Duratec v k series

[Esceptico]

Apologies if this topic has been done to death....

Thinking of getting a SL/SLR/R300/R400. Hoping to try a few next week when I visit a dealer.

What is the general consensus on the former K Series engines versus the newer Duratec powered cars? Worth paying a bit extra for the newer cars (with the new engine)?

[adsvx220]

Age old argument this. It depends what you are after?? Older cars k series newer duratec.

K series:

Revvier
Light
Older
Very tuneable with £££'s
Once tuned the engine turns into a screeming banshee even my subtly tuned 1800 k with cams, head work and throttle bodies the car sounded awesome and that had a limit of 7250rpm with 170bhp god know what 250bhp with 9000rpm is like. Bonkers I'd imagine.

Ignore the k series aren't reliable gang. If the engine is looked after and warmed up properly they are fine. My car had 26000miles with track use by previous owner and me redlining it through its lifetime I never had a problem.

Duratec

Very slightly heavier
Torquier
Lazier engine
Newer
Very tuneable for less £££'s I believe

It's personal choice I personally wanted a k but I would probably enjoy a duratec just as much. In fact my next 7 will probably be a duratec in R500 flavour.

[Esceptico]

^^^^

Thanks for that.

[coppice]

I have owned both and the K has character in spades- revs like crazy, sounds like a racing car and really suits a Seven. The Duratec sounds ho hum (unless you put on roller barrels , which transform it in every way ) , pulls like a diesel but revs freely and by all accounts is bulletproof. But I never had a problem in 40k plus of K usage so don't believe all that old tut about them having HGF every 5 miles or so. So..duratec for me if you get RBTB - otherwise a K .

[Esceptico]

In what way does the roller barrels transform the Duratec? Noise? Character?

[BertBert]

I'm a big k-series fan, but it would be daft to ignore the fact that they have HG weaknesses. I've been through a few. I also don't think that they will necessarily be ok if "looked after and warmed up properly". But if they are well put together, they can be fine.

As to which one prefers, I can't comment as I only have k-series experience! That's a poor state of affairs isn't it??

Bert

[coppice]

Esceptico said:

In what way does the roller barrels transform the Duratec? Noise? Character?

Both -the noise is amazing - feral induction noise and a wealth of pops and farts on overrun. But the response is the real thing ; the difference is extraordinary . Some say it costs a lot for ten bhp. I say it feels like at least three times that. Others say it drinks fuel with rbtbs - no it doesn't , it behaves as any other Seven will. Frugal if pootling ,dipso if hammering.

[forest07]

coppice said:

I have owned both and the K has character in spades- revs like crazy, sounds like a racing car and really suits a Seven. The Duratec sounds ho hum (unless you put on roller barrels , which transform it in every way ) , pulls like a diesel but revs freely and by all accounts is bulletproof. But I never had a problem in 40k plus of K usage so don't believe all that old tut about them having HGF every 5 miles or so. So..duratec for me if you get RBTB - otherwise a K .

The other option is Jenvey throttle bodies, I ran the direct to head ones, on my Duratec and I believe they don't drop out of balance as often as the roller barrels.

[andy97]

coppice said:

I have owned both and the K has character in spades- revs like crazy, sounds like a racing car and really suits a Seven. The Duratec sounds ho hum (unless you put on roller barrels , which transform it in every way ) , pulls like a diesel but revs freely and by all accounts is bulletproof. But I never had a problem in 40k plus of K usage so don't believe all that old tut about them having HGF every 5 miles or so. So..duratec for me if you get RBTB - otherwise a K .

Not sure about the Duratec being bulletproof. Don't know much about the Caterham installation but in the MX5 mk3 (same engine) they are known to be very sensitive to oil level and if they are not absolutely at the full mark all of the time can suffer damage.

As an aside, what are the Vauxhall XE variants like in comparison?

[culminator]

I've just returned to a VX XE after a Duratec R500, via a BDR. Strangely, the R500 didn't actually feel massively quick. It was of course but the engine felt a bit, err, dully,really. Can't explain why, it was on RBTB but just didn't excite. It didn't seem to want to rev...

The XE I now have is tuned to about 225bhp and whilst it's early days, it just seems a monster. Total linear power, great noise and bags of low down grunt but also very willing to rev. In a word, love it. (Ok two words!)

[Skyedriver]

Crossflow..........................

[Shropcat]

Having now had both a 230bhp K Series and a 260bhp Duratec I have come to the conclusion that the visceral screaming nature of the K far surpasses the 'lazy' big torquey power of the Duratec. Saying that a 2000 mile tour of Europe would be in the Duratec every time.

[FST]

Have just got back from a fabulous day at Cadwell with my Freestyle Duratec car (2.3l), previously (albeit briefly) owned by Culminator! Everything has now been properly set up and the car is massively quick and responsive. Last time I was at Cadwell I was in my 200bhp K series SLR - which was certainly more revvy and frantic, but the torque of the Duratec is amazing - it just pulls and pulls and rewards tidy driving with very quick lap times. I was there with another Freestyle car, Paul Hazell's, a 215hp car just remapped to 240, and we both agree there's nothing much that can touch these cars once correctly set up.

[andy97]

Who was it that is supposed to have said, "torque wins races"?

[sllimr]

Having just switched my old R400 K for an R500 D, I'd say they were both great in their own way, the Duratec is more usable on the road as it hunts about less and power is more usable, K was more "raw" at the the top end of the revs and more pronounced "coming on cam" but the Duratec still going into banzai mode as it hits its stride.

Loved them both (and my old VX which I believe was purchased from the previous VX exponent on this thread....), prefer the character of the Duratec myself but depends on how you like your engines IMO.