RB26 head water cooling trickery??

[Chris Wilson]

I have heard that there are various tricks to getting a better or maybe more even water cooling effect for race usage RB26 heads. Does anyone have info, or links to info on this subject? I am building a circuit car and want to give due consideration to all aspects of water and oil cooling options open to me. Thanks.

[RB26zcar]

This is what my buddy James Thagard is doing to my intake/head to help with the cooling. He speaks about it a bit in this thread showing my car during all the custom fab work he about finished with now.

Click on link >> http://forums.freshalloy.com/ubbthreads/sh...sb=5&o=&fpart=1

[discopotato03]

This reminds me of the head coolant logs used on some competition specific cylinder heads ie L series FIA and LZ Formula Pacific twin cams . The riser pipes to the collector log are usually off center to make the water centrifuge back towards its outlet . I think a lot of work goes into avoiding steam pockets forming around the water jacket adjacent the exhaust side of the chamber and ports . When this occurs no localised cooling takes place . I have seen pics of Cosworth YB engines with drillings into the head castings and lines rising to a common header tank to vent steam pockets .

It would be interesting to know what was done to Group A RB26's though freedoms may have been very limited . SK can you tell us your views on this .

I'm not questioning the fabricators intent but would three -8 fittings pass enough water to cool a highly stressed engine ? , it looks to me as if it would not pass as much as the std set up .

Just curious cheers A .

[R32-GTS]

I've also seen a fitting tapped into the back of the head with a braided line then going to the radiator. This was on a modified rb26.

[Sydneykid]

Hi guys, the biggest issue I see is with trapped air on engines that have aftermarket inlet manifolds fitted. Most don't come with air bleeds and many are too low for it to be effective anyway. I haven't seen any consistent issues with Nissan's standard solutions to this problem. Most times it is people not bleeding (all of the air out of) the cooling system properly. A header tank as the highest point in the cooling system makes this easier, but even that is not fool proff..

Using a header tank to make air bleed easier is tricky, and I am not a believer in playing with water flow patterns. I have seen NOTHING to suggest Nissan got it wrong in that area either.