MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - K Series failures

Some time ago I took stick from another member on this site for suggesting K Series engines failed with head gasket problems just as much in other vehicles as they did in MGFs!!

This post by a mg specialist in Kent would appear to support my observations.



++++++++++++++++++++++++++++++++++++++++++++++++++++
Posted 02 January 2009 at 18:23:01 UK time
Ralph Gadsby, Kent, United Kingdom

We do tend to see more cars with problems when there has been a cold spell. We're currently experiencing sub-zero weather in Blighty, and I've currently got 4 cars in the workshop/waiting for head gasket repairs. There are also 2 more likely candidates coming in within the next couple of days. Not one of these is an F/TF - most of them are MG ZSs or Rover 45s.
++++++++++++++++++++++++++++++++++++++++++++++++++++

Robert (Bob) Midget Turbo

Bob

I can't imagine you taking stick!

If you were obliquely referencing any comment from me... I still maintain there are very few HGFs in Spridget conversions.

BTW - the drop in F HGFs is no doubt due to many of them not being driven in cold weather(!)

As before, you'll be the 2nd person to hear if my HG fails.

A
Anthony Cutler

and of course it's a false premise unless you know all the production figures and work out 'failures per '000 cars on the road' or somesuch. Ideally it would be 'per 10,000 miles driven' but that would take some serious data gathering and manipulation.
David Smith

The phrase 'HGF' is never far away when the Elise is being discussed, particularly by prospective owners. I haven't a clue whether they suffer any more or less than other K-series cars though.
Jordan Gibson

Dont think it was you Ant, however this is just more evidence that the K series fails in any vehicle it is used in. So why does it not fail in Spridgets?
As you may remember I speculated that perhaps the use in Spridgets is not yet at critical levels. Not enough engines doing more than 20,000 miles since fitment.
I will look forward to you letting me know 2nd! Until that time enjoy your lovely car and I will enjoy my MGF!!
Robert (Bob) Midget Turbo

Just one more thing, further reading of Ralph's post would suggest that the K series engine is not tollerant of any over heating at all. Thus in normal use in family cars the attention to detail of loosing coolant and not stopping when overheating occurs does damage to the engine.
However I think those who use this engine in Spridget conversions do tend to be more attentative to detailed maintenance and are infinately more aware of coolant loss. This I believe could be also why perhaps Spridgets appear more reliable to date.
Robert (Bob) Midget Turbo

From research i have done, a lot of it is related to cooling system, which is modified in a midget.

Im by no means knowledgable about this, but from what i have read, and im sure many others too, the K-series was designed to warm up quickly. The cooling systems is shorter or something. This combined with something about the cylinder liners can be a cause for HGF. Maybe when installed in a Midget, with a modified cooling system, combined with less stress on the engine due to weight/gearbox etc, it just doesnt happen, or maybe it will, but just take a lot longer...

who knows. Its not that bigger deal if its fixed quickly.
Rob McGeown

Yes, Bob, I believe a lot of the issues from what I was told by a Rover garage guy was primarily that the ones that end up in the garage being dissected are the average joes who just carry on driving onwards and upwards despite a huge HGF occurring at their feet.

HGFs are very common in kits and Elises as anyone on forums with high concentrations of those owners can attest to! Though again, a lot of Elise owners are often more busy fiddling with their 'fro than their engine.

Usually the reason for 'less occuring on car x', epecially Spridgets is that Spridget owners are keen on following the Rover history and tend to be more aware of the issue. There are also a considerable number of workarounds and preventative measures for the HGF which Spridget owners seem more keen to try out. Couple this with the fact that, as you say, they don't reach 20,000 miles very often!
Rich Amos (1 Sprite 1 Midget!)

## fiddling with their 'fro ## =?
robnrrugby

Afro?
a borris

Keeping the K cool is paramount. An over heat on a rolling road was the death of our first head but it took several HGs and 2 split liners before we figured that out. Since replacing the head we have done many track days and sprints and the engine has never let us down (I had better go and touch lots of wood). I have gone from sceptic to fan. You won't beat it for power to weight with out going to bike engines and they have no torque.
James
t fisher

There may be two possibilities due to the cold weather

1: The thermostat "mixes" a set amount of bypass water with a variable amount of radiator water to reach the correct inlet water temp. This means that during the very cold months the actual water flow thru the head is much lower - so the temp gradient across the head will be a lot greater.

