A lesson in oils

General Chat About Cooling & Overheating

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richardpope50
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Post by richardpope50 »

As usual, thanks guys and sorry for the delay in updating ….

Part 1.
My heater circuit is 15mm I/D pipework with shut valve right at the heater matrix. My bypass is a 10mm tube (O/D I think) linking feed and return pipes as picture.

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Part 2
My setup: Dax Ally rad was just an ali version of the Cortina rad. Cortina rad is thin and tall so in a Rush cannot be vertical and extends below nose cone opening where there is no air flow. My rad is short and thick (75mm 4 core) to match / use all the nose cone’s air flow and be as vertical as possible.

I have a nose cone cowl that directs all air flow through rad. Unlikely for any air to escape.
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I have a puller Kenlow rated at 3,125m3/h. Highest capacity I could find and fits close to rad. I can feel plenty of air flow through my flared side panel when sitting at idle so there is plenty of room for air to escape.
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Thermostat is a straight housing (photo) and standard thermostat that opens correctly. Header tank is above all levels except probably heater pipework - cannot be located any higher. I do not use / lose any water from system.
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Fan speed 1 controlled by ECU sensor near thermostat housing – brown sensor in photo. Speed 2 controlled by inline sensor in rad input pipe – see photo. Same place as header tank pipe connection. Fan stage 1 = on 92, off 87, stage 2 = on 95, off 87. I consider normal to be 90 and too hot 105 / 110 being the temp I seem to be running at.

Part 3
Tom’s right, my belt only covers about a quarter of the pump pulley however there does not seem any sign of a shiny belt. That said, I found an old idler bracket I had made some time ago together with a sprung pulley wheel so I fitted it this week making a true ‘W’ arrangement. Went out yesterday and it does seem to hold the temp at 105 max and my fan comes on / off much more than it did meaning it heats up then cools down. On the 25 mile trip I also got the temp down often to < 95 so perhaps that was it. Still a bit too hot but will now try the 10/40 oil.

Part 4.
Got back and parked in driveway. Now I do not have any 12v ignition circuit! Never ends.


Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

r2d2hp
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Post by r2d2hp »

Where do the heater pipes connect to. Is it possible that the 10mm bypass pipe is flowing hot water from the top of the engine straight back into the bottom bypassing the radiator.

stevieturbo
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Post by stevieturbo »

The alloy piece is the bypass...and that black thing ? The valve ?

looks like the bypass is after the shut off valve, so the bypass can never work ?

Also looks like you have room for a larger diameter fan ok.

Spal make some of the thinnest and best fans about, yours looks quite bulky for a smallish diameter fan ?

On the top hose, what is the banjo'd takeoff for ?
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Ian Anderson
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Post by Ian Anderson »

stevieturbo wrote:The alloy piece is the bypass...and that black thing ? The valve ?

looks like the bypass is after the shut off valve, so the bypass can never work ?unless the valve is open in which case a lot of coolant has free movement

Also looks like you have room for a larger diameter fan ok. Yes but cfm rating of 1800 is fair

Spal make some of the thinnest and best fans about, yours looks quite bulky for a smallish diameter fan ?

On the top hose, what is the banjo'd takeoff for ?
I would presume to header tank and then a similar one to bottom hose which makes another fantastic flow circuit without the water going through the radiator.
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

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Post by stevieturbo »

quote didnt quite work right.

But it does look that way.

Fine for a small diameter air bleed, maybe 8mm max. Defo not for anything larger.

But it should go to a high location in a remote header too...not a low point
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Post by DEVONMAN »

I can't see if there is a second connection to the header tank. If it's a blind single bottom connection up to the top hose then I doubt it will be effective in removing air from the top hose and thermostat area. It needs to be arranged as an air trap /separator like the TVR's.

As Stevie has pointed out, the valve on the heater pipe when shut will block the thermostat bypass and any trapped air high in the inlet manifold will play havoc with the thermostat operation. The bypass H needs to be upstream of the heater control valve.
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


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richardpope50
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Post by richardpope50 »

Black thing is just a bleed valve in highest point of pipework. Another bleed valve is at top of radiator and a third is next to temp sensor at highest point of engine. There is no air in the system at all.

Shut off valve for heater is right on top of the heater within the cabin scuttle.

One heater hose goes to thermostat housing as shown in photo, other goes to T connection on inlet pipe to pump.

Thing in main hose from thermostat housing to top of radiator is a connection for the header tank and also there is the second temp sensor that triggers stage 2 of the fan. The pipe to the header tank goes to the bottom of the header tank. Header tank is just about half full and does not expel water.

(Originally I had a swirl pot in the system but removed that when I first started to have cooling problems and made it a more simple layout as suggested - see posts on this a few years ago. Cannot go back as it means welding stuff back on - ugh.)

