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MG MGF Technical - Exiges.com (k series info)
|Dont know if anyone reads SELOC or this may be on the Lotus pages on here but there's an interesting thread on Exiges.com|
A lot to get through but I'm sure it'll be of interest to messers Bell, Philips, Munns etc.
Basically someone is stating that a reliable 240bhp is attainable fairly easily from a 1.8K as long as the engine is put together very well. Seems to be a friend of Dave Andrews and Dave Walker and the man seems very knowledgeable. A lot of it's over my head but very interesting none the less.
|Thanks for the heads up Bob - I'll head over and have a look now. |
BTW - have replied to your post on the Knitting Circle...
|NEVER go to pistonheads.com as you will be there forever...must keep taking my medicine!|
That thread took a lot of digesting!!!
Quite a lot of arguing as well - as the two proganists seem to be arguing a slightly different point - if you read the thread, you'll see what I mean.
Interesting to read about the VHPD. The thrust of the argument regarding this engine is that it had nothing whatsoever to do with Rover, and has sullied the good name of the K-series through poor specification of parts and inadequate design/ tolerances.
Simon reckons that you could build a 200bhp K-series with a VHPD type head with 160lb.ft torque reasonably cheaply - that would be more cost effective than installing a Honda K20A VTEC (probably half the price, and a good deal lighter with a stronger torque curve to boot).
He's probably not wrong in the context of racing, where service intervals are short - but for a road car which is taken on track days? Here, long service intervals and ultimate reliability become far more important. Perhaps paying double for the Honda etc would pay dividens - which is the thrust of the anti-K-series argument...
I wonder if Dave Andrews et al have read the thread, and are prepared to comment? I guess we'll see...
|Anyone asked Simon for a copy of 'the article'?|
If so I wouldn'd mind a copy ;o)
V intersting reading. Wonder what a blueprinted 160 would put out? :D
|Yes - but not heard anything back yet Steve: I bet Simon has been inundated with requests for it!!! LOL|
A blue printed 160? Typically +10% - so hypothetically, 176 PS (174 ish bhp).
|Pardon my ignorance but what exactly does the term "blueprinting" mean/ involve|
|blueprinting is the process of making an engine to the specification declared on the blueprints. Commonly used to mean make an engine to the specification on the blueprints with a smaller error margin|
|Blue printed VVC engines were made available to competitors in the MGF Trophy a couple of years back. Blue printed by Powertrain, they were said to produce 10% additional power to the stock production engine...|
Not that we ever got to see a dyno plot of course! ;o)
Steve, I now have a copy of Simon's article. All 12 pages of it ;o) Will make fascinating reading on the train home tonight! LOL
What's your email Steve?
|crikey, can those Exige boys post. They make us look like part-timers, they must do even less work than me!!!|
|In all fairness exiges is usually dead as a graveyard but this has stirred it up|
|You can say that again Bob! Look how many posters have a post number of 1 or 2! Plus it's got us lot lurking on it as well!!! LOL|
|Rob, can you send it to the address on the left please :D|
|No worries :o)|
|Now that is an interesting thread. Guess he did a fair bir of research, otherwise, he wouldn´t be making these comments one "reputed" engine tuners. Still, from the thread, it is not clear to me what is involved in the blue printing programme. Some items are discussed, others aren´t.|
I received the article wihtin 1 min after applying. I´ll be reading it with a lot of interest.
|David, the whole engine is built to a set of specifications - as you know.|
What blue printing involves is making sure that all the components in the engine are EXACTLY the way that they were supposed to be from the original design specifications.
What this means is not only checking dimensional tolerances, and float/movement of moving parts, but also rotational balance of the reciprocating and rotational parts - ensuring that dynamic tolerances are met as well as static ones.
Vibration Free offer this service- seems surprising affordable if you have the engine already out of the car. Worth doing if the engine is to come apart for some reason (something else to have done, perhaps, come HGF time?)
|Surprisingly affordable? (ballpark figure?)|
|I seem to recall a 3-figure sum being quoted Will - which struck me as being much cheaper than I was expecting (ie not 1000s...)|
Website not especially helpful on the question of costs, but gives a good idea of the kind of work that Vibration Free do: http://www.vibrationfree.co.uk/
I guess my engine bay fan on the 97-VVC has made a visit to "vibrationfree" , anyone else with a small clip attached to one of the blades of said fan ?
|Yep, quite normal (even on my heater fan from 1979)|
After reading the article I couldn´t figure out whether the cranck and flywheel are balanced and counterweighed outside or inside the engine. Sorry for my ignorance, but it seems I´ll have go out and by Dave Walkers 4 stroke tuning manual. *LOL*
It is remarkable how unbalanced the cranck (be it AM Ot OEM part) is as opposed to final level balance by Vibration Free (guess they´ll be booked full for the next couple of weeks *LOL*). Actually most AM tuners are really, and I mean REALLY way off spec. The OEM item actually performs quite well to my surprise. Maybe I am misinterpreting some figures as the initial figure is the "unbalace level" and the latter the "in balance" figure.
