Hi All
Getting ready for some engine work and I'm thermostat shopping. Going with a high flow water pump and want a high flow stat as well. I see the Be-Cool stat selling in Summit for about twenty bucks while the Mr. Gasket and Milodon are about eight-ten bucks.

The only difference I see on the Be-Cool thermostat is that the description states:

"However, perhaps their most important feature is that if they should ever fail, they will fail in the open position"

Don't all high flow stats have this feature or is it only the Be-Cool and that's why the higher price??

Thanks!

I don't know the answer. But I run a hi flow modified (3 holes drilled in it) robert shaw. I got mone at Stewart when I bought my Hi-flow water pump. Accorcding to Stewart, a hi flow t-stat must be run with a hi-flow pump

http://www.stewartcomponents.net/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=Therm

I recommend these... $10 at Summit or Jegs.. http://go.mrgasket.com/ProductDetails.aspx?brandId=0&productID=20981&majID=300&minID=&selection=7&minselection=

The "holed" versions of these are NOT necessary for most high flow pumps. Stewart's recommends for Stage II and up models because they have no internal bypass. Stage I can run the standard. The problem with the "holed" versions is that your motor never gets to the correct operating temperature and makes the heater useless in most cases. They also assimilate that at higher RPMs with their non bypassed pumps this is necessary for proper operation.

I use Tuffstuff pumps exclusively and flog them regularly at 6800 rpms plus I am overdriving these pumps by 15% as well. That's equivalent to near 8000 rpms! They produce very good results and nary a problem with the regular high-flowing "balanced" thermostats as mentioned above.

Just my two sense.

[ 02-21-2005, 06:06 PM: Message edited by: HOTRODSRJ ]

You are paying for the fail open not fail closed feature

All high flow "balanced" style thermostats fail in the open position including the less expensive Mr Gasket models that have been provided.

The "holed versions" of t-stat are to provide additional path for the coolant until the t-stat opens, it also helps getting rid of any trapped air pockets in the cooling system.
It does take a little longer for the cooling system to reach operating or t-stat temp, and they maynot be really a good idea on cars running in the winter?? There is no problem reaching operating or t-stat temp. and have never heard of a problem with the heater or defroster.
BBC water pumps do not have a internal bypass, just an exterior bypass hose. High flow t-stats should be run with high flow pumps to insure you get full turbulant flow from your pump. Stewart strongly suggests hi flow t-stats for any performance application.

I would like to clarify more on Wayner's comments please.

First, I agree that high flow "balanced" thermostats are the best in ALL applications really because they are far more accurate, do not restrict flow and the best feature...do not stick in the closed position. They also have the side benefit of seeming to aleviate more air that might get trapped at the thermostat/thermostat housing for whatever reason (it's my theory that it's more about the thermostat housing design than thermostat), but generally when the thermostat opens the air present should relieve itself anyway. Bulbous style housings with stock thermostats I believe trap air by design making for finicky behaviour of the thermostat..so go figure. I don't see why one would want to use anything else in my opinion for all your applications..even everyday drivers. Just $10!

Secondly, once again about the "holed" or modified versions of the high flow thermostats (I have received numerous emails about this....and it seems there is still confusion about this?) that Stewart sells and/or recommends. I will try to put this to rest once and for all. This is also the "official" Stewart's line as well...so we are both in concert here.

First...Stewart's really only recommends their Stage III and IV pumps for racing and NOT for the street or strip/street! Secondly, Stewart only recommends the "holed" version of their thermostats for Stage II short pumps only and/or any pump that does not have a internal or external by-pass path. So, the excludes their Stage I models (as well as other manufacturers equipped with internal/external bypasses..which are most of them) and any big block that you have the bypss installed....you can run the regular high flow models that have been mentioned here in previous posts. They also agree that the "holed versions" will/can compromise operating temperatures to a degree and especially heater function. They absolutely will not recommend a holed version in moderate temperate climates just for this reason utilizing any pump with internal by-passes.

I can offer anecdotal evidence that I ran "holed" versions of these themostats for a couple of years and even in Atlanta in the dead of summer and could never fully achieve the correct cycling/operating temperature of the thermostat. This is magnified tremendously in the winter of course and in many cases will render your heater/defroster useless. I have had numerous emails about this very problem over the last few years as the product caught on..and have went back to just recommending the stock high performance thermostat INSTEAD of the "holed" or modified versions under the conditions set forth above.

