Hello All,
I too have been contemplating making these plenums as I'm still
struggling with keeping the back cylinder temps down. Today with some
engine static test I had the back # 3 cylinder temp at 260 to 265 F.
Not a problem at the current 60 F outside but I know the hot Florida
temps at Sun-N-Fun could again push the limit for me. Last year during
climb out there, and during our Tennessee heat wave they were a
problem. Lower climbs we're necessary. After many attempts trying every
suggestion talked about on this forum and elsewhere. My back CHT's are
still too high and when it's cold they are too un even from the fronts
as well.
My friend Steve Wright of the Stagger EZ fame told me that a plenum
would be the only way to get the heads running at an even and at cooler
temperatures. He made his with the RTV mentioned below. Unless I have
any other suggestions it looks like the plenum may be the way to go.
Can these be bought or is there anyone out there that has discarded
there's. If not I'll be making some as well.
Your thought are very welcome here.
Regards,
Jeff R.
A258 - N128LJ / Gold Rush 105 hours and climbing slowly.
On Mar 9, 2008, at 11:56 AM, D Wysong wrote:
>
>> Anyhow, I am curious about what type of fiberglass cloth and resin
>> system they use that could withstand the temperatures under the
>> cowling. Does anyone have any idea ?
>
> Hello Paul,
>
> Standard E-glass BID and EZ Poxy have been successfully used to build
> cooling plenums for pushers/canards (Long EZ, Varieze, etc.). Google
> "downdraft cooling eze" for some details. You'll need to post cure
> the plenums in order to elevate the temps at which the resin goes
> "soft", so any resin system that benefits from a post cure should
> suffice.
>
> Folks have also impregnated 2 or 3 plies of BID cloth directly with
> RTV to make their plenums. Sounds strange and messy, but it works.
> Put down a piece of plastic drop cloth, add 1 ply of BID (cut to
> shape), squirt on some RTV, add another piece of drop cloth, and use a
> rolling pin to squish the RTV through the BID. Build it up to 3 plies
> and, before it cures, pull off one side of drop cloth and stick the
> exposed RTV directly onto your cylinder fins and mold the 3-ply sheet
> to shape.
>
> D
>
>
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