Novice: Engine swaps Part 1, decisions, decisions…

This article discusses what to look out for if you are considering an engine swap for something a bit bigger.

Give me a large sum of money and i’ll get you a large power output. How many people in the UK NC world have that kind of money and ambition?

Probably about 3 🙂

So what about a reasonable amount of money and a reasonable power output? A strong reliable base which you could develop even further if you wanted? Maybe….

If you’ve read about 2.5 engine swaps on US based FB pages or forums then i’m sorry, but you need to quell your excitement and forget most of what you read, things are very different here in the UK and indeed, the whole of Europe. Over in the US a heck of a lot of cars and vans were fitted with 2.5 engines over a lot of years. In comparison we didn’t get many over here at all. Also what you’ll find is the average American will drive a new car out of a showroom and into a wall therefore writing it off. These facts mean there is an abundance of cheap low mileage engines over there.

Import one over here? After freight and tax you’re looking at about £1k and if it’s faulty then no chance of refund or return.

Generally all you can find over here are new crate engines or old high mileage ones.

To sum up so far, the NC came with a 2ltr*, as said 2.5 swaps are popular in the US because it’s readily available there, but here in the UK less so. We do have a 2.3 too and it’s often overlooked, not at DuratecNC it isn’t 🙂

Unmodified power figures for comparison:

 2.0: 158 Bhp  138 ft/lbs torque
2.3: 163 Bhp  153 ft/lbs torque
2.5: 170 Bhp  172 ft/lbs torque

As you can see the biggest gains are in the torque department, this is what Mazda wanted as the engines were going in heavy four door cars and is why they stroked them. What we need to do is take that engine, make it rev further safely and produce more power and torque.

*You may notice I never mentioned the 1.8. This is an engine performance company Blog so for all intents and purposes i’m expecting no-one to be really interested in this engine unless you have to meet a racing regulation of 1.8 litres or less. We can certainly replace a 1.8 NC with a more powerful engine, but remember you’ll maybe want an LSD as it never came with one and the ECU and engine have no VVT.

So 2.0, 2.3 or 2.5? (or even a 2.4, but that’s another story). Obviously you’ll make more power with each step up, but there are pros and cons for each.

Take a 2.0 for its revvy nature and maybe you need to meet class rules of 2.0 and less, it will rev further safer than all the others and give a decent BHP figure, but lack in torque.

For maximum potential and cost take the 2.5, less potential and less cost then start with a 2.3. You need to decide whether that extra money is worth it and if you’re putting in a brand new 2.5 new engine, a used 2.3 one, if you’re going to rebuild it for strength and power or not. Obviously if you’re just going to put in a stock motor with no mods then perhaps a new 2.5 is the way to go. If you’re going the whole hog with replacing components then the 2.3 with its lower initial purchase cost starts to look more favourable. What I mean is if you’re going to start throwing out the pistons, rods, cams etc to replace with more performance orientated components then there is less point in throwing new ones away which you may have just bought as part of a whole engine.

Would you put an untouched high mileage engine in? Well you might, but I certainly wouldn’t. We don’t get to spend any time with the cars the engines came from to fully evaluate the engines before they are fitted. You could end up fitting an oil burner and that would be a very expensive mistake.

All the engines we fit have been stripped down to the core, checked and rebuilt with many new parts to whatever spec you require. To rebuild it as standard is not a problem, but obviously adds cost and takes away any risk.

Many external parts will need to be swapped over to make the new one work so an original engine in one piece will be needed.

2.5 and 2.0 packages are also available, please contact us for details.