This is a stock $200 single pass all aluminum Summit Howe racing rad
modified
by Ed Klepeis to a two pass design. The core is 15 inches wide
and 24 inches long 2.25 inches thick. A bit overkill for an NA
engine if you do the ducting right. I will go turbo eventually
so I think I will need the extra core volume.

Paul Lamar

Now if he could modify a rad to make a double pass with flow divided
front to back we'd have something - counter flow.  I had asked Ron Davis
racing to do mine that way, and had been assured on the phone that they
could.  When I got the rad it was standard two pass side to side.  They
then tried to convince me it wouldn't make any difference.

Al

Looking at what he has done in the past I am sure Ed could do it Al.

Maybe it won't make a difference as the continuos fins still connect the tubes
front to back and conduct heat from the hot side to the cool side
defeating some of the purpose.

IMHO the best thing to do is use two thinner one row rads back to back
for the counter flow advantage. If you decide to build one I can check
water temps in various places in the rad and other places in the cooling
system on the dyno.

I discussed this with Ron Davis in person in AZ at length and I could
not get him to see the advantage.

I suspect that ultimately this will prove to be the best solution for
aircraft use as it will cut the frontal area of the rad and make it easier
to fit under the cowl.

Paul Lamar

Paul ... when you say "two" of anything, it just makes red lights go off 
that say "redundant?   backup?   safety?

Safety in numbers or the old Lindberg multi-engine rule? 
(2 engines = twice as many parts to go wrong).

If redundant = safety, i.e. if you can wizard up a way to 
isolate one rad if it is leaking and proceed on the other at reduced
power, then I am all for the redundancy.

Efficiency is one good argument, but a low cost cooling system 
backup, engineered into the radiator(s) in the event of partial
coolant loss is something else.  Perhaps a good spray bar system used 
intermittently in conjunction with partial power just
might keep you airborne in level flight at best L/D max?

I guess your power available would be highly dependent upon what 
percentage of water remained after the leak was isolated?  And
that done the quicker the better.  What say you?  Is this an impossible dream?

Dale Smith

In effect and in the number of parts it is no different than a two row core.

Paul Lamar
 
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