the circlip in the end of master cylinder, but don't worry, the spring wont shoot out ! You then need to get a small flat screwdriver & very carefully prize the plastic plunger out of the bore, go very careful not to scratch the clutch master cylinder bore.

When it comes out, it will have a very small circle of polythene on the plunger, remove that, then there is a rubber seal. Pull the seal out gently with the screwdriver, then tip the master cylinder on its edge to get the spring to fall out.

I then gave the master cylinder bore & reservoir internals a good clean up with some cotton wool buds. Get the new service kit ready, firstly the new spring goes in - wide end first. Then put new clutch fluid over the cap type seal to lubricate it & slide it in, dish side of the seal goes in first, and push it all the way back over the end of the spring. Then put clutch fluid on the the plastic plunger, the new plastic circle will then stick to the flat edge of the plunger (if you put clutch fluid on it), then slide it into the bore, plastic circle first, followed by flat edge of the plunger. Just double check that the end of the plastic plunger with the recess in it is facing out towards you, then put the screwdriver inside the plastic plunger & push it in until it clicks, allowing you to put the new circlip in. Then just use the screwdriver to press the plunger in a few times making sure that it operates smoothly without snagging on anything.

 I then gave my clutch master cylinder a quick lick of black paint, I know that the reservoir is really crappy, but I am not going to buy a new one when this is perfectly usable.

[jason82]

Update time, its been a while, the build has kind of come to an un expected stop, so I have decided to do an update.

The floors

The aluminium floors have been cut for quite a while now, but I had not installed them until recently due to finding the time to get the floors vinyl wrapped & getting the chassis mocked up onto the sub frames. Vinyl can be quite expensive, you need a vinyl 600mm wide to fit  the passenger side floor, unless you want to make a join. I settled on a company called www.plusbee.com, tel : [phone] or email: [e-mail] . I purchased 4 rolls of 3d carbon fibre, 600mm wide x 3m for £20 including postage. I know that its not as cool as 4d, 5d or 6d carbon fibre, but who is going to be looking that closely at a floor ?

  A bit of a warning, this stuff creates a ton of static & draws in anything in close proximaty ! Its a 2 person job, 1 person needs to keep the roll of vinyl taught & at an angle & the other one, needs to roll back the backing a bit while sticking it down. With this brand of vinyl, you peel the back off and stick it straight down, no soapy water etc like we used to do when we used to tint the windows in our Nova 1.3 SR's (ah, the fun days ! ).  The first method I tried was using my debit card as an air bubble removal tool, this created a really crappy job, so I peeled it back off, wasting the piece. What worked really well for me was using my hand, & rubbing it sideways across the vinyl, only laying about 2 inches at a time. I know that this is really time consuming, but the finish was well worth it !

  I was really happy with this vinyl, I dropped a spanner on it & it didn't even mark it.

The floors were installed with a thin bead of tiger seal around the outside & on the cross rails. I did not pop rivet the cross rails as my seat frame mounting bolts will be going through these cross members. I applied a load of pressure in this area to get the floor to securely bond to it.

  The seat mounting is really worrying me to be honest. Its thin wall box section, which I am drilling a 9mm hole through to take an M8 bolt. I have thought long & hard about this, & believe that the best way to mount the seats is to use a solid piece of mild steel bar, around 20mm ( I know that this will completely cut the cross member), drill a 20mm hole in the cross members where the seat mount bolts will pass through, then completely weld in the bar, drilling a 9mm hole in it to finish. This way you are putting strength into the cross beam rather than removing it. I know that seats have flat bar which crosses the two cross members, linking them, but still the entire assembly is being held in by a bit of thin walled box section, not ideal if you crash.

   From memory, the box section is 19 or 20mm square, minus the 9mm hole that you put into each tube twice, then the thin wall tube. It does not feel safe to me. To do this method, obviously the powder coating takes another hit. I am really regretting buying a powder coated chassis, I have had to remove it in various places for modifications which I believe need to be made to make things a bit more substantial. The rear chassis also had work done to it around where the fuel tank is located, because I was unhappy with the arrangement. I will put photos up with a description of work done in a later post, as the photo is on my proper camera, which I have lost the lead to.

