Ford focus 1.8 QQDB & MX5 L8 engines, are they the same

Technical Area Engine, Transmission, Exhaust etc
2

Just bought a mk 3 with crank /rod/or main that has tried to escape the block, common problem so I understand.

Is the Focus QQDB Duratec engine the same, as they both list 126 bhp on  the Autodata list. If not what are the differences please? I assume it easier to drop engine box down, rather than split and lift engine upwards.

 

Alaways got on well with my Mk 1, and Mk2 , so new experience with a 3

Any assistance would be great thanks. 

3

Nickwar

There have been some reports of Mk3 engine failure and Mazda changing conrod designs and then changing them back to what was originally in there but I did not think it was a common problem as you have just stated.

From your info I would be interested what percentage of cars are concerned.

I’m aware there have been some failures but to put it in perspective, modern BMW’s are breaking timing chains, Golf Diesels are loosing the drive to their oil pumps and towards the end of the Mk1 and the beginning of the MK2 MX5 1.8 engine there were reports of piston ring sticking and the odd crank rod problem.

4

Druntochty

 

Thanks for that reply, however, I have read on another Forum, of problems with early MK3 L8 engines, I do not think it is widely acknowledged though. The issue is not the failure, as I have been in Bus , Truck, and to an extent car industry most of my life, and most things have there Achilles heel ! 

Something has to go wrong sometimes !

 

My main interest was if anyone had used the QQDB block & head in place of L8 , purely from a financial point of view. They have same BHP on Autodata, and everything else appears  to be the same, or perhaps I am missing something .

 

Anyway, time will tell, and thanks for your interest

5

I think they upgraded the Mk3.5 engine in 2009, it has a forged crankshaft amongst other improvements.
See
http://www.roadster-nc.com/2013/08/the-2009-roadsters-facelift.html
Gales

6

Gales

Thanks for that, I had read that somewhere, still does not resolve the original question , but  does perhaps throw some light on what I had heard before regarding the MK3

 

7

There have also been a very few reports of MK3.5 conrod problems although the Mk3.5 had engine and gearbox mods to help reduce problems.

8

I was of the opinion the MK3 engine was based on the Ford basics but had certain Mazda mods so it would be difficult to work out the commonality of the Ford and Mazda engines at component level.

Short of comparing part for part I would suggest a post on miata.net