GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.
Home » Public Forums » GMCnet » [GMCnet] Engine oil cooler & system
[GMCnet] Engine oil cooler & system [message #78273] Sun, 28 March 2010 11:44 Go to next message
GMC_LES is currently offline  GMC_LES   United States
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
Senior Member
A few questions regarding the engine oil cooler & system.



1) Does the factory installed oil cooler system have a thermostat?

2) With the factory system, what temp does the engine oil run at on a
long haul in cold weather? ( around 32 to 40°F)

3) Does anyone know the line and fitting sizes on the factory oil
cooler system?

4) What is considered as normal idle oil pressure on a warm engine?



I read that there are a few that have considered running an RX7 engine oil
cooler because it has an integral thermostat.



5) Does anyone know what the operating temp specs are on the RX7
cooler?

6) What year of RX7 did the cooler come from?

7) How good a job did the RX7 cooler do in terms of controlling oil
temps on the GMC?

8) Where was the RX7 cooler mounted?



My coach no longer has an engine oil cooler system. It was removed by the PO
for some reason. I want to install a new system and have been looking at the
many possibilities available.



I like the idea of thermostatically controlling the oil temp, but have not
found an oil thermostat unit that opens at my preferred 200°F. Most units
start to open at 160F and are fully open at 180F. It is a well known fact
that you need over 200F to burn off the moisture in the oil which helps
reduce acids build up.



I’d like to hear what others have done as well as recommend.



Thanks,

Les Burt

Montreal

1975 Eleganza II 26ft



_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Les Burt Montreal 1975 Eleganza 26ft A work in Progress

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78274 is a reply to message #78273] Sun, 28 March 2010 11:56 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
>
>
> I like the idea of thermostatically controlling the oil temp,
>

this is another one of those things that have a history with the GMC.

Many years ago, these were tried and were a problem. The problem was, they
failed closed causing a heating problem in the oil.

Might be interesting to see who is doing this, and pros and cons.

Myself, I find I always need all the cooling I can get.

I think Chuck Aulgur (WHO?) was the one that did research on these.

gene


--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78278 is a reply to message #78274] Sun, 28 March 2010 12:06 Go to previous messageGo to next message
GMC_LES is currently offline  GMC_LES   United States
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
Senior Member


I can understand the need for all the cooling you can get if you are running
in the hot southern climates. Since I live in the great white north, I am
concerned about over cooling during the cool seasons. I guess I could use an
adjustable cover to control airflow through the cooler, but it just becomes
another item to monitor & maintain.

Thanks,
Les Burt

_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Les Burt Montreal 1975 Eleganza 26ft A work in Progress

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78280 is a reply to message #78274] Sun, 28 March 2010 12:15 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
Senior Member
Les, I run one. I think it opens at 170. Never had a problem with it and I know it stays closed a lot so engine oil is not getting real hot. Maybe it opens at a hotter temp. I run in series with my alum radiator cooler. I have unhooked my old external cooler for the tranny and have an rx-7 cooler to mount when I get home. It will also be in series with the alum radiator. We seem to climb a lot of mountains so I like the extra cooling.
If a guy was worried about the thermostat failing he could take it out and run the cooler all the time I guess.
I can not answer your questions.
Dan

3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78283 is a reply to message #78273] Sun, 28 March 2010 12:38 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Les,

This is just great, I have to head off to a grandchild's birthday, but I will get into this more - later.

Look at item 270551023985 on E-bay.

I have forgotten who makes them, but they are a great idea if all the original plumbing is gone.

Later

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78287 is a reply to message #78283] Sun, 28 March 2010 12:51 Go to previous messageGo to next message
GMC_LES is currently offline  GMC_LES   United States
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
Senior Member
Matt,

I'm very familiar with that type of oil cooler. VW uses them on just about
everything they make. Sure would prefer running one of them, but wonder if
they are capable of controlling the oil temps of a 455 pulling a long grade
uphill in 110F ?

