Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Observations on Tom Shiels thermostat housing for Subie
Forum Index -> Vanagon Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
dobryan
Samba Member


Joined: March 24, 2006
Posts: 11053
Location: Brookeville, MD
dobryan is offline 

PostPosted: Mon Jul 30, 2012 12:14 pm    Post subject: Observations on Tom Shiels thermostat housing for Subie Reply with quote

http://subaruvanagon.com/tom/Thermostat%20housingk.htm

Just wanted to post some of my observations on this.

Here is some back story. Several years ago I did a Subaru EJ 25 conversion of my '87 Westy. I sourced all the parts myself since there was not the great level of kits assembled like there is now. I used the yahoo group as a great resource. One of the items I installed was Tom Shiels thermostat housing. (This allows the thermostat feedback supply to go directly from the coolant manifold to the thermostat housing rather than going through the rear/front heater circuit.) I had a Scangauge on the dash so I could see detailed coolant temp info. I noticed that the engine operating temps were typically in the low 180's and would very gradually climb to about 200 when idling in the summer for a long period (stuck in traffic, etc).

Current story.... My current '87 Westy also has an EJ25 conversion which I moved from another Vanagon to this one. This conversion utilized the heater circuit to supply feedback to the thermostat (which is very typical it seems). I noticed that the coolant temps on this conversion were in the low 190's and seemed to have more fluctuation and at a quicker rate than my previous conversion. Last year I decided to retrofit the Tom Shiels thermostat housing to my current conversion. Here are the differences that I noticed after a year of operation:

-Normal operating temps were in the low 190's vs low 180's now.
-In the winter the temps would very quickly go from the low 190's to 200 (radiator fan would come on) when stopped at a light, now winter temps are in the low 180's and do not get above the low 190's at idle.
-In the winter the engine temps would be affected by the heater operation. If the heaters were on (cold outside) the engine would sometimes run in the mid to upper 190's while driving. No engine temp change (low 180's) with heaters on now.
-In the summer normal operating temps were in the low 190's but would quickly climb to the mid 190's and even 200 going up long grades. Now normal engine temps are low 180's and only climb to 190 on long climbs (even towing a 1000 lb trailer up a five mile grade).
-Max engine temps in both scenarios never got above 202.

So my observations are that in my case the engine didn't overheat under either scenario. But it seems that the Tom Shiels thermostat housing gives a better feedback loop to the thermostat. If the feedback loop goes thru the heater circuit some temp is lost (more in winter) thus making the thermostat think the engine is operating at a lower temp than it actually is. This is exacerbated at idle and in the winter when more temp drop occurs across the heater circuit.

I like the current setup since it gives me a little more piece of mind than the previous one. YMMV. Very Happy
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

Join the Vanagon Rescue Squad on the VanAlert app.
http://vanalert.com/

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Franklinstower
Samba Member


Joined: September 21, 2006
Posts: 1327
Location: PNW
Franklinstower is offline 

PostPosted: Mon Jul 30, 2012 5:57 pm    Post subject: Reply with quote

Hey Dobryan,
I use the Vanaru system which I think is a modified SC system that doesn't use Tom Shiels housing. My temps are typical 185-195 (this summer anyway) 195 being in the stop and go traffic. I have thought a lot about switching to Tom's method for a more consistent temp. Also I don't like the fact that you can't shut off the rear heater valve during summer travels with the Vanaru system.

What kind of changes did you have to make to swith to Tom's system?

thanks,

Paul
_________________
'89 Westy - EJ25/22 Frank 4.44 5mt
Back to top
View user's profile Send private message Gallery Classifieds Feedback
thummmper
Samba Member


Joined: November 25, 2009
Posts: 2015
Location: Meadow Valley, California Republic
thummmper is offline 

PostPosted: Mon Jul 30, 2012 11:13 pm    Post subject: Reply with quote

It was explained to me that without this 80 dollar device, it would overheat in the winter-- It has worked like a champ for me.
Image may have been reduced in size. Click image to view fullscreen.
Back to top
View user's profile Send private message Visit poster's website Gallery Classifieds Feedback
dobryan
Samba Member


Joined: March 24, 2006
Posts: 11053
Location: Brookeville, MD
dobryan is offline 

PostPosted: Tue Jul 31, 2012 5:09 am    Post subject: Reply with quote

Franklinstower wrote:
Hey Dobryan,
I use the Vanaru system which I think is a modified SC system that doesn't use Tom Shiels housing. My temps are typical 185-195 (this summer anyway) 195 being in the stop and go traffic. I have thought a lot about switching to Tom's method for a more consistent temp. Also I don't like the fact that you can't shut off the rear heater valve during summer travels with the Vanaru system.

