Rb26 Combustion Chambers

[Antimatter]

Question as per title pretty much. Car will be running -7's or something similar. Maybe Tomei 260 / 9.15 cams (then again - maybe not) - tuning via power fc of course.

Have heard that there is some magic to be achive by changing the shape of the combustion chambers? or am I just another casualty of hearsay....

[Simon-S14]

do you know what your doing?

if not theres your answer right there

[GeeTR]

Search SAU for "squish zone"

Off the top of my head, Its there to increase low speed charge turbulance, that promotes a more complete burn. The disadvantge is, that feature can lower the boundry of detonation when running high air flow rates (power).

JUN and others remove the area on some of their motors.

Searching should reveal more.

[Sydneykid]

Search SAU for "squish zone"

Off the top of my head, Its there to increase low speed charge turbulance, that promotes a more complete burn. The disadvantge is, that feature can lower the boundry of detonation when running high air flow rates (power).

JUN and others remove the area on some of their motors.

Searching should reveal more.

Based on what I have seen, the squish zone argument is more RPM than power related. The argument goes that if you are running 10,000 rpm or so, the squish zone are limited in their effect do to the time it takes for the air to move up the zone and the turbulance thus created. Keeping in mind the effect compression ratio and hence the piston crown shape has on the squish zones. I don't know the change over point, rpm wise, for removing the squish zones, certainly at 8,000 rpm we haven't found it necessary.

Keeping the above in mind, I would simply match the combustion chamber volumes and polish out any excessive roughness than can lead to hot spots and detonation. Porting of course is essential.

Cheers

Gary

[Antimatter]

Only know enough to get me into trouble it seems

I would have the combution chambers modded proffesionally (someone who specialises in GTR engines) But curious if it is worth the time and money.

do you know what your doing?

if not theres your answer right there