I thought I would share what I have been working on. My goal with this reshaped combustion chamber is a faster more complete burn and less chance of detonation. The finished chamber is on a 317 casting and the welded up rough chamber is a 243 that will actually end up on the car. This will end up on a gen 3 4.8 that will have a 76mm precision turbo on it very soon. I'm also going to pull my 862 castings off the car and cut a groove in them like the picture I uploaded and dyno before and after. This groove is supposed to improve/ increase the amount of turbulence in the chamber and help out with gas millage, resistance to detonation and increase midrange and bottom end power. If this works I will include this on my welded up 243 heads. I welcome all constructive criticism.

 

I've seen the groove on several local cars. Ones a turbo car and the other was a 408 . Both ran strong but hard to say its from using the groove.

 

If expanding gas is to be passing through the groove I'd probably try to remove some of the corner to avoid any hot spots. Although I'd think it would be most beneficial when reaching TDC on the compression stroke rather than pressure distribution ATDC on the power stroke.

An interesting idea for sure.

 

looks groovy! (sorry couldn't resist a corny dad-joke opportunity)
in for results

share with me your filler rod/welder seting please

 

I'll find out what filler rod and welder settings the dude who welded them used. I can't weld aluminum for S$%T. As far as smoothing the edges on the end of the groove I completely agree. I don't need any hotspots while trying to achieve a boost friendly 11/1 pump gas engine. If all this works out I'm planning on building a 4.03 bore 3.26 stroke 333 cube engine with much higher compression to be used with e85 or e100.

 

Groovey!

 

I'm really tempted to NOT round the edges of the groove because I feel it would help promote turbulence approaching tdc like Exidous mentioned but the whole hotspot issue is what's holding me back. Also at that point the groove wouldn't provide much of a benefit for flame propagation just after tdc on the power stroke. I'm also undecided about the direction I should aim the groove(s). I could position them 90 deg to the direction of swirl or roughly in the direction of swirl.

 

This would be an example of "with direction of swirl"

 

Interesting work. If you look at the AFR chambers, there is a strong resemblance.

And say it isn't so that you are porting heads for a turbo motor!
EVERYONE knows, all you need to do is add more boost.....
:-)

Keep us posted.

 

I am porting heads for a turbo motor! I'm also experimenting with a textured surface on the intake ports to aid in creating turbulence in the intake charge and improve laminar flow characteristics. My goal with the intake ports is to improve flow not just at .600 lift but as much as I can under the curve. Some of you may have noticed the weld behind the valve guide on the intake port as well. I have spent many hours on this design. As far as the chamber goes, I know it's not new or my idea. Many of the engines entered in the engine master's challenge use a similar design. I first came across a chamber like this on a trickflow R windsor head.

 

Turbo motors respond to flow improvements for sure. I agree that it's a good thing
Fun project.