Porting

[leaf200]

Does anyone know how much and where I can take material out of the inlet ports.

I have a late block.

I would be nice to see some pictures of a cut up block if anyone has any

Thanks

David

[squeak]

If you look up    sectioned seven engine    in the old forum there are contributions from Tony Press and Simon Jansen on 23/1/2017 there are a couple of pictures to be seen.  I was able to improve the picture but not transfer it from bravenet to this forum.

[Tony Press]

  Sectioned Austin 7 engine.jpg (Size: 116.5 KB / Downloads: 353)

Unfortunately doesn't show much of the block.

[Chris KC]

David,

You can find a fairly detailed description in "Austin '7' Specials" by Bill Williams, which is one of the basic course readers for A7 students.

I'm not sure how helpful these pics are I'm afraid.

My personal view on this is that a little basic flow improvement can only be a good thing; endless hours of polishing is a waste of time. You do need to be very careful not to take too much off.


  Capture2.JPG (Size: 42.4 KB / Downloads: 302)

  Capture3.JPG (Size: 38.59 KB / Downloads: 301)

[Renaud]

Hi David.

Could'nt those de-siamesing images and the followings HERE help you?
Renaud

[Austin in the Shed]

    This shows cross section of the port,check out the blocked waterways.

[Stuart Giles]

There's a photo of some modified ports in this thread: https://www.austinsevenfriends.co.uk/forum/showthread.php?tid=3395&pid=35726&highlight=inlet+ports#pid35726

[Austin in the Shed]

I would think the best improvement is opening out the valve throat area and the sharp radius. This is only one block,ie there would have been many patterns in use all possibly slightly different,and all dependent how the cores fitted producing the water jacket and ports.

[Peter Clayton]

Matching the manifold to block airways is critical , the block face openings can be transfered to the manifold by the use of a card template . Some reduction of the valve guides should also aid gas flow.

[Charles Levien]

There’s masses of material on this subject — one approach is to add stuff to the inlet ports behind the guides which you might think counter intuitive but flow rate is more important than volume perhaps. I’m not an engineer but this seems a good argument. So think twice before opening up the ports too much.
Matching the manifold to the block is a good starting point.