  To finish off the installation of the floor, I run a bead of tiger seal down where the gearbox tunnel joins the chassis rails. Maybe its a defect on only my chassis, but the tunnel is joined on my 2018 g type chassis with limited runs of weld, leaving gaps where you can see the floor, obviously not ideal for water ingress etc. My Tiger seal is black, matching the chassis, so no problem ( I understand why it was welded in short bursts, to minimize distortion, but surely once the weld has cooled you could complete the weld ? )

 Oh, forgot to mention, with the floor all sealed in beautifully, when it rains its going to fill up like a bath. So I used a 20mm holesaw, put a hole in each sealed section & popped in a 20mm blind grommet, which can be removed to let the water out. Grommets are pennies & a holesaw is a fiver from ebay. It works brilliantly !

As you can see, its hardly recognisable & is really practical. (Please excuse the blue effect on the photo, picture was taken under a blue tarp).

  Originally, I wanted to do some bead rolling on the floors, in an x shape, with the 20mm hole in the middle where the bead lines cross to aid water drainage. Obviously I would do 3 sections in each floor as the cross beams split up the floor from being one complete piece. It would add extra strength to the floor, would be a bit tricky to vinyl wrap, but it would be even more practical. I have not ran with this idea as I do not have a bead roller, & using a company to bring my creation to life was a bit more than what I wanted to spend. But hey, if you own a bead roller yourself, it will look really trick ! Maybe I will do this on my Riot 3 which I am desperately trying to pre order.

[jason82]

Radiator mounts

There is nothing in the build manual regarding fitting these. I mocked it up ages ago & realised that you need to mount the brackets as low down on the uprights as possible, because the top hose on the mk1 1.8 radiator fouls on the top cross bar. Please remember that you will need to slide the hose onto the rad & the radiator clip aswell, its a real tight fit !

  I done this job back in june or july, but I have realised that nobody has covered it in their build threads. To mock it up, I had my son hold the bonnet in place, then bolted the radiator to the mounts & got under the car to mock it up exactly as it needs to fit. Even with the brackets as low down as possible, they still need to drop a bit to make things a bit better.

 I drilled both uprights, and used rivnuts to take the 3 x M6 bolts on each bracket, to secure it nice and tight. Packers are require between the uprights & the radiator brackets, as the radiator is narrower (mk1 rad) than the front frame. Yes, the manufacturer supplied rad brackets are thin enough to bend into a curve so that you do not need to pack it, but I am not happy with that.

You can get rivnuts into the upright section really easy, then you can see how low I needed to get the radiator brackets to make everything work with the top radiator hose. I have no real need to buy one of the memfast rivnut kits. They cost just over £100 for a set, & to be honest, I will only ever use M6 threaded inserts anyway, so I bought one of these from ebay & they worked like a dream ! Slightly fiddly when used verticly, but they are cheap & work well.

www.ebay.co.uk/itm/M6-Heavy-Duty-High-Tensile-12-9-Rivnut-Rivet-Nut-Nutsert-Tool/123386908317?hash=item1cba6ece9d:g:b5MAAOSwJP1Zx8YM:rk:6:pf:0

I have used it loads of times & love it. I hope that this is of use to someone.

Here is the the mk1 radiator bracket plans:
mevowners.proboards.com/attachment/download/892

[jason82]

MX5 front upper ball joint replacement.

For this job you need an hydraulic press & a circlip pliers. To remove the old balljoint, turn the front upper wishbone upside down, make sure that you support the arm all of the way around underneath, except for the ball joint otherwise you will bend the wishbone. I then used a 32mm impact socket, sat it on the ball joint (threaded side) & pressed it out, It comes out fairly easy. Then if you are a mk1 lad you need one of these :

www.mx5parts.co.uk/front-upper-ball-joint-motorsport-mk1-p-4028.html?gclid=EAIaIQobChMI5vbVwP-F3gIVGeJ3Ch1oCwe3EAAYASAAEgJnuvD_BwE

If you have a mk2 :

www.mx5parts.co.uk/front-upper-ball-joint-motorsport-mk2-25-p-4099.html

They are identical to the Moog ones, but available here in the uk. The mk1 balljoints have a grease nipple in the top & the mk2's do not have a grease nipple. I have measured both MK1 & MK2 front upper wishbones & they have identical dimensions where the ball joints press into, so maybe if you have a mk2, buy the mk1 balljoint, this way you can service the ball joint. But please check that the actual thread itself is the same, depth etc as I do not have a mk2 front hub to do a dimension check on.

  So after my wishbones have been blasted, powder coated & had the banana fitted (I used M10 bolts for this, as they are a better fit than the M8 bolts that the build manual suggest & they will take more stick).

