Who has had a bad experience with a tuned K?

[KingK_series]

So Tut

this is for you and everyone else who has had a bad experience trying to get more out of their K

What work did you have done tuning your K series

who did the work

and why how did it go wrong??????

[pete]

Dear Mr King_K,

Why not just change that header to "who has had a problem with their K"?

I really like Lotuses - I've had three - but the weak link for me is the engine. I've had 4 HGFs on two engines all at lowish miles.

pete

[KingK_series]

Dear Mr King_K,

Why not just change that header to "who has had a problem with their K"?

I really like Lotuses - I've had three - but the weak link for me is the engine. I've had 4 HGFs on two engines all at lowish miles.

pete

there is another thread for "HGF"

If you read it and the link to the 2006 thread on seloc you will find out how to avoid the problem

but since you are here

in all 4 cases, who "fixed" the engine, and what EXACTLY did they do to fix the engine each time?

[Mikie711]

Not sure of the point of this thread and your reasons for wanting to know.

[pete]

Hmmm I don't think I'll name and shame. It wouldn't be fair.

(Although I would recommend Dan who has helped resolve issues for me in the past).

My point is that they shouldn't have happened in the first place- so in that respect then it's Rover who are to blame. I struggle to understand how you, a keen amateur (I think), seem to have solutions to all the problems that exist and yet the wider motor industry seems (in your opinion) to be oblivious.

Hope I'm not putting words in your mouth but when one has a widely used engine from a major (now defunct) manufacturer it is difficult for someone like me to understand why there are so many problems. It is also difficult to understand why, if the solution is straightforward it is not commonly applied within the industry.

Anyway I'm not looking to start a fight, but I wouldn't dream of tuning one. My purely anecdotal experience suggests that a transplant is the way to go if more power is desired.

[tut]

In my case Simon, N3 was already converted to Honda by BLiNK when I bought it, and I fitted the S/C.

The labour work on N1 was done by Ricky Gauld who you would not have heard of, local one man garage, one of the old school, also an ex racer. He is not a specialised Elise/K series expert, but is a bloody good mechanic, so he would treat the engine as he would any other, i.e. he has not read your posts regarding the importance of water pump, remote thermostat, hardness checking etc, so he would have probably had the head skimmed in most cases, replaced plastic dowels, checked liner stand proud, used standard Rover gasket set and new OE long bolts.

The head itself was converted by a friend of Ricky's down South, good reputation with Ferraris, Porsches, etc, but probably not experienced with the K engine, so would have done a standard rebuild to 190hp, 285M cams, Ivey valves, oversized ports, Jenvey's, Emerald, verniers etc. The car did tens of thousands of miles both on track and UK and European road runs, and I think in that period was the quickest car on S_E, gave me six years of very pleasurable motoring, was probably one of the best known Elises around, and I think had two HGF's in that time, repaired as above by Ricky.

What it did not have was the driveshaft/CV joint failures that I have had with both Hondas along the way, but hopefully that has now been sorted out with the upgraded ones.

tut

[KingK_series]

Hmmm I don't think I'll name and shame. It wouldn't be fair.

(Although I would recommend Dan who has helped resolve issues for me in the past).

My point is that they shouldn't have happened in the first place- so in that respect then it's Rover who are to blame. I struggle to understand how you, a keen amateur (I think), seem to have solutions to all the problems that exist and yet the wider motor industry seems (in your opinion) to be oblivious.

Hope I'm not putting words in your mouth but when one has a widely used engine from a major (now defunct) manufacturer it is difficult for someone like me to understand why there are so many problems. It is also difficult to understand why, if the solution is straightforward it is not commonly applied within the industry.

Anyway I'm not looking to start a fight, but I wouldn't dream of tuning one. My purely anecdotal experience suggests that a transplant is the way to go if more power is desired.

All engines have problems.....look at the honda thread, there have been a lot that have thrown rods

however K was designed before theoretical modelling was possible, so issues got delt with in the old fashioned way, common to ALL manufacturers - development. Sadly Rover didn't have the money to introduce some of their work, but all this stuff... pumps etc was done and much of it has gone into the new N series.

[campbell]

Certainly no harm in exploring the (potentially extremely varied) experiences which people have had with their K series engines (perhaps tuned or not!) over the years.