Cannot fit a larger fan as 12" is max and depth is max too at 80mm (at bottom where you cannot see). The Kenlowe was the largest fan throughput fan available a couple of years ago. It is a wapping 3,125cu/m one. It is a 24 amp fan too.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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Ian Anderson
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Post by Ian Anderson »

Ok
I see it you have three circuits for coolant
1) through heater matrix or bypass
2) through bleed from top hose to header and back to bottom hose
3) through radiator

I am of the opinion that circuits 1 and 2 are moving enough coolant that it diverts a significant amount away from the radiator.

Test by a g clamp or mole grip restricting flow on both of these circuits. If there is no air in the system they are redundant anyway.

Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.

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richardpope50
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Post by richardpope50 »

Ian, not quite correct I'm afraid..

1) through heater matrix or bypass
Yes, standard heater setup as per my TVR donor. I usually have the matrix valve off so the bypass is really only the way water can circulate and it is about an 8mm dia I/D bypass so cannot really take much of a flow compared to the 30mm or so main pipes The heater is in fact a

http://www.t7design.co.uk/index.php/hea ... eater.html

2) through bleed from top hose to header and back to bottom hose
No. The pipe from the banjo connector simply goes to the bottom of the header expansion tank as per TVR donor. There is no return at all.

3) through radiator
Yes!

My conclusion is that all the flow is via the rad and having changed the pulley belt to drive more of the pump pulley to reduce slip possibility it seems to have worked at least somewhat. As I said, I ended up after my drive with a loss of 12v ignition and having found the problem I am suspecting my whole 12v feed so I'll wait until I sort that out before I can do another test drive.

Thanks for all your help.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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Post by r2d2hp »

Hi Richard, think you will be surprised just how much water will by pass the cooling system via the 10mm pipe. Think it was Devon who shared the best way to configure the system a number of years ago.

My header tank has large pipe that goes to lower rad pipe and has a small pipe that feeds from the top of the rad but flow is limited by a blank in pipe with a very small hole just to allow air to move to top of header.

Have you tried clamping heater pipe and see what happens?

Have the same fan with you and it does flow a lot of air. Also found that if its on when trying to start engine volt drop is considerable and effected ECU so car would not start
regards
Reg

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Post by DEVONMAN »

I drove my car for years with a header tank connected like yours and always had problems with air in the system after a few runs out. It would run fine for a few day till any air generated in the system found it's way to the top hose area. I know you said there is no air in the system but there are several ways air develops in the system such as cavitation in the pump if you rev hard when the thermostat is closed and also bubbles which occur as a result of local boiling just like in an electric kettle even before it boils.
The TVR system relies on the swirl pot to trap the air and expels it through the header tank at the next start up from cold. Your set up probably just pushes mostly coolant into the header tank as the engine warms up and doesn't get rid of all the air.

I fixed my problem by feeding into the header tank above the coolant level and then into the bottom hose from the bottom of the header tank. both connection with 8mm hose. This worked for me as my header was high in the system but I'm not sure how yours would work with the header tank so low.

Good luck with the 12v supply problem.
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


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richardpope50
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Post by richardpope50 »

Thanks again guys.

Unfortunately I cannot just clamp my heater hose as the pipe is reinforced so will have to think what to do to test it.

Yes, Kenlowe fan will take 24amps or 18 with one stage so I already have a switch to turn it off when starting.

Will have to think how to change header tank plumbing in my situation.

I don’t think I have air in the system but on my list is to try out waterless coolant.

I’ll end that this thread for the moment but may well start it up again!
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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Post by unstable load »

richardpope50 wrote:Unfortunately I cannot just clamp my heater hose as the pipe is reinforced so will have to think what to do to test it.
Disconnect it somewhere and stick a bolt in each end.
Cheers,
John

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Post by DEVONMAN »

unstable load wrote:
richardpope50 wrote:Unfortunately I cannot just clamp my heater hose as the pipe is reinforced so will have to think what to do to test it.
Disconnect it somewhere and stick a bolt in each end.
It's important to have some sort of thermostat bypass and that H piece will act as an adequate bypass with the heater valve shut. (or open).
There doesn't appear to be any other bypass.

If you don't have some sort of thermostat bypass then there will be no flow up to the back of the thermostat when the engine is warming up and the thermostat may not open in time to prevent the coolant in the block and heads getting too hot.

I'm no sure if this point has been raised, but does the current arrangement keep the temperature down when the engine is ticking over with the fan on?
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


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richardpope50
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Post by richardpope50 »

DEVONMAN wrote:
unstable load wrote:I'm no sure if this point has been raised, but does the current arrangement keep the temperature down when the engine is ticking over with the fan on?
Used to but will check again - good thought.

Finally sorted my 12v problem on Sunday night - I have not had 12v / 13.5v for some time and will not go into why except that home made terminals and plastic did not mix. Now of course its raining so cannot test things but I did manage short 10 mile trip and engine stayed cool around 90 - fan did not come on but then I forgot to connect it in!.

I'm just wondering if the poor voltage upset the sensors / gauges so will check things a bit more when sun returns.

Will come back after being able to test on a long drive.

Thanks.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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