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Thanks Mark … 300 PSI, that’s good to know.
Have you said the word AIRPLANE to Fluidyne yet? Someone else on
this list said they won’t sell to you if application is aircraft use.
I did not mention my application other than Mazda Rotary/RX7
engine.
Jeff
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Tuesday, December 15, 2009 10:22 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Oil cooler
Here's the reply from the owner of Fluidyne concerning the
rated pressures of these coolers.
"The DB Series of oval tube
oil coolers are rated at working pressures of 300 PSI and designed to withstand
a proof pressure of 400 PSI. Nothing in the normal operation of your
Mazda engine oil system should have caused any deformation."
I'm always very careful on startup not to over-rev the
engine. So, who knows how it got damaged? I'm just glad it wasn't
an A/C evaporator core or the results may have been much different.
On Tue, Dec 15, 2009 at 9:00 AM, Jeff Whaley <jwhaley@datacast.com> wrote:
Mark, I can’t find any specs on the
Fluidyne coolers but they are in the same class as the one you have – I bought
mine new through Summit Racing.
Jeff
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark
Steitle
Sent: Tuesday, December 15, 2009 9:29 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Oil cooler
Do
you know the pressure limitations of your coolers?
On
Tue, Dec 15, 2009 at 7:53 AM, Jeff Whaley <jwhaley@datacast.com>
wrote:
Mark, I have two of the DB-30416,
single-pass coolers … no measureable pressure drop with 2 in series … I’m
seeing 80 psi max with the 13B.
JWW
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark
Steitle
Sent: Tuesday, December 15, 2009 8:36 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Oil cooler
I
have the Therm-Hx All-Pro 600 2-pass cooler, p/n DB-30617, as shown on http://www.fluidyne.com/pl_theoc.html#Therm-Hx%20Engine%20Oil%20Coolers%20DB-30716,%20DB-30617,%20DB-30417.
I've attached a picture of it. It is the one on the right. You can
see how flat the tanks are. The material is very thick, but I can't
get inside to measure it. My guess is .090" - .125".
Strange that this hasn't been a problem for other customers. Like I said
before, I suspect that someone before me over pressurized it during proof
testing. But that's just a hunch.
There's
a BTU chart on that page, but no pressure drop chart. Since I'm reading
90psi at the engine oil filter adapter plate, it doesn't seem like I've got a
problem with pressure drop. But then I haven't measured oil pressure as it
exits the oil pump either.
Thanks
for the design tips.
On
Tue, Dec 15, 2009 at 12:55 AM, Al Gietzen <ALVentures@cox.net>
wrote:
Mark;
Before buying a new one of the same design,
you may want to be sure it is designed to handle he pressure. If the tank
has flat surfaces, even just a few inches across, it needs to be about 1/8”
thick if it is aluminum.
I speced my custom design aluminum cooler
(built by Griffin) for 125 psi. I pressure tested it to 140. The
oil pressure on my 20B will get t0 90+ when cold, and runs 70-80 when hot; and
you want some margin, especially since aluminum is subject to fatigue when
cycled – and it is cycled every time you start your engine and shut it down.
You might also like to check if they have
any pressure drop data. Off-the-shelf coolers are generally designed for flow
rates typical of piston engines, typically about half of our engines. I
recall looking at some data on a Fluidyne cooler I was considering, and the
pressure drop was very high for flow up to about 16 gpm. If yours was
designed for single pass, and modified for double pass, it could be twice as
bad.
Just some things to check.
Al G
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of Mark Steitle
Sent: Monday, December 14, 2009 5:35 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Oil cooler
There's a third possibility that I hadn't considered until I
looked at the cooler again tonight after work. It is evident that the
cooler was pressurized to the point that the tank warped causing the divider to
pull away from the core (not welded where it meets the core).
This allowed the oil to go in and right back out again. The tubes
look fine, but the center of both tanks where there is no support, is
ballooned outward.
I'm debating on whether to send it back to Fluidyne for
inspection & repair, or to bite the bullet and order a new
one (assuming that this size is still available). This one is definitely
repairable, but not sure I'd feel comfortable flying behind it
afterwards.
I also need to ask Gary what the working pressure is for the
Fluidyne coolers. I'm wondering if I may have damaged this cooler with 90
psi oil pressure without realizing it?
On Mon, Dec 14, 2009 at 6:58 PM, Lynn Hanover <lehanover@gmail.com>
wrote:
I called Fluidyne today and spoke with Gary, the owner.
While the cooler is not under warranty, they are willing to look at it and
determine if it can be repaired. I'll send it off and see what they
say.
There should be evidence of a TIG bead half way around the
end tank near the center. Either its there or it isn't. If not and both
fittings are in the same end, it is the problem.......
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