{"id":42036,"date":"2015-10-10T00:00:41","date_gmt":"2015-10-10T00:00:41","guid":{"rendered":"https:\/\/namgar.com\/NAMGAR2020\/?p=42036"},"modified":"2015-10-10T00:00:41","modified_gmt":"2015-10-10T00:00:41","slug":"cooling-experiments-with-my-mgas-cooling-system-part-1","status":"publish","type":"post","link":"https:\/\/namgar.com\/NAMGARMAIN\/cooling-experiments-with-my-mgas-cooling-system-part-1\/","title":{"rendered":"Cooling! Experiments With My MGA’s Cooling System – Part 1"},"content":{"rendered":"

\"Cooling!I have never had any particular problem with the cooling system on my MGA. Since I got this car over six years ago, it has always run relatively cool with the standard engine driven metal fan.<\/p>\n

The water temperature was normally around 175, it never went much above 185; and the only time I ever suffered from any overheating was when I first got the car when one of the short air hoses fell off in front of the radiator obstructing the airflow slightly.<\/p>\n

So you may say, If it wasn`t broke, why fix it?<\/p>\n

Well my problem is probably that I read too many articles in the MGA forums and on MGA Guru etc., and sometimes (well maybe most times!) they get me thinking, \u201cI wonder if that would be better for my car too?\u201d<\/p>\n

In 2012 I was preparing the car for a tough journey to the Alps on which we would be climbing some long passes up to 10,000 feet, and so I thought that fitting a more efficient fan would be a worthwhile modification.<\/p>\n

As part of the preparation I also fitted an oil cooler, but not in the normal place in front of the radiator. I have always wondered about the logic of fitting the oil cooler there, my thoughts being that although it would cool the oil, it must at the same time put some of that heat back into the engine cooling system. Fortunately my car has a Sebring style front valance with no bumpers, so I made use of this by mounting the oil cooler beneath the radiator duct and then cut a vent into the front valance to allow air to flow through to it. This meant that engine heat removed by the oil cooler would vent out under the car and not go back into the radiator. I also fitted a thermostatic by pass valve into the oil cooler circuit, which only allowed the oil through the cooler when it reached 195 degrees so that it wouldn\u2019t over cool it.<\/p>\n

\"Firth
Firth Grill<\/figcaption><\/figure>\n

PLASTIC FANS<\/h4>\n

I read in the forums about some aftermarket plastic fans, which had much better fan blade designs than the standard MGA fan blade (which is basically just an angled piece of metal). When I looked into these, I found that there were a few types available; the Moss six blade fan with symmetrical blades, the Moss seven blade asymmetrical design, and also the NTG six blade fan.<\/p>\n

Opinions were that the Moss plastic fans had quite flexible blades, which in high temperatures, could actually bend forwards slightly, enough for the tips to catch on the radiator core. Also there was a possibility that if the car was driven through water deep enough to reach the engine fan, the blades could bite into the water and bend forwards into the radiator. So I opted to try the NTG fan which apparently had the following advantages:<\/p>\n

    \n
  1. A more rigid blade construction with little or no flex.<\/li>\n
  2. The blades are broader with a more efficient aerodynamic design to move much more air.<\/li>\n
  3. The blade diameter is almost 1\u201d larger which also increases the volume of air being moved.<\/li>\n<\/ol>\n

    To make fitting easier, I opted to remove the radiator which greatly improved access to the fan and also meant that I kept most of the skin on my knuckles. The slightly larger fan diameter meant that the outer edge of the blades would become really close to the metal finger guard on the back of the radiator’s top tank; so I carefully bent the guard upwards by \u00bc\u201d and this then produced plenty of clearance. Also my radiator had already been spaced forwards by approximately \u00bc\u201d to give more clearance for the slightly longer MGB water pump on my car and this provides plenty of clearance between the fan blades and the radiator cooling fins.<\/p>\n

    When I first ran the engine with the NTG fan, I noticed that the flow of air had increased significantly from what it was before. It became obvious just how much more air was being moved because the first time I revved the engine with my head under the bonnet, it actually blew my baseball cap off!<\/p>\n

    \"Firth<\/p>\n

    It certainly worked really well, the running temperature dropped by 10 degrees F to approx. 165 most of the time and our journey over the Alps also went really well with the engine temp never really getting far above the high 180s even on the steep climbs.<\/p>\n

    But the downside was the noise that the fan creates, I should have realised that moving more air would most likely mean creating much more noise! I think that this is mostly due to the square end design of the blades and the larger diameter. The howling noise that it makes at higher revs is more reminiscent of a passing double-decker bus, which is just not a great sound for a sports car.<\/p>\n

    I lived with this fan for a couple of years and then I booked a visit to Peter Burgess’ rolling road dynamometer for an engine tune up. During this, Peter advised me that my big fan was probably using up to five bhp at high rpms; so this made me decide to search for other alternatives.<\/p>\n

    The first one I found was the Flexolite fan, an American design having metal blades which \u201cfeather\u201d at higher revs, the idea being that the fan only really needs to push max airflow through the radiator at tick-over or at low road speeds. At higher revs when the car is moving, there is plenty of speed generated air flow through the radiator, and the Flexolite fan blades feather (flatten) and push less air, so this will reduce fuel consumption, reduce fan noise, and release a few extra horsepower from the engine that was previously being used to power the fan. However, the Flexolite doesn`t appear to be available in the UK and no one in the States seemed to know if there was a model that would fit the B-Series engine.<\/p>\n

    I also looked to see if there was any type of viscous coupled fan that could be made to fit the B-Series; these are fans, which have a sort of oil filled clutch mechanism in the hub. The principle being that at low revs the engine driven hub transmits all of its rotation into the fan blades, but as the revs increase, the clutch slips and therefore the fan blades rotate slower than the hub and save on wasted energy. This used to be the type of fan fitted as original equipment to Ford Capris and Escorts, etc. before electric fans came into regular usage. Once again though, there was little or no information on this type of fan being available for the B-Series and the few experts that I asked, advised me against fitting one based on reliability issues.<\/p>\n

    So, I next considered fitting the Moss asymmetric seven bladed fan, which apparently runs much quieter than my NTG fan because of its round ended blades and the uneven blade spacing, which significantly reduces fan noise.<\/p>\n

    Cooling Part 2: The Moss Seven Blade Design and Electric Fans will be posted on the website in due course.<\/p>\n","protected":false},"excerpt":{"rendered":"

    I have never had any particular problem with the cooling system on my MGA. Since<\/p>\n","protected":false},"author":1,"featured_media":44344,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","ngg_post_thumbnail":0,"footnotes":""},"categories":[14],"tags":[],"class_list":["post-42036","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-featured-tech-sessions"],"_links":{"self":[{"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/posts\/42036","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/comments?post=42036"}],"version-history":[{"count":0,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/posts\/42036\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/media\/44344"}],"wp:attachment":[{"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/media?parent=42036"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/categories?post=42036"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/namgar.com\/NAMGARMAIN\/wp-json\/wp\/v2\/tags?post=42036"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}