Mechanical – Page 3 – Chamber of Understanding

RX8 Project – Part 2

In part two we look at finally getting the engine clear. In reality due to the time I had available this process actually took something like three months. A qualified professional mechanic can remove the engine in an RX8 in as little as three HOURS! Clearly I’m not a professional mechanic!

I didn’t fully document the process as there are any number of people who have already done excellent write ups of this but hopefully I can offer a couple of pointers to anyone trying to do this. Officially the engine should be removed by dropping out the front sub-frame and not being able to do this easily on a driveway has led me to removing the engine upwards. This adds a few minor problems along the way but nothing insurmountable

One thing I found is that you really need to remove the crank pulley to clear the front crossmember. While you probably could yank it past regardless it makes the process notably easier.

With somewhat awkward visibility it can be hard to tell whats going on but it looks like this. You do not need to remove the main bolt – the pulley is just held on by the four small bolts around it (already removed in the photo).

The next major problem is removing the engine mounts. I found it virtually impossible to get at in any conventional way. You can get a ratchet on but they’re quite tight and there’s little room, and a breaker bar doesn’t have room to move. My solution to this was to undo the bolts from the top of the engine bay with a selection of extensions. These need to be 1/2″ drive as my 3/8″ drive ones were starting to flex a bit plus you will probably need a breaker bar. Due to the angle restriction a UJ is also required. While the whole assembly looks a bit bodged it works fine.

Also the oil line connectors, these are really awkward and are usually corroded solid. Hose them liberally with WD40 and let it stew overnight if they are a problem. If you plan to use them again don’t lose the small retaining wire ring, these can be hard to replace (though can probably be replaced by a snap ring from an engineering supplier).

After another brief pause for another project we started watching some car based youtube videos (Roadkill and Mighty car mods for anyone interested) and after feeling inspired to do car-ish things and pull the engine out.

My best advice on this one is – don’t try to remove an engine when it’s dark and drizzling!

Next up, rotary engine autopsy! Coming soon!

RX8 Engine Swap Project Intro

So the RX8 project involves making what is effectively a worthless vehicle useful again. For anyone not familiar with the Mazda RX8 they are a fairly high spec 4 seater car which is most widely known because it uses a Wankle rotary engine. This type of engine does not use pistons and so is incredibly smooth in operation and in the higher power (231) version of the car revs to 10,000 RPM as standard.

Sadly for all its good points the engine has a number of down sides. In terms of behavior the engine shares a number of similarities to a two stroke piston engine, one aspect is that it is designed to burn oil in normal operation to such an extent it actually has mechanical components to inject oil into the combustion chamber. This means the oil needs to be topped up frequently and it is recommended to check it every time the fuel is filled, though this isn’t as easy it probably should be and very few people do so. As a result many engines fail rapidly due to lack of lubrication once the oil gets low.

The other common failure is with the o-rings which seal the sections of the engine to each other if these fail water gets into the combustion chamber when the cooling system is under pressure (i.e. once the engine is hot). This is one common cause of the warm start/idle problems and where water gets into the oil you get lack of lubrication failure eventually as well.

The engines are expensive to get repaired assuming the fault is detected early enough and no major damage has occurred. If major damage has occurred then sections or even the whole engine may need replacement. Either way the repair is likely to cost more than the car is actually worth and this seems to happen at something around 60-80,000 miles. The combination of all of this is that these cars are abundantly available for very little money with engines in varying degrees of failure but with relatively few miles on the clock. This leads us nicely to exhibit A:

This is a 55 plate RX8 I bought from ebay for grand total of £300 taken on the day I bought it in July 2015. While technically still road legal at this stage the car wouldn’t idle when warm so was not drive-able for any real distance without serious difficulty. In order to collect it I had to impose on a friend who has a van and car trailer for moving his racing car.

My plan for the car was to remove the engine and dismantle it to see how far gone the internals were and if possible repair the engine and reinstall it. Failing that the backup plan was to try to swap in an engine from something else simply because buying a working replacement rotary engine would cost approximately £3500!

So having got the car home the next day we started taking things out:

This may look a little unconventional but in the UK the RX8 was Thatcham security rated. Part of this involved preventing the ECU from being removed because otherwise any wannabe car thief could just swap the ECU for one from a scrap yard for which they have the matching immobiliser chip, then either hotwire it or force the ignition lock like older pre-immobiliser cars. RX8’s from other countries do not have the steel retaining plates as they do not have this rating. Since the retaining bars (gold in the picture) were several mm thick and held in place with any number of rivets the only option (well the only one we could come up with at short notice) was to drill the rivets outs. I recommend centre punching (creating a divot in the centre) the rivets before drilling because they are domed and the drill will skid off. Now technically you could probably remove all the plugs on the engine and leave the ECU in place but we wanted to allow as much room as possible to take the engine out.

Unfortunately in the RX8 the engine is mounted very low and well back with a lot of ancillaries on top of it making removal a little more time consuming:

RX8 Engine Bay — There’s an engine in there somewhere!

Incredibly the back end of the engine is nearly level with the visible firewall and the front is indicated by the alternator! Yes is really is a very small engine and this particular one is the lower power RX8 – so the output of this engine is *only* 192 bhp!

And this was basically where we got to by the end of our first day removing parts. In truth this is only about three hours in as we’d had something of a heavy night and bright sunlight wasn’t helping the situation!

