K series MG Midget

Engine Test Fit!

2006-04-22T18:02:00.000+01:00

Engine lowered into place

So after a long break and contemplating selling the project due to time & domestic issues I have decided to get back on the Job!

I set about the heater tray with an angle grinder and made some room. (More about this another time) I then decided to try a test fit with the engine.

With no bellhousing attached I lowered it into place and immediately hit (literally) a few problems.

Problem 1 - I didn't think the Frontline oil feed take off adapter was designed as an engine mount -

Oil take off touching the chassis!

Problem 2 - The inlet manifold is fouling the body/chassis, not sure why this is but I am hoping its because the engine is not positioned correctly.

Inlet manifold touching!

Problem 3 - How on earth would I be able to get the hoses on the engine coolant outlet spout, let alone the temp sender wires?

Coolant outlet very close to chassis

Not sure where I have gone wrong here - perhaps my chassis is different or my engine, but I don't think so. As you will see from the following pictures the mounts are fully down on the chassis legs and the engine is still sitting to high for the bonnet to close.

Front engine mounting

Rear engine mounting

Engine sitting too high

(14) Starter Motor issues multiply!

2006-02-24T15:04:00.000Z

This starter motor issues is beginning to piss me off to say the least. Before grinding back the bellhousing I double checked my measurements to ensure that it would engage ok and everything seemed alright.

The Starter Motor & Spacer - its personal now

Then I noticed that behind the gear teeth in the starter motor is a great big boss which follows the gear teeth out when the starter is engaged. Not a problem except that it will make contact with the engine facing side of the flywheel, before the teeth hit the ring gear.

Closeup showing gear teeth and boss behind them
I though perhaps that my flywheel might be a none standard item and the ring gear are on the wrong side or something, but that's not the case. This is a Caterham spec flywheel and the ring gear is on the right side (gearbox side).

Test fit showing how boss will not clear flywheel

After speaking with Tim at FL he assured me that they have sold many of these units with no problems and that the boss does not follow the gear teeth out.

So I connected it up and tried it. Sure enough the boss does come out behind the gear teeth. So FL say send the starter motor back and they will prove it works. But I really can't see how it can and the last thing I want to be doing is posting a heavy SM back and forward.

Head scratching time.

I also think the original spacing issue I had might be due to the fact that Caterham make two bellhousings - for long shaft CR type 9 boxes and for short shaft standard boxes. I have been told the difference is the thickness of the mating surface with the engine. If this is the case it would explain why some fit ok and others don't.

(13) Fuel system bits aquired

2006-02-21T10:57:00.000Z

As luck would have it I have a friend who works at a Land Rover dealership and as a result I have acquired some cheap (very!) bits that I can use for the build. I have got two fuel pumps, both rated at 3bar, I think from a Freelander, although I don't care really because they are self priming and simple to connect.

Fuel pumps and quick connectors

You will see that I have already covered one of them with rubber from a coolant hose. The reason I did this is that I had problems in the past when these pumps are mounted using thinner rubber and then a bracket. The aluminium is very thin and if any steel is left in contact with it then it just tends to go porous in a matter of weeks.

I am also looking for a cheap way to make a small feed tank so that heavy cornering does not cause surge problems.

The hoses in the picture are standard Landrover quick release fuel pipes and make it much quicker to disconnect the fuel lines if required. No doubt I will be making plenty of use of them!

(12) Engine Crane Purchase

2006-02-20T12:04:00.000Z

With my requirements to shift engines and stuff around my garage and not wanting to have to rely on help each time I want to move the lump I decided an engine crane was a worthwhile investment.

Engine Crane used to support gearbox

I found this one on eBay from a company in Scotland. It cost £120 brand new, delivered. It folds up flat so it does not take up much space in the garage when not in use.

For the price I would recommend it to anyone.

(11) Starter Motor Woes

2006-02-19T11:26:00.000Z

After grinding the block I now have tried fitting the starter motor and spacer supplied by Frontline and immediately run into a problem.

Even with the spacer block the starter motor output shaft fouls on the back of the bellhousing cutout - that is too say its too long.

Bosch Unit with spacer fitted

The starter motor distance from bolt face to end of shaft is 70mm
The clearance from rear of bellhousing cut out to mating surface is 40mm
The distance from mating surface of starter motor to end of shaft with adapter plate fitted is 45mm

This makes the assembly 5mm too long to fit

I did ask Tim Fenna why they supply this starter motor and not the caterham derived one which looks neater and is of a different design and was told that they had multiple failures with this unit due to overheating. (The SM is mounted very close the exhaust manifold) and this does seem feasible. The Bosch one is apparently more resistant to heat, hopefully it will also fit.

