Sigma to Duratec

[Mrp]

Theoretical at the moment and just interested in the feasibility and looking for some expertise.

I have a 140 Sigma Roadsport with all the upgrades, big brakes, Slippy Diff and Nitrons etc etc. for sentimental and personal reasons I do not want to trade it in for a different car. In a quest for more power I have been investigating the Sigma tuning route but it seems a little expensive approx £ 6-7k.

What is  the feasibility of swapping to a R400 spec Duratec engine and what would be involved. Has anybody done it, what parts would be needed. Obviously the sale of the existing 11k mls engine could be used to offset some of the cost.

I would be interested in POBC's opinions.

As I have said, trading in the car for a different Duratec R400 is not an option.

Mrp

 

[DJ.]

How about supercharging the Sigma?

I don't know much about conversions, but it will give you the extra power and torque you want.

[martyn]

If you just want any duratec out of a ford mondeo then I expect it could be done quite cost effectively. However if you want an R400 spec one with all the ancillaries then I doubt you'll have much change from 6k.  That is assuming you dont find a nice second-hand one with everything you need.

I would seriously consider the power to weight of each route.  A £6k tuned sigma isn't going to be that far behind a duratec in terms of power to weight.  But then it will have the handling and breaking advantage.

[tangomikeromeo]

i suggest the phrase here is 'Ouch!'

My K has had just under half that already and needs another £3K to get to 200 bhp so it appears that this is just how much it costs. Oilyhands has a heuristic on £/bhp and hopefully will enlighten lest I misquote but taking the common or garden from mass produced, mass consumed, massive reliability engine past the 100 bhp/litre mark appears to be a case of TADTS without forced induction.

If the consensus is £6K for each option if you keep the Sigma doing it in steps will help the man maths ease through the Authority gates whereas D sounds like a big gulp/step.

(If you're married to me - the above spend is wine induced bragging and no intention is implied on the rest of it)

[nickhi]

I would think to swap from Sigma to Duratec would probably head over 6-7k, depending on where you source the engine and how much of the work is DIY.  Could always recoup some from the sale of current engine.  Maybe look at the price comparison between your car and a similar spec R400 of the same vintage.  I'm guessing the difference may be some of the way there already, if so the price of sentiment seems a bargain. 

Interested to know if anyone has done this swap
 

[cr500dom]

How much power do you want ?

And where are you getting £6-7k for the sigma tuning options from ?

Thats a lot of money, you could build a proper sigma for that.

Throttle Bodies`s, Proper Head and cams, lightweight Steel flywheel will all make a massive difference.

If you want 200hp, then you'll need High compression pistons and rods as well.

But 180hp is easily do-able with a ported head, cams and Throttle bodies which even buying everything new should only be £2k plus a remap to suit.

I have a set of Caterham 150 spec Throttle bodies "in stock" if you need some.

HTH

Dom

[martyn]

I suppose that is referring to the prices of certain off-the-shelf packages provided by some companies.

When compared against the cost of going it alone with upgrades it does look expensive as you've illustrated.  Factor in installation, development costs and expertise / experience.  And also consider that some packages include a lot more than you've listed there (bottom end modifications, new ECU, uprated clutch), the gap in cost starts to get a lot narrower.  It is still difficult to justify the difference over the raw part prices though.

I've always been tempted to drop a few thousand £ on a DIY route.  I think it would be a lot more satisfying and rewarding knowing that I researched and selected the spec.

[cr500dom]

Thats what Im getting at,

How much power do you want ?

If you don't go chasing 200hp or 9000rpm then you can eliminate  £1000 worth of pistons and rods, and the associated engine build costs.

If you limit yourself to head work, cams and intake mods, this can be done with a "Track & Road" remap by Steve G.

It can even be done on another head, so you could put it back to standard for resale, and swap the modded head and intake on to your new car.

Stuarts (PP) Kits are very good, with a lot of work behind them and a warranty.

But they don't suit all Budgets. There are many other people tuning Sigma engines, (Shawspeed, BPJ - Big Paul Jackson) who have not specifically targeted caterham owners.

[Mrp]

180hp seems like a good figure

Mrp

[12standish]

I am in the same position (although mine is not upgrade 125). I fancy putting a Duratec in rather than selling my current car and upgrading.

[elie boone]

You would need the Duratec engine, exhaust, engine mounts, if you can't use the sigma clutch you will need a to change the gearbox and the bellhousing and clutch assembly, possibly new electric connectors, not sure if they use the same rad either. if you would find a Duratec out of a Caterham would save some money but they don't come up very often for sale.

[Mrp]

How about a bulk buy of Sigma upgrade from Premier Power !

Mrp

[Ian Mackenzie]

I've done a K series to Duratec.......

From Memory, if using new parts...

• Engine, new circa £2K
• Raceline bellhousing £300 plus £300 clutch
• Clutch master and slave cylinders £100
• Raceline wet sump £450
• Oil filter housing (needed if imperial chassis) £100
• Throttle bodies £1000
• ECU £600
• Rolling Road £300
• Exhaust £1000
• Engine Mounts £100

Total £5,800

Not a definitive list or costs, but you can see it soon mounts up.....

I managed to get some second hand parts inc. Jenvey throttle bodies, R400 exhaust, raceline sump and bell housing and an engine out of a Morgan with 14K miles with oil changes every 6K miles so I got lucky there.

As other have said the sale of your existing engine can offset some of the costs.

Cheers

Ian

 

 

[7 wonders of the world]

plus....

alternator

alternator mounts

air filter

hoses

cams

valve springs

verniers

if your spending money on new cams etc you might as well add pistons and rods on and get more bang for your buck, these parts are rare on the used market.

Surely someone blows Sigmas TTS performance maybe ??

what's the used market like for selling on some of the redundent Sigma parts to offset the cost?

also factor in sorting the 5 speed box for some decent ratios and add and LSD too, maybe wider rear wheels and tyres................

 

i

[martyn]

Here is an interesting thread..  http://passionford.com/forum/general-car-related-discussion/366326-shawspeed-1-6-se-mapped.html

179bhp with the help of ShawSpeed. The spec is listed but essentially ported head, cams & throttle bodies.  Uprated internals would be recommended at this level I suppose, but would then form a good basis if you wanted to head towards 200bhp at a later date.

That would make for a much more interesting engine than "just another" duratec car on the road.  Plus for sentimental reasons, keeping the same engine has to be a bonus?

[cr500dom]

Thats what I was saying yesterday.

180HP is just "Head off" work plus TB`s and a remap

200 needs High compression pistons and steel rods, and the right set of throttle bodies (AT Power Ideally)

 

[antonio]

If i had a sigma engined Caterham, i would seriously consider 1.6 ecoboost engine.

a lot of work is needed but thats is the best engine you cant get for £1000

ecu cost a lot and you will need a stronger gearbox but you wont look back before 10 years

of course i am a little bit biased as i havé replaced my screaming k series by one of theses!!

[Domus]

 

Antonio

Would love to see a photo of that installation.

[cr500dom]

I suspect its LHD

Not much room for the Turbo on a RHD installation.

But I would be interested to see how you have done it too

[7 wonders of the world]

sure the turbo can be relocated with a little tubular imagination and fabrication.

[antonio]

the steering shaft needs to be relocated for both LHD and RHD

as you can see everything is a very tight fit under the nose cone but i finally managed to find a place for every parts!

 

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