Apologies in advance – this is going to be a long post (and it has a lot of pictures).

My engine install actually started with more preparation: covering the chassis tubes with pipe lagging and cutting strong cardboard for the foot-well heat-shielding.

I also wrapped the widest part of the gearbox with several layers of strong polythene (which was the bag the gearbox came in). The idea here is, sooner or later the gearbox is going to touch the side wall of the transmission tunnel which isn’t in itself a problem, but the gearbox’s sharp edges will damage the heat-shield or powder coat, so the polythene blunts of these edges. Make sure the gearbox output shaft plug is still in place, because the Caterham 5-speed Mazda gearbox is supplied full of oil, which is best kept in the gearbox.

Gearbox wrapped in polythene

The cam cover is actually very difficult to source as a spare part, and replacing it would lose your original manufacturing label, so several layers of masking tape was applied and a towel to protect it was applied.

It’s not possible to install an engine into a Caterham in my garage without either the engine hoist or the chassis beginning the process being outside – my garage just isn’t long enough. To make matters worse, my garage is also on a slope, so I chose to start with the chassis outside. Pushing the chassis uphill is easier at this stage, because it’s lighter than the engine and gearbox. Thankfully the weather was perfect for the install.

The ability to move the chassis during the install isn’t necessary, but does make life easier. If you don’t have wheeled axle-stands, then all the movement has to come from the hoist. The down side to this is that the hoist is harder to move (because it’s holding more weight) and the engine will tend to swing when you stop moving it, which is unwanted.

I use an engine load leveller when installing engines into a Caterham to be able to adjust the angle of the engine during the install. There seem to be two main types on the market here in the UK: I have been using my Clarke strong-arm leveller (https://www.clarkeinternational.com/shop/product/details/cll500-load-leveller) for a few years now, but I decided to try the other style for this build, and I purchased an SGS leveller (https://www.sgs-engineering.com/sll680-load-leveller). Functionally, I would say there is very little difference between them, but I preferred the SGS because it didn’t flake red paint all over my engine.

Select engine leveller

If you are using the hoist and axle stand combination for the first time, check that your hoist has enough reach to get your engine into the chassis and clears your axle stands before you attach your engine. Given this isn’t my first Duratec install using this hoist and wheeled axle stands, I skipped this part, but I did have this in mind even when I setup the axle stands before delivery. If you look back on that post you will be able to see the front stands are assembled differently to the rear to make them narrower. I suppose it would be wise to check that you have the height above the car for the hoist as well.

With the hoist setup and the load leveller attached the engine was lifted, and levelled as best I could, but not being designed for inline installation brings some unique challenges. The first is a benefit: the engine – even with the leveller at maximum (the end stop) – has a slight angle with the gearbox pointing to the ground. This is ok and simple to rectify with a jack near the end of the install, but more on that later. The second and the one that causes the biggest problem during the install is: the twist. You can see this from the picture of my first attempt to install my 360 engine back in 2016. The twist presents the gearbox at a different angle and therefore wider – and in extreme situations it simply won’t fit into the transmission tunnel.

Notice the twist in the engine, its almost at 2 o’clock

My solution to the twist comes from a ratchet strap attached to the left hand engine mount. You want a good quality ratchet strap, I think mine is rated for 250Kg. Caterham recommend an engine hoist capable of lifting 150Kg, so the strap should be man enough to take the load, and it does as angle is applied. Most importantly, it keeps the twist under control although does not removed it completely. Remember to check the left hand engine mount is secure before you start (and double-check all the lifting eyes for that matter).

At this point do not continue without assistance. An extra pair of eyes and a hand to steady the engine from rocking as it’s moved can be critical. My wife assists me and it’s fair to say its not her first time doing this, but she is still very much the novice mechanic. I had to remind her sometimes not to put hands under the engine or in places where they would get trapped if something went wrong. If the hoist or the chains failed I would only want to have to deal with a smashed-up chassis / engine.

So, time to lift the engine and bring the engine to the chassis. You start as level and high enough to clear the chassis. Make sure, the chassis and engine are lined up as much as possible, and look from a few different angles. The more accurate you are here, the easier the install will be.

Now lower the gearbox output shaft by increasing the angle using the leveller. And then start lowering the engine.

The process basically resolves around three actions: lowering, changing the angle (level) and moving the engine backwards into the chassis, all of which you want to do in a controlled manner. You will be doing one of these actions until you run out of space, and then you change to another action. Don’t be surprised if you can only move as little as 5mm at any one stage. This part of the process can take a fair bit of time. I prefer to take my time and minimise any damage potential, therefore after each movement I check what’s going on, in all the areas where the engine or gearbox are getting close to the chassis. Initially you will be increasing the angle (steeper), but later in the install you will be reducing the angle (flatter or more level).

