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1.8 K series


p.mole1

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 Just had my 1.8 K set up on a rolling road, Super Sport Cams, Vernier cam wheels, Power speed exhaust, Jenvey throttle bodies, Emerald K6 and a lightly cleaned up head. 144 Bhp@ about 6500 rpm. I was running the later blue injectors 191 cc/min but these maxed out at 5500 rpm! so I had to use the earlier cream injectors 239 cc/min.

I had a similar problem with my 1.4 the standard injectors were flat out!. I wonder if my fuel pump is unable to maintain enough flow or pressure? Should the standard 1995 injection pump be able to cope. I have never measured the the fuel pressure.

The car goes like stink! It makes 140 bhp 5700 and it continues till 7200  and has a flat torque curve 120 ftlb from 2750rpm to 6250 rpm with a max of 132ftlb.  This seems quite low compared to other quoted power outputs? but I can't fault the cars performance and that's what matters

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I’ve had / experienced similar. Have you converted from a 1.4 retaining the original pump? I had 149bhp with my 1.8k/ SLR Throttle bodies, Supersport, Verniers, Emerald, 4-1 race exhaust, was a tad disappointed. The mapper said it was leaning out at higher RPM suggesting it couldn’t get enough fuel, despite the cream injectors being at nearly full duration. 

I’ve since cleaned the injectors and replaced the pump but not had the time/ budget for a remap to see if it’s made any difference. The engine works perfectly, but Id hoped for nearer 160.

I replaced the pump with a upgraded one from Merlin Motorsport, model IPT101 for £77+vat. Not sure it’s made any difference until I get round to remapping it. 

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Hi Tom thanks, that's exactly what happened to me. I am using the original pump I naively assumed it would be ok. Does the original pump have any kind of stainer or filter fitted?  Just out of curiosity I would like to try and monitor the fuel pressure, is there any way of doing this using the Emerald data logging?

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Yes, the original pump has a gauze strainer - looks a bit like a rectangular tea bag.  Assuming you buy just the pump from Merlin, you'll have to swop it into the cradle/ mounting assembly, but it not too hard to do - once the pump is out of the tank. Which means (on mine) the boot floor, the tank protection, the filler neck, draining any fuel out, and finally getting the pump put.  Then the fun of resealling the gasket!

As far as I know there isnt a fuel pressure logging on the Emerald, and there isn't a fuel pressure sensor on the engine for the ECU to read.  I think you can get in line dial gauges that you plumb into the fuel line.     

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Not sure if this helps, but I'm certain I've read somewhere that unless you have a decent ported head fitted, you'll never fully realise the benefit of having fitted TBs... it'll make a nice noise and give you a few more BHP, but that is all...

DVA will be able to advise you...

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Nick, I've got an 1800 K with a DVA K04 kit which produced 170 bhp at the two Steves' rolling road. I think that's more than "a few BHP", but certainly there's a lot more power available if I pay a lot more money for porting and stronger internals.

p.mole1: Steve was concerned about my fuel pressure being maxed out, and he "solved" it by squeezing / compressing the fuel pressure regulator, which made it generate a higher pressure. I'm sure this is a well known hack / bodge, but I can't really find anything useful on the web about it. Of course, it means that my current map is tied to the unique fuel pressure created by my regulator.

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On DVA's  website he is quoting 160 Bhp+ for his Super sport throttle body kit which is same spec as my engine. I don't know if my fuel pump has enough flow to maintain 3 bar at maximum output?

Strangely if you do the calculations the cream coloured injectors are 239 cc/min  these should generate 145 bhp at 3 bar with a 80% duty cycle. Interestingly if you increase the fuel pressure to 4 bar it increases the injector capacity to 277 cc/min which would provide enough for 169 bhp at 4 bar. I don't think it would be a good idea to increase the pressure that high with the standard fittings and plastic fuel rail ? Which begs the question about how accurate, optimistic rolling roads are or how accurate the injector calculations are.

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The two Steves' road is well regarded, but I can also feel that this engine is much beefier than the 1.6 SuperSport that I ran before. It is possible that, at max power, everything is operating pretty close to its limits, but it's hanging together.