What kind of changes did you have to make to swith to Tom's system?

thanks,

Paul


No real difficult changes. I left the original cooling system in place and added the thermostat housing as per Tom's instructions. I plumbed a 1/2 line from just off the coolant manifold supply to the heater circuit into the housing to provide the feed.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

Join the Vanagon Rescue Squad on the VanAlert app.
http://vanalert.com/

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Franklinstower
Samba Member


Joined: September 21, 2006
Posts: 1327
Location: PNW
Franklinstower is offline 

PostPosted: Tue Jul 31, 2012 7:57 am    Post subject: Reply with quote

I have yet to over heat, 4+ years since the conversion. Even when I was in sun valley where the temps were -2 to 15. But I have never been particularily fond of using the heater circuit to supply the feed to the t-stat.

It is probably best to diamgram my system and compare it to Tom's newest version and go from there.
_________________
'89 Westy - EJ25/22 Frank 4.44 5mt
Back to top
View user's profile Send private message Gallery Classifieds Feedback
kalispell365
Samba Member


Joined: April 01, 2010
Posts: 871
Location: PNW
kalispell365 is offline 

PostPosted: Tue Jul 31, 2012 8:49 am    Post subject: Reply with quote

i honestly think the sort of variances described in temperature are common in the subaru itself...this is a solution to a problem that doesnt exist.the subaru motor seems highly underrated with vanagon folks,these motors are bombproof.kind of like adding all these aftermarket guages to constantly monitor the oil pressure,etc.as a subaru technician i can tell you that these engines will literally last FOREVER if simply ran with coolant and oil up to par,these are no waterboxer...after being a part of the subaru conversion business over the last four years,i think the worst things that happen to the subaru conversions are from people comparing the systems to their old van motor and constantly trying to "improve" things.i have had several customers tell me they NEEDED a new oil pump on their subaru engine because of it being old.i have never in twenty years of subaru work seen an oil pump in any way fail...old thinking applied to a modern powerplant.these deserve far more credit than that,there are so many old 1990 legacys delivering mail,constant stop and go,on rural roads with no maintenence at 400k plus.i work on several,brake jobs and oil changes!
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Jake de Villiers
Samba Member


Joined: October 24, 2007
Posts: 4742
Location: Crescent Beach, BC
Jake de Villiers is offline 

PostPosted: Tue Jul 31, 2012 8:51 am    Post subject: Reply with quote

Tom's thermostat housing is especially important if you want to use the heater in the winter. I struggled with this, running either too hot or too cold until I installed Tom's device. Now (like Goldilocks) its just right at all times of the year, under any conditions.

I wouldn't attempt a Subie conversion without one.
_________________
'84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7 Mercedes Wheels - answers to 'Dixie'
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com
Back to top
View user's profile Send private message Send e-mail Visit poster's website Gallery Classifieds Feedback
presslab
Samba Member


Joined: September 29, 2008
Posts: 1730
Location: Sonoma County
presslab is offline 

PostPosted: Tue Jul 31, 2012 9:03 am    Post subject: Reply with quote

7 years ago I hooked things up pretty much the KEP way. I just leave the rear heater valve open, it doesn't emit any heat in the summer without the fan and it keeps the core from corroding due to stagnation.

I have good heat in the winter, nothing extreme but less than 20F, and the engine temps are just fine. Without the heaters blowing the temp needle is just below the LED, and with the heaters blowing the needle is just above the LED. That variation in temperature is minor. While climbing steep roads at low speeds in 1st gear, the needle goes well beyond that to about 7/8 full scale, at which the fan turns on, and that is also normal.
_________________
1986 Vanagon Westfalia EJ25
1988 Subaru GL-10 EJ20G --- 2000 Honda XR650L
2010 Titus El Guapo --- 2011 On-One 456 Ti
Back to top
View user's profile Send private message Gallery Classifieds Feedback
kalispell365
Samba Member


Joined: April 01, 2010
Posts: 871
Location: PNW
kalispell365 is offline 

PostPosted: Tue Jul 31, 2012 9:20 am    Post subject: Reply with quote

presslab wrote:
7 years ago I hooked things up pretty much the KEP way. I just leave the rear heater valve open, it doesn't emit any heat in the summer without the fan and it keeps the core from corroding due to stagnation.

I have good heat in the winter, nothing extreme but less than 20F, and the engine temps are just fine. Without the heaters blowing the temp needle is just below the LED, and with the heaters blowing the needle is just above the LED. That variation in temperature is minor. While climbing steep roads at low speeds in 1st gear, the needle goes well beyond that to about 7/8 full scale, at which the fan turns on, and that is also normal.

