fbekholden.com

Hullo Fellow Holden Enthusiasts

Could somebody please assist me?

I've read previous posts regarding thermostats.

My car has a standard grey (FB) motor.

It seems from what I've read on these posts that Tridon would be the best one. Am I right here?

I'm a little confused, though, when it comes to the part numbers, such as "conventional" TT1-160, TT1-167, etc.

I don't think I'd need a "high flow" type, as from what I've read they're more for high-load conditions, which my car wouldn't be running under.

The last dealings I had with thermostats was in 1979, when the unit in my HQ 308 stayed closed, with disastrous results.

I'd be very grateful for any information given.

Regards
Apex

found this


http://www.fbekholden.com/forum/viewtop ... don#p95681

If you’ve got a used one one you can test it’s function on the stove top saucepan with the milk thermometer from your kitchen. Should be fully open at 82C.



Tridon are as good as any.


FB ute fixer upper, EK van on rotisserie

Hi, and congrats on your fifth post.... welcome aboard, by the way.

I have used Tridon and also CPC (spelling)... I really don't have a preference.
The main thing is that they operate at the correct temperature...

Not long after getting my old bus in 1972, I removed the temperature idiot light sensor from the head and fitted a capillary gauge unit.
I have always been a gauge "watcher".. and I understand how the thermostat readings relate to how the cooling system is functioning.

I have not noticed any difference between the two different types that I have fitted... with both my old greys - I used a 167 F or 74 C thermostat...
In operation, temperature continued to rise until reaching just over this temp - then quickly dropped by about 20 deg with the cold water from the radiator rushing into the block, and reaching the head where the sensor is located.

We must understand, that it is only the sensor's location which gives indication of the temperature at that point... not necessarily where the thermostat is located...

Do not ever be tempted to run without a thermostat... unless it fails to open. They are also positioned in the coolant flow path to restrict the amount of coolant "rushing " through the radiator.. without a thermostat in the path, too much flow can reduce the amount of efficient heat transfer that the radiator can provide... and warm coolant can again be returned to the engine block... also, we can get "over-cooling" which, from what I have been told by those in the industry - can lead to glazing of the bores... failing to allow the block to reach operating temperature...

The important thing to remember about all components in the cooling system, is to use a coolant and change/flush it at two yearly intervals.
It will keep all components in serviceable condition, which includes the water pump, thermostat and affords the best resistance to scaling and rust developing in the passages, welch plugs and radiator.... the radiator, is the "filter" of the entire system... any loose scale etc will be trapped in the top tank of the radiator.. or can also get lodged in the fine tubes of the element....
Removing the thermostat every second or third change of coolant and giving the entire system a "reverse" flush will go a long way to pumping out any build up of scale in the radiator... don't be tempted to use too high a pressure with the garden hose or in conjunction with compressed air... those tubes are only soldered to both the top and lower tanks... fracture one, and you not only loose coolant - but will also loose vital radiator system pressure... which, in our case is around 7 psi... raising the boiling point from 212 F or 100 C to around 220 F or 107 C....

I never allowed my old greys to run above 190 F.... if they got that high, it was likely they would go to boiling point..
Usual running on a hot day without towing anything resulted in running around the 175 mark under load..... just 10 above the setting of the thermostat opening.

If i was seeing these sort of figures - I knew my system was in pretty good nick.... if I saw higher figures - I'd be looking at an obstruction, or keeping a closer eye on the thermostat opening temps....

Forgot to add... I opted for the higher 167 F thermostat to keep coolant temp up when opening the heater valve in winter... I wasn't about to swap for a 160 F one seasonally.. both grey motors worked perfectly with the 167 thermo's... 7 deg might not seem a lot, but with a heater in operation during winter, the temp usually ran 5 deg lower than the setting.... so, we'd be running around at 150 and less on really cold days....

I run a higher thermo in the red motor - but you are not asking about reds..... grey's like to run around the 170 mark, seems they are quite happy slightly above and below that temp... they don't like to run hot - they leak too much oil and the tappets close up too much... with a red, the leakage issue is much less and the hydraulic tappets take care of rocker clearances....

