First bout with restrictor instead of thermostat

H

heinz wittenbecher

New member
Mar 1, 1998
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First... apologies for the triple post re TS-30. Computer misbehaving.

Installed the restrictor, havn't gone for a ride yet but have some comments
re behaviour.

After 15 minutes of running water temp was 135 vs the usual 195 by then. Oil
pressure seemed close to normal, meaning oil did warm up.

Wondering if that is normal temp to expect at warmup/idle. Gene... is that
how yours behaves?

It would stand to reason that with a restrictor one will have fluctuation
water temperature. Is that good? bad? doesn't matter?

I would think that it'll get warmer running, but it'll also move more water
and experience more airflow.

Hope to get it ready for a run this weekend. Got sidetracked building a
pressure bleeder for the brakes as I want to re-bleed. Actually I'm going to
bleed enough to change fluid as it colored somewhat.

Heinz
 
Heinz:

For whatever it's worth, up until last October I was running a 185 deg F
thermostat and then had to change out the water pump. At that time I put in
the recommended Robert Shaw 195 deg F thermostat.

With the 185 deg thermostat, my gauge would show ~190 - 195 deg at 60+ mph
regardless of the ambient temperature. Now with the 195 deg thermostat, the
gauge shows ~195 deg at 60 mph and climbs to ~205 deg at 65+ mph in over 65
deg F ambient temperature.

Checked the radiator for signs of deterioration and don't find any.

Now, I'm thinking of going back to the 185 deg thermostat.

Needless to say, I don't have much confidence yet with the new thermostat
and am curious to see what your experience with the restrictor will be.

Paul Bartz

From: Heinz Wittenbecher [mailto:heinz]
Sent: Tuesday, May 18, 1999 3:31 PM
Subject: GMC: First bout with restrictor instead of thermostat

Installed the restrictor, havn't gone for a ride yet but have some comments
re behaviour.

After 15 minutes of running water temp was 135 vs the usual 195 by then. Oil
pressure seemed close to normal, meaning oil did warm up.

Wondering if that is normal temp to expect at warmup/idle. Gene... is that
how yours behaves?

It would stand to reason that with a restrictor one will have fluctuation
water temperature. Is that good? bad? doesn't matter?

I would think that it'll get warmer running, but it'll also move more water
and experience more airflow.
 
> Heinz:
>
> For whatever it's worth, up until last October I was running a 185 deg F
> thermostat and then had to change out the water pump. At that time I put
in
> the recommended Robert Shaw 195 deg F thermostat.
>
> With the 185 deg thermostat, my gauge would show ~190 - 195 deg at 60+ mph
> regardless of the ambient temperature. Now with the 195 deg thermostat,
the
> gauge shows ~195 deg at 60 mph and climbs to ~205 deg at 65+ mph in over
65
> deg F ambient temperature.

That's probably pretty close to what I was getting. Perhaps a little hotter
on ambient, but I would see 205-208 in hot weather even at 55ish, but
towing. In the 60's and flat I think it stayed at 195.

I won't know until I actually get out there, but judging by 135 at idle it
means that the temp will probably go up as the fire gets bigger and then
when slowed down and perhaps in stop & go traffic, is it going to go back to
135ish or because it will have been heated up already will the temp be
somewhat constant until idling for longer. This may actually be favorable as
it might reduce heatsoak some and provide for somewhat gradual cooling.

Questions, questions, questions... I'll try and get some answers over the
weekend. Good excuse to go for a spin... as long as I can get it all back
together by then :-)

Have to leave next week for real so I better get my butt into gear and/or
reduce projects [g].

Heinz

>
> Checked the radiator for signs of deterioration and don't find any.
>
> Now, I'm thinking of going back to the 185 deg thermostat.
>
> Needless to say, I don't have much confidence yet with the new thermostat
> and am curious to see what your experience with the restrictor will be.
>
> Paul Bartz
>
> From: Heinz Wittenbecher [mailto:heinz]
> Sent: Tuesday, May 18, 1999 3:31 PM
> Subject: GMC: First bout with restrictor instead of thermostat
>
> Installed the restrictor, havn't gone for a ride yet but have some
comments
> re behaviour.
>
> After 15 minutes of running water temp was 135 vs the usual 195 by then.
Oil
> pressure seemed close to normal, meaning oil did warm up.
>
> Wondering if that is normal temp to expect at warmup/idle. Gene... is that
> how yours behaves?
>
> It would stand to reason that with a restrictor one will have fluctuation
> water temperature. Is that good? bad? doesn't matter?
>
> I would think that it'll get warmer running, but it'll also move more
water
> and experience more airflow.
>
>
 
I can't see any reason for a restrictor in the GMC motorhome. The engine and
coolant temperature will vary to much. Restrictors are used in race cars
where they are used for short duration, and they don't want to chance a
thermostat sticking and overheating the engine.

