Duratec 2.5 into a S2

[Lotusteve]

This thread follows on from the first part of my recent S2 rebuild topic. This covers the final install of the Twincam chassis and sourcing
a suitable Duratec engine to go in it.
The project started in early 2022 and by early summer I had lifted up the S2 bodyshell and pushed the chassis up into it with modded Acroprops, standing underneath and cutting grp as it progressed (not pleasant).
Lots of cutting in the mid section and a bit at the front. Suprising the internal difference between S2 and Twincam bodyshell.
I did know the wheelbase was also 1.5" longer for the latter, something I was temporarily trying to ignore!
Meanwhile in a previous project I had looked at a replacement for the Ford Crossflow and Twincam engines, and looked at the Cosworth BDG.
Startling expense and needing frequent refreshing as it's basically a race engine. So a no go. 
Looking round the Burton (London) Performance Ford website I came across the Duratec 4 cylinder range, with loads of Cosworth parts made for it. Slight complication was its actually a Mazda engine so bellhousing bolt pattern is not Ford. However it is light (I can lift it up, just, which I can't do to an iron block motor like the Lotus Ford) and for emissions has very good breathing, with large valves and ports. So with a cam change good usable power is there.
So this may be reinventing the wheel as other Europas may have been converted like this. I'd love to hear their stories as I was really working on my own in this.
So here are a few pics of the engine and chassis. Spydercars recommended using the strongest NG3 box, one from a diesel Espace. I can't seem to find gear ratios data for this, can anyone help? I suspect 1st gear is going to be annoyingly low. I used a Pinto clutch with a Ford/Renault thrust bearing.
I bought an old Duratec to Mazda RX8 gearbox adapter plate and stuck the engine box on end so that it was centred, drilled & tapped it for a different gearbox bolt pattern.

[BDA]

I would have thought that it might be easier to cut the car in half and graft a 1.5" piece in the gap!

This page (http://lotus-europa.com/manuals/) has a wealth of information - including searchable workshop and parts manuals. It also has links to two NG manuals. Unfortunately, if you work on an NG tranny, you should refer to both as neither one has all the information you need. They list the cars different ones in the NG series was installed in along with their gear ratios but I didn't see any references to Epace. Could there be a numerical reference for an Epace? Unfortunately neither of those NG manuals are searchable so you'll have to search with your eyeballs. The links are found under the "Renault Manuals" section near the top.

[Clifton]

Here's a few for the  Espace.
https://www.cars-data.com/en/renault-espace-rn-2-1-dt-specs/37851/tech
https://www.cars-data.com/en/renault-espace-rt-2-2-dt-specs/37882/tech

You can find the rest here
https://www.cars-data.com/en/renault/espace

Good gear calculator
https://www.blocklayer.com/rpm-gear

[Lotusteve]

Thanks for the gearbox data info. Seems that Espace has, as I suspected, a very short first at 4.09:1, something about 3 is better.
and from the data then has a too high (or is that low?) final ratio of 3.2:1, where I've found between 3.6 and 3.9 is better. Hillclimbers use 4:1 +
From the data looks like there is about 22mph gaps between the four gears, so maybe spacing isn't so bad?
Normal road use would be 25, 47, 72 and 99mph, but going to 7k plus redline would be 40, 74, 115 and 157(maybe)mph and 189 5th (certainly not!).
This all is dependent on engine power/torque whether a 3.2 final drive can be pulled. 4 pot Duratec 2 litre with fast road cams is circa 185bhp at the flywheel, 2.3 is 220 (my last project) and 2.5 is circa 250 with VVT giving good midrange. More than that needs high compression pistons and rally spec cams. 2.5 is from Danst Racing UK who get low mileage units from the States, checked for compression and oil pressure.

My other gearbox is from a Spanish Renault 21 Berlina, £120 inc delivery to uk, some mistake there?? Pic is of the NG9 label.
My mistake was thinking Renault 21 was 2.1 litre, so completely wrong as all sorts were fitted, mostly 1.4's.
 So this is not a strong box?
Anyone seen one of these, the clutch release shaft seems to work the wrong way?

[cazman]

I don't know if this owner did the swap, but there may be some info from this:

https://bringatrailer.com/listing/1969-lotus-elan-s4-16/

[Lotusteve]

Thanks for the Bring a Trailer link .... Certainly a radical conversion with the wide arches etc. Elan engine bay is obviously very cramped even with the original engine, so wide arches help?
 Plus 2 has 6" more room, but Europa bay (apart from the front Y fork chassis) is wider in comparison.
Duratec (Mazda) engine is a bit 'fat' as oil galleries etc run down the block sides. Here is a pic of my ST170 Zetec Plus 2 daily driver. Now has an airbox and dirt!

[Lotusteve]

Apologies, seemed to have mixed up my posts, couple of pics went astray of rear wheels showing before and after altering rear section of rear arch to accomodate 1.5" longer chassis

[BDA]

My other gearbox is from a Spanish Renault 21 Berlina, £120 inc delivery to uk, some mistake there?? Pic is of the NG9 label.
My mistake was thinking Renault 21 was 2.1 litre, so completely wrong as all sorts were fitted, mostly 1.4's.
 So this is not a strong box?
Anyone seen one of these, the clutch release shaft seems to work the wrong way?

I don't know about the clutch release shaft but according to one of the NG manuals (http://lotus-europa.com/manuals/misc/MRBVNG.pdf), the NG9 is for 2.2 liter engines while the NG7 is for 2.4 liter engines. However, the number of planet wheels is often used to gauge torque capacity and by the same manual, the NG9 has 4 and some NG7s have only 2. In club racing over here in the States back in the early '70s, Jensen Motors campaigned a very successful TC which had to use the 336 gearbox because of the 365 wasn't legal yet. The 336 only has two planet wheels yet it it was able to deal with a race prepared TC motor.

I'm no expert here but the way it seems to me is that for most any 4-cylinder motor one is likely to put in a street Europa, Any of the Renault trannies would be sufficient.

[Lotusteve]

Here is the label on my spare box, NG9000. Said by the supplier to be from Renault 21 Berlina (mid 80's?), sometimes fitted with 1.4 engines. Anyone come across these? Were they later than NG3's? I believe my 2.2 diesel turbo Espace box I've actually fitted is mid 90's -longitudinal engine.
No label so no idea what exactly that is!
These data sheets are showing all sorts of conflicting info on first gear and final drive ratios - Is it possible to turn the engine/input shaft and count revolutions on one drive shaft? ... do I lock the other driveshaft to stop it turning??

[SwiftDB4]

Turn both driveshafts together 1 turn and measure input shaft revolutions.