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Jonathan Smith

TR2 long door overheating

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I have an early TR2 longdoor TS349 with the early thermostat housing and no heater. The car was restored 25 years ago and has covered little mileage since the restoration.The car has been recommissioned over last few month having now covered in excess  of 900 miles. The problem I am having is that once engines is run at speed in excess of 40mph for any extended time the temperature gradually increases and once engine speed is reduced below 40mph engine temperature drops down. There are no apparent water leaks or trapped air. I have a new boxed moss uprated  water pump purchased some things me ago for my TR4 which I am considering fitting with new replacement bellows thermostat. It would appear that the problem is flow related . The engine and radiator have been flushed and all houses replaced. Any thoughts re possible cause and remedy?

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Hi Jonathan and welcome. Just because the rad and engine have been flushed doesnt mean they are clear of restricted passageways. The crud that builds up sets like concrete and a normal flush would not clear it. The 4 pot engine is very prone to the last cylinder liner getting a lot of sediment around it and an infra red thermometer might help you determine if there is a particular hot spot.

Normally things cool down as you speed up so something definately not doing its job.

 

Stan

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  Are you sure the thermostat is opening fully?  

 

 

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28 minutes ago, foster461 said:

Hi Jonathan and welcome. Just because the rad and engine have been flushed doesnt mean they are clear of restricted passageways. The crud that builds up sets like concrete and a normal flush would not clear it. The 4 pot engine is very prone to the last cylinder liner getting a lot of sediment around it and an infra red thermometer might help you determine if there is a particular hot spot.

Normally things cool down as you speed up so something definately not doing its job.

 

Stan

Just opened up the brass tap on the block  next to number 4 cylinder and no water flow. Cleared  water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed 

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14 minutes ago, RobH said:

  Are you sure the thermostat is opening fully?  

 

 

Hoping that clearing number 4 cylinder water way my have help but if tomorrow’s run  doesn’t show any improvement next port of call will be checking  thermostat. Will keep you posted. Thanks for help 

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3 minutes ago, Jonathan Smith said:

Just opened up the brass tap on the block  next to number 4 cylinder and no water flow. Cleared  water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed 

Well you get bonus points for getting the tap to open without the handle shearing off and double extra points for getting anything to come out of it. All positive signs for the block. 

 

Stan

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You can flush as much as you like but you'll NEVER shift this lot. Puzzle find the drain hole?

Tom.

DSCF0225 - Copy.JPG

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40 minutes ago, Jonathan Smith said:

Just opened up the brass tap on the block  next to number 4 cylinder and no water flow. Cleared  water the way with a welding rod and water is now flowing fast and clear. Going to try fast run tomorrow and hopefully may be sorted. Feels like too easy too a fix but fingers crossed 

Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. 

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7 minutes ago, Drewmotty said:

Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. 

Living in hope at the moment

7 minutes ago, Drewmotty said:

Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. 

 

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Here are some thoughts:

if the coolant gets hot (energy flow from the cylinder liners in the coolant) - can this be a problem of crud in the engine?

What temperature is the thermostat? Did you test the car driving without thermostat?

Does the (your) TR2 have a radiator card board? What fan is on the engine?

Ciao, Marco 

Edited by Z320

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If thermostat seems ok then I would suspect partially blocked radiator.

Bob.

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1 hour ago, Z320 said:

Did you test the car driving without thermostat?

Hi Jonathan

I'd try that. It's easy to do and check without too much upheaval.

Lovely car by the way. I didn't get chance to chat to you about it on Saturday.

Roger

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Hi Jonathan

A comprehensive account of potential causes of and possible solutions to overheating in the 4 cylinder engine can be found in this locked topic at the top of the General section.

https://www.tr-register.co.uk/forums/index.php?/topic/58689-4-cylinder-hot-engine-causesanswers/

Miles

Edited by MilesA

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17 hours ago, Drewmotty said:

Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. 

Living in hope at the moment

17 hours ago, Drewmotty said:

Unfortunately I think that you may have only cleared the tap. The waterway can only be cleared by stripping the engine down. 

Overheating update.