>First... apologies for the triple post re TS-30. Computer misbehaving.
>
>Installed the restrictor, havn't gone for a ride yet but have some comments
>re behaviour.
>
>After 15 minutes of running water temp was 135 vs the usual 195 by then. Oil
>pressure seemed close to normal, meaning oil did warm up.
>
>Wondering if that is normal temp to expect at warmup/idle. Gene... is that
>how yours behaves?
>
>It would stand to reason that with a restrictor one will have fluctuation
>water temperature. Is that good? bad? doesn't matter?
>
>I would think that it'll get warmer running, but it'll also move more water
>and experience more airflow.
>
>Hope to get it ready for a run this weekend. Got sidetracked building a
>pressure bleeder for the brakes as I want to re-bleed. Actually I'm going to
>bleed enough to change fluid as it colored somewhat.
>
>Heinz
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
> I can't see any reason for a restrictor in the GMC motorhome. The engine
and
> coolant temperature will vary to much. Restrictors are used in race cars
> where they are used for short duration, and they don't want to chance a
> thermostat sticking and overheating the engine.
>

Soooo.... does that mean Mr Mondello is off base on this one? and if so,
what does that do to all his other "recommendations"?

Just a'wondering whether to turn left or right.

Heinz

>
>

> >First... apologies for the triple post re TS-30. Computer misbehaving.
> >
> >Installed the restrictor, havn't gone for a ride yet but have some
comments
> >re behaviour.
> >
> >After 15 minutes of running water temp was 135 vs the usual 195 by then.
Oil
> >pressure seemed close to normal, meaning oil did warm up.
> >
> >Wondering if that is normal temp to expect at warmup/idle. Gene... is
that
> >how yours behaves?
> >
> >It would stand to reason that with a restrictor one will have fluctuation
> >water temperature. Is that good? bad? doesn't matter?
> >
> >I would think that it'll get warmer running, but it'll also move more
water
> >and experience more airflow.
> >
> >Hope to get it ready for a run this weekend. Got sidetracked building a
> >pressure bleeder for the brakes as I want to re-bleed. Actually I'm going
to
> >bleed enough to change fluid as it colored somewhat.
> >
> >Heinz
> >
> >
> >
> >
> >
> Tom & Marg Warner
> Vernon Center NY
> 1976 palmbeach
> "The beautiful Mohawk Vally"
>
>
 
Guys, All MY GMC manual says about the tstat is that use of units ABOVE 195
degrees is NOT recommended. The implication of that to me is that use of
LOWER temp tstats would be OK so long as the engine operates properly.
When I get to that point, I think I'm gonna change it out to a 170 or so and
see how things go. From a wear perspective, I'm guessing that -- within
reason -- cooler is better.
Dick 75 PB in Atlanta

>Heinz:
>
>For whatever it's worth, up until last October I was running a 185 deg F
>thermostat and then had to change out the water pump. At that time I put in
>the recommended Robert Shaw 195 deg F thermostat.
>
>With the 185 deg thermostat, my gauge would show ~190 - 195 deg at 60+ mph
>regardless of the ambient temperature. Now with the 195 deg thermostat, the
>gauge shows ~195 deg at 60 mph and climbs to ~205 deg at 65+ mph in over 65
>deg F ambient temperature.
>
>Checked the radiator for signs of deterioration and don't find any.
>
>Now, I'm thinking of going back to the 185 deg thermostat.
>
>Needless to say, I don't have much confidence yet with the new thermostat
>and am curious to see what your experience with the restrictor will be.
>
> Paul Bartz
>
>From: Heinz Wittenbecher [mailto:heinz]
>Sent: Tuesday, May 18, 1999 3:31 PM
>Subject: GMC: First bout with restrictor instead of thermostat
>
>Installed the restrictor, havn't gone for a ride yet but have some comments
>re behaviour.
>
>After 15 minutes of running water temp was 135 vs the usual 195 by then. Oil
>pressure seemed close to normal, meaning oil did warm up.
>
>Wondering if that is normal temp to expect at warmup/idle. Gene... is that
>how yours behaves?
>
>It would stand to reason that with a restrictor one will have fluctuation
>water temperature. Is that good? bad? doesn't matter?
>
>I would think that it'll get warmer running, but it'll also move more water
>and experience more airflow.
>
>
 
>
> Hope to get it ready for a run this weekend. Got sidetracked building a
> pressure bleeder for the brakes as I want to re-bleed. Actually I'm going to
> bleed enough to change fluid as it colored somewhat.