One word of caution for contributors to this thread. A broad indication of "who did the work" is fine, eg "local one man band", "experienced specialist outfit", "major dealer", etc. However specific references or detailed indications are a no-no lest we end up in libel/defamation scenarios. OK everyone?

Pete, my very high level understanding of the (perceived?) fragility of the K series is that it was never expected to end up in a mid-engined configuration, so the cooling setup is sub-optimal in that type of setting. Now many may say "ah but my Dad's Rover 25 had stacks of HGFs too", in which case this perception is clearly tosh. But from reading Simon's thoughts, and from the popularity of the PRT "fix", it strikes me that this is the simple core problem for any K whether tuned or not.

For tuned Ks, I remember reading something from Simon a long time ago which talked in earnest detail about the importance of balancing and reconstructing the engine with great attention to detail. I have no evidence to suggest that this creates a bulletproof 200bhp K series engine, but it sounded convincing at the time

Campbell
(complete and utter amateur...if that...)

[Mikie711]

Campbell, from my experience when you tune the K series you inevitably move further and further up the rev range. The importance of correct tuning and managing of the vibration within the engine becomes more and more important the higher you go. My engine made something like 190bhp at the wheels but rev'd to 8500 rpm to make it. The K has a really bad reaction to the 8000ish rpm range and you can feel that when it reaches that level.
In my case a straight forward engine balance proved ineffective and so I was left with 2 choices, leave it with a 8500 red line or cut the red line to just under 8000 in the hope that the engine would last longer, which I did and it did. It didn't make a lot of difference to overall output and gave the engine a break.
Having been down the K tuning road from 140bhp to 160bhp then to 220bhp if I ever did it again I would stop at about 160-170bhp. Reliable (ish) engine that won't self destruct quite as readily and doesn't require frequent and expensive rebuilds. Also in an Elise it's about the right mix of fun against drivability.

[KingK_series]

Pete, my very high level understanding of the (perceived?) fragility of the K series is that it was never expected to end up in a mid-engined configuration, so the cooling setup is sub-optimal in that type of setting. Now many may say "ah but my Dad's Rover 25 had stacks of HGFs too", in which case this perception is clearly tosh. But from reading Simon's thoughts, and from the popularity of the PRT "fix", it strikes me that this is the simple core problem for any K whether tuned or not.

For tuned Ks, I remember reading something from Simon a long time ago which talked in earnest detail about the importance of balancing and reconstructing the engine with great attention to detail. I have no evidence to suggest that this creates a bulletproof 200bhp K series engine, but it sounded convincing at the time

Campbell
(complete and utter amateur...if that...)

No it has nothing to do with mid engined install - KingK needs to be rewritten, I have got so much further than that now

The PRT helps - a lot, but it is no cure, the biggest single step is a proper water pump, but as I have said I have designed one for my engines but there is no commercially available pump.

[KingK_series]

Campbell, from my experience when you tune the K series you inevitably move further and further up the rev range. The importance of correct tuning and managing of the vibration within the engine becomes more and more important the higher you go. My engine made something like 190bhp at the wheels but rev'd to 8500 rpm to make it. The K has a really bad reaction to the 8000ish rpm range and you can feel that when it reaches that level.
In my case a straight forward engine balance proved ineffective and so I was left with 2 choices, leave it with a 8500 red line or cut the red line to just under 8000 in the hope that the engine would last longer, which I did and it did. It didn't make a lot of difference to overall output and gave the engine a break.
Having been down the K tuning road from 140bhp to 160bhp then to 220bhp if I ever did it again I would stop at about 160-170bhp. Reliable (ish) engine that won't self destruct quite as readily and doesn't require frequent and expensive rebuilds. Also in an Elise it's about the right mix of fun against drivability.

OK well it's head butting time again..........so many preconceived ideas I have been trying to slay for years and here they are again.

Will answer them all when you have answered two questions if I may,

1/ what did you do with your crankset? - aftermarket crank, or flywheel?

2/who balanced it? in Scotland or Silverstone way?

[Mikie711]

OK well it's head butting time again..........so many preconceived ideas I have been trying to slay for years and here they are again.

Will answer them all when you have answered two questions if I may,

1/ what did you do with your crankset? - aftermarket crank, or flywheel?

2/who balanced it? in Scotland or Silverstone way?

Why would you start a reply with "OK well it's head butting time again"

1) standard crank light weight flywheel (PTP or QED IIRC)
2) In Scotland but the who is irrelevant.