Some blame the thermostat being on the input - but in reality the systems behave much the same (except the input water temp is one that varies in this setup)

2: You can drive a fair way with no water in the engine, but the heater won't work. For a lot of people you can drive to and from work or the supermarket as long as you don't care about keeping warm*. As winter bites you have to get the heater working, or the christmas visit to the rellies or christmas traffic.



*as someone with mechanical sympathy this makes me shudder, but I know of at least one person who actively took this view.
Will Munns

I'm following this with great interest. I have a brand new 2000 K series 1.8 engine. It is in a Midget and hasn't been started yet. Should I use it as it is (when I've finished the rest of the conversion) or should I put one of the modified headgasket kits in it before the engine is commissioned. People I have asked so far seem to have mixed views.
I plan on renewing the cam belt anyway.
Thanks,
Neil
K series

Neil

My K is completely standard... was fitted in Mar02 from a late 2001 F with 4K on clock.

I've done 16.2K in it since.

My philosophy is don't dink with things that are working...

A
Anthony Cutler

K, Ant, what was the change date when the metal dowels and new gasket were introduced? ISTR it may be between 2000 and 2001...
David Smith

I believe it's a common misconception that the K-series engine warms up quickly. I do not think it does!

Certainly the temperature gauge needle in my cars reaches 'normal' very very quickly but, no way is that engine thoroughly warmed up then. This may play a part in reducing longevity in this, or any other engine given 'the beans' before fully warmed, particularly during spells of colder weather.

In our family we still have two K-Series cars bought new and both are still on their original cylinder head gasket. The 1.1C Rover Metro bought new in 1993 and an MG ZS 120+ bought new in May 2003. My better half mainly drives the ZS and I have explained the importance of allowing the engine ( in any car ) to become fully warmed before using larger throttle openings and revs to all my family members.

Both my son and I have recently replaced the cylinder head gaskets on friends' K-Series engined Rovers. It's a relatively easy job on the 4-cylinder cars ~ far easier than other DOHC 16 valve cars I could mention. The one I did was because of a repeat 'failed' recent replacement cylinder head gasket ( after only twelve miles ! ) as those who did the job actually FAILED to fit the all important metal dowel nearest the front of the engine. I believe that dowel not only locates the head~block interface, it also encloses the high pressure oil supply to the DOHC ~ leave the dowel out and engine oil is pumped all around the head~gasket~block interface. The WHOLE of the cooling system was filled with a brown chocolate mush mix of engine oil and coolant. I wrote up an illustrated thread over on MG-Rover.org if anyone cares to have a butcher's:

http://forums.mg-rover.org/showthread.php?t=234493&page=2

I did that job last winter and the car still runs fine. The original failure was simply down to owner neglect. They'd had the car for several years and it ran reliably so why bother to check things .... if you're the kind who only lifts a bonnet to check when things go wrong ... certainly things WILL go wrong.

I have stressed the importance of regular simple checks as recommended by all manufactures and despite being completely ignorant of things mechanical, I do believe they've got the message and that car will give some more years service.

Funny old game folks and their cars ~ If the gasket ever 'fails' on my ZS, I shall enjoy replacing it ~ that way I will know the job has not only been done, but done carefully ~ something never guaranteed even with the best professional set-ups .....

Attached is a picture of the old cylinder head ~ left in the boot ~ showing the locating dowell still present and not in the replacement cylinder head. That ommission caused all that work ..... :(
..


MGJohn

Hi David

I expect mine is the 'later' engine.

I like to see the oil at 70C before I use more than modest throttle openings and over 80C before I use WOT and 7K. (Same really as the Aseries and in fact any engine I drive.)

Happily, even with small throttle opening and <3K, the car is fairly brisk.

