Duratec in detail

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David
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Re: Duratec in detail

Post by David » Sun Jan 11, 2015 11:15 pm

An update:

Bad man flu slowed progress over the festive period - I had five days set aside and only managed one on the car :( But I did bolt the gearbox to the engine and then had a go at putting in the car

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But it just wouldn't fit :evil:

so tried again from underneath

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Still no joy . . .

The obvious problem was that the Sadev is a little taller and fouls the tunnel before I can drop the front down.

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But the factory fit these, so the real problem was that I have the deeper Cosworth sump - it needs a bit more of an angle.

Generally, with a Caterham, the accepted method of fitting engine and gearbox is together. But with that option ruled out, I ended up fitting them separately. Not too much of a problem - the main one being reduced access to torque up the bell housing bolts.

But the fit was extremely tight with clearance really being too small on one side. I expext some would be happy to run it like that (and accept the occasional contact with the chassis) but I think I will give it a little more thought, possible adjusting engine mounts to help matters.

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With the engine in I decided to put the seat back in and fit the gear lever to assess the position. I first tried it as the factory had supplied it.

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It was Ok, but I was unhappy with the angle - it would work better if it was a little more erect. I had been tipped off that trying it backwards might help.


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But this need the push rod length tweaked - but that was just another excuse to use the lathe :D

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The engine is now out again to allow me to tidy up a few things now I know were the gearbox sits. Amongst this is some new fuel line that will be used to upgrade the fuel system with a filter and return line..

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Last edited by David on Mon Jan 12, 2015 9:14 am, edited 1 time in total.
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Re: Duratec in detail

Post by tut » Sun Jan 11, 2015 11:27 pm

..it would work better if it was a little more erect. I had been tipped off that trying it backwards might help.

The only part that I understood David.

tut

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Re: Duratec in detail

Post by David » Wed Jan 21, 2015 10:54 pm

Just a little feedback on the BTB exhaust. I decided to have a look inside before the new season . . .

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It has done some serious events but no indication of any distress.

I'm sure the packing would have gone on for many seasons with only slight discoulration at the silencing end. The cat looks like new but has must have been getting hot as the E-glass packing around it was beginning to break down. I've ordered some new packing as the the old stuff is really too fragile to slide back in. A quality item - one of the nicest items on the car :)
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Re: Duratec in detail

Post by David » Mon Feb 23, 2015 12:59 pm

The SLS awards on Saturday. A great night with some cracking trophies. I got to take these home - at least for a while. The work over the year really paying dividends - just need to learn to drive the car properly now :?

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Never thought my name would be on a BTCC trophy - albeit in its new life as the SLS Class A trophy. A great idea and thanks to Gordon Shedden for donating them :)

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Re: Duratec in detail

Post by Ferg » Tue Feb 24, 2015 9:12 pm

Another successful year. Congratulations! Your build posts have been fascinating. :-)

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Re: Duratec in detail

Post by David » Sat Feb 28, 2015 8:51 pm

Drove the car for the first time today with the sequential. It was just really a test, and running it in, but the gearbox seem to work OK. I was using the default 'closed loop' settings for the Geartronics and MBE ECU, but the engine ECU needs a tweak to switch on a bit earlier. But overall very happy with the day.

Watch on YouTube

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Re: Duratec in detail

Post by GreigM » Sat Feb 28, 2015 10:33 pm

looks good David, always good that everything ran as expected after such major surgery.....looking forward to seeing what lap times you can get now when running in anger!
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Re: Duratec in detail

Post by David » Sun Mar 29, 2015 5:39 pm

Update time!

I took the car to Northampton Motorsport to do some mapping of the throttle bodies. While there, we tried some of the different MBE stratergies for the powershift. We found the torque reduction and torque recovery caused backfiring:

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

Ingnition cut was smoother. We believe what was happening was that the late ignition of torque reduction was happening when the exhaust valve was open. This resulted in the fuel being ignited as it entered the exhaust. Ignition cut meant the source of ignition never occured.