This is what you get in the kit :

 So put the wishbone in its correct orientation, then support everything underneath the wishbone apart from where the ball joint will be coming through.

Then I got a 32mm impact socket, then sat it on top of the new ball joint, then pressed it in. CAUTION !!!!!!! make sure that the ball joint gets pushed in completely square. In this picture I never put a rag between the socket & ball joint. I did on the second one after I put a mark in the ball joint (only a cosmetic scratch, but still irritating).

 

Then flip the wishbone over after the ball joint has been correctly seated. Now there is a thick groove right at the base of the ball joint, close to the wishbone, pop the circlip in here. It will spin freely, but I have been assured by MX5 parts that this is correct.

 

Then take the spring off the rubber boot & fill the boot with the enclosed grease.....

 

Slide the boot over the ball joint, making sure that the bottom of the boot goes completely over the ball joint housing, like in the picture.....

 

Then put the spring on. Do not use a screwdriver in the hope of flicking it on otherwise you may wrip the boot. I found the best way was to uncoil the spring slightly & kind of feed it down the boot until it seats in its correct location.

(There is a groove in the bottom of the boot, this is where the spring should live, once its been correctly pulled over the boot).

 

I temporarily put the castle nut on, put the split pin in & opened it slightly so that I do not loose any parts.

 

Once you have done this, flip the wishbone back over & screw in the grease nipple. I used a pliers to do it up slightly over hand tight, then used a grease gun to grease the nipple.

[jason82]

UPDATE !!!!!!!!!!!!

I have just managed to get my hands on a mk2 front hub & after comparing the Mk1 & MK2 front hubs together, I can confirm that even though the taper is correct, the mk1 front upper ball joint will not fit a mk 2 hub. The mk1 hub where the upper ball joint fixes to is thinner than that of a mk2, meaning that the thread in the mk1 front upper ball joint is not long enough to go through the mk2 hub & secure safely.

Mk1 Hub

Mk2 Hub

I have tried putting the mk1 front  upper arm into the mk2 hub, but there is not enough thread  for the castle nut to go onto & have the split pin locate, a nyloc will not fit either. So your option is either stick to the balljoint with no grease nipple or try & track down the Moog part in America. IL Motorsport the manufacturer of these parts sold by MX5 parts, do not offer the grease nipple on MK2 ball joints at all.

  There you go, a definitive answer.

[jason82]

I had a bit of trouble with my lazy tongue pop rivet gun that I purchased from ebay while trying to rivet my floors. Obviously as soon as you put the bead of Tigerseal on the chassis & drop the aluminium floor on, time is ticking before the adhesive sets. I kept having the gun jam every three or four rivets, my little back up riveter decided to let go aswell, so the only option was to strip the gun down quickly every time it jammed. I did not know how to do this originally, but racing against the clock & living in the sticks I had no option but to get stuck in. If you know how to do this, I am sorry, but if like me you don't, I hope that this helps !

I think that all of the lazy tongue rivet guns use the same set up.

Grab the black end of the gun as if it was a drill & unscrew it, leaving the nut in its location as the gun is sennsative to this being done up in different positions. You are then left with this ....

 

Unscrew this from the body

 

Then unscrew the end cap (where the rivets slide into) & gently pull it apart to stop the spring from shooting across the room.

 

Looking in the end of the cap reveals the culprit, a bit of pop rivet stuck in the jaws....

So I tapped the cap out on the worktop revealing 3 tapered jaws & the bit of rivet that was jamming it.

 

Putting the tapered jaws back in can be a bit fiddly, but once they are all in, tip the cup on its end with the narrow opening at the bottom, then get all of the jaws equal lengths, this is important.

 

 

Then re assemble. No spanners are required (on mine anyway), everything was just done up hand tight. Hopefully this will help someone, this job becomes a lot easier the more times that you do it. I was really anxious throughout fitting the floors, the thought of the Tiger seal going off on my freshly wrapped floors without being properly riveted to the chassis was too much. In the end, everything worked out perfectly. Don't bother with a small hand held gun, I had really bad blisters when I done my Haynes Roadster using one, they are ok for the odd rivet, but when you are riveting every 100mm your hands take a real bashing.

[jason82]

MX5 mk1 1,8 engine strip & inspection

A bit of background information on the car, its the original 1.8 mk1 mx5 engine, with BPO5-7-1 cylinder head & 97,000 miles on the clock. Due to its structural integrity, the test drive was very brief. My initial intention was just a new clutch kit, timing belt kit & a general thorough service. The rear cas ring was leaking, so the intention was a new one of those & a new rocker gasket.