Thanks,
Les Burt

_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Les Burt Montreal 1975 Eleganza 26ft A work in Progress

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78289 is a reply to message #78287] Sun, 28 March 2010 13:07 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
Senior Member
My plan is to mount this one in the lower radiator guard that Jim K. sells, made by Blaine Merrel. Bert Curtis has both of his mounted there but I already have the heavy duty oil hoses made for the now mounted engine cooler. It is mounted on passenger side in front of radiator.
I think you will like the rx-7 cooler. There may be variable temp thermostats, I just don't know. I have run several miles with mine not opening as it was not needed.
Dan

3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78306 is a reply to message #78287] Sun, 28 March 2010 15:34 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Les Burt wrote on Sun, 28 March 2010 13:51

Matt,
I'm very familiar with that type of oil cooler. VW uses them on just about everything they make. Sure would prefer running one of them, but wonder if they are capable of controlling the oil temps of a 455 pulling a long grade uphill in 110F ?

Thanks,
Les Burt

Les,
These used come come in different sizes, but I can not find a catalog on the web (there used to be one on my desk - when I had a desk). We put them on 7.9l test engines that would have liked to be climbing mountains at 110* just to relax.

They didn't exist when coaches were made or they probably would have used them. They are currently OE on many vehicle larger than what VW builds.

I found listings with no information at Napa.

They have many advantages over air cooled heat exchangers.

I will keep looking and maybe make some calls tomorrow.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78373 is a reply to message #78273] Sun, 28 March 2010 21:51 Go to previous messageGo to next message
Terry Skinner is currently offline  Terry Skinner   United States
Messages: 379
Registered: January 2004
Karma: 0
Senior Member
On Sun, Mar 28, 2010 at 9:44 AM, Les Burt <burtco99@yahoo.com> wrote:
> A few questions regarding the engine oil cooler & system.
>
> 5)       Does anyone know what the operating temp specs are on the RX7
> cooler?
>
http://www.rx7city.com/88manual.htm


--
Terry Skinner
253-686-2624
Roy. Washington
'76 GMC
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78741 is a reply to message #78373] Wed, 31 March 2010 13:20 Go to previous messageGo to next message
GMC_LES is currently offline  GMC_LES   United States
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
Senior Member
OK,

So I see that the ,88 RX7 oil cooler has a thermostat set to open around
140F-150F. A little too low for my liking.

Matt,
I really like the oil/water type oil coolers. They are great for cold
weather operation as they also serve to warm up the oil to operating temps.

If you find any info on a unit that has a high enough capacity to handle our
coaches, I'd like to know. I will also do some searching of my own and post
what I find here.


Thanks,
Les Burt
Montreal
1975 Eleganza II 26ft


_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Les Burt Montreal 1975 Eleganza 26ft A work in Progress

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78769 is a reply to message #78273] Wed, 31 March 2010 16:41 Go to previous messageGo to next message
Gary Casey is currently offline  Gary Casey   United States
Messages: 448
Registered: September 2009
Karma: 0
Senior Member
Les,
Well, that's a logical assumption, but it doesn't work out too well in practice. Problem is that the oil cooler is in the "cold" tank. The hot side of the radiator is pretty well regulated at the temperature setting of the thermostat - even a little bit of coolant flow into the radiator will keep the hot side at a constant temperature. Problem with the cold side is that as the outside air temperature goes down the thermostat will gradually close to keep the engine warm. At the same time the colder ambient allows more heat to be lost in the radiator. With the result (I've tested it) that the temperature of the cold tank drops about twice as fast as ambient. So the somewhat surprising result is that ambient air is more constant than the cold tank of the radiator. What to do? Put the cooler in the hot side. Sounds backwards, but it will result in more constant oil temps and will cool, even in hot weather, almost as well as when in the cold side.
Gary

Subject: Re: [GMCnet] Engine oil cooler & system
To: gmclist@temp.gmcnet.org
Message-ID: <0L05007NESAX5S70@VL-MO-MR005.ip.videotron.ca>
Content-Type: text/plain; charset=us-ascii


Snip from previous post:
Matt,
I really like the oil/water type oil coolers. They are great for cold
weather operation as they also serve to warm up the oil to operating temps.

...

Thanks,
Les Burt
Montreal



_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78849 is a reply to message #78741] Thu, 01 April 2010 07:10 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Les Burt wrote on Wed, 31 March 2010 14:20

OK,

So I see that the ,88 RX7 oil cooler has a thermostat set to open around 140F-150F. A little too low for my liking.

Matt,
I really like the oil/water type oil coolers. They are great for cold weather operation as they also serve to warm up the oil to operating temps.