Heinz,

How about posting some pictures of the pressure bleeder when you get a
chance?

Patrick
- --
Patrick Flowers
Mailto:patrick

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
Heinz I think you have to remember that Mondellos primary focus is on
building engines for racing. Most of the parts he sells is for that market.
He does however build engines for the GMC motorhome and sells special parts
such as real heavy duty torque converters for them also.

In the case of many of the parts he sells, it takes a certain amount of
expertise to understand why they are used and when, and the results that you
are trying to get. Remember he sells for the most part to a sophisticated,
very focused, market (olds 455 crowd)

I have a copy of an article that he wrote "Cool Tricks by Joe Mondello". In
it he says:

"I recommend a 180 degree thermostat for all non-smog control applications
and a 195 degree thermostat for all smog control applications. It is not
recommended to remove your thermostat. If you do, you should at least use a
Moroso 1" restrictor washer in its place. I also recommend a 15-17#
pressureized radiator cap. Also a plugged up air cleaner cartridge or
exhaust system, especially stock-type chambered mufflers will make your
engine run hot"

Notice that he does not recommend that you remove your thermostat.Notice
also that he recommends a 15-17# radiator cap WHICH WE WOULD NOT WANT TO
USE. So bottom line is that whenever you talk to Mondellos, make very, very
sure that they understand that you are buying parts for the GMC motorhome.

Put your 180 degree thermostat back in, take out the restrictors and relax.



>
>> I can't see any reason for a restrictor in the GMC motorhome. The engine
>and
>> coolant temperature will vary to much. Restrictors are used in race cars
>> where they are used for short duration, and they don't want to chance a
>> thermostat sticking and overheating the engine.
>>
>
>Soooo.... does that mean Mr Mondello is off base on this one? and if so,
>what does that do to all his other "recommendations"?
>
>Just a'wondering whether to turn left or right.
>
>Heinz
>
>
>>
>>

>> >First... apologies for the triple post re TS-30. Computer misbehaving.
>> >
>> >Installed the restrictor, havn't gone for a ride yet but have some
>comments
>> >re behaviour.
>> >
>> >After 15 minutes of running water temp was 135 vs the usual 195 by then.
>Oil
>> >pressure seemed close to normal, meaning oil did warm up.
>> >
>> >Wondering if that is normal temp to expect at warmup/idle. Gene... is
>that
>> >how yours behaves?
>> >
>> >It would stand to reason that with a restrictor one will have fluctuation
>> >water temperature. Is that good? bad? doesn't matter?
>> >
>> >I would think that it'll get warmer running, but it'll also move more
>water
>> >and experience more airflow.
>> >
>> >Hope to get it ready for a run this weekend. Got sidetracked building a
>> >pressure bleeder for the brakes as I want to re-bleed. Actually I'm going
>to
>> >bleed enough to change fluid as it colored somewhat.
>> >
>> >Heinz
>> >
>> >
>> >
>> >
>> >
>> Tom & Marg Warner
>> Vernon Center NY
>> 1976 palmbeach
>> "The beautiful Mohawk Vally"
>>
>>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
It'll still make me very nervous about any future dealings with Mondello,
which means it will become a parts source only and I'll probably use others
as part of justifying the paying of premium prices is to get good advice.

The bottom line being that I identified myself as 455 GMC user right away to
the "Tech Guy" as they refer to him.

That being the case, the restrictor should not have even been mentioned or
mentioned with the qualifier taht it's for racing use.

Very disturbing and hence I will re-evaluate my dealings with Mondello for
advice and recommendations.

I feel that if they want to do racing and GMC's they should have internal
checks in place to assure no accidental cross-over of advice and
recommendations as it can become downright inconvenient if not dangerous.

That said... and never having used a 180, can someone please give a
partnumber for a quality thermostat. The real thing please... not NAPA or
equivilant.