  As I have a nice sized man cave I decided ages ago to buy an engine stand, get it mounted & then do my bits. I had to remove the clutch, flywheel & engine plate for it to fit onto my engine stand. I then gave every nut & bolt a really good soak with WD40.

  The inlet manifold came off really easy, using a 12mm socket to remove it from the head, the exhaust manifold was a little more tricky, I used a 14mm socket  & they were rusted on quite badly. I then removed my injector rail which was held on by 3 bolts needing a 14mm spanner to remove, once the bolts are out just pull it clear. There will be 4 tiny seal stuck in the cylinder head. MX5parts do an injector rebuild kit, which at the time I thought that I would do, it was not on the 'to do list', but it made sense while it was all apart.

 I then wanted to try & mock up some kind of heater matrix by pass pipe. This was really easy, I used the two original pipes that went from the engine to the matrix, cut them up & joined them with a beaded, aluminium tube with a 19mm o.d pipe which I bought off ebay for £2.65. I bought a 60mm long connector, it fitted perfectly, but if I had to buy another one, I would get one slightly longer. The beaded ends are really important, as it helps to keep the pipe on the connector when the system is pressurised, finished off with 2 stainless jubilee clips.

I then took the pipe back off & put it in a storage box for engine re assembly. I then removed the altenator & power steering pump. Once you have removed the bolts just for the power steering pump, you will need to wriggle the pump like mad to get it to release from the bracket. The bracket for the power steering pump is a bitch to remove. The top two bolts came out easily, but you cant get a spanner on the bottom bolt.

So to remove it, push down on the nose of the power steering bracket, then push it back up, this releases the tension on the bolt, & you can unscrew the bolt by hand. Its complicated to explain how the bracket stops you from removing the bottom bolt, but if you physically look at it, you will know exactly what I mean.

Every bolt that holded the plastic timing belt cover snapped off, which was a good start , so new inserts it is then ! I got the timing set up perfectly, then slipped off the timing belt. Then I had to release the crankshaft pulley. I bought a really nice looking JAP motorsports crankshaft locking tool from the interweb......

Its a little dirty in this pic, but not bad for £25. Unfortunatley, this is where my in experience bit me ! The tool can only be used once the crankshaft pulley has been removed as it wont fit over the pulley. I had to get creative to lock the crank, so I put a 19mm spanner onto one of the flywheel bolts, then put a deep 21mm socket onto the crankshaft pulley bolt. I used a torque wrench for leverage &  the crank bolt came out lovely. (On my car the 4 x 10mm socket bolts, once removed, did not release the pulley). The pulley would not come off straight away, I had to get a rubber mallet & give it light taps at 12 oclock, 6 o clock, 3 o clock & 9 o clock, until it released.

Check the woodruff key, they should be a real tight fit. They have been known to fail, my one was perfect, but as a new one was only £3, its piece of mind. I took the water pump off aswell as a new one comes in the MX5 Heaven kit. At this point everything was going to plan, no issues, I am happy. I removed my rocker cover ready to do the cas o ring seal & rocker gasket & was hit by a horrible burning oil smell, bugger, that's now the head off to do the valve seals ! This was not in the plan or in the budget ! So I got my 12mm, 12 sided socket & started to remove the head bolts, gave the head a gentle tap & it released. The inlet valves were absolutely caked up in black crap, inlets were covered in a nice light colour.

I rotated the crank a few times just to check the cylinder walls as they were clearly visible. At a really quick glance, all four cylinders have very clear hatching, which is brilliant, but if you look really closely, cylinders 2 & 3 above have dark vertical marks in them, all the way around. There is no scratches or pick up on the walls, they are perfect, just with discolouring. So now things are starting to get a little serious, I then decided to drop a clock on the crank to measure crank end float & had another surprise, too much end float. Haynes manual suggests the standard endfloat between 0.080mm to 0.282mm, with the service limit being 0.3mm. So I really am at the ragged edge, but I hope that my thrust washer is worn. The Haynes limit is between 2.50mm to 2.55mm (nominal), So its scary times.