BTW - I agree with MG John... the water temp gauge only tells half the story... hence I use oil temp gauge as well. On the Kseries (at least in my installation) the oil and water appear to warm up at around the same rate; for the Aseries, the oil warms up much more slowly than the oil. In recent production cars, BTW, the gauges read as directed from the ECU, so is only an indication of temp as the ECU wants you to see; it's not nec a graduated gauge in the way that the capillary gauges that I use.

A
Anthony Cutler

Heres a great article on the K and its problems and how to overcome them...

http://www.sandsmuseum.com/cars/elise/thecar/engine/kingk.html
Rob McGeown

(Aseries: oil heats up much more slowly than the water; ie the head gets hot due to combustion; takes a while for the block to attain same temp being iron and plenty of it!)

A
Anthony Cutler

Just found this... http://uk.youtube.com/watch?v=4tb-ucz_Fpg

A
Anthony Cutler

very interesting. Funny how when the engineer is fitting the head, he misses the holes twice - might account for one HGF for bent bolts!
Rob McGeown

A Bit of engineering porn. I ran across this in my copy of "The High-Speed Internal-Combustion Engine" by Sir Harry Ricardo and J.G.G Hempson. It's a photo as I thought the whole thing was better than part but at larger than A3 I can only scan part on an A4 scanner.

It's a section drawing of a Napier Sabre aero engine, basically your common garden variety 37litre 24 cylinder H configuration sleeve valve engine. More here http://en.wikipedia.org/wiki/Napier_Sabre

Relevance to the thread is what looks like through bolts running the width of the engine but 45 years pre K series. They did say in the youtube clip it wasn't a new idea.


David Billington

I've really enjoyed this thread and it has now convinced me, (others may differ) that unlike say an A Series engine the K Series has no ability whatsoever to withstand overheating. But that said if it is kept cool (not overheated) at all times it should perform pretty well.

Must get a low water warning lamp on my MGF...

Great video Ant.
Robert (Bob) Midget Turbo

Overheating is a negative on any engine, so it should be avoided at all times. I guess if you can precent it any engine can withstand it...

Im sticking with K.
Rob McGeown

I'm intrigued by the K, myself. The whole failure issue reminds me of the mga twin cam, which was a stormer when properly tuned, but due to difficulty in access, along with owners not staying current on adjustments, etc., they began burning pistons, etc., and ate MG's lunch in warranty repairs.

It also reminds me of the Coventry Climax, a lightweight little powerhouse that was as much at home in small sports cars as in fire pumps.

Just out of curiosity, did you guys who have done K conversions to your Midgets move the thermostat to the engine outlet side? The article would imply that this is a part of the problem, at least in the mid-engine arrangement where the engine and radiator are separated by several feet of pipe.

-:G:-
Gryf Ketcherside

Gryf

I run the engine completely standard, incl pump/stat etc. The cooling system is modelled on a Rover 214 and I use std Midget x-flow rad.

All works very well, including hillclimbs/sprints, long motorway journeys at speed, commuting in heavy traffic in hot summer...

As with the Aseries before it, I carefully ensure there are no air-locks in the system.

A
Anthony Cutler

Rob I think in fairness the point I was trying to make was that an A Series engine can withstand a boil over or 2 without problem. In about 40 years of using a Series engines I have boiled a good few, such as top hose blowing apart, suddenly see steam out the front and you stop, no damage to the engine. Water pump maybe fails and again driving along smells kind of funny look at temp gauge!! flippin heck max, stop car no damage to the engine. these kind of occurances have happened to me no end of times.
However I believe if this kind of event were to happen to a K Series then the engine would probably be damaged in the HG area. Not particularly the engines fault as it ought not to happen, but in reality it does and the K Series seems to be intollerant to such things.
We all agree it is a very nice engine when it is running, I love my MGF, just as much as my Midget and MGA.
Robert (Bob) Midget Turbo

Robert,

In fairness to the K other engines can be prone to gasket failure when overheated. I had to have the head gasket done on my VW before Christmas and the guy said that it was very uncommon to have problems on my engine, a 2E IIRC, but he went on to say that some of the other VW engines are very sensitive to overheating and head gasket failure was the normal result.
David Billington

Wouldn't argue with that David, just remembering about the engine fitted to the Triumph Stag!!!!!!!!!!!