More to follow shortly…

Finished Pipe Vice

So I finally finished the pipe vice seen in a previous post after getting distracted by other projects. I actually needed to use it for its intended purpose which is something I never fully expected when I started restoring it. I needed to tap a thread into a section of bar as part of another long term project (involving a Mazda RX8 – soon to be added to this blog).

Somewhat appropriately the first time I used it again after putting it back together would have actually been my granddads birthday. Asking around the family by best estimations this vise was purchased for installing pipework when my granddad built his house some 55 years ago. With any luck it will last another few decades!

Anyway, here it is :

Refurbishing Vises

Another of the things I was given by my granddad was some well used Record branded vises, specifically a type 23 engineers vice, a type 91 pipe vise and a type 52 woodworking vise. All of these had clearly had quite a lot of use in their lives but were still functional. Unfortunately they clearly hadn’t had any attention for a number of years and just needed a bit of tlc before they started their new life.

Yet again I’ve decided to do it properly. The first step was to remove all the grime, there was old grease, loose paint and quite a lot of surface rust so I went to it with a powerdrill fitted with a rotary wire brush.

This removed the majority of the grime but I needed to use a solvent to degrease the surface prior to painting.

It’s probably worth pointing out at this point that due to me wanting to try out the new paint I didn’t clean the entire vise, that’ll have to wait for another day.

The key bit for me of restoring these vises was making them look the part, so while I could have painted them any colour I did quite a bit of research and found the correct factory original colour for them is BS381C-110 Roundel-Blue. I managed to find one place who could supply a this as a very high quality enamel paint – Paragon Enamel Paints it can be bought via Ebay or direct from their website. I’m not going to lie, it’s not exactly cheap but even the smallest 0.5l can goes a surprisingly long way so you can always retouch it if you need to. It’s also worth pointing out at this point that they specify PT8 synthetic thinner as there doesn’t appear to be much that works. I recommend buying this with the paint as it’s probably the best option for cleaning brushes/spills – sadly me being me it hadn’t noticed this and just cleaned the brushes with petrol.

Now having painted half the first vise I realised that while I was waiting for it to dry I couldn’t clean the other side. I admit that was obvious but I wanted to see what the paint looked like! So I started looking at the next vise:

This is a type 91 pipe vise is generally used for holding a pipe or tube usually to cut a thread onto the end without crushing it. Such fittings used to be used for water pipes in houses many years ago but that is no longer the case but threaded pipes and rods are still widely used in engineering.

This time I disassembled the threaded bar to avoid potentially getting paint on it as well as some other moving parts and all three jaws. I then cleaned it in the same way as the other vise – although with the addition of of a toothbrush to get into some of the corners.

Next up was painting it, this one was a little more fiddly as it wasn’t attached to anything – in retrospect I probably should have just screwed to to a bit of wood but hindsight is a wonderful thing! Also It has a few moving parts which will get stuck if paint gets in them.

So I need to finish it off and paint the areas where I was holding it and things but we’re heading in the right direction. The pair if vises now look like this:

Still more work to do to get it all looking spot on but that can wait until part 2 – where I’ll also have a go at the woodworking vise:

This gives a better idea of how they all looked before I started cleaning them – not terrible but in need of a clean.

To be continued in part 2…

Cobblers Last (Cobblers Anvil) Refurbishment

So my granddad recently gave me all of his tools as he decided he no longer had a need for them and I decided I would refurbish all of the tools I could and continue using them as long as possible – at the end of the day most hand tools are pretty simple and quite easily serviced given basic equipment and enough time and effort. The last two sadly being things which are in rather short supply at the moment so some of these will take rather longer than they probably should!

The first item I found in my granddads workshop which I really wanted to clean up and give a new lease of life was a cobblers last, these were quite common in antiques/vintage shops and auctions in recent years but I’m told are starting to get a little hard to find and while it is unlikely to ever be used to repair shoes again they can be used as a good doorstop.

It had been stored in an outbuilding for some considerable number of years and so had suffered as a result. It was covered in lots of rusty scale which would all need removing before I could do much else. Thankfully I recently got an offer I couldn’t refuse on a pillar drill so with the aid of a wire brush that job became much easier!

So following heavy use of the wire brush I was left with an altogether cleaner looking last with no loose rust at all.

So the next phase is to mask of any areas you don’t want painted – in this case I wanted to keep the original working faces clean so I masked them out prior to painting. In terms of paint in theory any metal paint could be used but I have found the best thing to use where a tough finish is required is an enamel type paint. In this case I used Hammerite smooth in a spray can. I’ve had some bad experiences using hammerite with it not curing properly but the key is thin layers, lots of thin layers. Turns out reading the instructions is actually a good idea! It does still take a long time to fully dry though…

Leave the whole thing in a dry place for a couple of days to dry fully and it’s ready for the finishing touches. Unfortunately because cobblers lasts are made of cast iron this finishing touch is definitely easier with power tools – I used an angle grinder with a flap disk but I’m sure there are other options and this was quick and easy! I carefully cleaned the working surfaces until they shined, I didn’t want the last to look completely new – that would detract from the point of the whole project – but I wanted it to look like it was still in use.

So here’s the end result ready to go back into use as a door stop or house ornament.