Well, that was a cock-up…

Not been doing too much to the car this last week but small steps forwards were made over the last couple of days. Mostly heater related. Being an ignorant person whilst also wanting to make sure I used as many standard parts as possible to make replacement due to failure easier I was insistent on using the original Herald heater valve. For those not in the know, it sits on the outside of the heater box which lives in the engine bay. It attaches to that by having a rubber olive seal directly onto the pipe of the heater matrix and the unit is bolted to the heater box so it’s secure enough to be cable operated. I couldn’t use the original any more as the engine is where the heater was, so I’ve used a mk4/1500 Spitfire heater box inside the car. And I couldn’t mount it directly onto the pipes of the heater matrix as one pull on the cable to adjust temperature would bend it all. So, one block of aluminium later there was a solution!

Those with a good memory will remember I was going to use a mk3 heater. I’ve swapped for a later one as it’s slightly faster. I’ve bypassed the resistor and now it’ll run at full speed rather than having two settings. I have no need for a slow fan. If I want less warmth I’ll turn it down with the heater valve. I only really want it for screen demisting anyway as I’ve not had a working heater for some time now and I’m used to it. I’ve also not cut any extra holes in the bulkhead for its inlet. Instead I’ve spaced it from the bulkhead so it’ll constantly be re-circulating cabin air. This may see the windows getting mistier as it heats moist air, it may not. It’ll certainly make bottom burps more potent.

I’ve also had a problem with a leaking fuel tank which after a bit of faffing was solved. But that lead to me spotting injector number four was leaking. After a bit of research I discovered that Mazda changed the insulator between the injector and inlet manifold early in the MX5 production. What I had fitted to my car was the early (and probably never touched before) one which didn’t like to be disturbed which I’ve obviously had to do to paint the manifold. The new ones were also used on mk2 MX5’s and will happily be removed and messed around with numerous times before they begin to leak. Turns out these new insulators aren’t very cheap either, well, I consider £20 for four little bits of rubber coated plastic to be expensive! So I bought an injector seal kit for the same price and set to it. Very quick and easy as it turns out, but then that could be in part to me being careful and thinking out a few things last time I reassembled everything with the intention of making strip down quick and easy!


So now it was time to fill the car up with water and discover my cock-up. I’d made my own manifold gasket when I took it apart. This is shaped and not reversible. I guess it’s for the engines original turbo configuration that it has a strange water way into the cylinder head at one end underneath cylinders three and four which doesn’t go anywhere. I’d made my gasket to fit perfectly, removed it, applied some sealant and then fitted it the wrong way. A fact I only found out when filling the car up with water and hearing it splash onto the floor. Whoops! Wondering if I’d cracked the head from using too much copper slip (still working hard to use up a tin of the horrible stuff) and hydro-locking a bolt hole or from running the engine with no water for a few seconds I slowly removed the manifold. Again, an easy job thanks to a little thought earlier. It was then that I saw the water way and gasket. I must have fitted it as a final job one day when tired. Anyhoo, new gasket is made and it allowed me to get some paint onto the areas which had been stripped from the petrol.


Oh, I also tinkered with the dashboard some more. I tried to use the film I had to coat it with and ended up with a horribly creased mess. So I went out and boat a can of spray paint and have it a quick blast.

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