I wonder if that was a problem cos it was an engine fitted up front! :-))
Robert (Bob) Midget Turbo

on the many subjects talked about on the 16v board, HGF is not one of them, this seems to be more of a problem for people without the K than it does for those of us that have them. I spent years trying to get my A oil tight so more than happy to spend a weekend to doing a HG, if and when it ever goes.


Alex Sturgeon

Ok then, I'm not being controverial here but following up on Bob's original post on the 4th January 2009, any K'ers had a HGF during the last 12 months?
Neil K

We seem to get a fair few K series heads in for skimming after HGF...not as many as we did a few years back but this probably coincides with less K series in daily use on the road. The Freelander seems to be naughty, many of these were repaired under factory warranty....maybe the weight of the vehicle makes a difference as the engine works harder with heavier vehicles.

We were advised to use a bluntish milling tip to 'smear' the gasket face to aid sealing of porosities in the coring.

We have had positive feedback re the uprated gasket sets.

Peter
P Burgess

that might be because of the gasket failing due to the head becoming annealed and the liners sinking into it - which seems to happen if it's been overheated but not failed as well as during the overheating that caused the failure.

so far i think it's an awesome engine, just needs looking after - sort of an odd mix of old and new. There ain't many NASP 1.4s putting out over 100bhp, even today.
Rob Armstrong

Mine went, no wait, it was still in the Rover lol

Thats how it made its way to my Midget :)

Steve


Steve Hipkiss

I reckon the K series sold its soul to the Devil to make all that horsepower and is summoned to fulfil its side of the bargain just like old Don Giovanni....thats when the head gaskets pop :)

Peter
P Burgess

Whilst the A series is pretty tolerant of almost any temperature, most ally engines would have the same HG issues if they spent too long deep in the red zone of the gauges! Any cast iron engine will be ok, as it doesn't expand as much as ally, so won't move things about as much, and as such is safer at higher temps.
One main cause of the problem in Rovers has already been pointed out: the ECU drives the temp gauge. And unfortunately it's not a linear driver. The pic shows how it moves, and why it can be such a problem.



S Overy

That makes me a devil worshipper then!!!!
Neil K

I could be wrong, but I suspect we Spridget K'ers are less likely to have HGF purely because we tend to know our cars and problems better than your typical Rover/MG driver. We choose K's for being British, reasonably modern and cheap with excellent power to weight despite reservations over HGF problems. We tend to be well read on the problem of HGF and take precautions.

My daily driver is a 06 Rover 75 1.8T which has now done 42K miles. It's been brilliant so far (touch wood!). I check coolant levels at least once a week and constantly worry about HGF, but the drive is worth all the grey hairs.

In contrast my previous car was a Vauxhall Vectra 1.9CDTI. I did 100k in it without drama or worry. I serviced it every 30K miles and never looked under the bonnet once, except to fill the windscreen washer fluid. All well and good, but it had no soul whatsoever.

I for one have always wanted to build my own car, or at least adapt one to go much faster, so going the K route in my Sprite for me ticks all the right boxes.

I suppose this is why K'ers do their thing despite the know problems! Karl

K W Seddon

Sorry to say no knowledge of K motors,but had a passing interest in a Napier Sabre.
In the 60's and 70's I was a forestry engineer in SW Scotland involved in establishing new forests.On the Upper Nithsdale hills we found a Typhoon partly buried where it had come down with some bones still in the remains.The Air Ministry were notified and I presume there records were completed.I remember marking my initials on the block with a centre punch,the Sabre was about 50 yards doxnhill from the wreck.
It is now on display in the Dumfries Aero Museum and the Hawker serial plate(which was on a Hurricane one reversed) is probably still with my Ex!
A.G Peters

Sandra and I will pop in to the museum and have a look next time we are on holiday in Dumfries and Galloway....never visited the museum before but now I have a very good reason to visit.

