+- Austinsevenfriends (https://www.austinsevenfriends.co.uk/forum)
+-- Forum: Austin Seven Friends Forum (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=1)
+--- Forum: Forum chat... (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=14)
+--- Thread: Cylinder chamfer (/showthread.php?tid=3883)
Cylinder chamfer - Howard Wright - 10-02-2020
Hi All
Engine building on the special has started and I have all the (standard) valves and springs in the block.
My friend is encouraging me to chamfer the top of the cylinder bores to aid gas flow. Bearing in mind I’m trying to build a “strong” engine not a race engine do the engine builders out there normally chamfer? If so by how much and to what profile?
Cheers
Howard
RE: Cylinder chamfer - Chris KC - 10-02-2020
Howard, this was aired on the forum not so long ago, as usual a range of opinions.
Mine is that a car will go pretty well without this mod and if reliability is your goal I'd simply leave it alone.
Of course there are others who swear by it...
RE: Cylinder chamfer - Ruairidh Dunford - 10-02-2020
The mod is described in Bill Williams’ Austin Seven Specials. If you do not have a copy let me know.
RE: Cylinder chamfer - Alan - 10-02-2020
If you are on standard valves, the flow restriction is in the valve throat. Chamfering the cylinder edge won’t improve breathing and will reduce compression. Unless you are planning oversize inlets and high revs, I’d leave well alone.
RE: Cylinder chamfer - Howard Wright - 10-02-2020
Hi Thanks all
I did try a forum search but nothing came up and very little on a Google search.
I do have Williams specials book but was more interested the efficacy of chamfering. The answers seem to confirm my thoughts and I will leave well alone.
Cheers
Howard
RE: Cylinder chamfer - Ruairidh Dunford - 10-02-2020
One such thread is here Howard: https://www.austinsevenfriends.co.uk/forum/showthread.php?tid=2242&highlight=Gas+flow
RE: Cylinder chamfer - Austin in the Shed - 10-02-2020
I'd go with Alan,derestrict around the valves and re radiused followers will make the biggest difference.
RE: Cylinder chamfer - Howard Wright - 10-02-2020
Hi Ruaridh
Shows the difficulty with search engines. I put “chamfer” in the search box with several variations and got nothing. If I’d put “relief” I’d have found it.
After reading the thread (which digressed somewhat from Jon’s original question) I am leaving well alone.
Cheers
Howard