GENERALLY

Heat is normally a symptom of some engine or combustion malaise. Any discussion on cooling must start with the premise that the reader has ruled out poor timing, too lean an air/fuel mixture, bad coolant, a radiator or cooling system blockage, a faulty water pump, bad combustion, poor lubrication, a lousy rad fan, a malfunctioning sensor, a bad thermostat, an imprudent camshaft selection or "badge" blockage.

Cooling a car generally concentrates on coolant temperatures and secondarily oil temperatures.

The coolant heat is dissipated by its passage through the radiator which is turn cooled by the flow of air that runs through it. As this flow of air greatly increases with speed and idling engine gets hotter than a cruising engine. Systems to deal with a stationary or slowly moving car must compliment the systems used to cool a cruising car.

WATCHPOINT FOR ORIGINAL PLUS 8s: I have heard and immense amount of nonsense in this area. :(   All engines and their fueling systems have a temperature range they are meant to run at. Plus 8s came in two basic versions, Carburetted and EFI. The first run with the lower end of the range set by their thermostats..82C for carb'ed cars and 88C for all EFIs. This can be confusing as Morgan often put their rad fan switches at the bottom of the radiator, where the coolant is coldest and yet the temperature gauge is installed at the top of the engine, where the coolant will be its hottest. (I experimented and had rad fan switches put both at the bottom AND the top of the rad.) The temperature difference is 4 to 5C. Of course, the temperature reading is best taken from the top, but one gets used to a chosen placement. The rad fan switch must be changed to reflect where the switch placement is. A good way of checking how accurate your gauge is to see how close to the rad fan switch's range is the gauge. The fan should come on when the gauge reads about 100C, assuming the rad fan switch is placed at the bottom of the rad and 96C if the rad fan switch is at the top. The temperature sender is just to the left of the thermostat housing if you are standing in front of the car.  It should not be confused with the EFI ECU temperature sender. All cars must run within their desired engine temperature range. However, owners often swear they have the craziest temperatures given by faulty gauges or, most likely, bad connections at the coolant temperature sender or gauge.  Once a year, remove the wire to the sender, clean the blade on the sender, and make sure your fitting is tight and does not wiggle.  Running temperature for a an EFI Plus 8s is around 91-98C. If it is under or over that, you have a problem.  It could be, as described, merely a bad connection or it could be worse. The later EFI vehicle (like GEMS) can be very sensiitve to lower temperatures, which will eventually force them into limp-home mode, requiring a computer reset in a world where such systems have not been installed by Land Rover for more than 22 years, which is older than many of the LR dealers mechanics!

WHEN CRUISING

Morgan cowls restrict the possibility of large radiators. The louvres do not improve the airflow much and must be considered decorative. The flow of air is funneled through the grill or from under the car. This being the case, the following aids may help when moving.

2. Install an air "dam" or rubber mat deflector underneath the car to force the cool low air (the lower the air from the ground the cooler it will be) up into and around the radiator.

3. Even better than 2. install an air scoop that will funnel large amounts of cool low air into the front of the radiator. A scoop can double the air flow into the rad. There is a Morganesque version designed by Maurice Owen and Bill Fink that replaces the original scuttle (the piece at the bottom of the grill cowl attached to the wings) with a new scuttle shaped "S" funnel that forces the air up from under the car and into the rad. It is remarkable how well these scoops can work. They are available from Isis Imports in San francisco or from the Morgan Factory.

4. Avoid "badge blockage" which occurs when our affection for badges on a badge bar and badges on the grill create a significant blockage of the free flow of air through the grill to the rad.

5. Be careful of your placement of your license plate...if you are  unfortunate enough to live in a jurisdiction where front license plates are required try to place it to the side rather than the center of the car if possible. A central placement of the license plate blocks the flow of air under the radiator and makes an air scoop impossible and prejudices even a simple air deflector.

WHEN MOVING SLOWLY OR STATIONARY

When moving slowly or when stationary the radiator does not have enough speed induced air flow to cool well. If these conditions continue, the car will overheat. The solution is to artificially create an airflow when needed with a fan. Obviously, the higher the power of the fan the more the airflow and the greater the cooling ability you will have when needed. Morgan fans are not famous for power but many good replacements are available. (see SPAL)

1. Do not install a fan mounted in front of the radiator. They are an easy install and inexpensive but they create the problem they are supposed to resolve. They block the airflow to the rad which contributes to the overheating and then they come on in effort to cool the rad to the point where they can stop and block the airflow again.

2.  Install the fan to operate on a radiator thermoswitch (if you don't already have one installed). This item switches the fan on at a certain temperature and off at a lower one. You can also install an manual switch override that forces the fan on regardless of coolant temperature to deal with a heating situation before it develops fully. Check with your supplier if you require a larger relay switch for the fan you purchase.

3. Remember that all rear mounted rad fans PULL air through the radiator. If you see your fan pushing the air back towards the radiator then simply reverse the wire leads to the fan and recheck the rotation.

IN ALL CONDITIONS

A BETTER RADIATOR.

Morgans are sporting old radiators, some as old as forty years. Their engines do not function as they once did, greater friction than originally is the rule and their radiators are no longer up to the original state of the engine let alone today's state. A better radiator improves cooling whether stationary or moving, but what is a better radiator? Here are some answers;

1. You have had your original radiator re-cored or you have had the coolant flow system of the radiator and the cooling facade and fins renewed. The rad returns (hopefully) to its original cooling abilities. The drawback here is whether the original cooling capacity of the radiator is sufficient for the present state of the engine. You have ignored the benefits of technological progress in the last forty years and you have used the old rad as a base which may be less than a solid foundation.

2. You have purchased a radiator larger capacity than the original though it is conventionally designed. The only drawback here is the technological one noted above and any loss of space considerations.

3. You have had an technologically advanced core installed to replace the original. A good option..but at this point why not go all the way?

4. The ultimate...a high tech aluminum radiator.  See An Aluminum Radiator for Your Morgan.

COATING YOUR MANIFOLDS

For some time, there has been an option increasingly offered of coating your manifolds or heddars with a ceramic based compound that very much lowers the heat of this part of your exhaust system..a prime radiator of heat. Essentially the compound..in a choice of colors or effects,  is sprayed on your clean sandblasted manifolds and then baked. It is inexpensive and aethetically very good looking, replacing the rust that all Morgan manifolds arrive with even when new. It does not discolor as does stainless steel (which doesn't lower heat).

Make sure that the INSIDE of the manifold is coated..this is more important than the aesthetics of the outside. There are a number of companies in the field and some can be found in the GoMoG General Parts Directory . Be careful of some of the better known firms which coat their products in bulk lots of many customers at a time, leaving a orange-peel effect to the finish.

Curiously, I have only found one coating service in the UK or Europe..though they are common now in North America, New Zealand, Australia, and Japan.

N.B. Please ignore the claims of massive horsepower increases. These are largely pipe-dreaming fancies...though a cooler engine can produce more power and leaves more room for "tweaking"  than one which is already running hot.

Wrapping your Headers (NO!!)

Many people still use heat wraps to lower their engine bay temperatures. Essentially, these are a wrap insulation which must be tediously wrapped around each exhaust branch. It is considered by many to be unsightly and will very much accelerate the rusting of the manifolds. They also, of course, do not improve the inner surface of the manifolds and thusly do not speed the flow of gases. They can, however, block the heat from the wrapped section.

Coating vs Wrapping

I get asked this question quite often, and there’s really no easy answer since each application is different, and everyone has a different budget. But in a nutshell, ceramic coating is the better option.

There are two issues when using a wrap that do not come into play when using a ceramic coating. These issues are thermal fatigue and moisture corrosion.

THERMAL FATIGUE

Wraps decrease under hood and under wing temperatures and because of that save other components. But they also shorten the life of your exhaust. Wrapping promotes thermal fatigue of the component you wrapped. It is a type of metal fatigue caused by repeated heating and cooling, also called creep damage which leads to premature component failure. Some owners believe that wraps help prevent thermal fatigue, but in fact, it is the opposite.

Wrap your headers and a few years later, there are holes in the piping. This can happen quicker than you might think.

MOISTURE

Moisture is the second issue with exhaust wrapping. The wrap will actually pull moisture in and keep it there, holding it against the component, which speeds up the corrosion process. Ceramic coatings are self-sacrificial in design, meaning that they will corrode/rust/oxidize before the substrate underneath will. It’s a good idea to go with a coating company that offers a warranty, be careful of companies that only cover 'rust-through', meaning that there has to be a hole in your exhaust before it will get covered!

Coating the Exhaust

The best option to manage heat is to have your exhaust ceramic coated. The coating actually bonds to the substrate (at about 10,000 psi) and prevents the heat from soaking into the substrate. If you get it done right, the rate of expansion of the coating will match that of the substrate, or the metal your manifold is made of. Your exhaust component can usually be coated on the inside as well, giving it thermal and corrosion protection inside and outside.

It’s also a good idea to go with a company that creates/manufactures their own coatings, not one that just buys it from an online coatings store and slaps it on. There's a lot more to the application/preparation than you would think, and if a company has the resources to manufacture their own coatings, odds are they’ve been in the game a long time and have the processes to near perfection. The downside to ceramic coatings is of course the cost. You can get enough wrap to do most of your exhaust for around $50-$100, compared to a full system getting coated for around $500. You get what you pay for.

