Chris Ryan
Moderator
Posts : 655
Location : Dubbo NSW
CF overheating- issues and solutions
Motor overheating is annoying and costly. I have met several people who regretfully sold their van because it always ran hot and was unreliable.
Firstly we have to consider the design of the van. It was designed to be used at slow speed
( 4 cylinder motor and high ratio diff) on a cold rock in the North Antlantic (England).
When GMH re-engineered the CF for Australia it was still designed to be used at slow speed
( 173ci 6 cylinder motor and the original high ratio diff).
Secondly, we have to consider the engine bay and location of the motor. It gets very little airflow around the motor and the carby is usually sucking hot air (not good).
From my experiences I conclude that the aerodynamic shape of a standard van prevents air flowing through the radiator when travelling at highway speed. A pressure front is created under the CF in front of the Crossmember and as a result the engine bay is pressurised. Some air will still get through the radiator past all the sheet metal. If accessories such as bull bars, bug mesh, or even just driving lights are installed a pressure front is also created at the front of the CF that stops air even getting to the radiator.
I discovered this after installing a new aluminium bullbar and then trying to drive to Bourke, a trip I had done many times before. The Van ran fine until I got on the open road and then the temperature gauge rapidly climbed. I slowed down and the gauge slowly went back to normal. With trial and error I found that I could travel at 89kmh OK but try 90kmh and it boiled fairly quickly. I attacked the bullbar with a hacksaw and was able to increase my speed to 98kmh. Still nowhere fast enough but I had to make do. When I got home I instigated modifications that allowed me to drive the van at its potential maximun speed (fast) over long distances.
Suggested modifications (some or all may be required)
Speed Limiter so that you can only drive slowly. As if!!!
Lower the van. Use Torana sports coils or CRS drop axles.
Spoiler. Stop the air getting in under CF.
Trim the sheetmetal in front of the radiator. Do not completely remove all metal in front of the radiator as I have seen done because you will adversly affect the body strength.
Bennett Bypass System- puts the thermostat in a seperate housing.
V8 radiator with 6 cyl fittings. Yes a 2 core V8 one will just fit. The mounts will have to be moved.
Thematic fans. Also less engine bay noise under normal operation. Davies Craig make one with a very thin motor.
Larger engine bay cover. Allows the air to flow past the motor. Danny Riley makes one that has a tray to sit your 6 pack in.
Larger winged sump and a slip-on heatsink for the oil filter or even a seperate oil cooler. Every bit helps.
Ducting to the air filter. getting cold air to the carby makes a little improvement to temperature and a big improvement to the performance
Larger flow thermostat. Note: do not completely remove it as the results are actually worse because the lack of back pressure causes the water pump to cavitate at speed (very bad).
Fit a Davies Craig electric water pump. Every bit helps.
Fit HPC coated extractors. Every bit helps. and it keeps the cabin floor cooler.
Water injection. Every bit helps especially with the crappy fuel we have nowadays.
What do I do? Depends on the CF and the motor installed.
An example is the problem above with the bullbar, a hoted up 308V8 T400 in a CFS.
The solution: Torana sports coils, spoiler, trimmed sheetmetal, 3 core V8 radiator, Twin DC thermo fans, modified thermostat, larger engine bay cover, air filter ducting and HPC coated extractors. The spoiler was made out of 8mm rubber matting and mounted on a flexible steel frame( you need a bit of give when creating roadkill). The result was a fast reliable CF that I could travel long distances quickly even in 48C heat!
Generally some modest trimming of the sheetmetal in front of the radiator and a small spoiler will be more than sufficent for a reasonably standard CF. My advice is that a CF can be made to run cool, it may just need a bit of work to achieve it.
26 Feb 2003 @ 02:05
ROD McMILLAN
Member
Posts : 99
Location : HEATHCOTE,, VIC OVER HEATING
OR YOU COULD INCREASE THE DOWN DRAFT AT THE REAR OF THE ENGINE BAY BY FITTING 75MM ANGLED ALLY STRIP TO REAR OF FRONT CROSS MEMBER TO INCREACE DOWN DRAFT OF AIR THUS SUCKING THE AIR PAST AND DOWN THE ENGINE ,350 CHEV ,T 4 AT, 140 KLMS PER 36 DEG DAY AFTER 9 HRS DRIVING LOADED 140 TO 180 ENGINE TEMP ALL DAY
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ROD
27 Feb 2003 @ 09:02
Rufus
Member
Posts : 33
Location : Diamond Valley, Victoria
Chris, do you have a model/serial # for that thin D.C. thermo fan? I'd like to fit a thermo and I've searched their website and dug through stock in shops but I couldn't find one thin enough. Downstream on my 202 set up there is about 25mm gap between the water pump shaft and the radiator wall, so it would have to be a really thin fan. I bought a 6 blade fan as an alternative to the 4 blade standard, but haven't fitted it yet as I'd like to take that load off the engine, and have air flow whilst stationary (bloody traffic lights!) I also saw the D.C. electric water pump and am curious as to whether you have to modify the mechanical water pump,(ie. remove shaft) or just slip the belt off and buy a smaller one?