Peter
P Burgess

Peter,when there ask for David Reid the curator also known as 'Plod'.He used to be a brilliant rally mechanic and refused an offer from Stuart Turner to join the works team at Ford.
A.G Peters

Thanks for that, I will ask for him.

Peter
P Burgess

BTW - I use original 'stat in my Kseries conversion.

The only 'care' I use with my K is proper warming up, ie. I stick to around 3K revs and 1/2 throttle until I see 70C+ on the oil temp gauge.

As pointed out earlier in the thread, hot coolant does not mean the block is warm so after <10 mins driving there will be stresses on the block/head.

BTW2 - I do this for every car I drive, regardless; where there's no oil temp gauge, I consider 15 mins / 10+ miles is needed to warm an engine properly. Maybe a little less in the summer, and a little further in the winter. (Same e.g. for track-day use and even hire-cars!)

[It has to be said that with EFI, you *can* drive a modern from cold with WOTs, unlike the old days where you'd have to play with the choke until engine was warm - they reminded you they were still cold...)

BTW3 - I've never had HGF since I started motoring in 1973.

A
Anthony Cutler

interesting graph Steve - I thought it was the gauge that was funny rather then the ECU output, could easily be either though - though I can't really tell now as I'm using the original mercury one in my K :)
Rob Armstrong

In these straitened times with the high cost of petrol I can't afford to "give it the beans" too often.

Dave
D MATTHEWS

Yes; thx for the graph. I indicated earlier that the ECU determined what the gauge reading would be, e.g. they damp normal fluctuations so that any other movement is more noticable.

This of course is true for all gauges which are driven off the ECU.

Does anyone remember the old M-B oil pressure gauges? They would be calibrated to 45 psi, when the engine was expected to run at 60+psi. So in normal driving, they'd be up against the end-stop, and come down 1/2 way during idle. This prevents you fretting about the pressure being 60 psi, or 55 psi, or even 50 psi when driving, since it didn't matter provided above 45psi. Quite clever.

Napier engine: extraordinary how complex last generation aero engines became. My virtual hanger has Sept-40 Hurricane, MK IX Spit, Mossy, and Tempest (Napier SaberII A or B); shame I don't have the time to fly them.

A
Anthony Cutler

Have done about more then 50.000km's(on a secondhand engine) with the K in and sofar no HGF(knock on wood) ;)
Like Ant does I always warm it up before revving it.
I do have a oil tempgauge installed for over a year just not connected yet...
check the coolant level and warmup the engine before revving and you have the same chance on a HGF like any other car.

In the beginning of this year I did think for a moment my HG was busted but having the symptoms explained on this bbs I was reasurred and drive it again when ever I like.
Arie de Best

So where's all the coolant going then Arie?
Tarquin

I think some of the problem is people consider HGF to be water in oil or oil in water? The K series is not always as blatant as this, it can be a slow steady loss of water. It can be held at bay with additives in the cooling system. It can be a matter of just topping up the water in the header tank.

Maybe the argument should be ' what constitutes HGF' or at what point does HGF become a problem to sort in K series engines? If a race engine uses 1 litre in a race so what as long as the engine doesnt fail? I think many people consider sudden and catastrophic failure to be HGF. Remember the shades of grey.

Sometimes the problem is porosities elsewhere and the HG gets the blame.


The uprated HG kit does seem to hold up well and you also get thicker gasket to offset head skimming. This will keep cam timing where it should be rather than retarding the cams as happens when heads are skimmed.

Peter
P Burgess

Hi Neil I forgt about this thread?

I have an MGF with a Kseries engine installed. It's 14 years old and not had HGF so that's good.

Not been with me all that time and has only done ahout 40000 miles from new so hasn't done too many miles but many K Series engines have given up the ghost at only 20000 Miles.

In the ime I have owned it I have been listening and gathering as much info as possible to undertand the problem.

I can only offer my opinion based on the things I have heard and seen.