IMO after reading the thread most people think the author means the K-series can be tuned to hi-power rather cheap. But that´s not what the author means. He says the K can affordably be turned into a bulletproof engine able to handle hig power outputs in a reliable way. Correct me if I´m wrong.
Can you email me a copy of the article please
|>> After reading the article I couldn´t figure out whether the cranck and flywheel are balanced and counterweighed outside or inside the engine. <<|
The balancing of the individual parts are all performed out of the engine - but I guess that the engine is then reassembled and the engine vibration measured? I'm not sure. Drop Vibration Free an email, I am sure they'd be delighted to answer your questions.
Your interpretation of what Simon is saying in the thread is pretty much mine too. The argument, such that it is, appears to be about two different things - and I think that many responding to the thread have got the wrong end of the stick. Essentially you're right: what Simon is saying that the K16 is an engine that is designed, with very little margin for error, as a 1.1/1.4/1.6 or 1.8. It was done this way to optimise for low weight, for optimal cooling and maximum power at these capacities. If you push the design parameters beyond what the engines were originally designed to do - ie 150-160 bhp @7000 rpm with 140 lb.ft torque for the 1.8, one should not be too surprised to find that the engine falls apart if you up the power to in excess of 200 bhp. However, sorting the bottom end of the engine to cope with 8000 rpm and 200+ bhp is not all that difficult to do so long as you know what you are doing - and it appears that a number of engine builders either don't know what they are doing, or worse, don't care.
Simon is arguing that the basic building blocks are there to build a reliable engine [but I am not clear whether Simon means a reliable race engine or a reliable road engine- the two are quite different]. However, the problem is that very few people have done what Simon is suggesting, and therefore Simon has faced a wall of scepticism for his pain.
It will be very interesting to hear what more experienced K-series experts and enthusiasts have to say.
|>> It will be very interesting to hear what more experienced K-series experts and enthusiasts have to say. |
Would be nice if Messr's Andrews or Walker would chip into the discussion, I think all the sceptics would do a sharp about face if Simon's links with these people were corroberated (sp?).
Wouldn't mind a copy of the article if you get 2 secs Rob. firstname.lastname@example.org
|Phil Brindley - Leicester|
|>>Would be nice if Messr's Andrews or Walker|
Believe me read the article and thread, and you´ll acknowledge he has spoken at length with them.
Simon´s car is a supercharged one (Eaton--> great, now I can drive a SC´d car and still keep the aircon;-))so I reckon he´s talking about a race spec car (>190bhp).
|Kevin, Phil, you both have mail! ;o)|
Although the two Dave's names are both mentioned on many occassions, it should be noted that this does not necessarily mean that they share Simon's view. Afterall, SimonE also mentions Simon Scuffham's name - and SimonS is certainly not of the same view as SimonE...
I am sure 101 people have already attempted to contact "The Daves" - I am awaiting to see what their responses are. ;o)
An aside: is it just me or are there too many Simons and Daves around??? ;o) LOL
|I agree Rob, fact that he has spoken to |
them doesn´t imply they agree, although he often says
"call Dave Andrews, he´ll tell you what I am telling you"
So at least one of the two must agree
|simon just wrote up a resumé of what´s needed to get a blueprinted +200 Bhp K engine. check out pg17 of the above mentioned thread,|
If possible could you e-mail me a copy of the article.
I was up to 4am on Friday reading the thread and it was pretty cool if somewhat mind boggling. Do you guys think it had much relevance to us MGF owners who may be using the cars for everyday transport?
I appreciate the K series is sensitive to tolerances, but I’m not going to be a hurry to pull out my functioning engine to blueprint it. Do you consider there may be worthwhile gains doing this over conventional tuning such as exhaust and induction mods or is it only relevant for in the rarefied 200bhp atmosphere these Exige boys seem to be breathing?
|Just copied and pasted Simon's 'instructions' onto the end of his KingK article (by the way did anyone get hold of a copy of the graph? All i have is a [placeholder] ).|
Personally i am sold on his approach - it seems to have been thoroughly researched and answers so mny of the 'issues' with the engine.
The biggest problem though is that there are very few places that can perform the work Simon mentions for a reasonable sum of money. This i feel is the only thing now missing from his theory. I'd like to see a list of companies who can perform this work and a ball park estimate of costs.
I suspect that this information will confirm my thoughts that the cost of doing this work are considerable due to the specialised nature of it (balancing to the very fine tolerances he mentions for example, he says himself is beyond the capability of *all* the tuners he has had experience of).
Costs are relative of course, what is cheap to an Exige owner is likely to be very expensive to an F owner - Exiges tending to be expensive 'toys' (or cheap racecars - perspective again) whilst F/TFs tend to be daily drivers and thus whilst it may be reasonable to expect an Exige owner to spend X amount of thousands on blueprinting his K for the track, it isn't so justifiable for Joe Schmoe in his 8 year old F to so the same.