CORRECT!
also,another misconception is that the subaru engine ONLY uses the heater feed to regulate the thermostat...one look at the block/water pump design will show this is inaccurate.if you are having heat up problems,there is a high possibility that you have an improper cooling system/air pocket,or a combination of both.
i have seen toms wiring work,he is a brilliant converter.i just know from experience,especially here where it is colder than anywhere else in the lower 48,that this iitem is unnecessary.all youve accomplished is several more junctions to leak.
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Team WorldTour Premium Member
Samba Member


Joined: September 02, 2010
Posts: 2136
Location: Der Vaterland
Team WorldTour is offline 

PostPosted: Tue Jul 31, 2012 10:31 am    Post subject: Reply with quote

@kalispell365-
While I agree with you 90%, I have to point you to one of my threads: H6 Conversion- My New Problem
Ultimately it came down to oil starvation.
With the new motor, I just dropped it in. No bolt-ons, nothin'! I hooked the cooling lines up to the custom made ones, bolted on the tranny, and re-installed the skid plate.
If you take my motor out right now, you could drop it straight back into a Legacy, no problems.
And the motor runs fine. The heater circuit is hooked to the original heater circuit, and the motor runs at a constant 92C. And in the winter (I live in Germany!), the heater ROASTS!
Sorry to say, but Toms T-Stat housing is (IMHO) not necessary.
_________________
1990 Feldjäger Syncro AAZ
Click to view image
H6 Subaru Engine Swap Thread
WV2ZZZ25ZFH094138(x)/ WV2YB0257LH057308(x)/ WV2ZZZ25ZLG113270/
"Where am I going? And what am I doing in this handbasket?" -Nicodemus Jordan
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address Facebook Gallery Classifieds Feedback
kalispell365
Samba Member


Joined: April 01, 2010
Posts: 871
Location: PNW
kalispell365 is offline 

PostPosted: Tue Oct 01, 2013 1:41 pm    Post subject: Reply with quote

I finally have seen a kennedy conversion,and must correct my ignorance...on the smallcar setup there is a fitting added onto the black heater pipe which goes to the water pump/thermostat bypass (black metal stock subaru heater line) on the stock subaru motor. this fitting has a small section of coolant hose that connects onto a fitting on the coolant manifold,therby creating a bypass. The kit that Tom has built does this for those folks thet have the kennedy style cooling setup.Otherwise,the rear heater loop is a MUST if you have the kennedy setup...otherwise the thermostat will not open and the engine will overheat!
I am sorry to anyone who has read this posting,has a kennedy setup, and been misinformed by my information.My ignorance to the Kennedy system is humbling...My apologies to Tom as well,his product is a necessity to the Kennedy kit,I now see...
Here is a link to a thread showing Bens bypass,which is the same as Smallcar.
Sorry!

http://www.thesamba.com/vw/forum/viewtopic.php?t=570430&highlight=subaru+rear+heater
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
dobryan
Samba Member


Joined: March 24, 2006
Posts: 11053
Location: Brookeville, MD
dobryan is offline 

PostPosted: Tue Oct 01, 2013 1:59 pm    Post subject: Reply with quote

Thanks for your post. Very Happy

BTW it is not unique to Kennedy. Many of the conversions use a similar setup and may benefit from the kit Tom does. The main thing for those with a Subaru conversion is please be very familar with how the thermostat gets its feedback on engine temp and be sure to provide a reliable feedback loop for it...
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

Join the Vanagon Rescue Squad on the VanAlert app.
http://vanalert.com/

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371
Back to top
View user's profile Send private message Gallery Classifieds Feedback
dorje
Samba Member


Joined: June 02, 2014
Posts: 47
Location: Berkeley
dorje is offline 

PostPosted: Tue Jan 08, 2019 1:50 pm    Post subject: Re: Observations on Tom Shiels thermostat housing for Subie Reply with quote

I just had the rear heater coolant lines tee'd together with a thin-diameter coolant hose. Provides plenty enough for a coolant bypass with a minimum of extra plumbing.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
danfromsyr
Samba Member


Joined: March 01, 2004
Posts: 12213
Location: Syracuse, NY
danfromsyr is offline 

PostPosted: Tue Jan 08, 2019 2:42 pm    Post subject: Re: Observations on Tom Shiels thermostat housing for Subie Reply with quote

though I haven't used it yet, it was brought up in one thread. that there is a OEM subaru waterpump for the legacy 2.2 turbo that has the added port built in.
but then you'd have to remember that specific part/pump 4yrs later when you needed to replace it.
Back to top
View user's profile Send private message Visit poster's website Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Vanagon All times are Mountain Standard Time/Pacific Daylight Savings Time
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2018, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB