Defurring the Cooling System

General Chat About Engine Build

Moderator: phpBB2 - Administrators

User avatar
richardpope50
Gold Member
Gold Member
Posts: 616
Joined: Thu Jan 28, 2010 12:25 pm
Location: Horsham, West Sussex

Defurring the Cooling System

Post by richardpope50 »

I am still having difficulty cooling the engine as it runs at 100+ with 110 often reached after a short stint in traffic (and takes ages to get back to 100 again).

Whilst I know now, I did dry store my engine for some 5 years so am wondering if there is some furring up happened. When I drain the system it is all a totally clear blue colour, though, and not a speck of dirt.

Is there a radiator flush product that will defurr things?

Yes, there are many rad flush products but I want a strong one or a specific one for this. I do have a couple of bits of copper pipe in my system for heater connections otherwise it is an ali rad.

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

User avatar
ChrisJC
Top Dog
Top Dog
Posts: 5039
Joined: Mon Nov 20, 2006 1:13 pm
Location: Northants / Cambs
Contact:

Post by ChrisJC »

I doubt if furring is the problem. What is the system / car / etc that it's in?

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

stevieturbo
Forum Contributor
Forum Contributor
Posts: 3979
Joined: Sat Nov 18, 2006 6:22 pm
Location: Northern Ireland

Post by stevieturbo »

I recall there was another thread....link to that with history ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

User avatar
richardpope50
Gold Member
Gold Member
Posts: 616
Joined: Thu Jan 28, 2010 12:25 pm
Location: Horsham, West Sussex

Post by richardpope50 »

Yep, the original post I hijacked was this ...
http://www.v8forum.co.uk/forum/viewtopi ... 3&start=75

Also sorry that Photobucket does not show my car anymore- think Se7en.

Basically I've still done everything and recently removed the bypass between heater pipe circuit. In short there are no air pockets, rad is cowled at the front, two speed Kenlowe fan, calibrated temp gauge via ECU, rad is 70mm core, etc..

The rad fan does cool the water but there are side bits that the fan does not cover. However the water temp on exit from rad is 45 degrees. I think the problem is throughput. Today I have removed thermostat to see if that will give more flow and keep the engine cool - will try later this week.

I thus wondered about fglushing system in case it was all furred up. I'm also thinkinh of taking off the water pump to see if that's at fault. Trying to do easy bts first.

Problem is simple. Temp stays at 90 until oil reaches its 90 temp and / or get stuck in traffic. Then water temp goes to 100 and does not come back down. Usually goes to 110 as soon as I do a short blast or traffic again. Then will rarely goes below 100.

If throughput is not the problem, an oil cooler may be needed but that's not easy to fit.
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

stevieturbo
Forum Contributor
Forum Contributor
Posts: 3979
Joined: Sat Nov 18, 2006 6:22 pm
Location: Northern Ireland

Post by stevieturbo »

So slow moving, low airflow it gets hotter ?

What temperature stat is fitted ?

When moving at say 50mph, does it cool to an expected level, or remain higher than expected ? ie it should have ample airflow available there.

I say expected...as cars dont always run at exactly stat setting, but they should be close and repeatable. Obviously if there are problems it can be hard to find this base level though.
If you fitted a colder stat for example...how does it behave ? Cheap and easy to try.

Thicker cores are usually less efficient than thinner...but when surface area is limited, not much else you can do there than go thicker.
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

unstable load
Top Dog
Top Dog
Posts: 1278
Joined: Mon May 04, 2009 6:53 am

Post by unstable load »

Drain it and fill it with white vinegar, let it stand for a while, drain it and flush it a few times.
I did it for my Honda and it made a big difference to low speed temps.
Cheers,
John

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

Running above the thermostat figure is normal with the SD1. Different rad, I know. My EFI even has the centre of the dash gauge marked as 100C. On the move it will run at about 90C, but in slow traffic goes up to 100C. But never over, unless something is wrong.
Interestingly, a MegaSquirt log shows the coolant temperture being much more consistent - the injection uses a different sensor in a different place.

I'd first check your dash gauge is accurate. Put the sensor in boiling water to check. On SD1s, it's common to find the wrong sensor has been fitted. Or a badly made one.

My car has only ever had London tap water plus the correct antifreeze. Last time I changed the water pump, the inside of the water jacket looked like new. The small passages in a rad can get blocked - but you've checked that by measuring the output temperature.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

User avatar
richardpope50
Gold Member
Gold Member
Posts: 616
Joined: Thu Jan 28, 2010 12:25 pm
Location: Horsham, West Sussex

Post by richardpope50 »

Thanks guys and some more facts

My test route is a meandering A road driving 40 – 60mph. Keeps cool (90) until oil gets to (indicated) 90 degrees or I pass through a very small town (Petworth). Once hot (97+) when both fans come on, it rarely reduces below 100. Quick blast, say, and temp goes to 110 and takes time to get back to 100.

