R500K Vs R500 Duratec, your personal point of view

[Paul Holywood]

Im sure its been done to death, so my apologies in advance if this is so.
But being very new to Caterhams, I'm genuinely interested to learn the difference between the older K series Vs New R500 Duratec, regarding drivability, reliability, performance and the pure smile factor.
I get the impression the Duratec is widely preferred out of the two, and if so why?
I understand the Duratec has more torque and 30 or so extra horses, so I presume the 0-60 and lap times will be down on the older K?
lastly, is the K series more of a drivers car?

[DCL]

Merry Christmas!

There are a lot of things to consider when comparing the two, and opinions will be firmly divided. That's one thing for sure.

Engines are engines, but it's easier and cheaper to make the the Duratec deliver the power reliably. But the Duratec is heavier with a higher C of G and that is noticeable in the seven. I think the revy versus torque arguments are somewhat misleading at the R500 power levels but there's no doubt they do have different characters.

IMHO, from an engineering point of view, the K was maybe a little ahead of it's time and the manufacturing process didn't do it justice. The Duratec, on the other hand, has some clever and well executed design features that are aimed at simplifying production, and as a result it tends to be a more consistent and reliable unit.

Edited by DCL on Thursday 25th December 00:30

[Paul Holywood]

Thanks for the very interesting input here,
Cog, isn't something I had thought of, but equally makes for good learning.

Revy Vs torque, I sit on the fence on this topic, as torque is always good to have, but a Revy engine that comes on cam can get the heart muscles pounding nicely, equally people's own personal opinion/experience is something I'm very interested to learn..

For now, Or at least until presents are open, and belly is full, then I hope to find more to read up on..
Until then I bid you goodby and a very Merry Christmas.

Edited by Paul Holywood on Thursday 25th December 07:56

Edited by Paul Holywood on Thursday 25th December 08:12

[Grubbster]

I think the general consensus is that the Duratec is more reliable at higher power and the K has a bit more character due to the rev hungry nature.

I love my K (230bhp) and it has been pretty reliable (which is surprising the way I drive it on track frequently using >8,500 rpm) but it does need to be warmed up carefully and oil level checked regularly (although mine doesn't lose a drop it seems). True that the Duratec R500 makes more power, I haven't driven one to compare but I doubt it makes a huge difference around a lap, I've certainly never thought about swapping my K for one. The Duratec is more 'torquey' but again my K will pull very hard from about 4,000 but goes banzai when it comes on cam which is the character I love - the fact that a Duratec means you can accelerate away in top gear from 30 mph is of no real interest to me, it isn't what a 7 is about IMHO.

As already suggested you'll get some quite different opinions on the 2, I've just given you mine.

[Paul Holywood]

Grubbster said:

I think the general consensus is that the Duratec is more reliable at higher power and the K has a bit more character due to the rev hungry nature.

I love my K (230bhp) and it has been pretty reliable (which is surprising the way I drive it on track frequently using >8,500 rpm) but it does need to be warmed up carefully and oil level checked regularly (although mine doesn't lose a drop it seems). True that the Duratec R500 makes more power, I haven't driven one to compare but I doubt it makes a huge difference around a lap, I've certainly never thought about swapping my K for one. The Duratec is more 'torquey' but again my K will pull very hard from about 4,000 but goes banzai when it comes on cam which is the character I love - the fact that a Duratec means you can accelerate away in top gear from 30 mph is of no real interest to me, it isn't what a 7 is about IMHO.

As already suggested you'll get some quite different opinions on the 2, I've just given you mine.

I was told they can consume serious amounts of oil when used hard, but I guess that's not every one, I will learn what mine is capable of in the new year. thanks for the input.

[rubystone]

Paul Holywood said:

I was told they can consume serious amounts of oil when used hard, but I guess that's not every one, I will learn what mine is capable of in the new year. thanks for the input.

You're talking about the Duratec I guess? Not sure that this is true for all Duratecs.

Eta, just seen that yours is a K R500. Rest assured, a K that uses a lot of oil is fked.

Edited by rubystone on Friday 26th December 08:29

[Paul Holywood]

rubystone said:

You're talking about the Duratec I guess? Not sure that this is true for all Duratecs.

Eta, just seen that yours is a K R500. Rest assured, a K that uses a lot of oil is fked.

Edited by rubystone on Friday 26th December 08:29

Sorry I was talking about K series.
Can you expand on the common reasons why high oil consumption equals a engine that is fked? And what would be the action required to fix such a serious issue?

[IBDAET]

The Ducatec seems to suffer reliablity issues as much as the K if used hard - in my track day group 2 of them have had problems this year, where the K's (and two of them are Evo2 1900s) have had none. Richard Ince (killer of many a K) destroyed a Duratec the first time he drove it!

The rest of the parts on either engine (alaternators, broken engine mounts, clutch issues etc) will fall apart and leave you stranded in any case if you insist on a 10/10ths approach to driving 100% of the time.

The key difference is the low down torque. The Duratec is a more relaxing drive its torque curve ramping up from 1500rpm lower rpm - you don't have to give it the beans to go quite quickly. Both deliver max torque high up at 6k, but my then the 2.0 Duratec has 30lb/ft more.

[BertBert]

Paul Holywood said:

Sorry I was talking about K series.
Can you expand on the common reasons why high oil consumption equals a engine that is fked? And what would be the action required to fix such a serious issue?

Interestingly my SLR k did use a lot of oil on track and hardly any on the road and didn't seem broken in any way. My R500-k didn't use much oil, but as it spent most of its time in my ownership broken I didn't really get to use it enough to tell.
Bert

[Paul Holywood]

BertBert said:

Interestingly my SLR k did use a lot of oil on track and hardly any on the road and didn't seem broken in any way. My R500-k didn't use much oil, but as it spent most of its time in my ownership broken I didn't really get to use it enough to tell.
Bert

Bert, I was told something very similar that a highly tuned K's can used well over a litre of oil per track session, and that consumption varies from engine to engine, however the fact still remains are the engines that use excessive oil "fked" as Rubystone has previously mentioned?

[BertBert]

Paul Holywood said:

Bert, I was told something very similar that a highly tuned K's can used well over a litre of oil per track session, and that consumption varies from engine to engine, however the fact still remains are the engines that use excessive oil "fked" as Rubystone has previously mentioned?

Well, it'll be interesting to get his take on it, but I didn't consider my SLR engine to be fked. I did a lot with it both road and track. It got reasonably consistent RR results over the years (albeit a tad down on "spec"). It did eventually blow up in the next owners hands but that's because (from memory) he filled #1 cylinder with coolant.
Bert

[DCL]

A engine built with correct clearances and in good condition should not consume large quantities of oil. But high performance engines that that have been built with after-market performance parts can struggle to to match the clearance of an OE engine so tend to consume more oil. In fact, larger clearance can be desirable and even deliberate in some applications. Horses for courses, really.

But an engine that has been built and run in with care, always warmed up gently, and treated with a degree on mechanical sympathy will bed-in and settle down. The seals won't have been destroyed and carbon deposits will start to aid sealing. In sort, an engine that delivers the power and consumes less oil than another of a similar spec is probabley the better of the two.

My experience of the K is that, if you can keep the oil in it, it will be as good as any other engine. The Duratec is not immune to failure, but it does have some features that help deal with abuse a little longer.

[edit to add]

Just to get a little more technical, the consumption is often a function of the pumping action of the rings.

Large quantities of oil actually pass the the rings in both direction (the oil is need to lubricate the bore) But the ring is designed scrap more oil off on the power stroke (gas pressure pushes the ring out). In practice this means there's a continuous pumping action of oil down the bore.

The bore wall temperature is low enough stop the oil being burnt during combustion but as RPM increases the rings pumping action become less efficient and the quantity of oil above the piston can build up to the point were it leaves the wall and is burnt.

Edited by DCL on Friday 26th December 14:41

[Paul Holywood]

DCL said:

Just to get a little more technical, the consumption is often a function of the pumping action of the rings.

Large quantities of oil actually pass the the rings in both direction (the oil is need to lubricate the bore) But the ring is designed scrap more oil off on the power stroke (gas pressure pushes the ring out). In practice this means there's a continuous pumping action of oil down the bore.

The bore wall temperature is low enough stop the oil being burnt during combustion but as RPM increases the rings pumping action become less efficient and the quantity of oil above the piston can build up to the point were it leaves the wall and is burnt.

Edited by DCL on Friday 26th December 14:41

Very interesting indeed, makes total sense.

[rubystone]

Paul Holywood said:

Very interesting indeed, makes total sense.

Has your R500 been rebuilt? You seem so concerned about it.

[Paul Holywood]

rubystone said:

Has your R500 been rebuilt? You seem so concerned about it.