Still, it doesn't make it any less interesting. Anyone up for a bulk buy of QED remote thermostats?
|No problem - what's your email Russ?|
>> I appreciate the K series is sensitive to tolerances, but I’m not going to be a hurry to pull out my functioning engine to blueprint it. Do you consider there may be worthwhile gains doing this over conventional tuning such as exhaust and induction mods or is it only relevant for in the rarefied 200bhp atmosphere these Exige boys seem to be breathing? <<
The advantages of blue printing an other wise standard engines are there, but probably don't justify the expense - whereas on an engine with a 8500 rev limit, blue-printing and balancing becomes mandatory.
Andy, from Simon's article, the only place you could trust to would be Vibration free - as it appears that many of the balance machines used for cranks appear to be way out of kilter. Or they'd be an unknown quantity.
QED versus MG remote thermostat - now that is an interesting question...
|Rob, could you please send me a copy of the article|
|I have had my expereiences with the QED thermostat, why would you still go that route ? Take the Original Rover PRT one OR the one from EliseParts. The QED thermostat had leaks from the start and is simlpy hold together by bolts, whereas the Eliseparts item is a one cast item.|
- comes with all the pipage
- one piece item
- and probably an instruction worht it's name..
|T, do you have a part number for the Elise item. You say all the pipeage is included - is that pipage suitable for an MGF?|
|Hmmm, i'd forgotten about your nightmare with the QED remote thermostat Thierry. Not good. :-(|
Also, i've just had a good look through the eliseparts.com site and there isn't a remote thermostat offered, although there is an 82 degree one (but this is a replacement for the standard one, and it is the location of the thermostat that is the main problem, not simply because it openes at 88 degrees).
|I think we should thing about some form of group buy for remote thermostat kits?|
Oh yes there is, its £99.99 and includes the pipework - pretty blue hoses, they look like Samco hoses. If they are the kit looks to be a bargain.
It is listed under something odd but I can't remember,
I'll have a look
|Look under upgrades, don't stop and drool at the lovely TBs....|
|>> http://www.eliseparts.com/images/upgrade/remotetherm.jpg <<|
Hmmm, nice... :-)
|See! it is there :LOL:|
|Please allow me to partialy high-jack this thread, could somebody identify in what way (cooling circui) the oil-water cooler is fitted on this elise ? |
|What seems missing in the remote thermostat kit (at least on the picture) is the O-ring for the old thermostat (which needs to be removed an replaced by an O-ring, as done on the TF)|
|I'm not sure. May be the existing rubber surround at the old thermostat may be enough. Can easy get pulled off.|
|Well the QED kit has this O Ring, the TF remaining pseudo-thermo stat has the Ring (as you can see on Robs pages) so I think it would be better to fit it not sure though. I think it will "emulate" the material gap the normal thermostat leaves when taken out.|
|So all in all, it seems like the argument to blueprint our K series in case we were ever had the opportunity to achieve 240 bhp reliably is a sound one and one to store for future reference!|
Personally I don’t know anyone capable of the work to do so, but I would be interested in anyone who could, what do you think that type of work would cost?
Regarding the remote thermostats kits, is the standard thermostat recognised be a contibutary factor to HGF or do we just like the look of the pretty blue piping?
Cheers Rob, hopefully e-mail should be attached this time.
|I am not pursuaded yet about the blue printing being only effective at +200BHP. I read that blueprinting by itself (without any other add-on)can give gains upto 15BHP. Not to be neglected IMO. Did some surfing and found some companies (albeit nog in the UK) offer the balancing service for about £ 250,- ! can this be.|
|David, lots of Co's do balancing, this article is pretty much common practise for blueprinting race engines- EXCEPT that he recons that the normal engine places do not do the work to the required tolerances/ balance using the right methods. |
Not having done any research or having any equipment to verify this, I am dubious, but I don't think that your £250 job will be enough.
I assume that his balancing job involves the adding of counterweights. The standard crank uses the fact that the crank is symetrical in weight across it's axis, but this weight is where the big end attaches, so the balance is shared between two sections (and across a main bearing) and there will be some flex, this may be terminal at very high speeds. If you add counterweights then each section of the crank is balanced and much less force is transmitted thru the main bearing. (just the amount required to balance the pistons and compression/explosion)
The pretty blue piping does it for me.....I'll get me coat.
But seriously, does anyone know if this bit of kit is beneficial to us MGF owners. Scarlet, any opinion? I would rather spend a £100 on this bit of kit as a first if it will help prevent the "thermal shock" of the standard thermostat system.
I was wondering about the O ring that the TF uses in place of the F stat (if that makes sense), I feel a call to Eliseparts may be of help. I would be inclined to fit whatever they recomend of the Elise - or is that too simplistic?
|>> Please allow me to partialy high-jack this thread, could somebody identify in what way (cooling circui) the oil-water cooler is fitted on this elise ? <<|
Thierry, I'm no expert on the Elise cooling system - but looking at that picture, I'd say that the oil cooler here is plumbed into the rad return pipe.
>> I think we should thing about some form of group buy for remote thermostat kits? <<
Steve - if I can't get hold of a TF PRT, then I'd definitely be interested in this :o)
>> What seems missing in the remote thermostat kit (at least on the picture) is the O-ring for the old thermostat (which needs to be removed an replaced by an O-ring, as done on the TF) <<
The O-ring with the TF PRT has an apperature designed to match the flow rate of the standard thermostat. I suspect that it probably is included in the Elise parts kit, but you could remove the wax-stat bulb from the thermostat and replace it if need be.
