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Old 28-01-2019, 05:09 PM   #59
Luke Plaizier
Lukeyson
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Join Date: Mar 2005
Location: Maitland, NSW
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Default Re: WQ Fiesta XR4/ST150 with Mazda SP25 engine

I wanted to find a specific reference to the deck height differences between the Duratec motors - but struggled. A lot of people talking about bits from one fitting into another. Some blocks the same, some different. Confused me. It looks to me like many of the 2.3L Fiesta upgrades in the UK are mainly internals swaps on the 2.0 block.

But I did find one place that provided a formula:

Deck Height = Stroke/2 + Rod Length (Centre to Centre) + Compression Height

The Bore/Stroke is available from the Wikipedia reference easy enough. But the Rod Length was harder to find - I eventually everything found in a table here

I'm going to assume the compression height will be the same across all versions.

And all together:



Which finally confirms it for me. The 1.8 and the 2.0 share the same stroke, rod length and deck height dimensions, while the 2.3 and the 2.5 share the same deck height dimensions but do so with differences in stroke and rod length.

I'm still trying to research the impact the 14mm deck height change would have on the standard headers in the fiesta. But at least now I'll know if it works for the 2.3, as long as it was a full block swap and not just internals, the same should be the case for the 2.5.


Lukeyson
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