"The K-Series Head Gasket" - PPC Magazine technical article. - Page 4 - MG-Rover.org Forums
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post #61 of 102 (permalink) Old 11-08-2010, 12:22
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Originally Posted by KingK_series View Post
Well I use my own stronger studs - so yes good idea, more clamping load, but the trouble is the block and the crank path were machined for the old OE unheat- treated bolt , about grade 8. So use a stiffer bolt and you will distort the block more, crushing the crank in it's path.

A similar situation happens at Scholar - they hone liners in blocks and occasionally crank paths, They are honed with their own grade 10.8, 10mm bolt done up to 60lbft. The OE bolt sequence 20Nm + 180+180 is equivalent to 40 NM - about 32lbft




so as I said building problems into the engine.

And as my uncle used to say," midbogglingly stupid"
Do they have more clamping load then?

I assumed the load would be the same since they are not tightened as much and it's just that they stretch less when additional load is put on them - thus the block would not be distorted?

Quote:
the MLS kit ( ZUA000080 ) which includes the new uprated oil rail. High tensile head bolts are WAM2293SLP. These are grade 10.9 which do not stretch as much as the originals. ( Grade 9.8 ) Once these are torqued into the heavier oil rail....they stay torqued !.

This oil rail is the same as was spec'd for the EU4 engine and is the one for the even newer "ultimate fix" gasket kit mentioned in another post.
So are the head bolts WAM2293SLP.
Only thing with the newer type is the torque settings change.

20Nm then 180 degrees and then 135 degrees instead of the current 20Nm then 180 degrees and then 180 degrees .

Last edited by Stu; 12-09-2010 at 16:59.
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post #62 of 102 (permalink) Old 11-08-2010, 12:29
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Originally Posted by KingK_series View Post
Part of what you say is absolutely correct, hardness testing of the head to min 95 brinnell, and the cause of most failures. Many garages do not understand this nor did /do many tuners


I have spent many hours with the gasket engineers at Payen Federal Mogul and Rover talking to and learning about the gasket technology. The fire ring is very sophisticated and designed to work with an engine that experiences head shuffle - like F1 engines.

The shim came about in a round about way. Payen were obviously working with Rover who were supplying parts through WSR to Judd for the touring car. Judd had a particular problem with gaskets eating into the head at the rear of the engine. NOT the front, just the rear, and tried all sorts of things to address this, 3 dowels, elastomer to seal, etc etc etc. They could not stop the issue, until they made a saver shim. Thus Judd were the first to incorporate one on a K.

Unfortunately, as so often happens the cause of the problem was not only missed by Judd, but Rover and Payen were not in the loop because they were not actually working on the Judd engine, just trying to help on the phone. What had happened was that Judd had removed one of the lugs at the rear of the engine which normally mounts the gearbox in order to clear the Hewland diff. Now I new from Robert Allebon then responsible for cranks at Eastworks that extra webs had had to be cast in those mounting lugs for production blocks, because DL1 pre production blocks without that extra web were cracking heads, losing gaskets by firerings working into the rear of the engine because of the twist put on the rear of the engine by the gearbox, in a road going car with road tires. Imagine how much worse it was with 180lbft, a Hewland box and Slicks for Judd. When I saw that, the answer was to radically redesign the gearbox mounting with stiffening plates along the block that doweled to the bell housing. The problem went away.

However the shim idea was in the air. Ford who were after a "visible" solution to the "HGF" issue persued the shim idea through payen with MLS, the added befit that it would alow soft heads to be reused.

Ford did not understand the issues, and fought a political war to introduce MLS AND shim, against the advice and wishes of the Rover design team. Some I know were furious about that, and in fact MLS was never signed off, it never passed all the tests a gasket needed to to be signed off, but was just sold on by Ford into the dealers after the collapse.

Same is sort of true about the new fire ringless gasket. Spoke to some of the guys at SAIC, old Eastworks engineers who know about it, but have no idea who makes it, and I can tell you the chinese made K uses a fire ring identical to the one on the Payen gaskets. No one in the office yesterday, had any faith that the ringless gasket could ever work on any K.
What an interesting read ~ thanks for posting that KingK_series.

I have been an admirer of the K-Series since I saw that Open University feature on it's design and construction some twenty years ago. Main problem with the K-Series is that it is a tad too sophisticated for the average AtoB car consumer most who never lift their car's bonnet unless something appears to go wrong ... Guess what...things go wrong..

When it was stretched and stretched well beyond its original 1.1 and 1.4 litre design capacity, they should have scaled up the engine accordingly and thus benefitted from the additional strength the extra bulk would provide. Seems that Judd did something on those lines to cope with the torque involved with the block-gearbox interface.
..

Apparently ... in a parallel universe MGJohn drives .........A.......

B>>M>>W ....

Arrrrrggghhhhh......... ......