Here's the result on a very wet and windy track:

https://www.youtube.com/watch?v=4yTtumXmG0s


So than brings the Sadev project to a close, but I will report back lap time comparisons once the weather improves.

Still more to report on the taper throttle bodies but due to some unexpected issues, I leave that until I fully understand what's going on and SBD have had a chance to look at it.
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Re: Duratec in detail

Post by David » Mon Apr 20, 2015 2:23 pm

It has been a month of head scratching with the car - the SLS power check suggested it was down 30 BHP on last year. I'm not convinced that it is, but clearly something was different. Anyway, with a degree of anxiety and a full check revealing nothing obvious, I entered round 1 one of the SLS .

First time driving in the dry for six months (and with the new box) it showed how quickly you become rusty. But, with a 55.9 in the first practice it suggested at least the car was working well. Qually was a very scruffy affair with lots of mistakes but did give me 3rd overall with a 55.5 sec and a PB. In the final things begain to settle down, but the one lap format meant tyres weren't at their optimum, so a 55.8 sec and 3rd in class, 4th overall. With power down on last year, that's a good result.

But the gearbox worked fine with flatshifts all but seamless. I'll maybe reduce the duration (tolerance) a little for the next one.

Here's a couple of qually laps

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Re: Duratec in detail

Post by Danny T30TUS » Mon Apr 20, 2015 8:23 pm

Hi David,

Cracking video. May I ask what camera and what software do you use to be able to get the lap times etc on the screen?

Thanks

Danny

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Re: Duratec in detail

Post by David » Mon Apr 20, 2015 9:27 pm

It's the Racelogic Video Vbox lite. A bit old hat these days as it is 4:3 PAL. But it does use a professional fully shuttered camera that makes it better for analysis. They have recently introduced a HD version, again fully shuttered. The graphics are added in real time as it records. Not sure if that is the best way to do it now. Sometimes it would be nice to have the raw footage and add the graphics afterwards.
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Re: Duratec in detail

Post by David » Sat Jun 20, 2015 5:00 pm

It's half way through the season now and I can't really imagine driving the car without the Sadev or flatshift. So with no real issues to contend with, I've decided to crack on with the long term goals of the project and purchased a full paddleshift set-up from Geartronics.

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As the car is used mainly for sprint events, I've opted for a high pressure bottle supply. This simplifies the installation and saves significant weight, but could be changed to a compressor relatively simply. The main challenge will be clutchless downshifts using a the throttle blipper. Having studied the software, it is clear that some clever stuff goes on. Looking forward to getting stuck in to the installation over the next few months.
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Re: Duratec in detail

Post by Dominic » Mon Jun 22, 2015 11:08 am

Impressive stuff David!

As someone who loves a project, and tinkering with a car, I wonder if it's the same for you? - do you enjoy the development project as much as the track action?
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Re: Duratec in detail

Post by David » Mon Jun 22, 2015 2:13 pm

Dominic wrote:Impressive stuff David!

As someone who loves a project, and tinkering with a car, I wonder if it's the same for you? - do you enjoy the development project as much as the track action?
Absolutely, driving it is a necessary evil :D
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Re: Duratec in detail

Post by David » Sat Nov 28, 2015 7:05 pm

Just an update on this thread

The engine had been extremely reliable last year, so this year I was tempted to play around with thinner oil grades to see if any power was on offer. Certainly there was more power, but one event saw oil temperatures getting rather elevated. I got the feeling that perhaps I’d pushed my luck too far.

The oil filter check confirmed a higher particle count than normal, but returning to a thicker oil for the final event of the year seemed to settle it down. But I knew a rebuild was on the cards, if nothing else, to give me peace of mind.

To give some perspective to what follows, the engine has completed 13 sprint events, and a similar number of trackdays, 6 rolling road sessions, 120 hours on the ECU, and about 1000 miles on the speedo. Reving to 8600, and producing up to 270 BHP

First impressions, when opening the cam cover, was that it all looked rather nice. The spark plugs were text book (if anything getting a bit hot) and the only thing that caught my eye was two small scores on one cam lobe.

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In hindsight, the two little scores where a clue to a more serious problem. And yes, the bearing next to that lobe was in trouble.