I do have the option to grind a hole in the back of the bellhousing to allow the SM to fit but I am worried that this might mean it does not hot the flywheel ring gear correctly and I'm back to square one, with a hole in my bellhousing!

(10) Making the gearbox fit

2006-01-10T14:27:00.000Z

The gearbox I have is a Ford type 9. Its a close ratio box, from a Sierra 2.0is model. This means it has the same long input shaft that the 2.8i Capri boxes do, but it does not have the 3rd bearing for the input shaft - in other words its a bit of a hybrid. This means a couple of extra bits of work will be required to make sure it seals with the bellhousing but that's for later.

First thing was to get the length of the input shaft right, at the moment it is to long and will foul on the end of the crank not allowing the bellhousing to be bolted up tight. Its vital that it does not touch the end of the crank or it will destroy itself very quickly.

The other problem I had is that the shaft is only machined enough for its original Ford fitment, and once I have cut some of that off the slightly larger unmachined part of the shaft would rub on the spigot bearing causing wear and eventual failure of the bearing and possibly the box. The fact that I didn't get my bearing in as far as it should go makes this problem even worse.

Grinding the input shaft

I came up with a novel way of grinding the shaft diameter down to a uniform 15mm. By using a strip of abrasive paper from the bench grinder, cut to the right width to just act of the unmachined part of the shaft. I used a cordless drill to operate the paper and found that if I put the Ford box in 5th gear the shaft itself would rotate slowly as I ground the shaft. This meant that I didn't end up with a square shaft. It worked perfectly.

The finished shaft - now 15mm all the way along

Once I did that I bolted up everything and checked how far the bellhousing was apart from the block when the shaft touch the crank. I got 11mm so I decided to shorten the shaft by 12mm to be safe.

Unfortunately I forgot to change the grinding wheel for a cutting wheel and ended up taking off 16mm instead.

The shortened shaft ready for test fitting

Even so it still went far enough in for support and ran freely so things look all ok. I was finally able to test fit the engine, bellhousing and gearbox on the bench.

The engine & box finally mated!

(9) First Stages

2006-01-09T00:09:00.000Z

I decided the first thing I need to do is get the engine, bellhousing and box bolted together so that I can test fit the engine and see what bits of the car I need to set about with a sledgehammer/chainsaw/grinder.

Job one was to grind so of the aluminum of the engine block so that the starter motor would fit. Because the K series engine was designed to fit many applications it has holes/bolts/extra bits all over the place. It was designed to take a starter motor that came in from the bellhousing/gearbox side, not one that came in from the engine side. In order to allow space for this to happen it needs some bits ground away - so 30 minutes later and after taking care to cover any holes into the engine where swarf could reach I ended up with a weight saving of about 100 grams!

Block after grinding

Next job was to fit the spigot bearing and sleeve. Rather than measure it all up and lubricate it I just offered the whole thing up and used a large block of wood to tap it in. Of course it didn't want to go very far in so I upgraded to a socket and then just a plain steel hammer. I got it as far in as I could before the sleeve started to roll at the edges and I lost my nerve.

The (badly) fitted spigot bearing & sleeve

(8) Problems on the Horizon?

2006-01-08T11:58:00.000Z

There are lots of unanswered questions and outstanding issues with this build, but I'm not the type of person to work things out ahead of time and produce a methodical Microsoft project schedule and stick to it. I'd rather just tackle things as I go.

Some of the issues I know I will be facing include -

The engine loom and wiring - I had unwittingly bought a EU3 compliant engine which means that it has more sensors and other bits and bobs to meet ever increasing stringent emission regulations. One of the downsides of this is that the loom is not plug compatible with the Emerald ECU I intend to use.

EU3 Engine Loom

The PTP 170 upgrade that was performed on this engine also meant modifications to the loom and the addition of an extra ECU which complicates things further.

PTP Modified loom plug for EFI ECU

I plan to cut of the connectors and make my own loom, using the EU2 plug which will fit the Emerald.

However after finding this very useful site (http://www.alcester-racing-sevens.com/ecu_converter.htm), I have the option of using the extra ecu and plug box to make a EU3 - EU2 converter which means I will have a choice to make at some point.