Last edited by Stu; 12-09-2010 at 16:59.
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post #63 of 102 (permalink) Old 11-08-2010, 12:49
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Quote:
Originally Posted by KingK_series View Post
No need the oe gasket works very well. IT IS NOT THE GASKET that fails, until a long time after the problem starts at any rate. 'HGF" IS A COMPLETE MISNOMER, engines fail because of thermal shock which distorts the head, causes leaks, then hotspots which causes annealing of the head, compounded by low liner heights, but the cause is always the head bending because of inadequate water temp control.

Materials and design of block is fine, trouble is people mess with it without understanding design and get it wrong, the 2002 - mid 2006 Touring car engine was an example in the case of lopping off the lugs.
Hoo ~ bleedin' ~ ray!

Some of us have been banging on about that for ages... but, the misnomer "HGF" mud sticks ad infi-wossname.

... one day I hope to educate the world ... but, it's hard going ...
Quote:
Originally Posted by MGJohn

Cylinder head gaskets rarely 'fail', they are first damaged by some other agency, often overheating stresses caused by loss of coolant... thus damaged, they can no longer do the job they are designed to do and thus "fail"....
.

Apparently ... in a parallel universe MGJohn drives .........A.......

B>>M>>W ....

Arrrrrggghhhhh......... ......
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post #64 of 102 (permalink) Old 11-08-2010, 13:07
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Hoo ~ bleedin' ~ ray!

Some of us have been banging on about that for ages... but, the misnomer "HGF" mud sticks ad infi-wossname.

... one day I hope to educate the world ... but, it's hard going ...

well said!

and all the engineers at Powertrain/Rover, now SAIC etc would say the same
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post #65 of 102 (permalink) Old 11-08-2010, 13:12
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Originally Posted by Windy View Post
Do they have more clamping load then?

I assumed the load would be the same since they are not tightened as much and it's just that they stretch less when additional load is put on them - thus the block would not be distorted?

The idea of the revised torque settings is to reduce the load, but it is a bodge frankly to try and do that retrospectively the block needs to be machined around the bolt at it's installed setting.

So there is little or no clamping load gained if you torque to the new setting, and you crush the crankpath if you torque to 32-36lbft which is the norm for a 8mm head stud,
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post #66 of 102 (permalink) Old 11-08-2010, 14:13
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So there is little or no clamping load gained if you torque to the new setting...
So their purpose is not to change the clamping load but to do something else...

It is possible that at the time the original bolts where specified it was not feasible to make bolts to the new specification and that these are in fact an improvement rather than a "bodge"?
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post #67 of 102 (permalink) Old 11-08-2010, 15:53
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So their purpose is not to change the clamping load but to do something else...

It is possible that at the time the original bolts where specified it was not feasible to make bolts to the new specification and that these are in fact an improvement rather than a "bodge"?

Well who knows??

At Rover, Powertrain before the collapse they had trialled heavier bolts, but then the blocks were machined to match and the bolts were torqued up to a higher load.

I do that on mine, but only the blueprinted engines. In truth it is theoretically better to have higher clamping load, but it is usually engines with a low liner height when you get heads lifting, and relatively rarely.

The reason I did my own studs was the blueprinting process requires the block torquing up 3 times, and since the oe bolts stretch they give a different [slightly] clamping load each time, so you have to use 3 sets new bolts to get that right - which is expensive, more so than one set of bolts done to x condition, since you are line honing etc anyway.
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post #68 of 102 (permalink) Old 11-08-2010, 18:25
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Personally not convinced with PRT, to many so equiped cars have been through our workshops with identical failures to tractional thermostat set up to indicate they are any advantage.

Quite agree that HG is not the failing part but the weak link that will fail due to another issue.

In rallying the Judd 2.0 K is not well regarded, in the S2000 its pretty much killed that car dead, underpowered, unreliable to expensive. the rest of the car is very good, but when you can buy a better bit of kit from 6 other manufacturers its easy to see why its died a death.
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post #69 of 102 (permalink) Old 11-08-2010, 19:06
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How much was an s2000 class MG when new? Out of interest.

I was looking at the new fiesta s2000 the other day.... dreaming of course
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post #70 of 102 (permalink) Old 11-08-2010, 19:25
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Prices were vague but running cost on engine make it a non starter.

Fiesta S2000 is no match for the Skoda S2000. Was over in Finland for 1000 lakes rally doing a few bits, Toni Gardemeister drove wheels off the Fiesta but just couldn't make any impression on the Fabia.
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post #71 of 102 (permalink) Old 11-08-2010, 19:55
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Prices were vague but running cost on engine make it a non starter.

Fiesta S2000 is no match for the Skoda S2000. Was over in Finland for 1000 lakes rally doing a few bits, Toni Gardemeister drove wheels off the Fiesta but just couldn't make any impression on the Fabia.
Fabia VRS... now with rally pedigree, he he.
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post #72 of 102 (permalink) Old 11-08-2010, 21:00
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Fabia has always had a strong rally pedigree, remember that amazing drive by McRae in the Fabia WRC?

The S2000 cars have very little in common with the road cars, the suspension doesn't even point in the same directions!!!!