Further, it is my practice to carry not only a spare fan belt, but also a spare thermostat and gasket...
And, on another suggestion - if you are going to carry a spare fan belt around - fit a new one and carry another new one as a spare.
I don't know how many times I look into the boot of cars at shows and see a brand new fan belt tucked away in the side panel... and look under the hood and see a belt which is either cracked or frayed.... it annoys me greatly.

Fan belt tension is another - I think deflection is around 5/8".. I see way too many belts done up much tighter than this... putting undue stress on the water pump and generator bearings.... keep the specified deflection and you will enjoy long service life from all three.... belt, water pump and generator...


Hope this helps..

frats,
Rosco

From the Heater Guide:

The thermostat is an engine coolant temperature control valve assembly that prevents circulation of coolant through the radiator until a predetermined engine temperature is achieved. This allows the engine to reach its operating temperature generally within the first ten minutes of operation. Upon reaching the predetermined temperature, the thermostat opens and allows coolant to flow through the radiator. This is especially important for stop/start type driving, short journeys, operation in cold weather or where the cooling system has excess capacity. In these cases the thermostat may not be fully open. If a heater is fitted it is permissible to use an thermostat with a “Start to open” temperature of up to 173ºF (78.3ºC) to improve the heater performance. However, should excessive detonation (pinging) be detected or if hard driving is employed, it is advisable to use the standard thermostat with a “Start to open” temperature of 160ºF (71ºC). Bearing in mind that modern fuels are significantly higher in octane than the original FB/EK Holden fuel (current unleaded petrol is 91RON and premium petrol is 95RON versus the original FB/EK Holden fuel of 86RON), detonation is less of an issue.

Grey motors use a non-bypass thermostat fitted with a jiggle pin that enables the system pressure to be stabilised so that the thermostat opens more easily. The jiggle pin also allows air pockets to move past the thermostat and the temperature to be regulated more efficiently. For motors where the cooling capacity is marginal, using a high flow thermostat may improve cooling system performance. They have a larger valve and allow approximately 30% more coolant flow than standard type thermostats. You will not "overcool" an engine with a thermostat in it. The thermostat simply shuts more. You will not get more cooling by installing a thermostat... the "water needs to slow down in the radiator" story is a myth.

The following TRIDON thermostats are suitable for this advice, and are readily available from most auto-parts stores:
Part number Type Flange diameter Opening temperature
TT1-160 Conventional 54mm 71ºC (160ºF)
TT2000-160 High flow 54mm 71ºC (160ºF)
TT1-167 Conventional 54mm 75ºC (167ºF)
TT1-170 Conventional 54mm 77ºC (171ºF)
TT2000-170 High flow 54mm 77ºC (171ºF)
Note that the corresponding TRIDON thermostat gasket is part number TTG29U.

If it was mine, I would go to SuperCheap/Repco/Autobarn and order a TT2000-160 thermostat and a TTG29U gasket. Same ones that I run in my greys.

Cheers,
Harv

Harv wrote: ↑Thu Apr 16, 2020 5:46 am From the Heater Guide:

the "water needs to slow down in the radiator" story is a myth.

Hmmmm.... I guess who ever wrote this has some authority - I am not disputing it, but firmly believe that even a stuck open thermostat should be left in the the housing rather than run without one....
I have explained my reasoning - I would very much like to see the engineers' justification for stating that a thermostat which restricts flow does not improve/retain acceptable flow rate vs running without one in situ...

I must check with the factory workshop manual.. or, is it from there that this nomenclature is derived, Harv...?

And yes, I believe the thermostat you suggest to be the most appropriate... a higher operating temperature, and a higher flow rate - it can 'throttle" down flow rate when needed as temperature reaches the lower threshold...

frats,
Rosco

Yep I would have to disagree with the you need to slow the water down is a myth.