The plumbing - The K Series has a known appetite for head gaskets, partly because it uses liners in place of traditional bores and partly because its very sensitive to cooling. Although I don't intend to use a heater I want to try and retain much of the factory cooling circuit as possible, which will mean making up various bypass pipes and hacking away at some of the cooling rails because they won't fit behind the engine in this installation.

K Series Lotus Style Water Rails

I will also probably use a remote thermostat, which will mean removal and modification of the original. I know I am going to have some problems here, but that's in the future so I'll come to that later.

(7) Aquiring more bits of the puzzle

2006-01-07T23:49:00.000Z

Now I had the engine, bellhousing and gearbox it was time to pick up a few other bits that I was going to need.

Frontline supplied the following bits

Engine brackets and mounts

Gearbox bracket & mounts

I already had the clutch arm, but needed the cable kit

I also needed a complete clutch kit (friction plate and pressure plate & housing)

Remote oil filter take off & remote housing kit

Complete propshaft (which is very good value at about £85)

Starter motor and Spacer for fitting to Caterham Bellhousing

Exhaust manifold and downpipe kit. I have some reservations about the diameter of the manifold headers where the bolt to the head - they look a little small to me and I can see that I am going to have to get the dremmel on these and possibly open them up a bit and re-weld)

You can see the manifolds here. Also pictured are the box section strentheners which slide into the chassis where the old cross member the orginial gearbox was mounted on is located. This needs to be cut out.

I also need a spigot bush - the input hole in the end of the crank is 22mm and the gearbox input shaft is 15mm diameter. If the shaft is just left to float around in there then its going to make it very hard to get into gear and ultimately wreck the gearbox. So it needs to be supported, frontline supply a needle roller bearing and a shim to make it a snug (very snug as you will see later!) fit in the crank.

(6) Bell Housing & Gearbox

2006-01-06T04:42:00.000Z

The simplest option appeared to be to use a Ford Type 9 5 speed box so I needed to find a bellhousing to suit this.

It turned out that Caterham use the same box in their K series cars (they also have a very nice and very expensive 6 speed box) so I found a bellhousing on http://www.blatchat.com/ and picked it up a few days later.

I had been told that the later K series engines (post 2001) all had a standard size flywheel that would be fine with the bellhousing. As soon as I saw the bellhousing I knew that this info was wrong! The Elise/MGF flywheel is huge, in fact it was wider than the entire bellhousing!

Luckily, blatchat helped me again and I got a brand new 1600cc K series flywheel for £40 from the same guy I bought the bellhousing from. As you can see the 1600 flywheel is much smaller, about 10" or 260mm including ring gear.

Next I found that a nice guy on the MG BBS (http://www.british-cars.co.uk/) had a spare type 9 going cheap so I went and picked that up. I had planned to rebuild it, but I think that can wait till I get things all together.

(5) Buying a K Series

2006-01-05T16:34:00.000Z

Next thing I needed was a decent K series engine for my car.

I had planned on a VVC engine because it would give 150-160 ish BHP and had a great head that would lend itself to more power later on if I decided to junk he VVC mechanism and add throttle bodies and new cams.

Some people have reported problems with VVC fitting under bonnet, but since my car already had a bonnet bulge to accommodate the KAD 16v head that would not have been a problem for me.

I had also planned to use a programmable Emerald ECU to avoid complications that can arise from missing alarm & immobilizer parts and also because it allowed greater flexibility in the long term whatever I decided to do with the engine. Being fully mapable it would also allow almost any K series engine to make more power.

I found several VVC units on eBay that were brand new, but they were selling for £2k+ without loom or ecu, so add £600 for emerald and then another £100 for a loom and you were looking at not far shy of £3k for the engine alone. Again with the benefit of hindsight I would have bought a smashed MGF with a VVC engine. This would yield lots of useful bits and breaking the rest on ebay would almost have got my money back.

In the end I found a low mileage ex Lotus Elise engine with the PTP170 conversion for £1200. The PTP conversion involved a new head and cams, VVC inlet plenum and piggy back EFI ecu system to make it all work. The engine was from an S2 Elise and had the close ratio box, which I knew I could sell for £400, so that made the engine £800 which was more reasonable.

After picking it up I immediately removed and ebayed the box, starter motor and the AP clutch plate and housing. This netted me £635 back so not bad.

(4) The A Series Engine

2006-01-04T15:48:00.000Z

First thing was to sell the currently installed lump to release some funds to the K Conversion.

With the benefit of hindsight I would have done things very differently.