Firstly thank you  everyone who has replied to the post.

Test run completed. Before the run I checked the engine drain tap again and as last night water flowed clean and fast  with no sign of rust or water staining. Checked spark plugs and engine has been running a little rich so weakened mixture slightly. Then ran engine with rad cap removed and couldn't get temperature gauge past quarter mark circa 135f. No noticeable drop in water level but not surprising at thermostat will not have opened. Ran car up to motorway in traffic circa two miles at max 30mph no increase in temperature followed by 10 miles of motorway at between 55 and 60mph.Once car was running at speed  temperature  gauge relatively quickly  increasing to fraction over the half way mark 185f. Once off the motorway with speed reduced to around 45mph  temperature reduced to fraction under 185f. On returning home checked the radiator water temperature with an electric temperature gauge and had very similar reading to cars gauge. Checked plugs and now only marginally rich. 

Appears  to be some improvement but not yet convinced problem is solved. Many thanks for all the contributions all of which are greatly appreciated as the target is to make sure the car is sort ready for the Bo’ness revival next weekend to celebrate 65 th anniversary  of the car racing at Bo’ness on 4th September 1954. Its a long run over 650miles in total there and back and don’t fancy entire journey at 40mph.

Next port of call I suspect will be thermostat checks and Roger suggests  and than possible water pump and progressively working through the closed post  off Miles one stage at a time. Any other suggestions or possible quick fixes will be very welcome 

Jonathan

6A8F2947-60A8-4517-B1D0-BCB7721F862E.jpeg

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Jonathan

those temps don’t look bad to me. 

Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run?

Mine runs up to the the next temp gauge mark that is about 207f 97c

my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water.

I know you have a very original car. So just make sure your temps are not too hot ie boiling 

do you have fresh antifreeze this helps raise boiling point  

it may just run hotter on the gauge. 

 

Rich is better and cooler than lean. 

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15 minutes ago, Hamish said:

Jonathan

those temps don’t look bad to me. 

Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run?

Mine runs up to the the next temp gauge mark that is about 207f 97c

my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water.

I know you have a very original car. So just make sure your temps are not too hot ie boiling 

do you have fresh antifreeze this helps raise boiling point  

it may just run hotter on the gauge. 

 

Rich is better and cooler than lean. 

Hi Hamish thanks for the info. I’m on 4psi cap and water didn’t  boil today although temperature did get higher on way back from Stratford on  Monday and was just starting to boil. No electric fan on the 2 as it’s running with factory set up and ideally I’d like to keep it that way if possible and have been thinking about acontinental fan upgrade as an option 

Not losing   any water although if I overfill the radiator neck  does dump water due to expansion so tending to fill approx 1inch below  rad cap  and this appears to work ok 

Going to check thermostat next and refresh antifree to see if this help a little more 

Because the car and engine were rebuilt 25 years ago  ago and only covered 300 miles before being put into storage as part of the recommissioning   work we have been keeping engine revs down around 2000 to 2250 max for the last 1000 miles miles and have only just started to slowly increase engine speed which has resulted in temperature increase. 

Feel a little better knowing yours get just over 185f although I don't expect I’ll  be running at the speed you do.

Jonathan 

PS if you are going to the gold cup at the weekend arrangements for picking up tickets are on Facebook. 

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Did the head get re torqued?  

That may be an issue as you only have done 300 miles on this engine.

it will run hotter if it is a new engine.

Peter W

Edited by BlueTR3A-5EKT

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4 hours ago, Hamish said:

Jonathan

those temps don’t look bad to me. 

Just over 185f 85-90c with 4lb pressure cap it’s well away from boiling. Do you lose water on a run?

Mine runs up to the the next temp gauge mark that is about 207f 97c

my elec fan controls this back down to 185f happens a lot waiting for sprint and hill climb runs. I also run an expansion tank so never lose water.

I know you have a very original car. So just make sure your temps are not too hot ie boiling 

do you have fresh antifreeze this helps raise boiling point  

it may just run hotter on the gauge. 

 

Rich is better and cooler than lean. 

