[DeTomaso] Radiators
Stephen
steve at snclocks.com
Mon Jun 29 23:31:55 EDT 2015
Kelly - great discussion! Will take it as exceptional guidance. You are right - most forced-draft industrial fin-fans have a significant transition zone between the fan and the tubes.
Stephen Nelson
-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of coffield at mchsi.com
Sent: Monday, June 29, 2015 6:54 PM
To: detomaso at poca.com
Subject: Re: [DeTomaso] Radiators
Interesting discussion on the coolant side. On the air side, in my experience, for axial flow fans, I would give slight advantage to pusher vs puller/sucker fans but only when you have ducts that smoothly transition the circular fan to the heat exchanger core opening and do so in transition lengths of ~ diameter of the fan or more. The flow from an “axial flow fan” isn’t completely axial and a portion is dispersed radially which causes further head loss when it must turn to go through the fins. Although the fan air speed is higher, the flow is concentrated in the portion of the core most exposed to the circular fans.
When fans are placed in close proximity (<<1 diameter) to the heat exchanger core/fins as in cars, a plenum with sucker fans seems to work much better at low speeds and more effectively motivating flow across the entire core which has less pressure drop than just the fan diameter portion of the core, but can give up some cooling capacity at high forward speeds compared to a non shrouded radiator because the plenum now limits the opening behind the radiator. Some folks install flapper doors on the plenum in an attempt to get the best of both worlds, but if a pair of fans touch the extreme dimensions of the core there’s not much to be gained.
Even though you have a lot more heat to dissipate at forward high speed because your engine is working hard, this rarely is where a street car is challenged. It’s almost always with no forward speed, where you are completely dependent on the fans for airflow and high speed excursions under full power are limited. Short circuiting of cooling air and pavement temperatures are a further aggravation. In race cars air flow must be sufficient to dissipate max power continuously without soak, but even so, typically suffer without (high) forward speed.
As with most things, the coolant circuit, flow, air circuit and flow al work in unison. There are trades in either area that to a degree can compensate for deficiencies in others.
Best,
Kelly
----- Original Message -----
From: "Stephen" <steve at snclocks.com>
To: detomaso at poca.com
Sent: Monday, June 29, 2015 7:34:46 PM
Subject: Re: [DeTomaso] Radiators
Being an engineer who has designed air-cooled heat exchangers I get a chuckle out of the logic some of the vendors use. I can easily understand why Marshall would believe multiple passes would be better - but there are so many other issues - turbulence being a biggie, and the reality that the limiting heat transfer coefficient is on the air side, making things like the heat transfer coefficient of the metals involved a lot less important.
As the folks at FlowKooler commented when I was talking to them about a radiator - it all comes down to cfm of air... Well, perhaps not all, but it matters a lot.
Which makes the system offered by Pantera Performance (two 13-inch sucker fans) and Hall (two 12 inch pusher fans) both odds-on favorites. Whilst I am not about to try to run the calcs, I suspect that the 12 inch pushers will beat the 13 inch suckers, especially when moving down the road at low speeds.
Still scratching my head on what to replace the Fluidyne with.
Stephen Nelson
-----Original Message-----
From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Ken Green via DeTomaso
Sent: Monday, June 29, 2015 2:27 PM
To: marshall smith; GR2835 at comcast.net; detomaso at poca.com; Charles McCall
Subject: Re: [DeTomaso] Radiators
It seems like experience and opinions on radiator are all over the place. The Stewart web site (http://stewartcomponents.com/index.php?route=information/information&information_id=13) has a technical article that says benefits from a modern multi pass radiator are a myth:
Tech Tip #5 - Radiators & External Plumbing Radiators Thicker radiators do have slightly more airflow resistance than thinner radiators but the difference is minimal. A 4" radiator has only approximately 10% more airflow resistance than a 2" radiator.
In past years, hot rodders and racers would sometimes install a thicker radiator and actually notice decreased cooling. They erroneously came to the conclusion that the air could not flow adequately through the thick radiator, and therefore became fully heat-saturated before exiting the rear of the radiator core. The actual explanation for the decreased cooling was not the air flow, but the coolant flow. The older radiators used the narrow tube design with larger cross section. Coolant must flow through a radiator tube at a velocity adequate to create turbulence.