I have a high revving little 283 and it used to overheat constantly until I restricted the flow in the radiator with a Moroso restrictor plate.

My situation was the high revs was pumping the water around to fast for it to cool off in the radiator with no thermostat. I also had some reduced size pulleys installed and that helped as well.

The only thing I couldn't prove is weather the water was cavitating or not with the high rpm of the pump and or low pressure spots in the system but i will never know as my problem was solved !!

Greg

Thank you all very much, 62ekute, Errol62, rosco, Harv and EK283 (Greg), for your informative and well-written descriptions.
I've learned a lot, and am now quite confident to go out and buy.
Regards

Rosco, thanks also for your welcome!

Apex.

Just a thought, if you are mucking around with thermostats. The top housings can corrode away over the years. I got this replacement one on Gumtree a while ago. It has an o ring seal, eliminating need for as gasket seal. This is a later red motor style but you get the idea.

Sent from my SM-G973F using Tapatalk

Thanks, great idea!

EK283 wrote: ↑Thu Apr 16, 2020 11:55 am Yep I would have to disagree with the you need to slow the water down is a myth.

i will never know as my problem was solved !!

Greg

I'd like to see something from a technical department or system engineer before I dispel my belief, Greg...

Yes, it could have been locally cavitating... in the true sense of the word... that is, boiling at below ambient temperature...
It is more likely to have been ventilating, ..... when it makes "air" bubbles..... and we get hot pockets where contact with the coolant is lost.

You rectified the issue - and that's probably all that matters here...
I continue to hold my belief that the thermostat restricts flow through the radiator and affords a more efficient transfer of heat from the coolant through the fins and tubes of the element...

On a side note, without a thermostat in the system... it is also my opinion that if coolant temperature cannot be kept below slightly higher than normal - there is every likelihood that it will continue to climb.... the entire contents of the coolant is at or above that temperature..... there is nothing "cold" in reserve from the bottom of the radiator which has been pre-cooled to quench this rising heat...

I offer these opinions as a lay man - I have absolutely no qualification nor authority to make them, other than "QBE"... "qualified by experience"...

frats,
Rosco

You will not get more cooling by installing a thermostat..... My belief.

Running an otherwise adequate functional cooling system without a thermostat will cause the motor to run at a cooler than designed operating temperature under normal operating conditions, and the engine will only achieve correct temperature under extreme conditions. Within limits, and eliminating any gas or air from the system, the faster the coolant flows the more efficient then heat transfer. The coolant will not be in the radiator for any less amount of time because it is travelling faster. It will be cycling through the radiator more often, making up for the quicker pass through.


FB ute fixer upper, EK van on rotisserie

One of the things I love about these cars is how the high bonnet line allows the radiator cap to be the highest point in the cooling system, allowing very good air bleed, and minimising the chance of any cavitation.


FB ute fixer upper, EK van on rotisserie

We'll agree to disagree then, Clay - if we can find an engineer... who can prove to me with physics that such is the case - I'll jump ship with my thoughts and beliefs...

Yes - radiator cap - where the blasted thing should be - highest point in the cooling system...
The debacle when Holden fitted the Nissan motor to the VL.... the Skyline had a very high bonnet which afforded the top of the radiator to sit above the head cooling jackets.... not so with the Commodore...

However, re purging... it always amazes me that you can re-fill a cooling system in our old buses - to the very top.. heater lines and manifold full.... '
Yet, when the thermostat lets go during the initial warming up period... there is a huge "gulp" of water taken into somewhere...

I use a hand made bottle arrangement to purge the system on a re-fill - which fits into the top of the radiator... it's full of water.... with a hole in the top of it.....
when the thermostat let's go... the level of water in the bottle drops significantly.... I don't know where the water goes - but it certainly "goes"....

It's all black art and science to me... guess we'll both sit with our opinions on restriction of flow via thermostat.... I'd hate to be responsible for starting a rift in the forum... warring parties - not that I'd ever let it get to that.... glass half full syndrome, if you like....

frats,
Rosco