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Blow or suck?

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burgundyben

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I'm just about to fit a kenlowe fan to the MGA, Goodwood Revival this weekend and traffic queues will be long, the fan I have can be wired either way round so it can blow or suck.

I'm not fitting the thermostatic switch, just going to have a switch on the dash for traffic.

Which way? Blow heat out the front or suck cool air in and out the underneath?

Its only for traffic and she runs at 190 when moving along no bother.

Thanks

BB
 
Which side fo the radiator has the most space?
 
It will have to be fitted in front of the rad, behind is the fan blade on the water pump.

Hence the question, blow out the front or suck in through the grill and out into the engine bay?
 
burgundyben said:
It will have to be fitted in front of the rad, behind is the fan blade on the water pump.

Hence the question, blow out the front or suck in through the grill and out into the engine bay?
Click to expand...

Hi, Ben -

If I understand your question, I don't think you have a choice - the fan will have to be oriented so the airflow will pass into the engine bay. Otherwise, the fan will be pretty useless pushing against the oncoming airflow as you drive.

Mickey
 
Hi Mickey

The fan wont be working as I drive, it will only be on in traffic.

Although I guess that helps to answer the question...if I have it so its sucking air in the grill and through the rad if I forget to turn it off it will just be helping out, if I have it the other way it will be fighting airflow when I drive off and leave it running.

BB
 
Another thing to consider is the temperature of the air being blown across the radiator. Air from the engine compartment will be much hotter than the air from the front of the car - very little, if any, benefit. So, you'll want to push the air through from the front.
 
I've wired it in such that I can easily swap the direction from blow to suck as it were...

I've got it blowing through the rad from the front into the engine bay as per the car driving along, we'll see what happens in the traffic this weekend.

Go cook my dinner now!

BB
 
Hello Ben,

to the best of my knowledge the fan blades will only be effective in one direction so if reversed you would also need to remove the fan from the motor spindle and replace it back to front.

I go with the general consensus of blowing from the outside to the engine bay. Incidentally, I have no engine driven fan on my Triumph, just a Kenlowe, which hardly ever cuts in except in summer traffic.

Alec
 
If the electric fan is in front of the radiator, it should be blowing towards the radiator. Even at idle your water pump fan is doing ~something~, and if you have a fan on the opposite side of the radiator pushing air in the opposite direction of normal air flow it will in theory make the situation worse...

If you install a thermostatic switch kit you can normally dial in the temp you want the fan to kick in. So, if you're comfortable with the car running at 190 while moving, you can dial the switch to kick in at 200 for when you're stopped.

Personally, I use a thermostatic switch with the electric fan I have installed. I also have it wired to continue running after I shut the car off. The fan switch I have installed shuts the fan off when the radiator temp drops to 160, and will continue to cycle the fan after the car is shut off until the thermostat cools enough to stay shut.
 
Ben,

Unless it has mentioned before.... An oil cooler is a great investment and will do wonders for the cooling of your A... along with the fan that will be 'pulling' air past it on its sojourn into your engine compartment, cooling will no longer be a problem, in a queue or on the road...

'Tis my plan to install one on my '57 MGA when it FINALLY gets on the road..

/bcforum/images/%%GRAEMLIN_URL%%/cheers.gif
 
I figured I did not want it fighting the fan on the water pump.

I had the thermostatic switch on my Healey, thing was that I never knew it was on or not...so this time a switch on the dash.

In time I might run the fan off a relay, that way I could have a little indicator light next to the switch.

Yep - oil cooler, off on sunday to collect a 1800 B engine, when that goes in next spring with a ford 5 speed on the back it will also have pertronix ignition and a oil cooler and alternator.

Finding the 1500 is a bit weak after the Healey (but it was half the money), should be able to make it a bit more long legged with plannned 1800 and 5 speed.


Thanks guys.

BB
 
you must have had a durn quiet fan then, or I have a durn loud one. I always know when mine is on even with a loud exhaust on my B.
 
Hello Ben,

I have mixed feelings about an oil cooler. My Triumph also has an oil cooler and to monitor the temperature an oil temperature gauge. Now I have never seen more than 60 degrees on the oil temperature so I expect that the oil thermostat never opens so the cooler is unnecessary and an added complication. If you fit a cooler, do fit a thermostat as well as overcool oil is detrimental.

Alec
 
Alec

Thanks for that, interesting to note that you think your oil temp is that low, I notice on the MGA that on a long motorway run the oil pressure drops off to about 40 PSI, I thought this was due to temperature climbing up and hence the oil gettign thinner (new god quality 20/50).

I very much beleive that relaibility comes form simplicity so I like to keep my old bangers simple.

Ben
 
For some reason, 6 engines run their lube system cooler than MG's. My first 6 back in 86 I put the cooler, t'stat and remote filter on, with a temp gauge hooked to the lines of the cooler as I wanted to see if I had the lines routed properly(it was a cooler with lower and upper fittings). Dang gauge never got above 180. Which for oil system is barely warm enough to not sludge.
 
A engines 10-25 idle and 30-60 normal.
 
Piman,

A curiosity... 60 degrees fahrenheit is not even ambient temperature...The oil cooler does transfer heat efficiently but a delta of 125 degrees F from the water based cooling system is outside of anything that I can justify.

Just to be curious, were you speaking of (and is your oil temp gauge calibrated in) celsius...

I have no trouble believing that your oil would run at 60C (140F).... Although 140F is not too bad when you consider the water temp runs between 170F and 180F. The cooling system actually transfers heat more efficiently than does the oil so, as I said, 140F should be pretty close to normal...

Just curious...
 
One other note....

According to a couple of sites that I visited -- An eight cylinder engine has a normal oil temp of around 220F.... with an oil cooler the temp would be decreased between 25 and 45F.

So, based upon Jack's number and Piman's... 140f - 180F appears to be well within the norm for our smaller 4 cylinder engines....

At least that's my two cents worth...
 
Ron,

Actually 180 degrees F is the optimum temperature forp most oils. You might visit this site:

Oil Tempurature Analysis

Although it is Porsche specific the data is still valid...
 
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