1) I would have split the engine into component form and sold /crank/rods/pistons/head/carbs/flywheel/clutch all separately, this would have netted me at least another £1500

2) I would not have sold the gearbox/oil cooler/exhaust system because I could have used them all for my conversion but you live and learn

So I was left with a very violated looking Sprite.

(3) The Donor Car

2006-01-03T13:24:00.000Z

After months of searching I found what I was looking for.

A 1967 registered Healey Sprite that had been reshelled and looked to be in great condition. Much of the work had already been done, the car had a Quaife LSD with hardened half-shafts, the frontline front suspension conversion that gave some negative camber and allowed fitment of decent adjustable dampers, rear telescopic damper conversion, 9.5" front discs with 4 pot calipers and the shell was a round wheel arch one that meant the car could run 14" wheels with no problem.

The body was immaculate and the car had no rust anywhere, which was vital for me because I didn't want to mess about stripping it and rebuilding it from the ground up. I like driving cars, not building them.

This car also had a huge spec engine and Toyota 5 speed gearbox. Which had me in somewhat of a quandary. Had I found the car I needed that I could just fill up with gas and use and forget the K series project?

The figures looked good, the engine spec was the sort of thing that A series boffins would kill for -

1460cc A+ Block, Omega Pistons, Carrillo Rods, Billet Steel Crank, Lightweight Alloy Flywheel all connected to a KAD 16v head with twin Webber 45's. The dyno sheets said 170BHP and after driving it I believed it. The toyota box felt great and I was left seriously thinking I might have stuck gold.

Then I looked at the huge folder of documentation I got with the car and worked out that in the two years it actually got used the engine was rebuilt/refreshed 5 times at a total cost of well over £10k!!!! I also cringed everytime it revved round to 9000RPM and just knew that by the time I got half way across France I would start to regret it. In fact by the time I got back home from Devon after collecting it, the engine had dumped oil, started overheating and developed a slight knock, that I knew would only get worse.

The K Series conversion was back on!

(2) Why K series Midget?

2006-01-02T12:56:00.000Z

I have owned a Lotus Elise for many years and had great fun on the road and track with the car. I recently started doing some European events with my Dad in his E-Type and they turned out to be great fun. Relatively cheap and full of great personalities. They often involved driving across Europe with close road hillclimbs and various trackdays included.

The ring in my Elise

Playing with Classic porsches, a bit of a cheat in a modern Elise!

A private French track in the E Type

I decided I wanted to build a car to do these events. The problem is that the car needs to be at least 25 years old, but reliable enough to stand 2500 hard miles, 6 or 7 tracks and various hillclimbs all in a week or so.

I decided that my budget would be around 10k and (with a tear in my eye) I sold the Elise and embarked on a search for a car.

Porsche were a favorite of the majority for these events and I looked very closely at a 924 Carrera GT, but couldn't find one that was good enough and cheap enough. I also like the idea of an Alfa GTV but in the end decided I wanted a softop and a Midget/Sprite just fitted the bill.

I knew that I would need to make some extensive modifications and wanted to try and locate a car that had at least some of the components already fitted that I wanted. I looked at lots of them and eventually decided that I was going to buy a sorted car and put a Rover K series engine in it. I knew the K series from my Lotus days and its a light, tunable unit that has the advantage of being very common and sourcing bits and spares would be very easy.

The engine itself started as a 1400cc unit, becoming 1600cc and eventually 1800cc. The 1800cc unit is found in lots of the Rover cars including the MG ZR and the MGF. Its also found in the Landrover Freelander and Lotus Elise.

I spent a long time looking at the MG Cars forum at http://www.british-cars.co.uk/ where there is a dedicated 16v Spite/Midget forum and this proved an invaluable resource while researching the build. From here I discovered that a company called Frontline Spridget produced a kit for fitting a K series into a Midget. So with the confidence that its been done before and that the web had lots of information on the subject I searched for the donor car.

(1) About this Blog

2006-01-01T23:07:00.000Z

Well its not really a blog at all is it. I used this site to create a build diary of my K Series Midget.

The blog format works ok but it does mean that the pages will start with my most recent progress rather than at the beginning. For this reason I have numbered each post to make it easier to see the build and my progress from the start.

For anyone else considering a conversion of this type, it should be known that my skill level is minimal. Although I have been known to wield the odd spanner in anger and I am quite capable of basic servicing or even a like for like engine swap; I have never tackled anything like this before. So if I can do it then anybody can. Whether or not I can do it remains to be seen of course!

At some point I will publish a complete list of all my costs and parts used, as well as the total time I take to complete this build. So watch this space!