[turbocon86]

Anyone tried this? I read about it in Popular Science. Looks promising. If you have done it on one of our engines I'd love to know the results and what exactly tou did.

http://somender-singh.com/content/view/7/31/

 

[mpgmike]

Yes, on several engines. Dez and ssheen both have grooved heads. Dez was cranking 22# boost on 93 octane and 30# boost with 93 octane and water/alky injection.

Mike

 

[turbocon86]

Have you done a bathtub head or a swirl head? One groove or multiple? Do you have photos?

 

[RPMurph]

my head has one of those grooves in it right?

 

[scott_s]

Mine is grooved. I have two per chamber. Another local friend did his as well. Both 782 heads. Only been driving it two days now. I idle around 700F cruise around town and county roads @90km/hr (55mph) around 775-825F. Saw around 900F once while in boost. But too many gauges to watch now. Cam time is spot on as I can do with out a degree wheel and ignition timing is 12 degrees.

My friend sees 1200-1350 in boost which is a 200F drop from before he did his. I do not have before numbers as I just added the EGT.

 

[mpgmike]

Firebaron90 has a G head with the grooves. Ask him to post pics of his. He doesn't have his installed yet as he's been too busy. I can post pics of his if he can't.

Mike

 

[scott_s]

A little more driving with the new setup. I see maybe a low of 875 on the highway to 950F. At 100-130km/hr. I richen it up a little to play and saw EGTs drop at idle to 600. Put it back to normal. Pretty cool though seeing the effect the extra gas has.

I am also running 8.6 C/R now as well. I use to get part throttle knock retard. No other changes, such as more fuel to cool things off, just the head and no more part throttle knock, so far. Still have to experment to see where the knock retard shows up now.

 

[puppet]

Where is the EGT thermocouple on your set-up scott_s?
On thing that might not be obvious is that if in fact those temps are that cold what effect that now has on combustion? Plugs got to be fouling ... no?

The other thing that I asked about in another thread concerning the grooves was what effectiveness there could be with our stock dished pistons? The benefit has to be a diminished with the increased space. There isn't a whole lot of quench area to begin with.

 

[scott_s]

Mine is on #4 about 1" maybe 1.5" away from the head. Thanks for the tip on the plugs. I will keep an eye on them. I do plan on playing with the fuel, ignition/cam timing etc. to maybe get the temps up a bit more. I broke 1000F today. Not to sure what it settled out at. I was 12psi of boost.

I was thinking of a custom piston to help with that. A larger flat area under the chambers flat area.