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MG MGA - Sleeved Thermostat??

I am trying to bring my tempature dowin in my MGA from 200-210 to the 190s and wonder if using the orginal(repro) Sleeved Thermostat from Moss will make a difference? Their description reads as follows:

The original design of most older British cars called for a sleeve type thermostat which moves to blank off the coolant bypass port when as the thermostat opens. This exact type of thermostat has not been available for many years. The amount of water that is allowed to bypass the radiator with modern replacement thermostats is enough to cause overheating in marginal engines. Early cars have large bypass ports, and cooling can be improved by installing our reproduction of the original style thermostat.

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=47024

How much can the Sleeved Thermostat make a difference verse the Modern Failsafes? Is my money better in the bank?

-Devin
DRE Devin

Devin,
JUST MY OPINION......

The key here is the term "Marginal Engines" meaning, "poor cooling systems". This includes the block, radiator, fan, hoses and water pump. You don't mention the condition/age of these items. How much can a sleeved thermostat make a difference? The only way to know is to try it. However, in lieu of having your cooling system checked out you might want to try a $4.95 165F
thermostat, or a $14.95 blanking sleeve to see what happens.

GTF
G T Foster

Devin, The cheaper blanking sleeve should have the same effect and allow you to vary cheaper thermostat/non-thermostat combinations.
Steve.
Steve Meline

Been using a blanking sleeve and regular thermostat for years without any issues and the car does not run over 190 on the hottest days here in VA. My B will creep up in heavy traffic (no sleeve) but the A never does.
Bill Haglan

200-210 shouldn't be a problem. That's not too hot. I'm sure you know this already, but.... 212 is boiling at atmospheric pressure, but the pressurized radiator/cooling system raises the boiling point significantly, at least 12 deg with a standard 4 lb rad cap, 21 deg with a 7 lb cap, and more with higher pct of water to antifreeze, and even a tad more with 'water wetter' additive. I have the blanking sleeve and other added items to improve cooling and my A runs around 200 as well. At very high, sustained speeds (75 mph for an hour or more) in 95 degree, high humidity, the car does push 220, but that's not a problem as stated above. I'm running with a 7 lb cap, around 25% antifreeze, water wetter, so boiling point is probably around 240. Vapor lock with the fuel could be a problem before boiling however, but I haven't experienced that. Stock heat shield for carbs should protect from that.

steve
Steve Nyman

Devin, I removed a 195 degree thermostat from my 58 mga and replaced it with a 160 degree bought at a local NAPA store for $9.00. temp.dropped from 195-210 to 185-190 on these very hot dog days.. outside temps are 90++.. temp. change is mostly stop go driving....
my $.02.... Mike
mike

Mike - If the new thermostat dropped your maximum temperature by the amount you printed, the original thermostat was bad and a new thermostat of 185°F would have done the same thing for you. The thermostat will only extablish the minimum temperature that a cooling system will run at, with a very small, if any affect ont he upper temperature, unless as stated earlier, something was wrong with the original thermostat. It is always worth a check though.

Devin - Modern "failsafe" thermostats are meant to fail in the wide open position rather than the closed position and then only at a predetermined maximum temperature, so their use will not really affect how hot your cooling system will run, only that they won't stick in the closed position (if they work as advertized). Adding the sleave around a standard thermostat may help bring the temperature down a bit, by routing more of the coolant through the radiator. If not, then the answer is to have the radiator cleaned out by a professional or recored with a good 4 row L type core and have the engine cooling passages completely cleaned out (which requires complete disassembly to do it properly). Good luck - Dave
David DuBois

Thank you all for your responses. To give a little bit more history on the car.

New Moss Radiator (China...)
50/50 Coolant mixer.
Felt Pad
10W-30 Synth.
Oil Cooler

* Purchased, but not installed – Fan Shroud.
I cannot install the fan shroud because my body is positioned at an angle with 1 ½ inches of clearance one side of the radiator and only 3/8 inches on the other side. I am not sure how to figure that one out??? Anyone interested in pictures?

* The car originally had an electric fan, which drained the battery and was not that efficient.

After reading these responses and other threads I am going to do the following changes/additions over the next couple of weeks.

30 Coolant / 70 Water
Add Wetter Water
Install a Coolant Recover system
Blanking Sleeve
Double-checking the timing.

Is there anything anyone one else can recommend?

-Devin
DRE Devin

Devin

If you have not read it yet I suggest you glance through the thread: "All out of ideas - overheating".

Tell us a bit more about your radiator (always a favourite of mine). How many core rows does it have - 2 or 3. If you only has 2 I would start thinking about changing it.

Steve
Steve Gyles

Devin - I would be suspect of the new radiator from Moss. All that I have heard, they are not a very good radiotor. A better bet (now that you have spent all of your money) would be a 4 row L type core from Modine, or one of the new high efficiency aluminum cores from the same source. A good radiator shop in your area can get this core for youand install it, but it will probably cost more than the radiator you got from Moss. I had the L type core installen in our MGB several years ago and have had excellent results from it. On the flip side, since you are not experiencing any boiling while the car is moving, the best bet at this time would be the installation of the coolant recovery system (e-mail me if you woul like a write up and pictures of one approach to the system) and wait until you start having difficulties with the existing radiator, then go for the better core. Good luck - Dave
David DuBois

>Is there anything anyone one else can recommend?