 

My head & block are due to go to a race engine builders to get a head skim & have an inspection on the block, crank etc etc. The trouble is, race season is still active, & they are absolutely rammed, so all I can do is wait my turn. As things are this far broken down, As a minimum I will pop a new oil pump onto the engine, get the head & block skimmed & new piston rings along with a cylinder hone. But the devil inside me is saying if things can be easily repaired, fit race spec con rods, main bearings, big end bearings, crank grind & a turbo installation. If they say that the engine is scrapped, then I have already started looking for either an impreza engine (second hand) or buy a brand new 2l Zetec from kit spares, whichever makes more financial sense. I can always sell on the brand new clutch kit, head gasket set & cam belt kit, along with the K & N 57i kit. I am not bothered about a Q plate, I want reliability.

[jason82]

Stripping the head ready for machining

Ignore the two allen key studs in the middle of the block, I don't know why they are there ? Anyway, start removing the inlet & exhaust cam caps, I partly released the tension on each cap, working diagonally on each cam, before completely removing the caps. Keep them in order, its important ! When you do the exhaust cam, the cas system needs unbolting from the rear of the exhaust cam to get the cam to come out (there are a few pipes around the area, I may be missing a step, just check your Haynes book for the correct procedure. Pull the hydraulic lifters out, keep them in order, then we are ready for the valve removal. I had a crappy old Clarke one for years that clamp down, then I thought that I would treat myself to one of these from Amazon ....

A brilliant bit of kit ! I removed the valves, really easily, but remember to keep them in order, also order grinding paste as you will need to lap the valves back in on re assembly. My valves were disgusting ! So I put them in a drill, and span them up rubbing them first with 80 grit sand paper, then 240 I think it was to remove the crap on them. I could have polished them up properly, but its pointless. I would like to add that before I cleaned the valves up, I checked them for damage & even though the Mazda engine is not contact, I still checked that the valves are straight. With the valves in the drill, I also sanded the shaft of the valve aswell because there was some build up on them.

Please ignore the markings on my make shift valve stand, like a doughnut I marked both boxes with an I and then the valve number. Just aswell inlet & exhaust manifolds are different sizes hey ?

Cylinder head almost ready for the machine shop....

One thing that I forgot to mention in previous posts, while preparing the block for painting, I noticed this beautiful hole just under where the altenator bolts up to. Luckily its out of harms way.

Just because your engine runs and drives, please don't think that all is well with the engine. This is the best time for you to do some simple checks that could save you a lot of hassle in the future. Just because you have the fastest build, don't neglect the heart of the project.  I believe that a lot of my engine problems have been down to bad service schedules, abuse & maybe out of site out of mind with some things. I have previously mentioned if this unit is beyond economical salvage, I will switch to either Ford or Subaru power, use a bell housing adaptor & run the Mazda drive line. I have spoken to quite a few people who drift these, & they say the drive line in good for around 300bhp. But I really want to keep the Mazda power plant as it is all original, but we will see.

  A quick tip for cleaning up the aluminium oxide off the rocker cover & associated parts, quite simply use a washing up scowerer. It is really gentle on the parts & does a fantastic job !

 



The rocker cover also came up nice, for more stubborn areas use a brass wire brush. These surfaces are going to get painted with ceramic paint, so this method works brilliant to get it ready for paint.

Oh, finally, if this engine is going to be salvageable, I will be porting the head. There is a lot of material that can be cleaned up to help increase bhp. I have been told to leave the inlet ports very slightly rough, to get the incoming air more turbulent & the exhaust ports need to be smooth. I will do this with various gritted grinding stones / flap wheels. The original exhaust manifold itself could also do with a bit of a polish.

[jason82]

Its been a very hectic couple of days with researching things to do with my engine conundrum. None of which are cheap, but at least now I know exactly what options are available to me.

1) Impreza unit. These engines are really cheap, obviously wider than the Mazda lump, but I can not find anyone that manufactures Impreza to MX5 gearbox adaptors. I have had a chat with a few Mazda tuners, the gearbox would take the power as long as the engine is in standard tune. So this is a no go.

2) Ford crate engine. This has been done before, engine is just over 1k, adaptor plates for zetec to mx5 gearboxes are available from Retroford, but only for the MX5 mk3 gearbox. So it may be cheaper to grab a 5 speed type 9 gearbox & prop, then get the back half of my MX5 prop welded to the nose of the Ford type 9 prop, or get an MX5 mk3 gearbox & as before, graft the props. Kitspares sell the 2.0 Zetec crate engine & will do the prop conversion, I will need to make new mounts, alter wiring, get ecu & radiator etc etc. So we are talking 2k maximum, this is firm quotes. I believe that the Zetec is taller, so significant work will need to be done to the front subframe.