Any real fast period such as 5 miles on dual carriageway at 70 and oil goes to indicated 95. Takes a long time to reduce to 90. Water 110.
First fan speed comes on at 92 and second fan on at 97. Rarely do they both go off

First fan controlled by ECU, second fan controlled by otter switch.

Thermostat is 82 and it opens correctly.

Plenty of room for hot engine bay air to escape as I have flared side panels.

Megasquirt ECU temp sensor calibrated and located front top right in water channel. Gauge sensor is immediately next to it (don’t use normal RV8 sensor location by thermostat housing). I thus know my gauge accuracy – out by 10 degrees even though CAI matched them for me!
Water channel behind thermostat housing is clean as a whistle.

Oil gauge not calibrated.

Thanks John, may try that.

Finally, since Photobucket has stopped free photo hosting, who does everyone now use?
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

User avatar
richardpope50
Gold Member
Gold Member
Posts: 616
Joined: Thu Jan 28, 2010 12:25 pm
Location: Horsham, West Sussex

Post by richardpope50 »

(Ignore Photobucket question, have looked up post.)
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

User avatar
richardpope50
Gold Member
Gold Member
Posts: 616
Joined: Thu Jan 28, 2010 12:25 pm
Location: Horsham, West Sussex

Post by richardpope50 »

Testing photo upload - position of two senders and note thermostst housing now a straight one, not RV8 one.

Image
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

stevieturbo
Forum Contributor
Forum Contributor
Posts: 3979
Joined: Sat Nov 18, 2006 6:22 pm
Location: Northern Ireland

Post by stevieturbo »

So it would seem the natural running temperature would be around 90degC, so despite a lower stat there would be no realistic expectation to get it down to 82degC.

It does really sound like it simply needs more water cooling capacity, rather than water flow, air flow etc.

I know it's a custom rad etc etc...that doesnt mean it's enough for the setup. An oil cooler may help...but I just doubt it will do enough seeing as oil temps arent getting too far beyond that of the water.

Is there a heater core inside the car ? How does water temp respond to this running either off, or fully flat out ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

DaveEFI
Gold Member
Gold Member
Posts: 4603
Joined: Fri Feb 26, 2010 4:27 pm
Location: SW London, UK

Post by DaveEFI »

Wonder if there's an easy way of measuring the airflow through the rad?
Something like a PC cooling fan that can give an RPM readout? So if driven round by the airflow only could tell how good at was at different speeds etc?

Aerodynamics seem to be a bit of a black art - with airflow not always doing what you'd expect.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y

stevieturbo
Forum Contributor
Forum Contributor
Posts: 3979
Joined: Sat Nov 18, 2006 6:22 pm
Location: Northern Ireland

Post by stevieturbo »

Try a short drive with the engine overs off if possible ?
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

User avatar
Ian Anderson
Forum Contributor
Forum Contributor
Posts: 2396
Joined: Sun Nov 19, 2006 9:46 pm
Location: Edinburgh

Post by Ian Anderson »

richardpope50 wrote:Yep, the original post I hijacked was this ...
http://www.v8forum.co.uk/forum/viewtopi ... 3&start=75

The rad fan does cool the water but there are side bits that the fan does not cover. However the water temp on exit from rad is 45 degrees. I think the problem is throughput. Today I have removed thermostat to see if that will give more flow and keep the engine cool - will try later this week
This sounds like you have sufficient cooling in the radiator.
Have you perchance taken the reading on the water temp on the inlet to the rad?
It could be that there is a total mismatch between the temp sensor and the gauges you are using and the shown 110 degrees is actually around 90.

Perhaps use an infra red thermometer and check the actual temps in and out using the same gauge.

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.

User avatar
ChrisJC
Top Dog
Top Dog
Posts: 5039
Joined: Mon Nov 20, 2006 1:13 pm
Location: Northants / Cambs
Contact:

Post by ChrisJC »

Are you saying that it's OK until the fans come on, then it never works OK after that?
1. Do the fans go off?
2. Are the fans pumping air the right way?
3. Does the voltage drop caused by the fans cause the temperature gauge to start to read inaccurately?
4. If you warm it up, then disconnect the fans and go for a blast, does that cool it down?

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8

Post Reply

Return to “Engines Area”