Jump to content
SAU Community

Recommended Posts

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....

Link to comment
https://www.sau.com.au/forums/topic/208833-rb26-combustion-chambers/
Share on other sites

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.

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

Only know enough to get me into trouble it seems :P

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 :D

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Mixing things up - installed some leather recaros to match the leather seat covered rear seats. Interior looks pretty schmick now except for some slight wear on the steering wheel which I will monitor and address if it becomes worse or actually noticeable!  
    • Didnt realise RB's had more then 1 head.
    • I'm normally copping my own abuse from neglecting my daily drivers. "Those suspension bushes will last a bit more", "Don't worry about the oil leak, just keep topping it up". The project cars I'm always doing things slowly on them as I'm wanting them to be done better, and neater, and nicer. Luckily I don't have to deal with 18 year old Matt's "Learning to wire" stuff in the project cars. And there's only one piece of wiring I'm displeased about in the Landcruiser, and it's about to be cut out... However, the box loads of parts that have been going through this place lately for the Landcruiser... Brake pads Brake Rotors Full handbrake overhaul Wheel Bearings Seals Swivel hubs Steering Boxes Half the suspension joints Shocks Air bags (Ones to go in the rear springs for towing) Water pump Timing kit Lower timing case Harmonic Balancer Radiator Lots of other little seals and shits Gas struts for the bonnet New power window switches And god knows what else I've forgotten... Ha ha ha I have my fingers crossed the pinion seals don't start leaking on the diffs, that the transfer case doesn't leak, and the gearbox input shaft doesn't leak, nor the rear main seal. As they're about the only seals I haven't replaced in the driveline! I'm seriously eyeing off buying new caliper rebuild kits front and rear brake calipers... I'll probably recheck all the valve clearances soon too, and hopefully, it should be all good and sweet to haul some long distance trips again!
    • Every time I pull my 3x gauges out of the console and see the crack-addict way that I did the wiring, and I just can't bring myself to tear it all apart and "make it nice", because it is currently working. In fact, the last time I was in there I probably made it worse.
    • The best part is when you own the car long enough that you look back and find your OWN ham fisted amateur shit!
×
×
  • Create New...