Don’t forget with a crane style hoist the engine moves back as its lowered.

With the Mazda 5-speed gearbox you must not let the main body of the gearbox get lower than the chassis transmission tunnel. There isn’t the space (even without any twist) to raise the gearbox back into the chassis.

When the engine is close to the mounting points, it is time to resolve that first problem and bring the engine and gearbox unit up to level. This is done, when the output-shaft of the gearbox reaches the transmission tunnel cross-bar (about half way down the chassis). You will need to use a jack to lift the gearbox output over the cross bar. The jack also sorts the twist (which is a bonus). You can see from my photos that I used a large lifting block and a small block, and even then the jack was at full stretch. This all depends how high you have lifted the chassis, and how much lift your jack has, so be prepared. I would avoid putting tall wooden blocks on the lifting surface of the jack, you don’t want them slipping off as the engine moves. However, I have used wooden blocks under the jack before successfully.

Remember is gets very tight in places. I have taken some photos of the engine as its squeezes past the pipe lagging. Without the protective lagging the chassis would be damaged. From the photos you can see how the cardboard saved the heat-shield from damage.

However, I didn’t manage to achieve 100% “no damage”. It is my first attempt with the Mazda 5-speed gearbox, and I assumed the widest part of the gearbox would be the place that was most at risk of touching the heat-shield. This assumption proved to be wrong once the gearbox was deep in the transmission tunnel. It damaged some of the aluminium tape used to secure the heat-shield. This requires a simple repair with a patch of new tape, which has to be applied before the gearbox mount was installed. With the benefit of hindsight, I would have applied polythene around the backend of the gearbox as well.

Once you have the engine in nearly in the correct place, it’s time to install the right-hand-side engine mount, but leave it loose.

To be able to fit the gearbox mount to the chassis, you will need to clear the holes from the heat-shield tape; I used a pick to do this. Fit the gearbox mount loosely. I have read other blogs, where the IVA inspector wanted the bolt downwards to make observing the thread through the nyloc nut easier. It makes no difference to me up- or downwards, but I suspect downwards is a bit more fiddly to install. I decided to fit the bolt downwards just in case, but it would be a simple job to change this at a later time. Now you should have all the mounts in place, and the engine still hanging but less than a millimetre or so off the rubber mounts.

Hoist remains in place until all the mounting bolts are torqued

Lower the engine the final bit, but not enough to touch the rubber mounts. You should now be able to get the gearbox mounting bolts and the right-hand-side rubber mounting bolt in place. Tighten them, but don’t torque the gearbox and right-hand-side mounting bolts (none of them). Now release the ratchet strap on the left and side engine mount and loosen it so you can get the left-hand-side bolt into the engine rubber mount. Remember, the engine rubber mount cap head bolt is imperial not metric so use a 3/8” hex drive. Getting these engine/gearbox rubber mounting bolts located can be tricky, and often loosening the engine mount is helpful to getting the bolts started. Once you have all the bolts in place, it’s time to torque them all up. Unlike the old 5-speed gearbox and the 6-speed gearbox – there is no adjustment built into the gearbox mount.

Only when you have all the bolts torqued up is it time to remove the hoist.

The manual calls for thread lock on the M14 mounting bolts. I wonder if this is old information, because a shake-proof washer is provided, but I still applied some Loctite 243 (https://www.henkel-adhesives.com/us/en/product/threadlockers/loctite_243.html) just in case. I applied the usual smear of copper grease to the rest of the bolts, and I marked them after the torque was applied to remind me that these bolts are torqued up.

  • Gearbox Mount to Chassis: 20Nm
  • Gearbox to Gearbox Mount: 40Nm
  • Engine Mount Rubber to Chassis: 20Nm
  • Engine Mount to Engine Mount Rubber: 41Nm
  • Engine Mount to Engine: 34Nm

Tools Used

  • Engine load leveller
  • Chains
  • Four Shackles
  • 22mm 3/8 Socket
  • 13mm 3/8 Socket
  • 6mm hex 1/4 Socket
  • 8mm hex 1/4 Socket
  • 3/8″ hex 1/4 Socket
  • Selection of 1/4 extensions
  • 1/4 3/8 adaptor
  • 6mm Allen key
  • 1/4 Ratchet
  • 3/8 Ratchet
  • 3/8 extension
  • Scissors
  • Knife
  • Aluminium Tape
  • 3/8 Torque wrench
  • Trolly jack
  • Small lifting block
  • Large lifting block
  • 13mm combination spanner
  • Engine hoist
  • Straight pick