If I was planning further upgrades then I'd probably have gone for bigger injectors and a new fuel pressure regulator, but I'm pretty happy with what I've got, and have no plans for more power. I've got other things on the car to fund :)

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Does anyone know what the BSFC is for the Rover K series,I had done the calculations on .5 however but after a bit of research it should be about .45? the lower the BSFC the higher the power output. In this case the 239 cc/min should be good for just over 160 bhp at 3 bar and 80% duty cycle. If my Injectors are close to the limit I should be making over 160 Bhp which would be at the ball park figure for DVA'S K04 kit. My friend has a Westfield with a Toyota 1.6 and his is putting out a quoted figure of 175 Bhp@ 7500 it's a fantastic engine! If you put the cars back to back there is very little difference in the performance?

I had a similar think happen with my 1.4 Super Sport with the same running gear, Oily did warn me I would be better just swapping it for 1.8k.  After all my work with the 1.4 including a Janspeed head I ended up with 127 Bhp and wasn't at the wheels, somethings not right

 

 

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I should point out the car is now running excellently. I am getting an extra 40 miles to tank, it must have been really rich at part throttle. I was using a base map and the car seemed to running really well, I was just throwing away petrol down the exhaust

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Your power seems to be rolling off too early.

The 2001 1.8 Supersport was rated at 140bhp @6800 rpm   - OK the 140 number may not be real, but I'd have thought the rpm quoted would have been at max. power.

Simon

 

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hi David,

144 bhp sounds quite high for a standard Supersport, I'm sure you will see an improvement. I am going to have my car put on the same rolling road as my friends Westfield. I will use this as a bench mark, I dare bet I will see a vast hike in power?

I am sure most rolling roads are quite optimistic, as most people want to see large figures. It's the before and after that matters, that said the 1.8 K series is has very small valves in standard form and a small bore limiting valve size. I can't fault my cars performance but I have nothing to compare it to. I'm just curious 

 

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The stock head is a limiting factor, some are also quite badly machined which will lead to a further reduction in potential. The bore size will allow 33.5mm inlets and 29mm exhausts which is a fair bit of valve area. The SS is simply a cam upgrade and remap, to think that this would lift the horsepower by 24 is cloud cuckoo land. TBH the claimed SS 138BHP is wishful thinking, in my experience 128-132 is nearer the mark.

Oily

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I am putting my car on a local dyno on tuesday. The same one that dyno'd my friends Westfield. It will give me something to compare it to. The increase in performance compared to my 1.4 is unbelievable, especially when you compare the power graphs.  I may have been better fitting shorter air horns since I am using very mild camshafts this is probably why peak power is lower down the rev range but on a positive my torque curve is flat. Or maybe I have the camshaft timing advanced too far 

It will be interesting to see the results, it could just be I'm hopeless at putting engines together

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Local dyno was a bit of a waste of time as the readings were all over the place and print out did not make any sense as the power and torque curves did not merge at 5250 rpm?. It looks like it's 144bhp, a bit disappointing after all that expense and effort. I have come to the conclusion the intake trumpets are too long 90mm and the cam timing may be too far advanced on its current settings. I may be loosing about 15bhp at the top end? I may try some adjustable trumpets and an open air filter and try retarding the cam timing. On a plus I don't use a drop of oil and it pulls from tickover and still has plenty go at 7000rpm.

 

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Generally longer trumpets are better for providing power lower in the rev range, shorter ones produce better results higher up the rev range. However this also depends on camshaft timing if you have longer duration camshafts you can use longer trumpets to smooth out the torque curve and produce a better overall power curve. In my case I have quite mild cams. 

This is of course a generalisation  it's a very complicated subject and can depend on many other factors.

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Mathematically, horsepower equals torque multiplied by rpm. H = T x rpm/5252, where H is horsepower, T is pound-feet, rpm is how fast the engine is spinning, and 5252 is a constant 

I was wondering if expressing one of those in different units accounted for your observation that "the power and torque curves did not merge at 5250 rpm".

Could you post the curves?

Jonathan

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