The turbulence allows the water in the center of the tube to be forced against the outside of the tube, which allows for better thermal transfer between the coolant and the tube surface. The coolant velocity actually decreases, and subsequently its ability to create the required turbulence, in direct relation to the increase in thickness. If the thickness of the core is doubled, the coolant velocity is halved. Modern radiators, using wide tubes and less cross section area, require less velocity to achieve optimum thermal transfer. The older radiators benefited from baffling inside the tanks and forcing the coolant through a serpentine configuration. This increased velocity and thus the required turbulence was restored.
Radiators with a higher number of fins will cool better than a comparable radiator with less fins, assuming it is clean. However, a higher fin count is very difficult to keep clean. Determining the best compromise depends on the actual conditions of operation.
Double pass radiators require 16x more pressure to flow the same volume of coolant through them, as compared to a single pass radiator. Triple pass radiators require 64x more pressure to maintain the same volume. Automotive water pumps are a centrifugal design, not positive displacement, so with a double pass radiator, the pressure is doubled and flow is reduced by approximately 33%. Modern radiator designs, using wide/thin cross sections tubes, seldom benefit from multiple pass configurations. The decrease in flow caused by multiple passes offsets any benefits of a high-flow water pump.
Gross flow radiators are superior to upright radiators because the radiator cap is positioned on the low pressure (suction) side of the system. This prevents the pressure created by a high-flow water pump from forcing coolant past the radiator cap at high RPM. As mentioned in the radiator cap section, an upright radiator should be equipped with radiator cap with the highest pressure rating recommended by the manufacturer. The system will still force coolant past the cap at sustained high RPM.
Kinda hard to know what the current truth is? Maybe 30 years ago a multi-pass was better but not with a modern radiator?
Ken
From: marshall smith <marshallgsmith at sbcglobal.net>
To: GR2835 at comcast.net; detomaso at poca.com; Charles McCall <charlesmccall at gmail.com>
Sent: Monday, June 29, 2015 1:43 PM
Subject: Re: [DeTomaso] Radiators
In reference to the Independent Antique Radiator described below, I would be a little skeptical about having only 3 rows and more concerned about coolant making only one pass through the unit. I believe the coolant should make two passes through the radiator to properly cool the liquid.
JMHO....
M
--------------------------------------------
On Mon, 6/29/15, Charles McCall <charlesmccall at gmail.com> wrote:
Subject: Re: [DeTomaso] Radiators
To: GR2835 at comcast.net, detomaso at poca.com
Date: Monday, June 29, 2015, 11:27 AM
Quick reply from
Mishimoto:
Charles,
Thanks for the E-mail!
Unfortunately, at this time we do not offer an aluminum radiator for
the DeTomaso Pantera. I am sorry for any inconvenience. However, I will
be happy to add your information to our product suggestion list! If we
do decide to come out with a product that matches your description, we
will be sure to contact you!
Please let me know if there is anything else I can help with!
Mishimoto strives for the best Customer Service. Have I fully resolved
any questions or concerns you were
contacting us about today?
Thanks,
Gerry - thanks for the info... Quite interested, although a little
turned off by the fact that I would need new tubes under the chassis. A
few years ago I bought all new SS tubing (so that it would never wear
out!!) Let us know how you like it - I'm thinking that Santa would be a
perfect guy to guy shopping for me, so I'm not in a hurry but am
keeping my eyes open for the best
solution
From: GR2835 at comcast.net
[mailto:GR2835 at comcast.net]
Sent: lunes, 29 de junio de 2015 17:54
To: Charles McCall
Subject: Re: [DeTomaso] Radiators
Charles,
You wanted
lifetime.........warranty
Independent Antique Radiator in
Algonquin, Illinois , will be
selling an all brass, 3 core, extruded tube (no seams), single pass
radiator that is a direct replacement for a Pantera radiator. It even
has the new dimpled fins for more heat dissapation........designed for
the air conditioning condenser to be mounted in front and sucker fans
recommended by Jon Haas to be mounted behind.