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There was noticeable wear on the cam bearing and the cap looked a bit distressed too. Luckily the unloaded side (the head itself) seemed not to have suffered to the same degree.

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Now the cause of this is difficult to say for sure. The cam had two little hammer marks on the bearing surface which were within the oil groove most likely caused by it ingesting something via the oil.

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But the bearing cap also looked porous, so maybe a problem there. Anyone’s guess to be honest.

One issue that played on my mind was the length of time this engine had been at idle. It has spent most of its time idling away, warming up, and waiting for sprint starts, so maybe low oil pressure played a part too - or at least assisted the failure.

I say failure, but it hadn’t failed really - the measured clearance was still within an acceptable limit, but it was not what you want on your race engine. The jury is out on the fix, but I will give it some thought, and probably look at the rest of the engine first.

Moving on to the bottom end, things looked much as expected at first. Big end 1,2, & 3 where all running normally. But number 4 had clearly picked up something and was showing signs of distress and failure was not too far away.

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Particles were causing little dents and disturbing the wear pattern. Speaking to various suppliers, it seems the VP2 tri metal bearings are designed to behave like this - absorbing any foreign matter (out of harm’s way) and buying you some extra time.

Having looked at many Duratec big end bearings now, I would recommend regular replacements if you are using high RPM on a frequent basis.

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The mains looked like a totally different engine: the printing still present and not signs of wear whatsoever. That was a big relief as they are the one item that is difficult to replace due to the numerous grades.

All the journals should be serviceable after a polish, certainly not at a regrind stage yet.


I was curious about the cylinder bores as this was the first engine I've run-in solely on the dyno. The initial results were outstanding on leak-down and BHP. But the second season did seem to take its toll and the last check suggested it had lost a little.

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Clearly the bores have done some work, but I can't detect any measurable wear and all the ring gaps are the same as recorded in the build. There's no hint of any bore wash, and the honing marks are still visible, even through the heaviest of wear (more on that later). I'll give some thought as to whether to just lightly de-glaze the bores and rings, or do a full hone and replace the rings.


One unexpected surprise in cylinder 3 bore was a corrosion ring. The car is stored in the dry, and run on a regular basis so I was initially puzzled by it.

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But thinking back, there was one occasion that I put the car to bed with a wet filter (it's a foam one). I guess the cylinder with the inlet valve open must have drawn in moist air as the engine cooled. It looks worse than it is, so hopefully it will come out with the de-glaze, or light hone.

But be warned if you have a foam filter - remove it from the air-box if it is wet!


There's not an awful lot to say about the Supertech pistons and Cosworth rods. They all came out with hardly a mark on them, just a hint of slap on the top edge.

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But it's clear combustion temperatures were high as they were self cleaning around the exhaust valves. There's no alternative to forged pistons at this level of tune.


Duratecs don't have a reputation for cylinder head gasket problems, so I fitted the standard gasket on this engine. However, on close inspection, there's some evidence of movement and wear.

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I think it would be fair to say that the standard gasket will do the job, but it probably has a limited lifespan at these sort of power levels.



Those with a good memory may recall the burr embedded in a cam bearing. When it was removed, it left a sizeable hole. Well, there seems to have been some healing going on, and it looks better now.

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This is something I've noticed on aluminium bearings before - they seem to improve with age. The Bearing material seems able to move around to fill the imperfections.


The dismantling of the head concluded the strip-down. I'm pleased to say there were no problems with the valves or followers - nothing more than a light lapping of the valve seats and a clean and polish will be needed.


So what's the conclusion?

I Think I should have done it a year earlier! There's no doubt that once you go to 260+ BHP, the life reduces. At a guess, this engine is wearing out about 10 times faster than a road car engine. Possibly I encouraged the bearing issue with the thinner oil. This does release more power, but ALL your bearings do need to be in perfect condition. Probably something only for the race teams with big budgets, and plenty of spare engines.

The Duratec can be reliable at this state of tune, if not immune, from problems. But I would strongly recommend a seasonal rebuild/check/refresh if you are racing.
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