Tracy Crook wrote:

Here's some progress shots of Bernie Kerr's RV-9A project.  Amazing how

that

Griffin rad fits in the cowl .

Tracy Crook
tcrook@rotaryaviation.com

Yes it fits but the back side is not unobstructed enough
and the exhaust will transfer a whole lot of heat to the
back side of the rad. Good luck Burnie :-)

What does he have against putting it under the engine?

Paul Lamar

Hey Tracy!
Bernie's rad looks great!  Shouldn't be any problem with heat if he uses a
heat shield on the exhaust.
Vaughn.
PS, who's redrive is that?

It still won't work. The necessary heat shield will add further obstructions
behind the rad. In effect it is little different than the Power Sport
rad mounted too close to the firewall. That also does not work. Am I really
saying this or is it my imagination. Is anybody reading this?
What have I been doing the last four years?

Paul Lamar

Paul, if it makes you feel any better, I plan on using all your data so far, and will be
installing my rad under the engine.
Some people just need a little more persuasion.
Tom Webber.

I agree. Sometimes I think I need to give a course in graph
reading 101. It is so frustrating sometimes. I dug up everything
I could find on aircraft liquid cooling systems  for the last four 
years, spent hundreds of dollars on technical books and papers, 
flew around the country with my water manometer testing peoples 
airplane, spent a couple of weeks building a rad air flow test rig 
for the van, nearly got thrown in jail for bombing a shopping market, 
spent thousands if not tens of thousands of hours on the internet 
and some people just don't get it.  Certain people do not counter 
with new data or even dispute the data offered with other data 
from other sources but merely express their uneducated 
gut felt negative opinion. Or perhaps they have an agenda. I think 
I am dealing with more than just ignorance.

Bernie Kerr has an excuse. He is not on the list. 

Just to reiterate here are some pertinent graphs from Kuchemann & Weber
yet again. Placing a large rad within ten to fifteen inches from the block, 
intake manifold, exhaust manifold (no matter how cool) or firewall is a 
no no if you want it to work well. It is particularly important
with a two inch thin or thinner rad (what we are dealing with here) as 
the flow velocity is higher than about 40% of the forward velocity. 

This causes an impact pressure build up on the obstructions 
which in turn reduces the flow through the rad. If you want your
airplane to cool make absolutely sure the back of the rad is
totally unobstructed.

Paul Lamar
 
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