Rover K series (turbo) - can it be made reliable now?

[s91]

I'm considering using a turbocharged K series in a project car, but trying to find information on reliability is a bit difficult, the K series fans will tell you it's a great engine and their's hasn't ever gone wrong and everyone else will repeat the usual tales of HGF, add to that the various "fixes" over the years and the different combinations of engines and parts used, the standard 1.8 turbo lump vs turboing a 1.4/1.6 which some claim to be stronger, VVC vs solid cam, and so on.
I've always dismissed the K series but recently came across another so called "fix" which uses parts from the new N series which is supposed to be a development of the K and apparently reliable. You can buy a kit with the new oil rail, HG, and stronger bolts.
I've read about various other problems that relate to HGF such as incorrect liner heights, thermostat/cooling system design, etc, and have found some old posts on here on the same subject so I'm sure this has been discussed many times already but a lot of those posts are quite old so I'm hoping things have moved on since then.

Basically what I want to know is can the 1.8 turbo K series (R75/MGZT) be "reliable"? Not looking to run silly amounts of power, just low to mid 200's which I'm told the standard pistons and rods can cope with, it's the rest of the engine I'm concerned about.

[Plate spinner]

You’ll get plenty of opinions and anecdotes. Suggest you have a chat with Dave Andrews at DVA Power.

He built my k series engine when I had a Caterham. It delivered the numbers, was used extensively on road and track and was 100% reliable during my time.
Based on that I trust his opinions and some regard him as a bit of an authority on the k series.

Hope that helps.

[kambites]

Yes its possible to build a reliable K-series, but there's no single golden bullet upgrade which does it.

The N-series stretch-bolts and oil-rail does seem to be a good upgrade in terms of improving head/block interface pressure consistancy but it's not going to help if your liner heights are off or the head is porous. Most of the K-series' problems were more down to shoddy quality control rather than fundamental design flaws so "fixing" a K-series is different for every unit depending on what they screwed up when they manufactured it.

Starting with a pre-BMW engine is a good idea because they were generally better made.

Edited by kambites on Sunday 11th March 11:43

[ManOpener]

Possibly worth having a chat with StuBalls on here? He built a 1.8 turbo K for his 200BRM, it went through several iterations, a couple of rebuilds but I think is now running reliably.

[Ikemi]

The more expensive option is to go the Honda Type R route, with the ability to add a supercharger and a charge cooler too, for additional power. Turbo Technics used to (might still?) offer turbo upgrades for K Series engines. Is there a distinct reason as to why you'd like to keep with the K Series?

I used to love the K Series engine in my previous Elise; it's simple to work on, cheap parts and has bags of character. However 3 head gasket failures later (over 100,000 miles) took the shine off the engine's positives. Most Elise/Exige owners who look for more power opt for the Honda or Duratec engines. Some owners opt for the Audi turbocharged engines.

My current Elise has an Audi turbocharged lump, with surprisingly linear (but brutal!) power delivery ...

[s91]

Ikemi said:

The more expensive option is to go the Honda Type R route, with the ability to add a supercharger and a charge cooler too, for additional power. Turbo Technics used to (might still?) offer turbo upgrades for K Series engines. Is there a distinct reason as to why you'd like to keep with the K Series?

All I'm looking for really is a cheap project, strip the car back to a bare shell, remove as much weight as possible, take the engine apart put it back together with the parts that are needed to make it "reliable", it's just as enjoyable to me to build something as it is to drive it.

I've considered an EP3/DC5 and turbo'ing it but the cost is a bit high as I only really want it as a bit of fun on the side, something to build and then use as a track/weekend car, an MG/R parts bin special seems ideal as ZR/ZS shells are cheap, as are most of the parts for them. Most people would probably go with the T16 but it's a heavy old lump and I quite like the power to weight ratio of the K series, as long as it can handle around 230-250bhp.

[Limpet]

kambites said:

Most of the K-series' problems were more down to shoddy quality control rather than fundamental design flaws so "fixing" a K-series is different for every unit depending on what they screwed up when they manufactured it.

Edited by kambites on Sunday 11th March 11:43

This. The casting quality was so patchy that some engines left the factory as ticking timebombs, while others never hiccuped throughout their working lives. If you're saddled with a bad one, it doesn't matter what you do, it will never be reliable.

It was an engine that needed far tighter production tolerances and more careful assembly than Rover were willing or able to give it, particularly later on when the cost cutting started to bite.

[s91]

Limpet said:

This. The casting quality was so patchy that some engines left the factory as ticking timebombs, while others never hiccuped throughout their working lives. If you're saddled with a bad one, it doesn't matter what you do, it will never be reliable.

It was an engine that needed far tighter production tolerances and more careful assembly than Rover were willing or able to give it, particularly later on when the cost cutting started to bite.

I've seen various comments about engines from certain years are more reliable than others, is there any truth in that or is it just pot luck?

Does anyone else other than those already mentioned have any experience with the 1.8 K turbo? And what's the deal with VVC vs solid cam, I see a lot of the high performance versions of the K series use a solid cam, is that because they are more for race applications where revs are continously kept within the powerband where VVC isn't really necessary or is there a problem with it? It seems daft to not bother technology like that when it's available.