Jack Wilson, the tech guru of Stewart's, will always ask for your application for any of their pump products and will mirror my comments here.

Now...is there anything wrong with running "holed" versions when you don't need them. The answer is kinda iffy. One, the motor doesn't come up to optimum temperature quickly, if ever. Two, if your motor won't reach at least 170 degrees, you risk increased wear (due to low oil temps), poorer atomization of fuel and the accummulation of moisture in the crankcase which is a no-no as well. The magic number is around 170-180 degrees operating temperature. So, that is the negatives involved. If you can get your motor to the correct operating temps using the modified versions...more power to ya! No biggie!

I hope this clears a few questions up.

Originally posted by HOTRODSRJ:
I would like to clarify more on Wayner's comments please.


I hope this clears a few questions up. Thank you for clarifing my post, although I didn't think my post needed it, we are all entitled to post our experieances/opinions?? What questions needed clearing up?? Who raised them??

I respect your opinions, however, my experieance/results with holed thermostats differs from yours.

Wayner.......no disrespect meant in my post to follow yours and moreover the clarification was directed at all the posts content(s) including my own ramblings and NOT specifically yours. And I don't doubt your experiences at all and you are certainly welcome to post them as far as I am concerned. I think you have read this wrong from me. Actually I think its interesting that you don't have an issue with either a heater problem (since I remember you are in Canada) and/or keeping proper operating temperatures at all. This is more an issue with 180 degree or below cycling temps and esp 160s which you shouldn't be running anyhow. This could be that your cooling system is near the "wide-open" mode all the time and is perfect for your environment.

For your information...I received five separate authored emails (NOT PM) that asked the basic question about using "holed" versions of thermostats and which to use. They had referred to this thread. Instead of emailing all of them back (and more to come if any), I referred them to this site where I told them I would do another follow-up addressing the exacting issues.

After rereading the entire thread I could see how one could be corn-fused at some of the recommendations, hence my last post.

You coincidentally did make the statement that you never heard or observed the issue of the "heater" problem with the modified versions when in fact I hear it all the time. This was in fact the exact question/content of all four emails. And, Stewart does NOT recommend the "holed" version of the thermostat with most, if any street application (with by-passed waterpumps) according to Jack Wilson of Stewart's. I rechecked with him again before writing the last post to make sure my memory served me on this. I, for one, do not see any benefit in running "holed" versions of these with by-passed pumps. But no biggie as I said as long as everything else is in line.

I think you would agree to answer who emailed me would be a little bit private don't ya think... since if they wanted to ask the question publically they could have just posted it here and/or didn't want to bother....or whatever....I really don't care...but, I guess since they (the five emailers) thought that I write tech articles professionally and for several media outlets (especially on automotive cooling) they felt comfortable with asking me to provide a clearer answer for them.

That's all nothing more nothing less.

Wow, this is good! I like the info here on this particular subjuct. Last weekend I removed a 190* Robert Shaw t-stat and replaced it with a 180* standard brand X.

My operating temps with the Robert Shaw were 195* at idle and around 200* normal driving up to 205* under pulls up long hills and in mid July.

I run a 7 blade hard fan with a regular duty clutch. Everything is new including the radiator. The sending unit for the guage is in the left head, not the intake.

After putting in the standard brand X 180* my normal operating temps went to 200* on up to 205*-210* underload. I do not like that at all so I ordered a BeCool 180* high flow from Jegs part number 134-78001. This one here:
BeCool Thermostats (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=146676&prmenbr=361)
It will be here Friday and I will get to put it in this weekend. As soon as the weather clears I will take it for a test drive. I have my fingers crossed it will hold my normal temps around 180*
graemlins/beers.gif

I really don't think temperatures of 210 under load up hills or towing is bad necessarily....if it stabilizes there. I know alot of people think they have to have right on 180 degrees to be comfy...but not so.

Plus, operating beyond the cycling range of your thermostat (ie...temperatures of 210 with a 180 thermostat) is a deficiency in the cooling systems ability in some corner? I would say that an investment in a heavy duty flex fan series from Derale such as a part number 17218 is a better investment. This would increase airflow at idle about 33% and would not give up as much air as the clutch would when going uphill as well.

Try it...you will see that it will work. I suspect that the BECOOL thermostat will be no different in similar operating conditions.