>> I am not pursuaded yet about the blue printing being only effective at +200BHP. <<
I agree David - there are definitely benefits of doing this at any level - BUT the point I'd make is a cost/benefit one. Whilst getting the engine blue printed by a company like Vibration Free may not break the bank cost wise (I think that 250-400 is about the range we're talking about), the labour associated with removing the engine, dismantling, reassembly and re-installing the engine pushes up the costs significantly, unless you're someone who can do this kind of work yourself.
|I called Eliseparts who had no idea if the kit would fit the F. H did say that the kit fitted "beneath" the existing stat which, when questioned was not the inlet manifold site but the exhaust manifold side. I assume that the exhaust manifold on the elise is basically the same as the F and therefore wouldn't this mean this kit sits underneath the exhaust manifold?|
Also, the pipes in the kit are short so it would seem that the stat is only moved about one foot away from its existing location? is this really of any help?
|you've made a mistake, under the exahust manifold there is the alternator and the oil filter - no water there!|
There is water alongside the exhaust manifold (rear end of the engine) it's where the water leaves the engine.
The current thermostat is on the inlet side, no matter which car the engine is fitted to!
This stat tries to emulate the cooling systems of the 60's, it regulates the temps comming _from_ the engine, rather than the temps _to_ the engine. I honestly cannot see why this might cut 'thermal shock', in fact I can only see it being _much_ worse.
|The stat is mounted on the outlet hose of the Engine. (hot water coming from the engine goes to the radiator)|
The pipes length seem fine for that purpose if plumbed into the location I have in mind.
It is mounted where you would have put the oilcooler, with a bypass. Take a look here : http://www.mgf.ultimatemg.com/hgf_pages/why_do_hgfs.htm
|Thanks Will, I was not sure if I had heard the guy correctly. |
The "problem" seems simple to me: The existing stat is in the inlet which means that v cold water comes in from the rad to a v hot engine and this causes thermal shock.
The "answer" is as simple: take out the existing stat and put a new stat on the outlet side.
|That's precisely how the remote thermostat is mounted Kevin :o) (See Thierry's answer too)|
|Really stupid Q now:|
Does it work, is it worth doing? now with a std engine or in the future with a modded engine?
Does anyone with more knowledge of the pipework on the F know if the Eliseparts remote kit will fit?i.e. straight in or do mother pipes need to be ordered?
|It took a while, but I started reading the thread yesterday evening. Didn't manage to read it completely as I had to get up early, but I received Simon's KingK article a few minutes after my request to the hotmail address.|
Anyway, I've got a headache now, but don't know if it is related to the reading :o(
Anyway, I like Simon's idea and style. It takes quite a few postings before people starts thinking about his ideas
- we do notice differences in performance on standard cars and on the otherhand we are paying for (for the common F owner and enthusiast) expensive upgrades without fine tuning the whole engine.
Not really the same, but I told my technician to fit the PTP kit very correct and with some care for every single detail, otherwise an expensive kit could become worthless.
- rather new to me is the reliability of the engine in combination of its spec's as given by Simon. Always had the idea that the K-series was at the end of its career, but it looks like the engine will have a second life in the hands of some enthusiastic track day racers. Maybe we need to start with a definition of reliability and in which environment it will be used (track, day by day, ...).
- the document itself is very valuable IMO as it puts a lot of knowledge together.
|>> Does it work, is it worth doing? now with a std engine or in the future with a modded engine? <<|
The remote thermostat does work - Simon Scuffham has proven it in his albeit modified Elise. The results are more dramatic on a race engine than they are on a road engine, as the stresses are greater, and the thermal shocks more critical - but yes, these benefits will be seen, over a long term, on an un-modified road engine.
IMO it is worth doing - especially if you intend keeping the car for a while, and enjoy 'spirited' driving ;o)
Erik, I completely agree with your synopsis of what has been said and of Simon's article.
Like you, I am not clear what exactly 'reliable' means in this context. I suspect, in regard of a 220+ bhp engine, we should regard 'reliable' in the context of a full racing engine: an engine that needs fairly extensive work at the end of each season.
However, I wonder if the engine's durability deteriorates exponentially from 180 bhp on?
perhaps this is something that we can ask Simon...
|>The "problem" seems simple to me: The existing stat is |
>in the inlet which means that v cold water comes in from
>the rad to a v hot engine and this causes thermal shock.
Follow this thru to it's logical conclusion, and you will see the problem turned on it's head (puntastic)
The thermostat regulates the temp comming into the engine, it does not 'snap open' or 'snap shut'. With the thermostat closed there is little water flow thru the engine, that waterflow goes to the back of the thermostat via the bypass and/or the heater, if the engine is worked hard then the outlet side of the engine gets a little warmer, but the inlet side is clamped at 88 degrees.