TIA - Heinz

> Heinz I think you have to remember that Mondellos primary focus is on
> building engines for racing. Most of the parts he sells is for that
market.
> He does however build engines for the GMC motorhome and sells special
parts
> such as real heavy duty torque converters for them also.
>
> In the case of many of the parts he sells, it takes a certain amount of
> expertise to understand why they are used and when, and the results that
you
> are trying to get. Remember he sells for the most part to a sophisticated,
> very focused, market (olds 455 crowd)
>
> I have a copy of an article that he wrote "Cool Tricks by Joe Mondello".
In
> it he says:
>
> "I recommend a 180 degree thermostat for all non-smog control applications
> and a 195 degree thermostat for all smog control applications. It is not
> recommended to remove your thermostat. If you do, you should at least use
a
> Moroso 1" restrictor washer in its place. I also recommend a 15-17#
> pressureized radiator cap. Also a plugged up air cleaner cartridge or
> exhaust system, especially stock-type chambered mufflers will make your
> engine run hot"
>
> Notice that he does not recommend that you remove your thermostat.Notice
> also that he recommends a 15-17# radiator cap WHICH WE WOULD NOT WANT TO
> USE. So bottom line is that whenever you talk to Mondellos, make very,
very
> sure that they understand that you are buying parts for the GMC motorhome.
>
> Put your 180 degree thermostat back in, take out the restrictors and
relax.
>
>
>

> >
> >> I can't see any reason for a restrictor in the GMC motorhome. The
engine
> >and
> >> coolant temperature will vary to much. Restrictors are used in race
cars
> >> where they are used for short duration, and they don't want to chance a
> >> thermostat sticking and overheating the engine.
> >>
> >
> >Soooo.... does that mean Mr Mondello is off base on this one? and if so,
> >what does that do to all his other "recommendations"?
> >
> >Just a'wondering whether to turn left or right.
> >
> >Heinz
> >
> >
> >>
> >>

> >> >First... apologies for the triple post re TS-30. Computer misbehaving.
> >> >
> >> >Installed the restrictor, havn't gone for a ride yet but have some
> >comments
> >> >re behaviour.
> >> >
> >> >After 15 minutes of running water temp was 135 vs the usual 195 by
then.
> >Oil
> >> >pressure seemed close to normal, meaning oil did warm up.
> >> >
> >> >Wondering if that is normal temp to expect at warmup/idle. Gene... is
> >that
> >> >how yours behaves?
> >> >
> >> >It would stand to reason that with a restrictor one will have
fluctuation
> >> >water temperature. Is that good? bad? doesn't matter?
> >> >
> >> >I would think that it'll get warmer running, but it'll also move more
> >water
> >> >and experience more airflow.
> >> >
> >> >Hope to get it ready for a run this weekend. Got sidetracked building
a
> >> >pressure bleeder for the brakes as I want to re-bleed. Actually I'm
going
> >to
> >> >bleed enough to change fluid as it colored somewhat.
> >> >
> >> >Heinz
> >> >
> >> >
> >> >
> >> >
> >> >
> >> Tom & Marg Warner
> >> Vernon Center NY
> >> 1976 palmbeach
> >> "The beautiful Mohawk Vally"
> >>
> >>
> >
> >
> >
> Tom & Marg Warner
> Vernon Center NY
> 1976 palmbeach
> "The beautiful Mohawk Vally"
>
>
 
>
> Mondello's recommends the restrictor for GMC applications

Gene,

Can you give me an idea as to temp behaviour.

Am I correct in the following assumptions:

Lower than 180 normal until actually driving?
What are your temps in the city?
On the highway?
When Outside Air in the 90's?
After a western downhill run?

Even a guesstimate such as lower than, higher than would be helpful (sorry,
I don't recall the type of temp guage you have)

As long as the temperatures stay reasonably constant once on the move I
think it may actually be better to have slower warm ups and more gradual
cooldowns, and the restrictor may provide that.

I am going to leave it in, at least for my test run which will hopefully be
this weekend. Then I'll decide if a longer run, I.e. trip is warranted.

I will however be carrying a 180 degree in addition to my regular 195 spare
along with gasket goop and wrenches :-) hopefully that'll be the only thing
I'll be taking apart on the next trip. [g]
 
Heinz:

The "recommended" thermostat is a Robert Shaw, p/n 330-195, so I guess you'd
want to try a p/n 330-180. AutoZone carries them.

Paul Bartz

From: Heinz Wittenbecher [mailto:heinz]
Sent: Wednesday, May 19, 1999 11:54 AM
Subject: Re: GMC: First bout with restrictor instead of thermostat

That said... and never having used a 180, can someone please give a part
number for a quality thermostat. The real thing please... not NAPA or
equivilant.
 