This radiator has the heat sensor screw in mounted on the drivers
side as recommended by John Haas and included in his radiator fan
controller kit.
This radiator requires new
tubes to be made from the under chassis
tubes.....Inlet on the passenger side and outlet on the drivers side.
Current prototype is running in my car. The radiator should be
available in about 2 weeks....$650.00 .+ shipping..I can send pictures.
Their warranty
is unconditional excluding damage not caused by
manufacture.
Independent Antique Radiator
200 Berg St.
Algonquin, Il.
Image removed by
sender. 847-458-7400
Gerry
VP Great Lakes Pantera Club
_______________________________________________________________________
From: "Charles McCall" <charlesmccall at gmail.com>
To: "Al Chelini" <pantera at cox.net>
Cc: "Mike Drew" <mikeldrew at aol.com>, detomaso at poca.com
Sent: Monday, June 29, 2015 7:29:21 AM
Subject: Re: [DeTomaso] Radiators
Inquiry sent, Al, thanks. May be in the market for a new radiator, as
mine
is marking its territory a Little more every day. A lifetime warranty
would
be fantastic!
On Mon, Jun 29, 2015 at 1:44 PM, Al
Chelini <pantera at cox.net>
wrote:
> Hi, gang,
> FWIW, I just got thru
with a leaky radiator project on another
> (extensively modified)
make vehicle, which came with a Ron Davis
(RD)
> radiator.A That RD
unit developed some serious leaks along the
top &
> bottom ends where the
side tanks meet the supporting rails; and I
> thought I'd share this
learning experience with the group.
> After calling RD's
Customer Support seeking repairs, I found that:
> 1) they can't repair an
aluminum radiator once it's come in
contact
> with radiator coolant.
They claim it contaminates the metal,
making it
> impossible to TIG weld
successfully.
> 2) they will be happy to
sell me a new unit .....A about $1000,
> delivered.A But,
with only their standard 90 day limited
warranty.
> Kinda' chintzy policy
for such an expensive part, when the GM
> replacement version is
only $150. Are these things considered a
> consumable, like brake
pads?
> 3) On a recommendation
from a trusted source, I picked up a
Mishimoto
> radiator for about 40%
the cost of a new RD, and it has a Lifetime
> warranty. Everyone who
has seen the new part claims that the
> workmanship is superior
to the RD.A
> 4) But, I checked the
[1]mishimoto.com website, they don't offer
one
> for the Pantera
(yet).A But, I did leave an email suggesting that
they
> market one.
> Here's the pitch: Maybe
if a few other list members would contact
them
> expressing a desire to
buy their Pantera version, they might be
> motivated to start
producing them. They make radiators for cars
which
> are much lower volume
than the Pantera.
> Bonus: Mishimoto is a
huge company, and their customer service is
> outstanding. The
Lifetime warranty sold me.
> Final thought:
> The OEM Pantera radiator
is a very good part; but, some of these
were
> not built correctly.
Technical Service Bulletin (TSB) #8, article
61
> describes a correcting
modification which can be done by a
competent
> radiator shop.
> FWIW,
> Al (3915)
>
==================================================================
> On Mon, Jun 29, 2015 at
1:26 AM, michael barnes
> <[2]michaelbarnessrt10 at hotmail.co.uk>
wrote:
>
> I bought a
Superior radiator,it was made upside down so
obviously
> wouldn't fit
.After sales was shocking , three months and no
> replacement d-!
> Sent by Michael
Barnes
> > On 29 Jun
2015, at 07:05, Ed Mendez <[3]edducati at mac.com>
wrote:
> >
> > I have a
stock radiator for sale if anyone interested. It has
a
> radiator cap on
it which weird but I suppose you can weld that
off?
> >
> > Ed
> >
> >
> >> On Jun
28, 2015, at 21:10, marshallgsmith
> <[4]marshallgsmith at sbcglobal.net>
wrote:
> >>
> >>A
Don't discount the original radiator. It is very good and
has
> cooled my
> >>A
car for many years.All that is needed is modern day high
volume
> fans.