Still with me?
there is a slight lag whilst the (slow) hot water gets to the thermostat, but the thermostat mixes the very cold water from the rad with the very hot water from the bypass and makes sure there is equal temp water entering the head at all times. Only the flow rate changes.
now take a thermostat on the outlet side
The thermostat is regulated by the water comming out of the head, more power means more heat and the thermostat opens as the hot water from the engine hits it, so it gets to open faster than the other system, but come off the gas and whilst the water is being flushed thru the engine the thermostat is still wide open, in fact it doesn't shut untill the engine is packed full of really cold water from the rad. Thermal shock anyone?
A better solution is one where there is a high flow rate of bypass water, but the problem with this solution is the max cooling of the engine is effected as the thermostat cannot mix enough cold water into the inlet. The fix for this is to make the thermostat stem the waterflow from the bypass at wide openings.
A mid term solution is to use a much narrower bore pipe for the bypass - currently the system uses a wide pipe (16mm?) and a restriction, so the water flows slowly thru the wide pipe and they thermostat opening gets delayed. If you were to use a narrow pipe for the bypass then there would be less delay, but you would have to pick the size carefully to retain the same amount of overall restriction.
|Oh bugger, I've now got two completely opposite viewpoints - Rob and Will - and I can see that both talk sense. Which do I believe?|
I think I will have to go with Rob (and Thierry) and the others. I'm sure that Elise parts wouldn't have bothered with the kit for no reason, or QED or the others for that matter. Plus the fact that the TF also uses a remote stat in the outlet side and the HGF monster appears to have gone away to a large extent in the later cars?
|>I'm sure that Elise parts wouldn't have bothered with |
>the kit for no reason, or QED or the others for that matter.
If enough people will pay for it then that is reason alone.
The TF stat is the only one I would have real trust in as MGR would not make the engine more costly for no reason.
The TF stat has not been around long enough to tell if it has tamed the "HGF monster" any more than the previous mods (dowels/better gasket etc)
|I'd agree that the MGR solution is going to be the best solution - afterall, one can be sure that MGR would have looked at the remote stat as a potential solution for HGF, and yet chose not to.|
BUT the remote stat has been proven to work and is race proven too. Simon Scuffham claims to have figures to prove the point. Moreover, the Elise boys have a far more sensitive temperature read out on their Stack displays - and with the remote stat, the water temperature at the engine outlet remains far more constant that the standard set up could ever achieve. Therefore the problem that Will highlights does not, I believe, happen - but it is worth doing some more research to be 100% sure.
|>BUT the remote stat has been proven to work and is race |
>proven too. Simon Scuffham claims to have figures to
>prove the point.
but how big is his sample size - 10,000? 1000? 100? 10? less?
Over how many miles?
in what conditions - rain? blistering heat? snow?
The Lotus boys claim to never see any fluctations in temp except for when idleing and stopped - and this is with the standard stat!
|If you suffered a HGF every race with the standard stat, but none since going with the remote thermostat with no other modifications, then you don't need a big sample size to determine statistical significance Will. The "Bloody Obvious Test" usually suffices ;o)|
However, there is an important point you made Will: there is no hard and fast statistics available on road cars. We haven't got any for the PRT either, although a little bird tells me that warranty claims for HGF on cars fitted with the new stat have all but dried up...
|I'm always late to the interesting threads - this one no exception, as I've been offline a bit this week. Not that I have too much to say once the more technically aware get going :-)|
However, one thing that I've learnt over the last few years is that these damn cars, simple as the basics can appear, are emormously complex once you start tinkering. Make a small change here or there and the knock-on effect can be very different from and perhaps sometimes even the opposite of what you might expect. Too many variables. I guess it's why there are so many tuners and tinkerers - all with their theories and experiments.
So, my simplistic view point looks for evidence wherever possible and trusted opinion where there is not too much evidence. On this count I think Will's point
>>The TF stat is the only one I would have real trust >>in as MGR would not make the engine more costly for >>no reason
weighs more heavily with me than than the Elise boys 'proven' approach.
However, I think his next point is worth challenging!
>>The TF stat has not been around long enough to tell if it has tamed the "HGF monster" any more than the previous mods (dowels/better gasket etc)
The PRT has been around long enough on the Freelander to provide evidence of a tumbling of HGF warranty claims - or so I'm told - be a source I trust :-)
|>If you suffered a HGF every race with the standard stat|
Then you clearly have another problem - perhaps with the bypass pipework?
>but none since going with the remote thermostat with no other modifications
Except changing all the pipework!
>although a little bird tells me that warranty claims for
>HGF on cars fitted with the new stat have all but dried up...