My TR3a has under 1000 miles since the engine rebuild and refurbed radiator. It has the bellows thermostat and a 4lb rad cap. Its running temp is 185f, the middle of the dial. If the car stays moving it will stay at that temp all day but if I get stuck in traffic on a hot day it will creep up to the next tick on the gauge just like Hamish. Once moving again it will slowly return to 185 and at no time do I feel like the engine is in distress. I on the other hand get very hot when it is 100 degrees out and very high humidity like most of July.

Stan

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21 hours ago, BlueTR3A-5EKT said:

Did the head get re torqued?  

That may be an issue as you only have done 300 miles on this engine.

it will run hotter if it is a new engine.

Peter W

Thanks for reminding me about the cylinder hard re torque. This should have been high on the recommissioning list but some how didn’t think about it. If I hadn’t posted on the forum could have ended up with a costly problem.

Re torqued the head this evening and re set tappets and new bellows thermostat due at the weekend and with some luck all will be good.

Cant thank you enough for the reminder about the cylinder head and just shows it’s always worth sharing a problem  even if you think you know the answer as could be something basic you have forgotten 

Many thanks Jonathan 

Edited by Jonathan Smith

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Just took the bellows stat out of my car and replaced it with a Tridon item which is a modern wax type item without blanking sleeve.  The bypass has a restriction down to 8 mm in it..  

Reason for doing this change was erratic temp.  Under 185 for entire 100 miles to IWE  them a needles width over 185= all the way home later in the day 

Temp is now solidly on 185 including motorway and A roads.

Cheers 

Peter W

 

 

 

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Hi Peter,

you know about my "long time bellows with sleeve - experiment".

In my opinion to get rid of the sleeved bellows and use a wax thermostat with 8 - 9 mm bypass will finally be a very goog idea.

Ciao, Marco

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22 hours ago, BlueTR3A-5EKT said:

Just took the bellows stat out of my car and replaced it with a Tridon item which is a modern wax type item without blanking sleeve.  The bypass has a restriction down to 8 mm in it..  

Reason for doing this change was erratic temp.  Under 185 for entire 100 miles to IWE  them a needles width over 185= all the way home later in the day 

Temp is now solidly on 185 including motorway and A roads.

Cheers 

Peter W

 

 

 

Can I ask another numpty question

is this the bypass hose that benefits from the 8mm restriction?

does one install a stainless / Ali washer type thing ?

i presume is encourages more water through the rad ?

thanks

H

C9572F4A-E142-4099-9893-A64FA354D5F3.jpeg

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That’s it Hamish. People use all sorts to restrict it. I favour a nylon plug about 25mm long with the o/d machined to just slide into the hose. 

If you ask what size the hole should be you get answers varying from 8mm down. I know that some people completely block it. 

I have a plug with a 6mm orifice in one car and the other runs a plug with a 3mm orifice just to allow any trapped air out. Both cool slightly better with the plug but I haven’t been able to detect any difference when changing from a 6mm to a 3mm orifice. 

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Im my opinion the Triumph engineers did everything correct with the younger TRs.

They reduced the bypass to about 8.5 mm on the TR4A water pump housing and down to 8 mm on the 6 cylinder water pump housing.

With the wax thermostat opened it comes very fast to the point (on the TR4A) no water flows the bypass.

I would not use less than 8 mm to have as much water flow as possible while the engine heats up.

Ciao, Marco

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P1050532-c.JPG.8878fec6a023a489b9c33a4f32b08eda.JPG

 

Edit:

By the way, with my work on the cooling system one time I found the 8.5 mm bore particular blocked by a solid piece of rusty cast iron.

No Problem with the 8 mm bore, but a 3 mm bore would have been blocked.

 

 

Edited by Z320

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On 8/20/2019 at 2:24 AM, Lebro said:

If thermostat seems ok then I would suspect partially blocked radiator.

Bob.

I agree with Bob. I think it is unlikely that the block would be badly corroded after 25 years IF it was cleaned when restored and there was antifreeze in it.  The radiator would be a far more likely suspect in my opinion and if that's the case even an in car flush might give you a few more degrees of cooling before your trip.

Tom

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