Chamber softening

would our BBF heads need chamber softening for heavy nos applications --- i guess chamber softening is altering the flame travel as well as giving it certain direction. Some heads don't have enough quench pad to be able to do this. A slight taper on the pad will give it direction and create the desired turbulence

just curiuos

here is a pic of one done

It looks like they are taking all the edges off the chamber, "softening" to remove hot spots I guess?

Bill

here is a pic of another chamber done ..... this is to slow the burn rate down

one was from Steve's site and the other was from yb

I have seen something like this on a set of Thor heads. Didn't know what it was called at the time. Charlie actualy showed me the set.

good to know that Charlie knows the benefits from this ...would like to get my new heads done with that feature

bruno wrote:good to know that Charlie knows the benefits from this ...would like to get my new heads done with that feature

I don't know if he knew the exact benifits as it was a set of heads that was being repaired. I believe Laws (sp) was doing the repair work. This was a couple of years ago Charlie and I was roaming Kentucky! LOL

Doesn't it seem like you could accomplish the same thing with an altered piston design? That way if the modification doesn't work out it would be a lot easier to reverse.

so they are doing this to the heads to increase the cc of the chamber and to increase the quench .... i dont think you could acomplish that with piston design ???????

Look around and see if you can find that article by Larry Windmer about "The Soft Head". The idea is not so much one of increasing the chamber or quench size but rather using those areas to try to move the mixture around once it's in the cylinder and being compressed into the chamber for combustion. I think the whole point is to try to reduce charge stratification and to make the mixture very even and this is supposed to allow better combustion as well as higher compression ratios to be used without detonation.

All seems mostly theoretical but it might be worth an experiment. There are also some ideas about exhaust port sizing which are also in that article. Sizing the port so that it deliberately goes super sonic for more of the exhaust cycle etc. Who knows, maybe that part just acts like an EGR valve and THAT'S what makes it reduce detonation...

http://www.theoldone.com/articles/The_Soft_Head_1999/

thxs for the info Dave, great read

I remember reading the original article about Widmer's airflow theories. His list of customers included the Elliott's and Glidden. Elliott's engines were at the top of the field during that era. Glidden being Glidden mentioned Widmer didn't know sh*t about cylinder heads, although he had set the NHRA P/S speed record during the Winter Nationals with cylinder heads on his engine bearing Widmer's logo! I think the Texan was on to something, and others wanted the idea for themselves! Couldn't imagine that!

Dave.