3) RX8 engine, not really an option due to rotor wear fears & the gearbox is different.

4) Rebuild if possible my 1.8 MX5 engine. No way in the world am I buying a second hand engine, I could end up with another lemon. The engine is being dropped off at the builders on Thursday for an assessment, so I will update the thread if anyone is interested with the out come.

Here is what I found with my engine.

Remove the 18 x 10mm headed bolts around the sump, If you are using an engine stand like me, you will need to get a little creative because of the mounting holes. Be careful when you start to pull the sump off, the oil splash tray may stick to the sump, & as it is bolted to the block, you may bend it.

Then you remove the 3 nuts & bolts - 10mm socket

 

Leaving you with a nice view of the crank.

I removed the first conrod cap & found that it was shot ( the other 3 were the same). Remember to keep the caps in their correct orientation when you bolt them back to the conrod cap once the piston has been removed.

 

Even though the oil was drained from the sump, with the engine turned upside down, some oil remained inside the pistons. Once the conrod end cap was remove, I gave them a good push & then pulled them out of the other end of the block. If the pistons are being re used, number them, does not matter how, as long as you know where they go. I personally call piston 1, the piston closest to the crank, then 2 etc etc. 

 

As you can see from the picture above, these pistons are now going to become desk art. Unlike the cylinder walls, the marks in the pistons are actually deep scrapes. My idea of what has happened is down to oil starvation & the engine partially seizing, ally pistons are softer than the cast block, hence the marks. I am not sure, I am not a mechanic, but given the smell of the oil when draining the sump, it had been a while since the last oil change, maybe the damage could be down to using the wrong oil for the engine or cheap oil ? I don't know, & wont know until a professional looks at it.  

I mentioned excess endfloat on the crank previously, I know that some mx5 engines suffered thrust washer failure causing them to fall out & the crank to grind on the block, but I was good on this. The thrust washers are located on the main bearing cap 4, so from the crank, count back 4 main crank caps & you will hopefully see these little fellas being pointed at  by the yellow arrows. Haynes manual say that on the mk1 1.8, the thrust washer thickness should be between 2.5mm & 2.55mm nominal. So for me, they are badly worn, out of spec, so if my maths is right, replacing these should correct my end float.

 

This is what a new set look like incase you are interested.

With the pistons removed you can see the marking on my cylinder bores. All 4 are identical, there is no scratches, there is honing in places, but mainly black marking from the pistons. The block is measuring a standard bore for a 1.8, as there is no scratches, I am hoping to get away with a hone, but as I said before, if the expert says that it needs a bore, then so be it.

 

I will need new pistons regardless of the over bore or hone, this is a huge expense, with an average set coming in around £400 including rings

My crank measurement is coming in at 44.5mm & the Haynes spec on this is 44.940mm to 44.956 nominal, so I will need a crank grind. I am using a cheap digital vernier, so things may be better or worse than my measurements when it gets onto the proper machine.

So, going by my rough estimates, without labour, here is the run down :

Crankshaft front oil seal £7.25

Crank rear seal £27.72

Main crank bearings £77.23

Head skim £50

Pistons £400 (rough estimate based on internet prices, so may increase)

Conrods bearings £69.84

Front sump gasket £11.93

Rear sump gasket £11.93

Oil pump £166.62  (I want to replace this as a matter of course, my builder said that the standard oil pump is a major weak point).

Dip stick oil ring £4

Labour

Conrods (upgraded) £190 ( I have also been advised that this is a weak point).

Engine assembly lube £12 - (already purchased).

Timing belt kit £80 - (already purchased)

Exedy 4 piece clutch kit £135 - (already purchased)

Head Gasket set £80 - (already purchased). 

So without labour (machining that I cant do, I will build the engine) the total guess of bits that I need will be £1319.52. I am sure that I have overlooked something, so there we have it ! I trust this engine builder 100%, he builds race engines for lots of teams, hence the huge wait to get stuff done. I will obviously get his quote before I pull the trigger, because the Zetec option above may end up being cheaper. I have not chosen my engine builder because of the companies impressive achievments, I have chose them knowing that they will not put their company name on expletive deleted workman ship. This car is going to be a cruiser, it needs to be reliable & I want to pass this down to my children.