> >>
> >>A
Marshall
> >>
> >>A
Sent from my Verizon Wireless 4G LTE smartphone
> >>
> >>A
-------- Original message --------
> >>A
From: Julian Kift <[5]julian_kift at hotmail.com>
> >>A
Date: 06/28/2015 8:52 PM (GMT-08:00)
> >>A
To: [6]mikeldrew at aol.com,
[7]steve at snclocks.com,
> [8]detomaso at poca.com
> >>A
Subject: Re: [DeTomaso] Radiators
> >>A
For other options in aluminum Ron Davies makes a nice
radiator
> for the
> >>A
Pantera by all accounts and Superior Radiator sells their
> version on
> >>A
eBay with some happy customers.
> >>A
Julian
> >>A
Date: Sun, 28 Jun 2015 21:10:23 -0400
> >>A
To: [9]steve at snclocks.com;
[10]detomaso at poca.com
> >>A
Subject: Re: [DeTomaso] Radiators
> >>A
From: [11]detomaso at poca.com
> >>A
In a message dated 6/28/15 15 34 37, [12]steve at snclocks.com
> writes:
> >>>
Whilst I am enjoying driving 5332, I noticed that I have a
seep
> from
> >>>
where one of the radiator tubes enters the header tank.A
Looks
> like
> >>A
it has been
> >>>
there a while, small seep, but left a puddle when I ran the
> engine at
> >>A
1500
> >>> rpm
for 10 minutes to charge the a/c.A It's a Fluidyne
> radiator,
> >>A
bought
> >>> and
installed in 2011, with perhaps 4,000 miles on it.
> >>>
>
>>>>> Bummer.A A Many have discovered
to their sadness that
> Fluidyne
> >>A
radiators
> >>A
(at least the first-generation models for the Pantera)
cooled
> very well
> >
>
_______________________________________________
> Detomaso Forum
Managed by POCA
> Posted emails
must not exceed 1.5 Megabytes
> DeTomaso mailing
list
> [13]DeTomaso at poca.com
> [14]http://poca.com/mailman/listinfo/detomaso_poca.com
> To manage your
subscription (change email address, unsubscribe,
> etc.) use the
links above.
>
> On Mon, Jun 29, 2015 at
1:26 AM, michael barnes
> <[15]michaelbarnessrt10 at hotmail.co.uk>
wrote:
>
> I bought a
Superior radiator,it was made upside down so
obviously
> wouldn't fit
.After sales was shocking , three months and no
> replacement d-!
> Sent by Michael
Barnes
> > On 29 Jun
2015, at 07:05, Ed Mendez <[16]edducati at mac.com>
wrote:
> >
> > I have a
stock radiator for sale if anyone interested. It has
a
> radiator cap on
it which weird but I suppose you can weld that
off?
> >
> > Ed
> >
> >
> >> On Jun
28, 2015, at 21:10, marshallgsmith
> <[17]marshallgsmith at sbcglobal.net>
wrote:
> >>
> >>A
Don't discount the original radiator. It is very good and
has
> cooled my
> >>A
car for many years.All that is needed is modern day high
volume
> fans.
> >>
> >>A
Marshall
> >>
> >>A
Sent from my Verizon Wireless 4G LTE smartphone
> >>
> >>A
-------- Original message --------
> >>A
From: Julian Kift <[18]julian_kift at hotmail.com>
> >>A
Date: 06/28/2015 8:52 PM (GMT-08:00)
> >>A
To: [19]mikeldrew at aol.com,
[20]steve at snclocks.com,
> [21]detomaso at poca.com
> >>A
Subject: Re: [DeTomaso] Radiators
> >>A
For other options in aluminum Ron Davies makes a nice
radiator
> for the
> >>A
Pantera by all accounts and Superior Radiator sells their
> version on
> >>A
eBay with some happy customers.
> >>A
Julian
> >>A
Date: Sun, 28 Jun 2015 21:10:23 -0400
> >>A
To: [22]steve at snclocks.com;
[23]detomaso at poca.com
> >>A
Subject: Re: [DeTomaso] Radiators
> >>A
From: [24]detomaso at poca.com
> >>A
In a message dated 6/28/15 15 34 37, [25]steve at snclocks.com
> writes:
> >>>
Whilst I am enjoying driving 5332, I noticed that I have a
seep
> from
> >>>
where one of the radiator tubes enters the header tank.A
Looks
> like
> >>A
it has been
> >>>
there a while, small seep, but left a puddle when I ran the
> engine at
> >>A
1500
> >>> rpm
for 10 minutes to charge the a/c.A It's a Fluidyne
> radiator,
> >>A
bought
> >>> and
installed in 2011, with perhaps 4,000 miles on it.