We heard this when they changed the dowels
and again for the gasket
and no doubt will again next time they change anything!
|>..The PRT has been around long enough on the Freelander...|
To show a change, but not definitly a fix - what if it just delays the inevitable to after the warrenty runs out?
|For thoes of us already out of warrenty even a deferment is worth having!|
|Not saying it's not worth having - just it may not have bannished the problem for good.|
|>>it may not have bannished the problem for good.|
An impossibility surely - too many variables again - not to mention all those HGFs caused by poor maintenance/service/bleeding/awareness of coolant loss.
|>For thoes of us already out of warrenty |
Or those who can no longer claim warranty because of various modifications. *ugh*.
|Will, I know that you are playing Devil's advocate here, but I am not the one to defend the remote thermostat. All I am doing is relaying what I've discussed with Simon Scufftham in the past.|
I'd suggest that a simple change in the pipe work is not going to be the explanation to the reduced rate of HGF in his hands. If only things were that simple ;o) Simon may well have other problems contributing to his HGF woes (poorly balanced crankshaft perhaps? ;o) ;o) ) but look at the empirical evidence: HGF before change. No HGF after. Thermal cycling observed before - none after. One has to draw the conclusion that the remote thermostat does seem to be doing its job. But feel free to draw your own conclusions... ;o)
>> Not saying it's not worth having - just it may not have bannished the problem for good. <<
Given the non-existance of a HGF-free engine anywhere in the world, then clearly extending the period between failures is surely the best result one can aim for. If the probability alters from 1 every 30,000 miles to 1 in every 100,000 miles, then clearly this is a modification worth having?
Re original post
Have you seen copy of article yet?
I agree with your cost/benefit, blueprinting is fine when buiding engines but is unlikely to produce more than say 5bhp. Air inflow is the key and this depends on head casting, I assume reference to fettling,and valves.
Rovers own tolerances are production tolerances and not necessarily those of the engine designer.
|Thinking about removing thermal shock ... why not remove the thermostat completely?|
Ok the engine would take longer to reach optimum temperature, but how much longer.
The bypass would ensure that the pump was supplied with water a little warmer than in the radiator. As the water pump is pulling water towards the engine it would sorely pull from the least resistance = so some of the water from the by pass would be pulled in to the engine.
Before you start flaming me, just think about it!
I'm just putting on my fire proof undies.
|no need for fieproof undies.|
you could do this, but firstly the economy would suffer badly (think being constantly on choke). then the oil would never get hot enough to burn off the condensation and blowby. The over rich requirements to keep the engine running when cold would cause 'bore wash' where the walls of the cylinder liner get wet with fuel which washes past the rings and dilutes the oil, washing the oil off the cylinder liners and diluting the oil in the sump. The exhaust would take much longer to get to temp, so the cat would be useless and would get poinsioned quickly from too much fuel and the exaust pipe would rot thru as it wouldn't get hot enough to evaporate the acidic condensations.
Oh and the heater would never get warm.
|Not much effect then !!!! ROTFL|
|Paul - yes, got a copy within minutes of emailing Simon. It makes for very interesting reading. Whether the standard bottom end really is man enough to cope with 8500 rpm and 200+ bhp I don't know - but I guess the proof of the pudding will be in the eating...|
Steve, I would definitely agree with Will there: removing the thermostat is not a good idea!
Spent an interesting evening chatting to Peter Carmichael - he of 250bhp 1.7 litre K-powered Caterham fame. TimW introduced me and we spent the evening oo-ing and ah-ing over beautiful alloy engine bits... Boys toys... :o) ;o)
It's always good to get another perspective on a problem - and Peter certainly had a very clear idea on how the standard cooling system ought to work.
In fact, if the standard cooling system were set up correctly and the bypass flow rate adequate, there ought not be any problems with thermal cycling at all. But there is - or appears to be... :o/
Just a quick synopsis of the cooling system then:
The cooling system can essentially be described as two almost entirely separate circuits, but with a common resevoir in the engine.
One is the radiator circuit - running from the engine outlet pipe along large diameter pipes to the radiator and then back to the thermostat. Flow through this circuit is slow - and only commenses when the thermostat opens.
The other circuit is the engine bypass circuit - running from the engine outlet pipe through narrow diameter pipe work and back to the thermostat and into the engine. The flow though this circuit is very fast in comparison to the radiator circuit, and is continuous: the thermostat condition has no impact on flow rate.
The only determinant of flow through this circuit is the speed of the water pump.
So far so good.
The engine runs at an ideal temperature - let's say it is A. If the flow through the bypass pipe is fast enough, very little heat loss will occur, and the temperature in the bypass circuit at the point that it meets the thermostat will also be A.
The water temperature returning from the radiator will clearly be a lot cooler - temperature B. This can be over 20 degrees celcius cooler than temperature A - but actually, this ought not to matter too much.
Firstly because the thermostat is not a binary switching device. It opens slowly and closes slowly - and thanks to the nature of the thermostat, the closure temperature is typically a little lower than the opening temperature. Also note that the amount that the thermostat opens is dependent upon the temperature of the water returning via the bypass circuit.
This is a classical closed loop control circuit.
The crucial thing though is that the flow through the bypass circuit is sufficiently high for a given thermostat opening to capably 'blend' the cool radiator circuit water (which is a low flow system, remember). If the thermostat is sufficiently senstive, it means that once the engine temperature rises above the set point temperature, A, to temperature A', the thermostat will open, and the bypass circuit coolant at temperature A' will mix with the radiator return coolant at temperature B, that will drop the coolant temperature inside the engine gently back to the set point temperature A with minimal overshoot.
So that is the way that the coolant system should work. From this, you can also see why not having a thermostat would be a 'bad idea' - the thermal cycling without a thermostat would be pretty dramatic, and be road and water pump speed dependent...