  Its my fault, had I had my time again, I would have bought a really well serviced, low mile car. At the time, I was fighting a super tight budget, & this heap was all that I could afford. I had a short drive around a set of council garages, not sufficient I know, but its all that I could work with.

  I am not a big one for not having a Q plate, I know that it may effect the value if it ever got sold but there you go. As it stands, its the original engine for the car that I bought. I have been warned that the MX5 mk1 oil gauges were junk, they either worked or didn't if you know what I mean, they were never that accurate. Maybe this engine issue was down to a weak oil pump as various specialists have said, or maybe its just down to having people neglecting servicing the car, yes the previous owner drifting it did not help, but from my understanding, these engines were built for turbo use, not actually non turbo, so they should be strong.

 If like me, you could not find the engine number for love nor money, here it is ......

Double click on the pic to see properly, it has not uploaded properly. Basically, with the crank pulley facing you, put your hand in the top right hand corner of the block, and you will see a rectangle, its there. I got a washing up sponge with scourer on one end & gave it a good scub, go carefull if using anything more abrasive as the numbers are not punched in very deep. I believe that the 1.6 engine number is on the rear left hand side.

  There is no way that I could have left the engine as it was, I would have probably failed my emmisions, the car would have run like a duck & broken down more times than the old Skoda Estelle !

[jason82]

If my engine does get sorted, I plan on doing some head work myself, getting the inlet & exhaust ports smoothed out in an attempt to get the head breathing a bit better, increasing economy & freeing up a few ponies.

Here are a few pictures of my cylinder head before it goes off for a skim (if the engine is salvageable).

Sorry for the bad pictures, if you feel inside where the inlet / intake manifold & exhaust manifold bolt to the cylinder head, feel inside & if your head has not been polished & ported they will be really rough from the casting. There are various youtube videos regarding the subject, but the general opinion is that on the inlet ports, you get them as smooth as possible, with a very slightly spiral effect to them to try and get the inlet air to become turbulent. Then on the exhaust side & on the manifold itself, get them both as smooth as possible, like glass.

  You can buy various polish & porting kits from ebay, mainly little 80 grit flap wheels which attach to a dremel type tool, then once you have got rid of the main roughness, increase the grit of the flap wheels to smooth out the ports as much as possible. A carbide tip is also available, which speeds up the roughing out of the ports.

Check out this Eastwood video, it explains exactly what you need to do.

Before I do this, I will also get the engine builder to inspect my valve guides. If my engine is a saver, I will post my after pictures.

Here is an image of a generic polish & port before & after

Not the best of pictures, but you get the idea.

[snowbird1]

Oct 22, 2018 18:51:02 GMT jason82 said:

My crank measurement is coming in at 44.5mm & the Haynes spec on this is 44.940mm to 44.956 nominal, so I will need a crank grind. I am using a cheap digital vernier, so things may be better or worse than my measurements when it gets onto the proper machine.

If the crank looks good - i.e. has the original polished finish on the bearing journals it is probably OK, measuring the crank may be misleading even with a decent micrometer trying to measure to hundreths of a millimeter can be difficult. More important is the crank to bearing clearances, this can be checked with Plastigage.

[jason82]

Thanks for that. I am booked in for tomorrow lunch time, so everything crossed ! The wife is aware of the situation & has my debit card in a head lock, I tried avoiding my disappointment, but apparently loud bad language can be heard from the kitchen, drawing attention to my bad luck.
If everything is ok ish with my engine, I am thinking of fitting yellow (RX8) injectors to my engine, as a turbo install should be done by March (if the engine is salvageable). Forged pistons & upgraded con rods will be fitted now on the rebuild because I need to replace the parts anyway.
Is there any reason why yellow injectors can't be used on the standard mapping until I have enough money for my turbo install & my upgraded ecu ? It probably won't get used much to be honest, but there is no point in me buying new injector seals for something that I am going to throw away.

[jason82]

So I have had the verdict back from the engine builders Race Developments in Gloucester & the news is surprisingly good. The crank shaft wear is well within tolerance, the limits are as follows :

Crankshaft endfloat minimum : 0.006mm

                           upper limit : 0.282mm

                          Serviceable : 0.300mm

Mine came in at 0.152mm, so pretty much smack bang in the middle, which is a huge surprise, it goes to show the difference between a cheapy measuring tool & the real thing. The crank is perfect, no pick up, gouges etc etc, so that is brilliant. The cylinder bores are within tolerance, just requiring a good honing. The piston rings are un usable, the verdict with the marking on the pistons & cylinder bores was pick up. With the pistons being softer than the cylinders, they took the brunt of the pick up.

