What you will find here: Intended to display minor modifications to my Westfield SEi, this blog now witnesses the two year rebuild (and more) after a major crash in October 2011. Have fun and feel free to add a comment at the end of any post.
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Tuesday, December 10, 2013

Kent Crossflow (X-flow)

One of the most popular Ford engines ever built was named “Kent” since the Dagenham plant where it was produced is located in the county of Kent (1). In this synopsis, I want to display some  information I found about one particular type of Kent-engine called “X-flow”. But I will not rewrite what has been written … because there is a lot. A sources section at the end has links to specialist’s websites if you want to read more.
There is a lot of literature available about the Pre-X-flow (1959) as well, that’s why I want to explain the difference right from the beginning before concentrating on the X-flow.
In the beginning of the Kent, the engine had a cylinderhead with the exhaust and the intake on the same side. A re-design (1967) went for a change, together with other features like the combustion chambers in the pistons and the exhaust opposite to the intake to improve gasflow. From then on, it was called the X-flow. The following pics show the block and the pre-X-flow cylinder head from different angles. Most visible are the combustion chambers in the cylinderhead.

In comparison, the X-flow cylinderhead (aluminium):
The block came in different castings and heights, depending on capacity. The very beginning was made with a 997cc unit, up to 1600cc at the end of production. The latest blocks could be bored for larger capacity. It was and still is used in Formula Ford 1600, that’s why for some time it became difficult to find engine blocks. Production has been renewed since 2010 and you can buy new blocks (2).
The 1600 came as
2737e as seen in early Ford Cortina Mk II
681e … later Ford Cortina Mk II
691e … early Capris
711m … Capri, Cortina, Escort and a lot of Kitcars and small production cars,
plus the AX block as the toughest with some 5kg more on the scale, but with a better casting and suitable to be bored out even more. The cast engine code is visible below cylinders 1 and 2 on the exhaust side together with indications for capacity: 6015AA = 1300cc and 6015BA = 1600cc (3)
The most sought after engine block is the 711 with a better casting. The AX is quite rare. You can rise the capacity and use oversized pistons, cast or forged. The word goes you should not exceed 1700cc and 6800RPM, but you may come across larger figures. Although, life expectancy is largely compromised and there are other engine configurations more suitable.
The common 1600 out of a Cortina MkII had 84hp with a single carburettor. Depending on tuning, power rises as you add larger valves, sharp camshafts, higher compression, bigger double carbs a.s.o. Kent engines have been supercharged or turbocharged.
It is very common to find good road-going mildly tuned engines with 120-135hp. For more power, you really have to do a lot of work and apply steel components and Accralite pistons to make it work. Personally, I wanted to try the injection route and added individual throttle bodies to a reasonably tuned engine.
There are companies specialised in tuning this engine and it is a matter of money how fast you want to go. A lot of home-built engines show that it can be done in a private workshop as well. Parts are largely available with an engine having been built by millions over several decades. On this website (4), you can see what Cosworth did to it and how this engine has been the basis for a lot of sports- and racecar engines. For quite an extensive web article about Cosworth engines, read on:  http://www.italian.sakura.ne.jp/bad_toys/cosworth/
Further development led to single overhead (SCA) and double overhead (BDA and following) camshafts, geardriven or by belt.  
As this is all still based on the Kent engine, but with quite a big development work behind, I will stop it here and the next post will be about the cylinderhead.

3) Casting Numbers
4) Cosworth (by Sakura)
5) Burton (parts and more)
6) Wilcox (parts) 
7) Article
8) Article
9) Article
10) Story