My problem with this is that everyone else seems to be very confident that thermal cycling occurs - which suggests that the control loop is not well balanced. You can get this if the flow rate via the bypass circuit is too low, if the flow rate via the radiator circuit is too high, or if the thermostat opening characteristics are suboptimal (either snapping open, or perhaps even opening too slowly).
My problem with all these things is that we know so little about how the cooling system actually behaves in the MGF/TF. It appears that the ideal condition does not actually exist in the cooling system - afterall why else would the good folks at MG have now fitted the PRT thermostat...?
|Correct about everything except for the radiator circuit potentially being too fast, this can never happen dut to the nature of the thermostat - but I am left wondering about the description of the bypass as 'fast', it should be, and it could be made much faster - but is it currently fast enough?|
Did you buy multiple temp sensors Rob? I have a diffrent cooling problem!
|Nice explanation Rob. Did Peter not have any opinions on the thermal shock issues that we all, urban legend-wise, believe exist in the F?|
The other change associated with the new PRT is the removal of the jiggle valve that sat in the hoses.
There clearly must be a reason for this as well.
|>> except for the radiator circuit potentially being too fast, this can never happen dut to the nature of the thermostat <<|
Yup, that's very true Will - thanks, well spotted. :o)
Have I purchased multiple temp sensors? Unfortunately no - TimJ was looking into his ADC temperature logger, but I think that he's been so busy that he's really not had much of a chance to make any more progress with it. Therefore I've not pursued the purchase of the sensors until I know that I can make a record of the readings.
What's your cooling problem Will?
|Not very good at high speed, I can tell the incline of the road at 70 by looking at the position of the needle!|
this spoils the car a little, with all the power on tap and only being able to use it for overtaking (or very short spells at 110!).
Not sure why yet, could be a number of things, such as too little main flow, too little airflow (backpressure in the engine bay?), to slow bypass flow (limiting max water flow thru the engine), not a good enough radiator (although Ant has no trouble apparently), clogged cooling paths in the rad, or even the exhaust pipe heating the temp sensor!
Maplin sell a sensor kit, but although in the docs it says there are two probes available, they only sell the low temp probe (good to like 90 - which is too low)
|Dave, I did raise the question of cycling with Peter - and even mentioned what SimonS did with his Elise - but Peter didn't express an opinion on that; I think he was being somewhat statesman-like ;o)|
Bottom line? We really need to do our own testing.
Will, I guess you'd want the sensors sooner rather than later? I'd really like to nail the thermal shock question in our MGFs - and also to test out whether a EBP in the bypass circuit after switch off is a good idea or not - so perhaps we could work together on this?
Dave - interestingly, Peter was suggesting a Davies Craig EBP as being a 'very good idea' - and reckoned it would only need to function for 20 seconds after ignition switch off...
|20 secs! But we think the Exige runs it for several minutes don't we?|
|Yes, according to the Lotus notes, it can run for up to 20 minutes after switch off - but is temperature dependent. What Peter proposes is something that comes on irrespective - which is what we had in mind with the timer concept.|
Seems to something of a chasm between the two points of view: again, it all boils (erm, no pun intended!) down to testing...
|If all you're trying to do is prevent localized boiling then 20 secs is probebly enough (quite a long time - more than twice as long as a BMW 1 series takes to get to 60!). The extige runs the coolant thru the heater matrix, so there is a larger heat sink in the circuit - the F does not have this, so circulating for much longer than 1 min is lightly to be pointless.|
|@Will: or air in the circuit, or a faulty temp sensor|
Localised boiling.. everybody speaks about it but nobody says what the temperature at which the coolant boiles actually is, I saw figure ranging from 135C to 180C.
> The extige runs the coolant thru the heater matrix,
>so there is a larger heat sink in the circuit - the F >does not have this
Correct, unless the driver has choosen to have the heater on (Winter anybody), you never know, better to have the pump running for a bit longer.
|Anyone considered using evans|
|>> Localised boiling.. everybody speaks about it but nobody says what the temperature at which the coolant boiles actually is, I saw figure ranging from 135C to 180C. <<|
Depends on the pressure in the coolant circuit Thierry: the higher the pressure, the higher the boiling point. At atmospheric pressure, coolant boils at 104 degrees - but under pressure, the figures you quote may not be too far off the mark.
>> Correct, unless the driver has choosen to have the heater on (Winter anybody) <<
Ah - but remember that in an Elise the heater is an 'always on' matrix - you regulate heat into the cabin by adjusting the vent flow into the cabin - but in an F/TF where the heater matrix has an on/off valve, a longer duration of run-on would do no harm :o)
|Pressure is 0.9 - 1.2bar, 104C is way to low, 50:50 OAT should boil at a much higher temperature. Doing a bit off research now.|
I was aware of the Elise heater matrix design :O
My point was that if you plan to have an electrical pump work after the engine has been swichted off you better consider that the the heater bypass might be open on an MGF/mgtf.
|NOCO PREMIUM RC EXTENDED LIFE 50/50 ANTIFREEZE |
Boiling Point > 339-398°F (171-203°C)
Shell (ethylene glycol):
For example, at a 50-50 mixture of water and antifreeze, the coolant's boiling point will be raised to 130°C
Coolant In Mix B.P. at atmos. press B.P. @ 14 psig
40% 222F / 105C 259F / 126C
50% 226F / 108C 263F / 128C
60% 232F / 111C 268F / 131C
70% 238F / 114C 274F / 134C
|Please note that I have deducted the 0.9-1.2 bar figure from the coolant cap.|
|Ok there we have it :|
The temperature of the coolant can sometimes reach 250 to 275 F (121 to 135 C). Even with ethylene glycol added, these temperatures would boil the coolant, so something additional must be done to raise its boiling point.
