QUOTE(76-914 @ Jan 8 2019, 10:20 AM)
@SzoylentGreen At times, ignorance reigns supreme. Here is the condensed version. When I went to a larger radiator I thought it a good idea to enlarge the front opening. In doing so I increased the incoming air volume/pressure to the point that it began heating the gas in the gas tank. Ignorance helped me overlook my mistake and told me the radiator was getting too hot although the temp gage never moved off dead center.
Ignorance took my hand and convinced me that the fuel pump was cooking the gas so out came the tank and another was installed with an external pump. Didn't help a bit.
Again, ignorance convinced me to changed out the lines to a larger size but the gas tank was still getting hot and causing vapor lock. It was too hot to touch sometimes! Finally I ducted the radiator exhaust out the wheel wells and Viola, success.
There was absolutely no temperature or performance differences noted between the small hoses
vs the larger hose. I'd also like to mention that contrary to what I'd heard, running the hoses thru the longs
did not transfer any heat into the cabin or sidewalls.
What I learned: 1) Don't violate the 20% rule e.g. the exit area should be 20% larger than the intake area. 2) Duct the radiator if you can. Then the cabin will remain as cool as it did before the H20 conversion. I have a V-8 conversion that allows hot air to enter the cabin, albeit minor. I've ridden in other conversions that also allow unwanted heat in the cabin. I will say that if the top is removed it isn't as noticeable.
Hi, this is Andy from FB BTW.
Thanks for the info. Hey, how low does the EZ30 oil pan hang? Is it much lower than the type 4 motor oil pan?
I’m still working on the design for my center radiator. It’s defintly going to be ducted.
If you look at the ideal ram air duct, This one is used in almost all of the modern race cars, no matter open- or closed-wheel racer car. This design changes the speed and the pressure of the incoming air. The basic principle behind this is to slow the air in front of the radiator and transform the dynamic pressure to static pressure, raising the static pressure at the same time. This type of duct is usually made long, so that the air has time to settle.
In most cases, automotive applications can’t get very close to the ideal shape beciuse of packaging constraints.
In my case, I’m sandwiching the radiator between then bumper and the tub (porsche 912), and going to try to make the underside of the bumper act like the ram duct, smaller entrance and an expansion chamber. Then, behind the radiator will be a duct that directs the exhaust air downwards. This approach puts the inlets and outlets across a large pressure difference areas (in front of the bumper is always the highest pressure, and under the car is a low pressure region). The approach I’m going with is actually kind of similar to what Porsche did with the 996, and also very similar to the Toyota MR2. In fact, the MR2 only has about 3” behind the radiator, and most of this is taken up with fans, much like my planned duct.
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