Thank you much, Paul.

> Heinz:
>
> The "recommended" thermostat is a Robert Shaw, p/n 330-195, so I guess
you'd
> want to try a p/n 330-180. AutoZone carries them.
>
> Paul Bartz
>
> From: Heinz Wittenbecher [mailto:heinz]
> Sent: Wednesday, May 19, 1999 11:54 AM
> Subject: Re: GMC: First bout with restrictor instead of thermostat
>
> That said... and never having used a 180, can someone please give a part
> number for a quality thermostat. The real thing please... not NAPA or
> equivilant.
>
>
 
Ok Heinz I made a mistake, and Gene is correct on Mondello installing
restrictors in all of his engines. I quoted from Joe Mondellos article "Cool
Tricks" in my previous post and since than he has changed his advise. Talk
about the power of the Net! Called him minutes ago in California and we
discussed the restrictors versus thermostats. In the last 2 years he has
witnessed a major upturn in cracked heads and manifolds in motorhomes due to
sticking thermostats and other causes. He reasons it is from several things
including minerals in the water, and reformulated gas, and the decrease in
the quality of thermostats. Only exception is he recommends thermostats in
realy cold climates.

now thats from the horses mouth

>>
>> Mondello's recommends the restrictor for GMC applications
>
>Gene,
>
>Can you give me an idea as to temp behaviour.
>
>Am I correct in the following assumptions:
>
>Lower than 180 normal until actually driving?
>What are your temps in the city?
>On the highway?
>When Outside Air in the 90's?
>After a western downhill run?
>
>Even a guesstimate such as lower than, higher than would be helpful (sorry,
>I don't recall the type of temp guage you have)
>
>As long as the temperatures stay reasonably constant once on the move I
>think it may actually be better to have slower warm ups and more gradual
>cooldowns, and the restrictor may provide that.
>
>I am going to leave it in, at least for my test run which will hopefully be
>this weekend. Then I'll decide if a longer run, I.e. trip is warranted.
>
>I will however be carrying a 180 degree in addition to my regular 195 spare
>along with gasket goop and wrenches :-) hopefully that'll be the only thing
>I'll be taking apart on the next trip. [g]
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Power of the net indeed.
I was hoping you'd get directly to the horse :-) and set us straight [g].

I guess that'll favor leaving it in for the first trip at least and to
report temps to the net so that everyone can decide for themselves.

Thanks again for the extra digging and adding a little fresh straw to the
stable.

Heinz

> Ok Heinz I made a mistake, and Gene is correct on Mondello installing
> restrictors in all of his engines. I quoted from Joe Mondellos article
"Cool
> Tricks" in my previous post and since than he has changed his advise. Talk
> about the power of the Net! Called him minutes ago in California and we
> discussed the restrictors versus thermostats. In the last 2 years he has
> witnessed a major upturn in cracked heads and manifolds in motorhomes due
to
> sticking thermostats and other causes. He reasons it is from several
things
> including minerals in the water, and reformulated gas, and the decrease in
> the quality of thermostats. Only exception is he recommends thermostats in
> realy cold climates.
>
> now thats from the horses mouth
>

> >>
> >> Mondello's recommends the restrictor for GMC applications
> >
> >Gene,
> >
> >Can you give me an idea as to temp behaviour.
> >
> >Am I correct in the following assumptions:
> >
> >Lower than 180 normal until actually driving?
> >What are your temps in the city?
> >On the highway?
> >When Outside Air in the 90's?
> >After a western downhill run?
> >
> >Even a guesstimate such as lower than, higher than would be helpful
(sorry,
> >I don't recall the type of temp guage you have)
> >
> >As long as the temperatures stay reasonably constant once on the move I
> >think it may actually be better to have slower warm ups and more gradual
> >cooldowns, and the restrictor may provide that.
> >
> >I am going to leave it in, at least for my test run which will hopefully
be
> >this weekend. Then I'll decide if a longer run, I.e. trip is warranted.
> >
> >I will however be carrying a 180 degree in addition to my regular 195
spare
> >along with gasket goop and wrenches :-) hopefully that'll be the only
thing
> >I'll be taking apart on the next trip. [g]
> >
> >
> >
> >
> >
> Tom & Marg Warner
> Vernon Center NY
> 1976 palmbeach
> "The beautiful Mohawk Vally"
>
>
 
Myth killed!

Appologies to Joe Mondelo.

Ingore previous post. (digest delay)

Keep us posted, Heinz. We're a lot more interested now.

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)
 
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