The cooling system uses pressure to further raise the boiling point of the coolant. Just as the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi)(around 1bar), which raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures.
So I think that we can estimate an 136C boiling point for the MGF/MGTF.
|Hmm - not quite what I found: http://www.mgf.ultimatemg.com/coolant/|
But as I mentioned earlier - a pressurised system can see the boiling point rise (remember those triple phase diagrams in school Physics classes?) - so yep, 135C would certainly be possible.
|Why are you saying that it would not be quite what you found ? It is exactly the same.|
Look at the page (How stuff works):
50/50 = 106C
You found 104C so where is the difference? Do not say it's 2C :P
It is only under pressure where the boiling point is elevated to 135C, yet another reason to have a good working cooling cap actually building pressure up.
|While speaking of coolants, I also came across a coolant which supposely changes it's color when there is an Head Gasket Failure. Anybody know if it works?|
|>Will, I guess you'd want the sensors sooner rather than later? I'd really like to nail the thermal shock |
>question in our MGFs - and also to test out whether a EBP in the bypass circuit after switch off is a good
>idea or not - so perhaps we could work together on this?
Fine by me, i've found sensors which are £3.20 (RS - 218-3826) a piece, you can program them to act as temp controlled switchs, and talk to them with I2C, which means you can chain many on the same wires! of course in addition they'd need a display and driver chip, but you only need one of these per system.
|As already mentioned on this board, I have a page up explaining my (and, to a certain extent, Rover) POW about HGF and remote thermostats on the K:|
I'm still desperately looking for a 32 mm T-shaped hose to fit the PRRT on my Elise...
the MGF circuit is very similar to the Elise one, main difference is the heater circuit without a valve on the standard (non A/C) Elise/Exige. the piping is also running on different places, but the diagram is the same.
|It would also help if you could get the parts from MGR!!( 4 months and still waiting). On the subject of Blueprinting, when Formula Ford 1600 started using blueprinted standard engines only 1 camshaft in every 40 was up to spec! much easier to slap on a pair of 40's together with a nice lumpy cam!(Kick the tyres, Light the fires, Last one off is a cissy!) Reading this thread, my tuning days are long over, I ain't got degrees in Physics,Electronics etc, I never cease to be impressed by the technical know how on this board. Regards.|
Fine by me, i've found sensors which are £3.20 (RS - 218-3826) a piece, you can program them to act as temp controlled switchs, and talk to them with I2C, which means you can chain many on the same wires! of course in addition they'd need a display and driver chip, but you only need one of these per system.
That sounds very interesting Will. Regarding a display - could you use an old Laptop and run the data into a text file that is compatible with Excel? That way you could graph the data out. In your case, you might want throttle position/ engine speed as extra channels?
|Whoh there, this design is not finished yet, consider the groosh, here is a beer that is matured....|
Yep, you'd still need an interface chip, in fact the work needed is almost exactly the same*, I'll make sure that both are supported.
There are a few other sensor chips which act as switches, 'programmed' using a variable resistor - sound promissing enough for the 'production model' ?
*actually logging of data thru the serial port is step one in the design!
|>> Whoh there, this design is not finished yet, consider the groosh, here is a beer that is matured.... <<|
ROFL Will! ;oD
Okay - definitely your area of expertise: what you've got planned sounds exactly what is needed :o)
Try www.maxim-ic.com and look for DS1701K this is probably what you want but is $60.
On the positive side you may be able to get the sensors as free samples.
Are you referring to 4 life which has a range -42
180 degC, and change colour if there is a head gasket leak and has an anti-foaming agent to reduce hot spots.
You can also buy a test kit for approx £35
|Errm yes, a bit - not totally sure on the whole 'one wire' interface stuff, the two wire interface is much easier to use (will require a four wire 'bus' between the devices- clk, data, ground, power)|
|Exactly Paul, does somebody have any experience with that product ? (out of curiosity)|
>32 mm T-shaped hose
Demon Tweeks sell these in nearly all dimesions, not sure if they sell them up tp 32mm however I saw some of them in their catalogue (can't find them online).
|Go to a radiator guy and get them to make you some pipeing to do the same job, then just use rubber hoses - Much cheaper solution, and take the opertunity to fit a boss to take another temp sensor|
Yes being used in a number of BV8's but HGF is not usually a problem.
My only concern is with heat transfer which is the problem with using anti F, although increasing boiling point does not aid heat transfer.
This thread was discussed between 15/07/2004 and 23/07/2004
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