If you find any info on a unit that has a high enough capacity to handle our coaches, I'd like to know. I will also do some searching of my own and post what I find here.

Thanks,
Les Burt
Montreal
1975 Eleganza II 26ft

Les,

It is my opinion that the RX7 set point is too low, but that engine is largely oil cooled (even more so than a piston engine) and the set point may reflect that.

I have a long list of reasons why I like heat exchanger at the filter plan, but I am currently sort of embarrassed that I can't find the supplier (I used to order several hundred year for test operations). I am waiting for a call back from a compatriot of years gone by.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78864 is a reply to message #78273] Thu, 01 April 2010 09:37 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Les,

Good News/Bad News

Good News:
I found them, Modine.
You can access a brochure at
url/<http://www.modine.com/publications/litnav.php?c1=Automotive&c2=*Engine>
You want 44-156

Bad News:
No Reps - they only sell direct and a minimum quantity is 30.

No prices because I didn't bother to get a quote.

Over the coming months I will try to work the few friends I have that are still in working (getting fewer daily) in that area and see if we can work something, but it does not look very promising.

I know that they were OE on Turbo Regal, Turbo-coupe and Viper, but I don't know what size any of those were. I bet Viper would do.

Matt

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78880 is a reply to message #78283] Thu, 01 April 2010 11:49 Go to previous messageGo to next message
mike miller   United States
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
Senior Member
mcolie wrote on Sun, 28 March 2010 10:38

...
Look at item 270551023985 on E-bay.

I have forgotten who makes them, but they are a great idea if all the original plumbing is gone. ..

Looks a lot like the one on our Audi 2.7t.

<http://www.gmcmhphotos.com/photos/showphoto.php?photo=17232&cat=3698>

Do not let the much smaller size fool you liquid to liquid heat exchangers are MUCH more efficient than a liquid to air.

I suspect one from an "American design" might be easier to use.


Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78915 is a reply to message #78880] Thu, 01 April 2010 15:39 Go to previous messageGo to next message
GMC_LES is currently offline  GMC_LES   United States
Messages: 569
Registered: October 2009
Location: Montreal
Karma: 0
Senior Member
Thanks Mike & Matt,

The Audi oil cooler I am very familiar with, but I wonder if it has
sufficient oil flow capacity? Without any specs, I'd be hesitant to install
one as I would be concerned about potential oil starvation.

I had a look online to see what I could find on Modine. They sure make nice
products, but don't appear to have much in terms of an aftermarket type
supplier network. I'll keep looking for a Modine supplier, but it doesn't
look hopeful.



Thanks,
Les Burt
Montreal
1975 Eleganza II 26ft


_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Les Burt Montreal 1975 Eleganza 26ft A work in Progress

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78923 is a reply to message #78915] Thu, 01 April 2010 17:11 Go to previous messageGo to next message
zhagrieb is currently offline  zhagrieb   United States
Messages: 676
Registered: August 2009
Location: Portland Oregon
Karma: 0
Senior Member
Check Summit Racing. they have endless sizes and types of oil coolers.

On Thu, Apr 1, 2010 at 1:39 PM, Les Burt <burtco99@yahoo.com> wrote:

> Thanks Mike & Matt,
>
> The Audi oil cooler I am very familiar with, but I wonder if it has
> sufficient oil flow capacity? Without any specs, I'd be hesitant to install
> one as I would be concerned about potential oil starvation.
>
> I had a look online to see what I could find on Modine. They sure make nice
> products, but don't appear to have much in terms of an aftermarket type
> supplier network. I'll keep looking for a Modine supplier, but it doesn't
> look hopeful.
>
>
>
> Thanks,
> Les Burt
> Montreal
> 1975 Eleganza II 26ft
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Glenn Giere, Portland OR, K7GAG '73 "Moby the Motorhome" 26'

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78933 is a reply to message #78915] Thu, 01 April 2010 19:50 Go to previous messageGo to next message
mike miller   United States
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
Senior Member
Les Burt wrote on Thu, 01 April 2010 13:39

... The Audi oil cooler I am very familiar with, but I wonder if it has sufficient oil flow capacity? Without any specs, I'd be hesitant to install one as I would be concerned about potential oil starvation. ...


