Cooling Question

[Massive Type IV]

911 fans don't kill engines, they just don't run as cool as other set ups do.

My main emphesis on the tests were to find out what works and what don't, and which ones drwaw the most power.

The 911 fans without a doubt sucked up more power, and the head temperatures were al over the place. Eneven running temps increase your chances of warped heads, cylinders and head leaks due to them. keeping the engine above its optimal temperature also effects efficiency and hurts power as well as fuel economy.

It will gain you some room, but thats about it. It will also gain plenty of eyes from guys that haven't yet found out the truth for themselves.... Alot of guys look up to 911 cooling systems as being the only way to keep an engine cool..... I look down upon them from a position that cost me alot to reach the summit of.

[fast70]

Jake,

If you don't mind me asking, what modifications did you do to the 911 shroud to make it run cooler? Any info would be great. If this is priviliged information, you don't have to tell me or if you could send me an email. This is just for my use only.

Thanks for the help,
fast70

[Massive Type IV]

Drilled holes in the shroud!!!

[fast70]

Can you be a little more specific?

[cnavarro]

Nickies would most definately resolve cooling, sealing, and longevity issues. We have customers running our 90.5 and 92mm Nickies, under boost, both of which use registers of a 94mm cima/mahle, so the walls are extra thick!

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

[blue4400]

Now I'm even more confused. I though the porsche fan cools the cyclinders and heads better?? I know it uses a little more power, but that was fine by me as long as it cooled better. Which is the best way to go about cooling the engine better??

[cnavarro]

A 911 fan just delivers more cooling at lower rpms than a stock fan, but there reaches a limit where you just can't push any more air over the cylinders. The same net effect can be reached by changing your pulley ratio and keeping your stock cooling setup. On the other hand, by putting on aluminum cylinders, you can dissipate more heat, which makes better use of the limited airflow that can be pushed past the cylinders.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

[boygenius]

Originally Posted by blue4400

Now I'm even more confused. I though the porsche fan cools the cyclinders and heads better?? I know it uses a little more power, but that was fine by me as long as it cooled better. Which is the best way to go about cooling the engine better??

Here are a few things to consider. The 911 fan was designed to cool a 6 cylinder engine and not a 4 cylinder engine. It pushes more cfm than can flow past the cylinders and heads. You can slow the fan speed down to correct the cfm for a 4 cylinder but then you run the risk of under charging the battery. The other thing to consider is that the 911 kit shrouds don't have any directional vanes inside them to direct the air to where it needs to be. One side of the engine may get more air than the other side of the engine and thus cause a temperture difference. Since it takes more power to run you need to give the engine more throttle while driving to maintain speed so the engine is under more load and therefore running hotter. An engines operating tempurture is infuenced by more than the cooling system used. It is influenced by compression ratio, cam choice, carb jetting, fuel grade, ect...