1.4 K to 1.8 K engine swop.easy?

[pkw2704]

ok ,in my search for my first caterham i have been offered a 1.4K,which isnt a bad thing.My question is, has anyone changed from a 1.4 to a 1.8? is it an easy engine swap,what is different or needed to do the conversion?

[Wrightpayne]

This may help...there may be other posts in the archive...

https://www.lotus7.club/forum/techtalk/converting-14k-18k

[TomB]

I did several years ago.  In a nutshell, I fitted the 1.4 Supersport head to a 1.8 bottom end, transferred the ancillaries over, fitted larger injectors and ran it on the MEMS ECU.  This retains all the wiring loom and senders, and by fitting the bigger injectors, you provide the increased fuelling but the ECU still thinks its a 1.4k. I later refined it by fitting SLR throttle bodies and an Emerald with proper mapping.  

It partly depends on the 1.4 set up youve already got - mine was ex-race Supersport, so had dry sump, 4-1 race exhaust and verniers.  All these swopped over making a very nice spec 1.8k.  

If I was doing it again, I would definitely fit stronger pistons (Trophy 160 or forged) - I retained the standard 1.8 pistons and its holding me back from further tuning as the bottom end is the limiting factor.  I would probably fit the Emerald instead of the MEMS from the start to get the mapping bang on.  

 

[Wrightpayne]

Some 1.4s were nicely specced - has it got the 6 speed box? If yes its a sweet combination of revvy engine and closely stacked gear ratios to keep it in the power band. 
 

5 speed is OK but ratios not ideal (better for touring)

[Richard Price]

PKW2704,

What year is the 1400 that you have been offered?

Understanding what the car is will help determine the answer to your question.

[SLR No.77]

The year is important and whether it is subject to emissions testing for the MOT.

Stu.

[pkw2704]

its a 2011,5 speed car looks nice but i feel i would soon need more power.So was thinking of changing it for a 1.8.was hoping it was almost plug and play

[StevehS3]

Can the internals be changed to get to 1600 or 1800? I believe the head is the same. Obviously it's EU3. Edited to say that it's been linked above.

[TomB]

I don’t believe you can with the 1.4 - I think it’s possible with the 1.6 to 1.8. It’s not as simple as dropping a new engine in, partly due to to the ECU. If you’ve not bought the car and are immediately thinking of a 1.8, it might be easier to keep looking. 

[Wrightpayne]

If you're 99% sure you'd want more power I'd probably wait for the right car (budget permitting). Two reasons - if can often cost more to build your ideal car than to buy it. Secondly, the Caterham 'market' seems to like standard spec original cars. That said a car with OEM type upgrades is generally OK. If you stuck an Audi TT engine in it you may have a problem selling it.

The search / chase is half the fun. A friend was looking for a Seven project and was offered (and bought) a v low mileage car that had been unused for 20+ years - you really dont know what will show up when you place that wanted advert! (I think my mates came via facebook)

 

Regards

Ian

 

[revilla]

1.4 internals can be changed to 1.6 or 1.8 provided that it's not the very early wet liner block (which you can recognise from the diagonal ribbing on the outside). So long as it's the later damp liner block, going from 1.4 to 1.6 means an increase in bore (new liners, pistons and rods) and going up to 1.8 means an increase in stroke (so a 1.8 crank in addition to the above). I've built tuned 1.8 VVCs on 1.4 blocks.

The problem I've found lately is pistons ... used ones tend to be worn beyond spec and you can end up with an oil burner. New piston and rod units are no longer available. What I've been doing is buying brand new AE (OEM) pistons, getting them machined to take circlips and then fitting them on steel rods. The alternative would be forged pistons, also on steel rods. Things like forged pistons and steel rods are generally only available for 1.8 and not 1.6 so going all the way to 1.8 may be easier.

I've got a set of 1.8 Omega forged pistons on rods here from an R400. They were declared as usable by a friend's engine builder. I did contact Omega to ask what the relevant wear limits were for serviceability and their reply was "at the discretion of the engine builder" which was hardly helpful. They look OK to me. Happy to measure up with a micrometer if anyone has any numbers to compare to.

Is the engine EU2 (distributor) or EU3 (coils on top of the plugs)? If EU2 you'll have fun and games with the ECU and getting the mapping close enough as the ECU isn't programmable (however 1.8 EU2 ECUs are cheap and freely available on eBay, they'll be standard MG or Rover maps but I'm not sure Caterham-supplied ECUs would have been any different). If EU3, the ECU is mappable. You could either go for a custom mapping from somebody like Kmaps to get a bit more "zing" or I could flash a standard Caterham-supplied EU3 1.8 map onto your existing ECU for you. Converting an existing engine between EU2 and EU3 can get a bit more complicated and require cam swaps to get the right triggers.