Top quality ceramic coatings can reduce engine bay temps by over 50%, and the more common cer-met or ceramic-metallic coatings can reduce temperatures from 30%-40%. Another added benefit is that you will see power gains anywhere from 3-5% by keeping the exhaust gas velocity up. Increase spool-time in a turbo system, and increased scavenging is another benefit of the increased exhaust gas velocity.

So, when the time comes to do some heat management, do some research for yourself, look at your budget, and determine which direction is best for you. If you can only afford the wrap at that point in time, get it so you don’t cook the rest of your components in your engine bay, just keep in mind that it’s a “quick fix” and get your components coated when you come into a bit of cash.

I rely on the musing of Rob Wells, a British engineer, Morgan Agent and famous/successful race preparer. There is also a amateur owner with a very early Plus 8 who has posted a YouTube video of his car travelling with ribbons...and though it is interesting watching and was a welcome exercise for early Plus 8ers, it is difficult to accept his conclusions or glean any general fixes. However, Rob's analysis covers all the bases and matches common sense as well. I have made my conclusions and tested them. Mine match Rob's but my "fixes" (aka tweaks) are for a road-going Plus 8s, not racers. Racers operate a specialized environments, with perfect surfaces, no rush hour traffic and operate with their support infrastucture always a few meters away. The cooling risks for road going owners are much higher as their ambient conditions vary far more and the consequences of failing to meet the conditions sadder.

Rob discovered, like the airflow experiment shows, that the air flowing at the front tends to veer AWAY from most of the radiator, to the sides, underneath and into the cowl but then OVER the rad. I have a rather more powerful Plus 8s than most (aka more heat) and, after trying Morgan standard rads (the earlier copper ones) a Griffin, two Ron Davis rads (different) and two Mulfab rads, have settled on the later Mulfabs as the best. All of the aluminum rads are better than MMC stock for Plus 8s.  Obviously, the more air forced THROUGH the radiador..the better the cooling of the engine will be. That is Rob's diagram at the right.

Rob addresses this with a wind dam splitter.

Plus 8s & Cooling (et al) Component Confusion (1995-2004)
by Lorne Goldman

The Confusion.

In the last 2 days, my inbox has been filling with cooling questions from Plus 8 owners. There must be a forum or "guru" somewhere feeding that part of the community with erroneous information. This is understandable as Morgan Plus 8s departed from the then current Land Rover norms from 1989 on. It is further complicated for owners and their mechanics as, for a period during that era, Morgan used a different fueling system and ignition system for cars they sent overseas (the majority of Plus 8s from 1999 to 2004)  from the cars they sold to the UK and Europe. So not only are the Morgan setups different from Land Rover's, they are different from each other!!  The confusion gets worse as Land Rover was selling diesel models as well!  If you look for a part, mechanic or owner, and you give the engine maker, model and year, you will often be giving the wrong part. And then who checks the supplied part?!!

Let's start with basics. Land Rover had a number of V8 block variations and three (3) fueling & ignition systems in the period from 1967-2002 ..or Morgan up to 2004). SUs, Strombergs, 4CU Flappers, 13CU Hotwires(1987-1988) 14CU Hotwires in 1989 and 14CUX HOTWIRES, 1990-1995. and then the Land Rover GEMS era spanned 1995-1999. Finally, Land Rover moved to BOSCH MOTRONICS 5.2.1 in early 1999-2002d).  This last system was NEVER used on Morgan Plus 8s. The Morgan Company ceased producing Plus 8s when they could no longer source the correct version of GEMS and they ran out of the safety bag system. Most of these major fueling eras had subvariants

from 1998-2000 (though these dates are misleading as Morgan labelled later cars earlier to allow the importation). From 2000, all Plus 8s, European/UK or Overseas, used the standard GEMS system that the Land Rover had used (see above) from 1995-1999!

You can see how easy it is for suppliers, owners and even experts, to get component confused. Only that era's Morgan cogniescenti have an easy time with it. Later and earlier pros and amateurs simply make mistakes. Of course, in most cases, the wrong component simply does not fit or work and the only things lost is time and frustration. However, in some cases, the wrong components fit!! This creates long term problems. Let's examine the issue of cooling components, which are interchangeable among all versions of the Plus 8 from the early Buick 215 to the last 4.0/4.6 LR blocks, most specifically the rad fan switch and the thermostats.

As noted above, the happy running temperature range of a engine/fueling/ignition combination is fairly small. This is the range where the engine runs it's most efficiently  and where internal damage can best be avoided. Lower temperatures may produce a bit more power at lower rpms, but the engine innards will reflect the lower temps in unhelpful gunk and goo.