Fiesta runs massive massive positive front castor and heavy positive rear, fabia funs negative rear castor!

sorry all off topic I know!
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post #73 of 102 (permalink) Old 14-08-2010, 17:56
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headgasket gone on mgf - in great condition

I am looking for advice on:
  • the value of my mgf 1999 to sell (needs new headgasket) and
  • possibly good places to sell my 1999 T reg MGF.
Looking for more of a die hard MG fan or someone with the time to fix the headgasket as obviously the part really cheap it's just the time/ expertise.

Basically its in really, really good condition, bodywork great, new starter motor & wheel bearings within last year, MOT Jan 2011, seats in great condition (not worn a all), only 62K on clock, new perfect black softtop hood (2.5yrs old). I've looked after it very well. However the other night - the head gasket went.

I know I can get this fixed for 500 (I got a good price) but it's not worth my investment as I'm about to work overseas for 6 months as of Oct 2010. So my plan was to sell or park up - but with the gasket going 2 days ago just seems like it should go to new home.

Everything is working, elec windows, 6 cd stacker in back and has all the normal features, alloys, elecwindows, etc. British racing green with faux wooden interior wheel/ clutch.

Please can you point me in the right direction of where someone could buy this absolute bargain! and honest price i should expect to sell it for when it is in brilliant condition - just only needs new owner to buy and do the headgasket.....
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post #74 of 102 (permalink) Old 22-09-2010, 13:32
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Smile service intervals mgf 1.8i cambelt

Hi first timer ive just brought my first mgf 1.8i 2001 model,service history states cambelt changed in 2007 at 38000 miles.Car has now done 59000 miles when should i change cambelt again.Hope someone can help.
Kind regards symone brown
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post #75 of 102 (permalink) Old 04-10-2010, 18:13
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Originally Posted by KingK_series View Post
engines fail because of thermal shock which distorts the head, causes leaks
Although a contributing factor, this is a long way from being the whole story. I have written at length about this in the past so won't repeat myself, but the weakness of the gasket is due to a combination of half a dozen questionable features.

During development, the gasket is tested for its ability to withstand thermal shock more than any other running condition. The engine is run on a rig alternately at full load and power with closed thermostat up to 110C, then the engine is dropped down to idle and suddenly flushed with chilled water. It spends many weeks and hundreds of cycles running this test.

In the case of the K series engine, no amount of thermal shock testing would cause gasket failure. This had never happened before, so a special test was devised with a new rig giving a more extreme and sudden temperature cycle, but the engine still passed with flying colours.

Thermal shock obviously affects the gasket, but from the results of this test the K series would seem to be more resistant than other Rover engines. The position of the thermostat makes things a little worse than usual in the vehicle, but not to the extent that it would override the results of this extreme test.
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post #76 of 102 (permalink) Old 11-11-2010, 18:40
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In my view, there is one overshadowing factor that affects HGF, and that is overheating, ususally, and almost exclusively, as a result of water loss.
The best option is to install an alternative temperature gauge, and to visually check the level of cooling fluid often, as in daily.

It is obviously an overkill for all the days where nothing has been lost, but it comes in quite handy for failing T-pieces, water pumps, radiator caps, inlet manifolds, not to speak of rotten hose pipes, general laeks and other unfortunate events.
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post #77 of 102 (permalink) Old 11-11-2010, 19:16
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My choice would be a coolant level sensor so that I got a warning before the overheat started.

We trashed the first two K series development engines by overheating them! Oops!
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post #78 of 102 (permalink) Old 11-11-2010, 19:21
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In my view, there is one overshadowing factor that affects HGF, and that is overheating, ususally, and almost exclusively, as a result of water loss.
The best option is to install an alternative temperature gauge, and to visually check the level of cooling fluid often, as in daily.

It is obviously an overkill for all the days where nothing has been lost, but it comes in quite handy for failing T-pieces, water pumps, radiator caps, inlet manifolds, not to speak of rotten hose pipes, general laeks and other unfortunate events.
Thats what i have done, very handy it is too, observing the temps in "real time"
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post #79 of 102 (permalink) Old 11-11-2010, 22:37
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My choice would be a coolant level sensor so that I got a warning before the overheat started.

We trashed the first two K series development engines by overheating them! Oops!
You are right! That is the best option. But here are problems with the existing plastic tank. Guess one would have to build one in aluminium.

So next best option, install temperature gauge and physically check!
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post #80 of 102 (permalink) Old 01-03-2011, 12:41
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Hi all,

I have to admit that this is a very informative thread about the K-series HGF issue. I have got answers to a lot of my questions/toughts about this issue, but there is still one thing that I haven`t got a clear answer for. What causes the low liner heigths? Does the liners drop after a while, or are some engines just delivered from the factory with low liners?

I am in the middle of a project were I am trying to get my overheated K-engine up and running again. It had a coocked head and low liners. My solution is to shim up the liners and put on a reconditioned cylinder head that are within spec.
I have an ongoing thread about this project here: This car had 2x HGF, need some advice
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