[KingK_series]

Campbell, from my experience when you tune the K series you inevitably move further and further up the rev range. The importance of correct tuning and managing of the vibration within the engine becomes more and more important the higher you go. My engine made something like 190bhp at the wheels but rev'd to 8500 rpm to make it. The K has a really bad reaction to the 8000ish rpm range and you can feel that when it reaches that level.
In my case a straight forward engine balance proved ineffective and so I was left with 2 choices, leave it with a 8500 red line or cut the red line to just under 8000 in the hope that the engine would last longer, which I did and it did. It didn't make a lot of difference to overall output and gave the engine a break.
Having been down the K tuning road from 140bhp to 160bhp then to 220bhp if I ever did it again I would stop at about 160-170bhp. Reliable (ish) engine that won't self destruct quite as readily and doesn't require frequent and expensive rebuilds. Also in an Elise it's about the right mix of fun against drivability.

First off, whe you tune ANY engine, na you go further up the rev range, K is no diffeent from any engine ever designed in that regard

second, the K does NOT have a inbuilt "bad reaction" to the 8000ishrpm rev range, - IT DOES HAVE a really bad resonant frequancy at 6900-7100rpm which causes wobbling of the rear of the crank which if held long enough at that point can break the crank. The PTP flywheel is too heavy at 4.2kg with a standard [heavy] pressed steel type clutch to significantly affect this - in fact VHPD engines break notoriously, not because they have 170 or 190bhp, but because they tend to get revved to that frequency. The solution is a much lighter flywheel and clutch to move the resonant frequancy entirely above the rev range, or more simply go through it more quickly, ie an engine with a 9000rpm limit revved to that is much safer than a 7500 or 8000rpm engine that gets short shifted. All engines and all cranks have resonant frequancies, that includes the honda K20 too -

Third the PTP flywheel is massively out of balance as was, I had a number of them tested for PTP and they were all about the same 350-400gmm out, ie 4 times worse than stock Rover. That will make the engine do 2 things - feel rough [bit like a honda K20 which is about 350 [crankset] or 600gmm [ewith clutch] out of balance in stock form, it will also make the engine extremely slow to rev, for friction and binding in the bearings [also like a stock K20] but it will not break your engine.

There is absolutely no difference in what is required to build a reliable short end K series 140bhp to 250bhp except forged pistons.

if you avoid aftermarket flywheels and cranks [obviously this is not great on track] do not linger at 7000rpm, fit forged pistons, - that will work just as well in a 160bhp engine as 250bhp, [aside from water pump issues etc etc].

[campbell]

The PRT helps - a lot, but it is no cure, the biggest single step is a proper water pump, but as I have said I have designed one for my engines but there is no commercially available pump.

Well, we are not much further forward then, are we?

Except that a PRT seems to be a really good idea. That part presumably is commercially available to mere mortals like us.

[Mikie711]

First off, whe you tune ANY engine, na you go further up the rev range, K is no diffeent from any engine ever designed in that regard

Obviously, but we are talking about the K series not any engine.

second, the K does NOT have a inbuilt "bad reaction" to the 8000ishrpm rev range, - IT DOES HAVE a really bad resonant frequancy at 6900-7100rpm which causes wobbling of the rear of the crank which if held long enough at that point can break the crank. The PTP flywheel is too heavy at 4.2kg with a standard [heavy] pressed steel type clutch to significantly affect this - in fact VHPD engines break notoriously, not because they have 170 or 190bhp, but because they tend to get revved to that frequency. The solution is a much lighter flywheel and clutch to move the resonant frequancy entirely above the rev range, or more simply go through it more quickly, ie an engine with a 9000rpm limit revved to that is much safer than a 7500 or 8000rpm engine that gets short shifted. All engines and all cranks have resonant frequancies, that includes the honda K20 too -

Sorry for not being technically correct in my wording, but resonant frequency is felt as vibration and I should have said "my K" had a bad reaction to 8k.

if you avoid aftermarket flywheels and cranks [obviously this is not great on track] do not linger at 7000rpm, fit forged pistons, - that will work just as well in a 160bhp engine as 250bhp, [aside from water pump issues etc etc].

So, you recon that you should use a stock flywheel even if you build a 200+ bhp engine that revs to 9000rpm. What about countering the extra weight of the forged pistons which are heavier than standard pistons by IIRC 60g each.