> >>>
>
>>>>> Bummer.A A Many have discovered
to their sadness that
> Fluidyne
> >>A
radiators
> >>A
(at least the first-generation models for the Pantera)
cooled
> very well
> >
>
_______________________________________________
> Detomaso Forum
Managed by POCA
> Posted emails
must not exceed 1.5 Megabytes
> DeTomaso mailing
list
> [26]DeTomaso at poca.com
> [27]http://poca.com/mailman/listinfo/detomaso_poca.com
> To manage your
subscription (change email address, unsubscribe,
> etc.) use the
links above.
>
> References
>
> 1. http://mishimoto.com/
> 2. mailto:michaelbarnessrt10 at hotmail.co.uk
> 3. mailto:edducati at mac.com
> 4. mailto:marshallgsmith at sbcglobal.net
> 5. mailto:julian_kift at hotmail.com
> 6. mailto:mikeldrew at aol.com
> 7. mailto:steve at snclocks.com
> 8. mailto:detomaso at poca.com
> 9. mailto:steve at snclocks.com
> 10. mailto:detomaso at poca.com
> 11. mailto:detomaso at poca.com
> 12. mailto:steve at snclocks.com
> 13. mailto:DeTomaso at poca.com
> 14. http://poca.com/mailman/listinfo/detomaso_poca.com
> 15. mailto:michaelbarnessrt10 at hotmail.co.uk
> 16. mailto:edducati at mac.com
> 17. mailto:marshallgsmith at sbcglobal.net
> 18. mailto:julian_kift at hotmail.com
> 19. mailto:mikeldrew at aol.com
> 20. mailto:steve at snclocks.com
> 21. mailto:detomaso at poca.com
> 22. mailto:steve at snclocks.com
> 23. mailto:detomaso at poca.com
> 24. mailto:detomaso at poca.com
> 25. mailto:steve at snclocks.com
> 26. mailto:DeTomaso at poca.com
> 27. http://poca.com/mailman/listinfo/detomaso_poca.com
>
>
_______________________________________________
>
> Detomaso Forum Managed by POCA
> Posted emails must not exceed 1.5
Megabytes
> DeTomaso mailing list
> DeTomaso at poca.com
> http://poca.com/mailman/listinfo/detomaso_poca.com
>
> To manage your subscription (change email address, unsubscribe, etc.)
use
> the links above.
>
>
_______________________________________________
Detomaso Forum Managed by POCA
Posted emails must not exceed 1.5
Megabytes
DeTomaso mailing list
DeTomaso at poca.com
http://poca.com/mailman/listinfo/detomaso_poca.com
To manage your subscription (change email address, unsubscribe, etc.)
use the links above.
-----Inline Attachment Follows-----
_______________________________________________
Detomaso Forum Managed by POCA
Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list DeTomaso at poca.com http://poca.com/mailman/listinfo/detomaso_poca.com
To manage your subscription (change email address, unsubscribe, etc.) use the links above.
_______________________________________________
Detomaso Forum Managed by POCA
Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list DeTomaso at poca.com http://poca.com/mailman/listinfo/detomaso_poca.com
To manage your subscription (change email address, unsubscribe, etc.) use the links above.
_______________________________________________
Detomaso Forum Managed by POCA
Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list DeTomaso at poca.com http://poca.com/mailman/listinfo/detomaso_poca.com
To manage your subscription (change email address, unsubscribe, etc.) use the links above.
_______________________________________________
Detomaso Forum Managed by POCA
Posted emails must not exceed 1.5 Megabytes DeTomaso mailing list DeTomaso at poca.com http://poca.com/mailman/listinfo/detomaso_poca.com
To manage your subscription (change email address, unsubscribe, etc.) use the links above.
More information about the DeTomaso
mailing list