  I asked if the marking on the pistons & the cylinder walls could be down to piston slap & Tim said that the lines go too far up the bores for it to be that, they go almost up to the crest of the bores. Regarding the pistons, he actually said that they were salvageable. I laughed & thought that he was having a joke with me, but no, he was serious & told me to buy some scotch brite & scrub the marks out. So I was really curious & gave it a try, this is the pistons before ....

The scourer pads were bought from Home bargains, 38p for 5 big pads & I used WD40 to lubricate the scotchbrite against the piston.

After 20 minutes, all of the scratches were removed & I was left amazed ! I was positive that these things were junk !

This is how I done it, its easier to show you.

Please excuse the quality of the videos, I don't make youtube videos, but I just wanted to show people what could be done with a 38p pack of scourers & some WD40. In the pictures & in the video I only done one side of the pistons for demonstration purposes, but they were the worst of the bunch, & they came up like new ! Hopefully this will help somebody, as pistons cost a few hundred quid, but sometimes this cost can be avoided by spending some time & 38p for scourers.

  I want to thank Tim at www.racedevelopments.co.uk for giving me this tip ! He is based in Gloucester & is possibly the most honest & genuine person that I have ever met, & extremely humble. Check out his web page for his work on the record breaking Skoda Octavia, he builds race engines for superbike teams & is an absolute Audi Wizard. He is busy, but well worth the wait !

  Back to my engine, I have purchased brand new main bearings, thrust bearings, big end bearings, bottom end gaskets & some RTV sealent. I will be replacing the oil pump, as I know that this thing is a weak point along with the conrods. The standard pistons will take turbo to around 250 bhp safely according to various sources, trust me, I have been doing my homework, so I will be getting Manley forged conrods & an upgraded oil pump from America. The cylinder bores are not oval, which is good. I had set my heart on Supertech pistons, but I am really on the fence as to scrapping good pistons for forged ones when I am only aiming for around 250 bhp. Obviously now is the time to do it, but we will see, I have purchased new piston rings for my original pistons just in case I stick with them.

  I have ordered a set of yellow RX8 injectors, its almost as cheap to buy them than recondition standard injectors. They will be a vital part of the turbo build. The engine will be built in stages to make the cost easier to swallow, so I will do all of the internals now, then around the start of summer add the turbo & aftermarket ecu  ( I am not sure which ones to go for yet, I am still looking around & weighing up my options).

  Finally, I have decided to get the car on an even bigger diet. I have been looking around the Miata forums & have come across people making their own front sub frames  from tubes & box section. Its a lot lighter than the Mazda lump, but is strong enough to keep things on track. They can be bought from a fab shop on facebook, I think that its called crappy engineering, for around £350 powder coated & delivered. I can weld, & I have always wanted to buy a proper tube bender (not a crappy £100 pipe bender that will kink the tubes). So I can kill two birds with one stone. Here is a generic picture of custom front subframe:

My cylinder head is still at Race Developments, so when that comes back, I can get stuck into rebuilding everything.

[hammy3601]

Yeah those subframes are by Clare of Crap Engineering. She's vey well known for awesome work

[jason82]

I have just started refurbishing the gearbox & have come across a really good bargain which I thought that I would share to try & help people. I have already purchased a new slave cylinder, stainless clutch flex line & rebuilt the clutch master cylinder & rebuilt all of that, now I have the gearbox in the shed.

  The gearstick bottom bush & the top of the gearstick rubber boot are absolutely non existent in my car, so originally I started looking for these parts ready for the rebuild....

So that's £28.20 including vat & delivery for the bushes & gaskets. But after watching a youtube video series where they fitted short shift kits to an MX5, I realised that this kit replaced the top washer which costs £19.95. So out of interest I started looking for the shift kits & came across this kit...

 

Now its identical to the Japspeed kit which costs £43 on ebay, the kit looks identical for £20 less, then after some searching on the company selling both kits I realised that they were the same company. So I bought the kit thinking oh well, for an extra fiver I get a short throw kit & the boot replacement, but when it got delivered, it also came with the little bottom bush, meaning for £4 odd less, you are getting a better product, with everything that you need for less.

Incase you are interested, as I would be, the ebay item number is : 183204433993 . The parts came through really quickly, & the quality is second to none. I hope that this helps everyone.