Thanks Steve, no problem here. You make some good points.
I do feel that automotive cooling is not an exacting science, there is just to many variables. Air and coolant temps and flow, water pump flow, antifreeze concentration and type, engine spark timing, system pressure, amount of coolant bypass, length of hoses etc... that affect each cooling system and a change in 1 factor affects results of others.
That is why I post my opinion/experieance, for other members to read and compare and make informed decisions based on info from several sources, not just 1, because we know that what worked in 1 vehicle to keep it cool, maynot work in another, just too many variables.
And in no way am I questioning your credentials, wealth of experieance or knowledge. graemlins/thumbsup.gif

Wayner........I agree more heads are better than one!

Ok guys I got my new BeCool t-stat in today and it works perfectly! At start up temps went to 195* and the t-stat is open by then. It drops to 185* then levels at 190* AND no fluctuating of the temp. Stays steady all the time. I am glad I bought the BeCool hi flow t-stat.

Some very good opinions out there
question ??
If the engine had no problem transfering heat to the coolent ... then why would we want to push it trough the radiator faster then we could give the radiator a chance to do its job with a high flow water pump ? isnt there a window of cooling efficency that the big three calaculated .. I here two fast.. or to slow.. is a deturent to cooling effiency ?

graemlins/beers.gif

This is a common misunderstood subject and source of myths abound! I would like to offer some help.

Simply put,.....the higher the flow the more BTUs get transfered...or at least that's the way all the physics books relates it...and my experience in designing such systems and certainly within the constraints of the automotive cooling system which is a closed-loop system. However, if you increase the flow where you are producing cavitation and unwanted/unproductive eddy currents and create "hotspots" where nucleate boiling can start, then that's a different science all together due to MECHANICAL DESIGN of the cooling jackets, NOT FLOW/heat transfer issues. And believe me, there are plenty of older style heads with poor water jacket design as well as old pump designs that introduce unwanted air to the system. MOre modern designs take much higher flow rates into account to make the cooling system that more efficient. Generally speaking, high volume pumps will offer much improved heat carrying capacity in your cooling system. But, your radiator has to be efficient enough to get rid of the increase in heat transfer over the time given.

The radiator actually gets more efficient at higher flow rates too. All equations relating to such show a linear BTU transfer relationship with increase in flow rates thru the system, at both transport points. Also,think about this..... as you slow or retard the flow in any closed-loop system, the source will of course will continue to heat the coolant transfer media towards it's corrected vapor point (boiling point at rated pressure). The coolant will lose some of its ability to move heat as it approaches this point, so it will take more volume to essentially move the same amount of heat per unit volume. The excess heat gets deposited in the metal of the engine and can domino into "overheating" hell.

Also, the increase flow rates increase turbulence and stymies lamimar flow, this too makes the system very efficient making sure every molecule of coolant is evenly filled with heat and disperses it prudently at the radiator surface as well. One other benifit is that increase in flowrates in a fixed volume system also increases the "working pressure" of the system. Older style systems used to produce less than 7lbs at the radiator cap. Now newer systems with higher volumes and higher flow rates and pressures can easily make over 12 lbs of pressure at the cap. This is a reason to upgrade your caps when upgrading your other components.

A more simplistic analogy would be something we all do! When you spoon up a hot soup or food you blow on it to cool it off more rapidly or increase the flow of the cooling media. Water works the very same way in your radiator. It is also the reason our hearts will beat faster in hotter conditions (and conversely in colder conditions) to bring cooling to body from the radiator (the skin and lungs). Basic physics at play here to.

HOTRODSRJ

Thanks for the clarification on this. The application I described for my car in previous posts in this thread work best for me. I know that it may not be the best for the next guy and his engine set up because there are so many variables in engines.

Thanks!!

Originally posted by alumitech:
isnt there a window of cooling efficency that the big three calaculated .. I here two fast.. or to slow.. is a deturent to cooling effiency ?

graemlins/beers.gif The big "3" were desigening a cooling system for stock engines, make any changes to the engine or any system that would affect air or coolant flow and their calculations are out the window.

Steve (HOTRODSRJ), has taken the time to provide a great in depth explanation to why increased flow is beneficial in most cases.

Took my car for a small road trip tonight and I really liked the way the BeCool T-stat worked. There was no fluctuating of the water temp at all. Once the motor came to operating tempurature, it stayed steady at 185* either driving through town at slow speeds or highway driving at 55 MPH. This will be great for this summer going to shows and parades.