Some suggestions I have found appear to be total nonsense when considered in a rational manner. The one that sticks in my mind is the story that as the thermostat open thermal shock causes HGF. ???
What?? if that were the case then simply removing the thermostat would instantly cure he problem (pity MGR) didn't simply remove the thermostat then they would possibly still be in business.

There are others just as ludicrous that do not cure the problem, in fact nothing actually does cure the problem although a few companies do offer a lifetime warrenty so perhaps the work they do may be the right approach? only time ill tell.

I personally believe the same as Ant. If you allow the engine to warm up slowly then I think you have a good chance of avoiding problems and it is how I treat my car and touch wood great so far.

I also believe like many modern engines the K Series is a great piece of kit, however in my opinion the stretch bolts and strange headgasket is fundementally flawed in design. But with headgasket repair below £800 you just can grin and bear it and enjoy the really good times.
Robert (Bob) Midget Turbo

I think the thermal shock issue causes the block to shrink a bit - over time this wears the liners into the head = HGF?

the main problem with it seems to be small coolant flow round the head and poor flow through the block past the liners. this is compounded by poor service practice (especially in MGFs) by garage monkeys not bleeding the system properly, apparently this accounts for the large number of failures after the 'coolant flush' item in the service history @ 32K.

IMO stretchy bolts is clever, my 1.4K weighed 96KG with all ancillaries on it. I can just about lift the whole engine by myself. It's light.

This in an interesting if oddly written book - http://www.amazon.co.uk/Rover-K-16v-Engine-1989-2005/dp/1841556882

though I didn't pay 50 quid for it!!

I've also seen the stretch bolt aero engine in a book called Driving Force, very advanced for it's age :)
Rob Armstrong

OK Rob do you think that if the thermostat were removed then HGF would cease because thermal shock would be a thing of the past?

Or simply a smaller bypass around the thermostat?

Seems a very simple cure if true?
Robert (Bob) Midget Turbo

Hi Rob

If it was thermal shock failure would it not manifest itself with failure on the gasket with the bore nearest the influx of cold water?

Peter
P Burgess

I'm not saying it's the only cause of HGF - just suggesting a possible reaon why it might cause it. removing the thermostat would certainly reduce thermal shock - wether this would make any difference or not is debateable. I've got a hole in my 'stat to help reduce it when it opens.

Though thinking about it more, the stat rarely shoots open all in one go - so maybe the thermal shock effect is small? Not sure where it would cause it to fail, as I guess the stat opening and closing will also change the outflow of hot water from the head..

I'm not sure where the K's tend to fail - my old silicone gasket was perilously close to a water-oil interface at the very back of the engine, where the exit for hot water is.

I do know from hunting in the 16V section of this site that the bypass flow seems to be critical to the smooth operation of the engine.
Rob Armstrong

For yee unbelievers in thermal shock failure:
http://www.mgfmavhh.ukf.net/
Arie de Best

With courtesy of Paul Walbran who made us aware of this source of information. :)
Arie de Best

Hmm.

So the Kseries 'stat closes after a small amount of cold water is let into the block mixed with hot, and cycle repeats; this should reduce thermal shock, compared with the Aseries:

For the Aseries, the stat opens when the water in the head (esp at the front) reaches 88C; hot water continues to flow into the rad, meaning cold water is entering the block; when this cold water reaches the stat, it will finally close. It would seem the Aseries gets a bigger dose of thermal shock compared with the K...


A
Anthony Cutler

I'm not an expert, but i have a very interesting document on the K series. I have put it on the top of my page. called "King K"

http://cusworth.net/mg/
d cusworth

I know I've said it before, but ...

Trade customers here who deal with a lot of K engines advise that in 99% of cases, HGF is a response to a problem elsewhere rather than spontaneous. If you fix the head gasket without finding the problem, it will happen again. Ditto if you fail to check the head hardness and liner protursion to see if there has been serious effects on the alloy from overheating.

In my view, the use of the bypass flow to activate the thermostat is an issue. If the flow is interrupted somehow, you get problems as then the stat is seeing only the cool water from the radiator and stays firmly closed. This is why eliminating air in the cooling system is critical. Interestingly, a colleague notes the same experience with other makes of engine which have the thermostat on the engine inlet and rely on bypass flow to operate.