Don't worry about it! ;-)

Seriously, if the only "problem" is that your engine temp is 210º, I'd argue you don't have a problem. As long as it's not boiling over and/or obviously running poorly from the heat, it's fine. A hotter engine is more efficient (more power/better economy), lubricates better, and is generally happier....

The blanking sleeve in conjunction with a 195ºF thermostat would help ensure you're getting the most out of your cooling system whilst still keeping the temp up where you want it. Other than that, I'd say drive the car and enjoy!

HTH!
Rob Edwards

I really have to agree with Rob, drive the car and enjoy. Cheers - Dave
David DuBois

Why do people keep referring to how many rows of tubes the MGA radiator has? Factory radiator cores are 'cell cores' not tubes and fins (except the twin cam). Cell cores are hard to come by these days but there is still one source in the US located in Maine. In a cell core rad the material that forms the fins is one and the same with what forms the water passage, therefore heat transfer is more efficient than with a separate tube and fin arrangement. However, I don't believe that cell core passages can be 'rodded' without damage to the core, when clogged it is best to replace the core. The limitation on an MGA radiator is the width of the lower tank. On works cars they used a 1/2" wider lower tank and a 1/2" wider cell core, they didn't use a tube core. When you use a narrow multi tube core the tubes become lined up one behind the other and as a result there is very little increased cooling. Most MGA heating problems are a result of excessive build up of sediment in the block, blocked passages in the radiator, repro grills that reduce air flow and what I consider most important, modern thermostats that don't restrict flow through the radiator bypass in the head. Improper timing for modern fuels and badly worn cams can also cause major cooling system problems.

Just my $0.02

Frank
Frank Graham

Frank - I am no expert on MGA radiators, but I believe that they are the same as the MGB radiators and are termed a L type core. These cores are available from the Modine company and any good radiator shop can obtain them for the customer in whatever size is needed. When used to recore the radiator, they look and are, in fact, the same thing as the original radiator. Perhaps by refering to 4 row, Modine means that it is a cell core equivalent to 4 rows. All I know first hand, is that they work REALLY good. Cheers - Dave
David DuBois

Frank

Most interesting bit on radiator construction. Thanks. I also agree with the timing issues.

Steve
Steve Gyles

I just ordered one of those new Moss thermostats. I've heard of a lot of people having problems with the modern thermostats (such as the one that's currently in the car), so I figure it's worth the investment. Between that, some felt for the bonnet, a radiator pressure test, back flushing the engine, and putting the missing 4" hoses in behind the grill, and I'm confident my overheating problems are a thing of the past. I'll keep everyone posted...
Rich

Devin, I have a Chinese radiator and have had no problems. I also have a 7 lb cap which I believe helps. I also agree that there is sediment clogging waterways in the block. Oh, yes, I have a 165 degree thermo and it;s Hot here in North Carolina. Hope this helps, Neal Turner
Neal Turner

When I had my 1960 MGA-1600 overheating in "STOP-AND-GO FOR MILES AND MILES TRAFFIC" was a real problem.("STANDARD" L.A. - San Diego after a "FENDER-BENDER" on the Freeway!) I too noticed that it RAN COOLER WITH THE 160 DEGREE THERMOSTAT THAN THE 180 DEGREE, back around 1969! Both thermostats were from the SAME MANUFACTURER, but the specification that's MISSING here is HOW FAR DOES THE CENTER ELEMENT OPEN? Is it THE SAME for both 160 degrees and 180 degrees? My bet is that it is NOT THE SAME! How far it opens would determine the FLOW RATE, another thing we DON'T KNOW! Anyone hang a thermostat on a coathanger wire in a pot of water heating up on the stove with a TEMPERATURE GAUGE stuck in the water and observe AMOUNT OF MAXIMUM OPENING? I also used a "JURI-RIGGED THERMOSTATIC SLEEVE" - CENTER SECTION OF EITHER THERMOSTAT PULLED COMPLETELY OUT & THERMOSTAT PUT BACK IN MINUS CENTER SECTION. This worked OK in the Summer, but IT TOOK THE CAR FOREVER TO HEAT UP IN WINTER! "ROAD & TRACK" or maybe "SPORTS CAR GRAPHIC" magazine said THE GRILLE RIBS ANGLE was "ALL WRONG" and actually DIRECTED AIR AWAY FROM THE GRILLE OPENING! Some guys I knew BENT THE GRILLE RIBS TO ALLOW MORE AIR FLOW, but you had to be careful NOT to have a rib BREAK OFF if you did this! Mine no longer overheated WHEN SOMEONE BASHED MY GRILLE ALL THE WAY IN & I RAN IT WITH NO GRILLE AT ALL!
wattswh1

This thread was discussed between 14/07/2005 and 27/07/2005

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