If it's a very early 1.4 setup with a stepper motor on the throttle body (EU1 I believe) then you'll have further problems as you'll need to replace all of that and the wiring loom to match, but I suspect these would have been the wet liner blocks anyway.

The Caterham engine loom is a separate, self contained unit separate from the main vehicle loom. So if you found a complete engine, ECU and loom package it should be fairly easy to transplant the whole lot into any K Series car. One gotcha is that very early K cars used a different connector between the engine loom and main vehicle loom so if they don't match, you may need to just rewire one plug. I've got a diagram of what's needed.

Having said all of that, I do tend to agree with some of the comments above; if you're already thinking of upgrading it might be better to wait until you find a car that's closer to the spec you want.

[Wrightpayne]

Andrew,

What are your thoughts on this package....

https://www.eliseparts.com/shop/track-performance/performance/k-series-engine-short-block-package/

Regards

Ian

[TomB]

New Chinese block (I presume) is interesting I wonder what our engine gurus think of it?   

[Wrightpayne]

More on the chinese version here....

https://en.m.wikipedia.org/wiki/SAIC_Kavachi_engine

[revilla]

Yes that's the SAIC TCiTech / Kavachi block. Significantly more rigid, I believe they pretty much resolved the head gasket issues (in conjunction with the modified rail and new gasket design). Pretty much compatible with all earlier K Series parts, and I believe Regin Jensen (RJ on here) successfully built a K on one of these blocks.

The liners are Westwood spun-cast L1634s which should be good for anything normally aspirated I think.

At first sight it looks like quite a lot of money but for all-new parts, as soon as you starting adding up the cost of even standard Rover parts to make up a similar package you easily pass that total. Rimmer are wanting pretty much that full amount for an OEM crankshaft alone! They want £978 for a new block or £438 for a New-Take-Off (basically stripped from an engine that was built up but never installed or run).

If you wanted to put together an as-new K for a performance application then it looks like a decent base pakage.

There are no pistons included, so you would still need to source your choice of pistons as above.

Then of course you'll need a head to do it justice. Depending on what spec you want to go for, that could be where all the cost goes.

One comment, K Series blocks need to be modified to fit the RWD starter motor in a Caterham installation. Quite a lot of metal needs to be ground off, and you're working very close to an oilway (head bolt channel). Several people have ended up putting holes in their blocks. Doing that on a £100 used block off eBay is one thing, holing a brand new Kavachi block would bring tears to your eyes. I don't know if there are any changes to the casting internals which might bring the oilway wall closer to the surface and affect tolerances or not (probably not, if they were increasing rigidity I'd probably expect more metal rather than less in this area). I'd certainly be working with extreme caution.

[SLR No.77]

Going back to the original post, having done a 1400 to 1800 conversion, my comment would be that if it were an early to mid '90s car, I'd so go for it.  There's less dependence on getting through an emissions check at MOT time with early cars, but for a 2011 car I'd leave it 1400 and enjoy it for what it is.  A lightweight Caterham with a 1400K and 6 speed gearbox is a lovely combination, IMHO a 5sp tends to deaden it though because it works better with a wider power band / more torque than the 1400 has on offer.

Stu.

[Tony Whitley]

Short answer: it's easy. I did it years ago when the 1.4 in my car failed.  I had to retain the flywheel and ECU from the 1.4 (different trigger pattern), grind off the rib on the block so the starter motor fits and shorten the first motion shaft.  As mine was a Supersport I also used its cams and there was something about picking the right colour (i.e. capacity) injectors.

It was a great improvement, the yawning gap between 1st and 2nd was no longer such a problem and there was loads more torque everywhere.

[TomB]

 picking the right colour (i.e. capacity) injectors

Straw coloured injectors.   

[oilyhands]

I've put together half a dozen engines using the Chinese block, two of them based on the EP package, the rest separately sourced using Westwood L1634 and a couple with Westwood ductile liners, none have given any issues so far, the block is structurally more rigid, but there are some small detailed differences between the new and old blocks, the main one being the crank sensor mounting which is allowed for in the EP kit. There are a small number of improvements one being improved drainage behind the rear crank seal (this is something I do on Rover blocks as a matter of course). You wont go far wrong , but the costs might be a bit rich for some.

Oily