Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Plus 4 GDI: exact type of engine

Can anyone provide the exact type and name of the Ford GDI currently found in Plus 4s? Sometimes I see the name Duratec, or EcoBoost, and so on...

And does anyone have the gear/diff ratios for the MX5 gearbox in a current Plus 4?

For my 2005 PLUS 4, all these datas are in the Morgan Owner's handbook page 3.

For the 2005 PLUS 4
the rear axle ratio is 3.73:1

gearbox (FORD MT 75)
1st 3.61 / 5.31mph @ 1000 rpm
2nd 2.08 / 9.20mph
3rd 1.36 / 14.09mph
4th 1. / 19.15mph
5th 0.76 / 25.10mph

Mazda gearbox had the same ratios except for 1st : 3.87. But perhaps depending on the year?

Found in another topic:

Gear Ratios:
5-Speed Manual
1st - 3.136:1
2nd - 1.888:1
3rd - 1.330:1
4th - 1.000:1
5th - 0.814:1

This is for the NC Miata gearbox, 2nd generation.

I think it is probably an eco boost, only because I think it superseded the Duratech, which is non-direct injection. Issues with GDI engines may be yet to come. It is said that they may emit more particles than older indirect injection engines and even more than a modern Diesel engine, as the air/fuel doesn’t get mixed as evenly. We will probably see the need for improved particulate filters as politicians look for something else to cause the motorist a bit more pain! There are also fears that valve seats can get sooted up as they only handle air and not a nice slippery petrol/air mix. Time will tell. Has anyone done 50k with a GDI yet??

"There are also fears that valve seats can get sooted up as they only handle air and not a nice slippery petrol/air mix"

It is true inlet valves and inlet tracts get encrusted but the reason is because of PCV crankcase oil fumes. Mine will never get sooty since I've plugged the PVC pipe inlet in the inlet manifold and run the breather to a catch tank. I have advocated this several times for GDI engines and use the same system in my BMW 340i.

It's not the Ecoboost, that's turbo charged, and it's not a Duratec or and MZR engine.
Although much of the engine shares very similar architecture with both of the above.
The engine is the Ti-VCT GDI I4 used in the Us version of the Ford Focus and not available in the European markets

Simon @ SiFab.co.uk

This now quite old article explains the differences.

In essence the GDI being the first direct injection n/a engine replaced the Duratec. The Ecoboost shares the same bore centres but is substantially different to handle turbo power.

The handbook of my Plus 4 built in March 2018 shows the following figures (same as posted by CBY for the Mazda gearbox):

rear axle ratio 3.73:1

1st 3.87
2nd 2.08
3rd 1.36
4th 1.00
5th 0.76