The F with it's long and inverted cooling tract to the radiator at the other end makes it more marginal and affected by low coolant and easier to trap air in the system.

We realised the bypass flow was marginal when we inserted another 6" and a couple of bends (of good diameter) in the K Midget's bypass in order to allow better access to the crank sensor. The stat wouldn't open until about 4000 RPM, which was fine when competing but hopelss in city traffic! A full-flow bypass PRT fixed that.

Overheating has to be really serious for the head or block to be affected from my own experience in the family Rover 200 with VVC engine. We had a complete loss of coolant after hitting a hapless black dog one rainy night in the country and taking out the bottom of the radiator. With the rain pouring down didn't notice the coolant on the road, and didn't realise until the temp gauge rammed into the red a couple of miles later. That was at 200 000 km. The engine has now done nearly 300 000km. (We've had the car from new and so know its full history.)

So yes, I subscribe to the theory that some people just drive on despite the overheating. In fact one customer drove nearly 100 miles knowing the engine was seriously hot! And needed another engine for his trouble.

Unlike the Rover, our MGF has suffered from "HGF". Well, it didn't really. I just believed all the hype when the engine overheated and jumped to the wrong conclusion - there was nothing wrong with the gasket we found on stripping it. I wonder how often that has happened.
Paul Walbran

I'm not familiar with the MGF set-up, but does the cooled water really leave the radiator via the TOP hose as shown in the diagram?

Dave
D MATTHEWS

What would be most interesting would be some mention from the K series engine designers/testers, I can remember Rog Parker telling me about the bhp outputs of the K series on the dynos in the early 80s. i am sure the thermal shock failure must have reared its ugly head during testing.

Tis like the problem with the SD1 radiator failing under vibration.....it used to be featured on one of the Open University programmes and showed the pre production testing to destruction process. To overcome the problem Rover put four upright thin metal rods vertically on the rads.

Peter
P Burgess

That would be nice indeed Peter.

However,

Arie yes the guys from the MGCC F Register have done some great work identifying sensitive areas of the engine and Techniques and Modifications that can limit the damage.

Note I choose my words carefully and State LIMIT and not CURE.

The Engine has a fundemental problem that MGR have failed to cure, whether the Chinese have managed to cure the problem only time will tell.

As I remember the very first thing that MGR attempted to cure was the head moving around on the block by replacing the plastic location dowels with steel dowels (Did that cure the problem ?) certainly didn't harm it. But many have failed since.

Must admit whilst researching the problems with this engine I found the vast majority had marks on the cylinder head around the top of the cylinders that appeared to have been caused by the liners "moving" around on the head (or visa versa) however these marks were more pronounced on the exhaust side of the head?

As I have mentioned before the VAST majority of knackered K series engines I saw that had HGF were in fact from the Rover saloon range.
Robert (Bob) Midget Turbo

The marks on the head arise when the head has gone soft from overheating. That's why it's worse on the exhaust side. We've seen plenty of heads (most) which don't have this problem because the car wasn't run with the cooling system on the blink for too long.

And yes, the plastic dowels were an issue. They cracked.
Paul Walbran

I have only just picked up on this thread and two interesting things spring to mind.

Firstly I have not had a K, but my understanding was that one major reason for failure was that the block holds very little water compared to similar size engines and therefore any loss soon becomes critical hence as stated many times above lack of regular checking of the coolant or carrying on when it boils gaurantees failure.

Secondly Gryf mentions the Climax engine earlier. I ran one of these years ago in my Sunbeam Imp Sport. These engines failed regularly too, but those of us using them soon discovered that they only failed if the engine overheated. Again this only happened if you lost coolant. The other key factor we soon learnt was not to use pattern head gaskets as though they were a third of the price they didnt work. An OE gasket and regular checks on coolant meant they lasted well despite being regularly revved to 7500.

I think this shows that most ally engines suffer trouble if not maintained properly especially if they boil up.

Trev
T Mason

This thread was discussed between 04/01/2009 and 29/01/2011

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.