No, please don't get me wrong I'm just learning about the seven and thought I would throw some questions out there, as this will be my first seven.

I have nothing to worry about apart from how long I have to wait for good weather.
when I pick it up end of January, the car comes with warranty.
I also see the car start from cold after not been started for two weeks and no smoke, the engine pulls like a Trojan once the cams come into play, and I have managed to trace some of the cars history from speaking to some who know the car.
The only thing that has concerned me was the layshaft rattle, and have since spoken to many who say it's common, if it ain't broke etc etc..

I have learnt so much just from my thread here, and that's the great thing about open forums like this, you get a great deal of knowledge being offered, people pointing you in the right direction and for me I'm truly grateful.

Edited by Paul Holywood on Friday 26th December 23:49

[rubystone]

Paul Holywood said:

No, please don't get me wrong I'm just learning about the seven and thought I would throw some questions out there, as this will be my first seven.

I have nothing to worry about apart from how long I have to wait for good weather.
when I pick it up end of January, the car comes with warranty.
I also see the car start from cold after not been started for two weeks and no smoke, the engine pulls like a Trojan once the cams come into play, and I have managed to trace some of the cars history from speaking to some who know the car.
The only thing that has concerned me was the layshaft rattle, and have since spoken to many who say it's common, if it ain't broke etc etc..

I have learnt so much just from my thread here, and that's the great thing about open forums like this, you get a great deal of knowledge being offered, people pointing you in the right direction and for me I'm truly grateful.

Edited by Paul Holywood on Friday 26th December 23:49

Good. You'll love it. Just treat it with respect. Warm it up before giving it the beans and try to make sure the tyres have some heat in them in this kind of weather.

[Gatecrasher]

rubystone said:

Paul Holywood said:

No, please don't get me wrong I'm just learning about the seven and thought I would throw some questions out there, as this will be my first seven.

I have nothing to worry about apart from how long I have to wait for good weather.
when I pick it up end of January, the car comes with warranty.
I also see the car start from cold after not been started for two weeks and no smoke, the engine pulls like a Trojan once the cams come into play, and I have managed to trace some of the cars history from speaking to some who know the car.
The only thing that has concerned me was the layshaft rattle, and have since spoken to many who say it's common, if it ain't broke etc etc..

I have learnt so much just from my thread here, and that's the great thing about open forums like this, you get a great deal of knowledge being offered, people pointing you in the right direction and for me I'm truly grateful.

Edited by Paul Holywood on Friday 26th December 23:49

Good. You'll love it. Just treat it with respect. Warm it up before giving it the beans and try to make sure the tyres have some heat in them in this kind of weather.

I can't comment on the R500D but to emphasise the point above my R500K was spinning up over undulations in 5/6th at well over 100mph. That was with 235 width Kumho V70 super soft sprint tyres at Oulton Park on the straight between Druids and Old Hall a few weeks ago when it was drying/damp.
Ignore me if this is patronising but take it easy to start with and learn what the car can do, once you're used to it you'll have a ball. They're brilliant but be careful. A very experienced driver did some rather embarrassing piruettes the first time he drove mine at Dunsfold last year. Anyone remember the Yellow R500 taking out most of the cones on the handling test last year?

[rubystone]

I spun my R500 twice on the road in these temperatures some years ago. On a standard map, the power band is narrow and before you know it, it's spun up the rear tyres so quickly, you'd have to be Lewis Hamilton to catch it.

The wheelspin in the first 5 gears in the damp was always amusing...at least it was consistent and a damp Druids was epic fun for as long as a blind eye was turned by the officials! I still miss the car now. But not in the winter!

Just one point on the topic of an engine built with poor quality parts using oil. Minister specified top quality parts for the R500 and the original Minister spec for the engine went beyond what Caterham finally decided on. This choice was made on the grounds of cost. That's why I maintain that a K that uses oil (and I don't mean blows it out into the catch tank/s) is not in the best of health. I had a Mini Cooper once...nearly as quick as my race-prepped Midget...nice and loose, used copious amounts of oil..eventually went bang at 2am on the A414.

[DCL]

Here's 250+ bhp on cold tyres - OK, my son was provoking it, but it shows how quickly it can bite back.

https://www.youtube.com/watch?v=g1jF7P4HnC8

Edited by DCL on Saturday 3rd January 11:04

[BertBert]

Very nice barrier avoidance!