Your theories on air displacement are food for thought for me as I've got a bullbar and was curious about it. The front spoiler sounds like a good thing and I'll make up something "road-kill flexible". I'll be modifying the grill as per your advice. Does a scoop/air intakes in the bonnet help at all?
Any advice would be appreciated.
Thanks guys
02 Mar 2003 @ 03:05
Chris Ryan
Moderator
Posts : 655
Location : Dubbo NSW
The fans I got were from Davies Craig and were accessory fans. I don't know the model number as any fans I have needed in the last 10 years I have been able to get at swap meets for as little as $5.
When fitting Thermo fans, I take the radiator out and lay it on the ground. I then put a piece of box type cardboard on the core as a spacer and then locate the fans on the core. I weld up a support frame that bolts to the sides of the radiator and clears the motor ( can be tricky!).
When mounted in the CF without the cardboard, you should get a neat installation.
09 Mar 2003 @ 06:17
Anonymous
Unregistered
Posts :
Location : Hot 6
Having no room for a thermo fan upstream or down, I had no alternative but to stick to the mechanical fan. I now run the six bladed fan and it certainly does suck more air, but robbed me of some power. I am about to experiment with a plastic one as I have been told they work a lot more effectively. A 72'C thermostat, new hoses and clamps, new water pump, new 3 core radiator, and she's running a lot cooler. Still heating up at the traffic lights, but no way near as bad. I am still curious about electric water pumps, if anybody has fitted one to a 6 cyl set-up, and if any modifications to the mechanical water pump had to be made. There seems to be a couple of styles out there on the market and any input would be appreciated. Cheers!
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08 May 2003 @ 08:24
ROD McMILLAN
Member
Posts : 99
Location : HEATHCOTE,, VIC otto or manwell
anonamouse is your cf auto or manual if auto it may be the autos heat in the rad causing problem
?? if it to is in rad ator more imput please
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ROD
08 May 2003 @ 10:14
Rufus
Member
Posts : 33
Location : Diamond Valley, Victoria
Annon is me, posting without logging in ....sorry 'bout that. I have a VK Commodore 5 speed gearbox. It seems that unless I have air moving through the front she gets warm sitting and idling. The guage hasn't gone past 1/2 way yet, and I still have some other mod.s to make, but it makes me wonder what's gunna happen driving around the top end, where's it's a lot warmer and humid.
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~Rufus~
08 May 2003 @ 10:47
ROD McMILLAN
Member
Posts : 99
Location : HEATHCOTE,, VIC hot comod
Hi I thought that comodes had centrifical multy blade fans very eco and cool if it is running hot and tem other temp gauge to test a v8 rad will fit if you alter the spouts ??
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ROD
09 May 2003 @ 10:20
conrad
Member
Posts : 115
Location : newcastle
or...
i bought my cf of some yuppie in sydney
it was running hot as buggery, possibly due to heater circuit being replaced by a very kinked short piece of hose.
i replaced the hose with a longer bit, noticed a lot of rusty built-up in the thermo housing.
oh, and got the rad flushed and a hole welded up while i was at it
helped a bit
drove on regardless
got super hot one day and melted the new temperature guage i had bought
2 warrenty guages later it got really hot
AND BURST A HOLE THRU A WELSH PLUG!!!
have any of u tried to change the 202 welsh
plugs with the engine still in?
15 hours later... i thought i may as well get a
new thermo housing in there (cost 5 bucks or something) and put in a hi flow thermo
pulled it off
AND THERE WAS NO THERMOSTAT!!!
bloody yuppies
needless to say my 79 cf is fairly beatin up,
but thats ok.
im currently performing a bit of a heart transplant.......
i'll keep u posted
20 Jun 2003 @ 05:04
Anonymous
Unregistered
Posts :
Location : overheating tips
The engine bay as we all know is so small in cfs and no matter who you talk to,overheating is a huge problem.The motor heats up quickly and once again,pull off to the side of the road frustrated.The major problem is that the engine bay traps the heat and is locked in, cooking the motor in its own juices.There is one thing to ask yourselves. Where is my intake on my aircleaner located. is it directly above the motor or to the side.It is extreamly important where the air intake is located.It must be well away from the motor itself.Why.Because the motor must breath cool air, not hot air,if its breathing air from inside the engine bay.You will only increase the engine temp very quickly.Its a big problem a lot of us seem to overlook and with bedfords its critical.You must locate the air intake a in position as close as possible to the front of the vehicle,or at least well away from the engine itself.Anyway must go. Paul.
