Ecoboost 125/140 Difference

[reece101]

Hi there everyone, bit new to these engines so needing a hand!

Just bought a 65 plate mk7 Ford Fiesta 1.0 Ecoboost 140hp Red Edition. its a non runner and i might have to stick an engine in it but what im wondering is could i stick a 125hp in it but still use my ECU that i have now? will that bring the power back up to 140? are the only differences in the engines the head gasket and the map? if you can help me out that'd be great cheers 🙂

[Blatto]

Not sure about the possibility of using the 125bhp engine,  but other things to consider is that the 140bhp variant had different gearing to the 125 and also a different Turbo.

 

[reece101]

Ah yeah I was aware its got a different diff and turbo, fingers crossed it doesnt need another lump! 

[Eric Bloodaxe]

I guess the only person who could give a definitive answer on this one is someone who's actually swapped a 125 into a 140.

According to this article, it does seem the only physical difference in the engine itself is the head gasket:

https://www.automotiveworld.com/news-releases/new-140-ps-ford-fiesta-1-0-litre-ecoboost-powerful-1-0-litre-volume-production-road-car-ever/

so presumably if you put the 140 head gasket in the 125 it could be ok with the original 140 ecu.

Otherwise you could install a 125 with its ecu and possibly consider a remap on that if you felt more power was needed. The 100/125/140 all end up around 155-160ps after, for example, a Superchips Bluefin.

 

[reece101]

thanks! thats a big help, worst comes to worst ill have to stick a new engine in it and can only try the 140 ecu and head gasket on a 125. even if it doesnt work with a  140 ecu, ill go for the 125 and ill get a bluefin and bring the power up, just quite new to these engines so unsure as to what you can do to them

[Eric Bloodaxe]

Another random thought. Don't know it you're looking for a quick fix at minimum cost or a bigger project?

The standard 5 speed box seems to be a weak point with the Mk 7.5 140 - here's an excellent thread on fitting the stronger 6 speed from a Focus. I guess the job could be a bit easier if an engine c/w box was sourced from a Focus. 

 

[reece101]

Needing it on the road ASAP as I'm without a car at the moment, possibly something I'll look into though, I have saw a lot of people complain about the 5 speed