As the engine is a twin turbo with oil lines feeding both turbos I suspect it has the capacity needed for our normal inspired 455's.* That little engine (165 cu in) puts out 250 hp and a LOT of heat! Newer versions put out even more power.

While I agree you about finding out the specs before relying on it. My concerns are more along the lines of mating it up with out leaks (Audi's are known to leak...) and finding one at a price I could live with. (I am a bit cheap.) The ones designed for American iron would probably work better and be cheaper... used anyway.

*Jim K's big double turbo'ed Caddy would need something a bit more... I suspect.


Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo' http://m000035.blogspot.com

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78941 is a reply to message #78933] Thu, 01 April 2010 20:24 Go to previous messageGo to next message
Kosier is currently offline  Kosier   United States
Messages: 834
Registered: February 2008
Karma: 1
Senior Member
You might look at the one used on the mid-eighties Corvette.

Gary Kosier
77EII & 77PB
Newark, Ohio

----- Original Message -----
From: "Mike Miller" <m000035@gmail.com>
To: <gmclist@temp.gmcnet.org>
Sent: Thursday, April 01, 2010 8:50 PM
Subject: Re: [GMCnet] Engine oil cooler & system


>
>
> Les Burt wrote on Thu, 01 April 2010 13&#58;39
>> ... The Audi oil cooler I am very familiar with, but I wonder
>> if it has sufficient oil flow capacity? Without any specs, I'd
>> be hesitant to install one as I would be concerned about
>> potential oil starvation. ...
>
>
> As the engine is a twin turbo with oil lines feeding both
> turbos I suspect it has the capacity needed for our normal
> inspired 455's.* That little engine (165 cu in) puts out 250
> hp and a LOT of heat! Newer versions put out even more power.
>
> While I agree you about finding out the specs before relying on
> it. My concerns are more along the lines of mating it up with
> out leaks (Audi's are known to leak...) and finding one at a
> price I could live with. (I am a bit cheap.) The ones
> designed for American iron would probably work better and be
> cheaper... used anyway.
>
> *Jim K's big double turbo'ed Caddy would need something a bit
> more... I suspect.
>
> --
> Mike Miller
> `73 26' X Painted D.
> `78 23' Birchaven
> Hillsboro, OR
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78962 is a reply to message #78273] Thu, 01 April 2010 22:20 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
As far as being on the turbo Regal, I have a few and none have the plate type cooler. It's the same basic system that the GMC used, oil filter addaptor(for smaller PF52 or shorty PF47) and send return lines to the right tank. When you say someone (PO) removed the system, it's part of the radiator so do you mean the screw on addaptor and line set? Unless they swapped the radiator for the wrong one you still have the integral cooler. The line sets are offered but the addaptor will have to be salvage I believe.

John Lebetski
Woodstock, IL
77 Eleganza II

Report message to a moderator

Re: [GMCnet] Engine oil cooler & system [message #78965 is a reply to message #78962] Thu, 01 April 2010 23:03 Go to previous messageGo to previous message
GMCWiperMan is currently offline  GMCWiperMan   United States
Messages: 1248
Registered: December 2007
Karma: 1
Senior Member
Just remember: If the PO eliminated the in-radiator oil cooler, it may have
been because it was contaminated. Be sure it's flushed well (JimK insists
removed and professionally cleaned) before re-connecting it.

Ken H.


On Thu, Apr 1, 2010 at 11:20 PM, John R. Lebetski <gransport@aol.com> wrote:

>
>
> As far as being on the turbo Regal, I have a few and none have the plate
> type cooler. It's the same basic system that the GMC used, oil filter
> addaptor(for smaller PF52 or shorty PF47) and send return lines to the right
> tank. When you say someone (PO) removed the system, it's part of the
> radiator so do you mean the screw on addaptor and line set? Unless they
> swapped the radiator for the wrong one you still have the integral cooler.
> The line sets are offered but the addaptor will have to be salvage I
> believe.
> --
> John Lebetski
> Chicago, IL
> 77 Eleganza II
>
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Report message to a moderator

Previous Topic: Ham Antenna Mounting
Next Topic: [GMCnet] Blinds/overhead cupboards
Goto Forum:
  


Current Time: Mon Nov 18 11:26:17 CST 2024

Total time taken to generate the page: 0.05125 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.1.
Copyright ©2001-2021 FUDforum Bulletin Board Software