Edited by s91 on Monday 12th March 18:38

[kambites]

The VVC doesn't really provide any extra power so its not particularly useful for race type applications where you're always at the top of the rev range anyway. I think it also limited the revs the engine can run to (I've never seen a VVC unit reving ot above about 7500rpm) and obviously adds complexity and weight.

As for engine years... things generally got worse under BMW ownership as Rover were pushed to cut costs, but every era has its good and bad examples and most engines will have had some sort of work by now. Your best bet is probably to try to find an engine which has had a well documented top-end rebuild, including proper measurement/correction of liner heights, etc.

[98elise]

Limpet said:

kambites said:

Most of the K-series' problems were more down to shoddy quality control rather than fundamental design flaws so "fixing" a K-series is different for every unit depending on what they screwed up when they manufactured it.

Edited by kambites on Sunday 11th March 11:43

This. The casting quality was so patchy that some engines left the factory as ticking timebombs, while others never hiccuped throughout their working lives. If you're saddled with a bad one, it doesn't matter what you do, it will never be reliable.

It was an engine that needed far tighter production tolerances and more careful assembly than Rover were willing or able to give it, particularly later on when the cost cutting started to bite.

Agreed. It's a great engine but poorly executed.

[J4CKO]

Havent MG sorted the HG issue in the MG6 etc ?

Do those bear any relation to the older ones ?

[kambites]

J4CKO said:

Havent MG sorted the HG issue in the MG6 etc ?

Do those bear any relation to the older ones ?

I certainly haven't heard of any head-gasket problems with the N-series but with volumes being so low in the UK I'm not sure that tells us much. Even if the N-series doesn't suffer from it, it'd be hard to know whether that's down to changes to the oil-rail and stretch bolts, improved manufacturing processes, or both. I suspect both.

[anonymous-user]

I have no idea why you'd want to use an old k series these days for anything?

There are plenty of 1.6 / 1.8 and 2.0 engines in breakers that are already turbo'd, and will make 200 bhp all day long with OEM reliability? I'd get the engine out of a breaker, and budget £1.5k for a reasonable aftermarket ecu to drive it...

[kambites]

Max_Torque said:

There are plenty of 1.6 / 1.8 and 2.0 engines in breakers that are already turbo'd, and will make 200 bhp all day long with OEM reliability? I'd get the engine out of a breaker, and budget £1.5k for a reasonable aftermarket ecu to drive it...

I suppose that rather depends on what the project is. Most four-pot turbos are a fair bit heavier than a K-series which might or might not be an issue, depending on what it's going into.

Having said that, most cars which are light enough for it to matter don't really suit turbocharged engines anyway.

[turbotoaster]

you can get plenty of power out of a rover k series turbo.

You just need to know where to and where to not spend the money.

Alot of the stock components are good, a few things need extra clearance and picking the correct components.

All stock component bottom end.

382bhp/341ftlbs.....simply ran out of turbine housing at 25psi, else easily over 400bhp

Forged

470bhp/370ftlbs on lowish boost up to yet, will be turning it up next month with the aim of 600bhp.



If you want advice on how to make 300bhp and keep it happy long term let me know

[227bhp]

ManOpener said:

Possibly worth having a chat with StuBalls on here? He built a 1.8 turbo K for his 200BRM, it went through several iterations, a couple of rebuilds but I think is now running reliably.

Think again, his is an excellent example.

Rather than spending money turboing a K, just cut out the middle bit and go bang your head against a brick wall. It's ok as an N/A if built by someone who knows it.
If you want something light, cheap and reliable get a Duratec.

[anonymous-user]

kambites said:

Most four-pot turbos are a fair bit heavier than a K-series

Back in 1995, when 4 pots had iron blocks and iron exhaust manifolds then maybe. Today, er nope. I typical modern 1.6 with an ally block and SS exh manifold (or exh-in-head type arrangement) will be as light, or maybe even lighter, especially when you strip off the stuff like EGR and cats etc! Modern engines make extensive use of plastic parts to keep mass down too.

[Ive]

I did not turbocharge mine, but run a Rotrex supercharger on my former K for 12 years.
In its strongest iteration, it was running 1 bar of boost from a Rotrex C30-94 spun to its rev limit , VVC160 head with Newman ph2 cams.
The big trick were forged pistons and Westwood nodular iron liners.
But then I was also running methanol water direct port injection, charge cooling, wideband lambda with full time closed loop fueling, a J&S safeguard knock controller, 2.5" exhaust system etc.

I have decided in 2016 to go NA for some time and ended p building a 2.2l Honda K-series stroker.
My old bottom end now still happily potters along in an other chap's Elise with 0.8bar of peak boost from a Rotrec C30-74 and somewhere around 260HP. It now features a functional VVC and a lower rev limit of 7k.

[DVandrews]

They would be ductile iron iners, they have around 2.5 times the hoop strength of the regular liners.

Dave

[westwood35]

DVandrews said:

They would be ductile iron iners, they have around 2.5 times the hoop strength of the regular liners.

Dave

Well said that man...... Nearer to three times tensile strength.