02 Sep 2003 @ 04:01
Anonymous
Unregistered
Posts :
Location : pauls crappy over heating tips
hello everyone.Another idea which i have not tried myself but is very common on a lot of cars, is to fit a radiator fan cowling on.(if possible)to our bedfords.This should help in concentrating the air flow passing through your radiator a lot better.It draws air in over the hole surface area of the radiator,forcing air through with the fan blade.It may be of help in keeping our cfs a bit cooler.Anyway no worries Paul.
07 Sep 2003 @ 14:15
Anonymous
Unregistered
Posts :
Location : appalagies from Paul.
my appalagies to everyone using the word, (Crappy),in the overheating tips.
07 Sep 2003 @ 23:42
Chris Ryan
Moderator
Posts : 655
Location : Dubbo NSW
G'day
Tridon Australia offers a High-Flow Thermostat
to improve cooling system performance. Something like 30% more open valve area:
http://www.are.com.au/feat/techt/thermostat.htm 02 Oct 2003 @ 23:21
Anonymous
Unregistered
Posts :
Location : Paul
Ive just fitted a 60 degree C or 160 C thermostat with a new three core radiator and ran it for at least half an hour just sitting there.Got to temp pretty quick.Thermo cut in at about 180 C and settled eventually and kept at a constant 170 C and didnt move,going buy the small temp gauge that was with it when i bought it.I cant say if it will be sucessfull at this stage.It needs to go on the road with different temp conditions.Not ready yet but will let everbody know if sucessfull or not.
04 Oct 2003 @ 04:09
marky
Member
Posts : 39
Location : mullumbimby nsw.aust
v8 radiator
does v8 radiator fit into existing mounts ie frame that exists already or does new frame have to be made,or just mounts on radiator to fit 6cyl frame?
25 Nov 2003 @ 09:15
Bree
Member
Posts : 104
Location : Main Arm NSW
THE MOUNT MIGHT NEED TO BE CHANGED....YOU CAN CHECK MINE OUT IF YOU NEED TO SOMETIME....IT'S FITTED WITH A 3 CORE RAD. IT'S BEEN MOVED BACK ABOUT 60mm.
WHAT'S IN YOURS AT THE MOMENT....IS IT ORIGINAL??
25 Nov 2003 @ 11:49
Bree
Member
Posts : 104
Location : Main Arm NSW
NO...MOUNTS STAY SAME....NEW FRAME...
25 Nov 2003 @ 11:49
paul walker
Member
Posts : 58
Location : mitcham vic Re-V8 Radiator
What i did was cut the top cross member bar the whith of the rad,then welded steel supports from there, down to where the bottom of the grill sit's.There is a lip that runs across the front.I did'nt weld the side supports to that but drilled a 3 eightth hole and bolted the side supports and the radiator side supports together through the lip.
As far as modafying the radiator mounts to fit in,I did'nt,I cut the front of the shassi enough to slip the radiator down in position,keeping the radiator as far forward as i could.I (dont) recommend to do that at all.
Keep in mind where the bottom rad hose is positioned or will be,I'm running a 308 and the oil pump was up against the hose.
Also to, I repositioned and mounted the altenator to the top,in front of right hand rocker cover to stop the fan belt (close to rubbing) up against the bottom radiator hose.That led to heater hose problems.
As far as the transmission cooler location,i modifyde the heater fan induct.Cutting back the front of it enough so the cooler would fit down infront directly beside the radiator.Some of the plating around the head light support also needed to be cut back. Running the hose one side was a problem but overcome with one hugh drill bit.
I spent a lot of time getting it set up but its come up well.
If your not running a V8 and basicily standed running gear,It should be straight forward (I think)
Anyway thats how I went about fitting mine.
Good Luck, Paul.
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25 Nov 2003 @ 22:52
neil walker
Member
Posts : 8
Location : adelaide sth aust engine temp
my Bedford has a home made air intake snorkel that the previous owner had fitted as he was concerned about the location of the standard air inlet.
Maybe Im lucky but my Cf tray top does`nt run hot at all.
He also modified the heater core to include a radiator cap this is well above the standard radiator cap and eliminates air blocks by being above the engine, sounds strang but it works!!
Neil
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21 Mar 2004 @ 06:29
Bevan
Member
Posts : 7
Location : Chch, New Zealand front spoiler
Chris,
Any chance of posting some pics of the front spoiler you talked about earlier, made from rubber matting and steel?
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