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MG MGA - How to RAISE engine temperature

Yes, you did read right!

I have a problem reaching a working engine temp. I have the rad 80% covered, Oil cooler is also blanked off. Air temp is around freezing, and I cannot get an operating temp above 70C even in traffic. On a run, Even when driving hard, I get ice forming on the inlet manifold, even though this is directly above the exhaust.

Thermostat is working and is a 70C standard one. I have tried an 80C thermostat, which appeared to be working, but this made no difference. Just in case I swapped it with a new 70C one.

Coolant mix is 50% antifreeze / water.

If I leave the rad uncovered, the engine reaches just 50C tops.

Car is with Jusdon SC, Oselli Stage 2 head, 1622 engine running about 11:1 compression (waiting for the copper head gaskets to arrive to reduce this).

Any suggestions?
dominic clancy

Uh - yes, you can use 11:1 compresion OR a supercharger, but not both.

Unless you reduce compression down close to stock, you may still have problems with the blower. If you blow the thicker copper gaskets, either change pistons or do some grinding in the combustion chambers to gain some volume.

No idea on the cooling problem - I've driven them in the cold and not had it with stock carbs. No idea whay having a Judson on it should change that.
Bill Spohn

Dominic,

You may need to run two head gaskets to get the compression down. Most supercharged cars are about 8.0:1 from memory, so you might have to swap your pistons.

As for temprature, are you worrined about the heater not working, or the inlet manifold freezing. My friend had the same problem with ice when he tried this with his MGA.
I think he ended up running hot water around the manifold.

Hope this helps.
<MARK>
Mark Hester

Dominic:

I'm surprised a warmer thermostat did not help.

The observation of ice on the intake aside, for the time being, have you checked the accuracy of your temperature gauge?

Also, it is very unlikely that you are running lean, if the temperature reading is correct. Is it possible that you running too rich to accomodate the supercharger and prevent pre-detonation?


Steve
Steve Brandt

Thanks for the comments

Bill and Mark, if you read carefully you will see that I am waiting for the copper gaskets to reduce CR - I have ordered one 2mm and one 3mm to see what is better.

I am worried that as I canot reach a suitable operating temp I will experience engine damage from running too cool.

I can perhaps add that the engine and head are so clean inside you could eat from them - they are all like new in terms of no rust or scale in the system. Similarly, the rad and hoses are brand new, water pump is the old one, oil cooler is also new.

I have checked the engine temp readings with a sensor into the top rad hose and a laser temp reader. It's spot on what the gauge says. This means I get no heat from the heater (would be handy in these temperatures!). I am losing no coolant.

I am not running lean or rich, the mix is perfect according to the exhaust gas test machines at the local workshop (the Holley carb has an accelerator pump to rich up the mix on acceleration).

It seems that the coling system is too efficient, or that the engine is breathing too well so the exhaust gas doesn't stay around long enough to heat up the engine. It's certainly quick!

The thermostat change made no difference at all. The ice on the inlet manifold is amazing considering how much heat is usually in this area.

So guys, the challenge is on......

What to do?
dominic clancy

Hello Dominic,

One of the MGA dealer accessory items that was originally available were grille muffs. I believe they were specifically intended for Alpine regions. There were made of leather, they completely cover the grille opening and they attach using snaps that enable reattachment. Obviously, they are very hard to find today and when they are found they are quite expensive. I believe they might be easily reconstructed by a creative upholsterer. I can send you close-up pictures if you want to go this route. I have a pair on my factory rallye replica coupe.

Another option is to make a jacket for the radiator itself. This would be more difficult to deal with as it would likely involve the removal of the grille. Not something one would want to do regularly.

Tom
Tom Balutis

Interesting problem Dominic. One thing that is confusing is that the engine temperature drops if the radiator is uncovered even with the thermostat installed. There should not be any flow through the radiator with the thermostat closed, so it being covered or uncovered shouldn't matter until the engine came up to the temp rating of the thermostat. Your indication of the lowered engine temp indicates that there is leakage past the thermostat allowing circulation through the radiator. If this is the case, then you're dealing with the efficiency of the radiator in colder conditions. I would suggest trying a reducing sleeve or disk in the upper radiator hose to reduce the flow.
As far as the possibility of engine damage, I'd be more inclined to think you'll start to see problems when the engine temp gets higher. Watch for pre-ignition due to the high compression and higher combustion chamber temps.
Bill Young

Dominic,

Carburetted aircraft have carb icing issues, but on the carb venturi, which will, upon icing up, make the engine very quiet. Most small planes have a lever in the cockpit that allows the pilot to add carb heat...an air duct coming off the exhaust manifold with an adjustable damper. General aviation planes also use air dams made of sheet metal and flexible rubber or silicone to seal the engine from the cold that comes with altitude.

Random thoughts: Does your car still have a heat shield between the exhaust and carb system? If so, would removing it in the dead of winter help? Ditto for the cold air duct from the grille to the carb. Would sealing the open end help?

I also liked the idea of sealing off the grille with a device made of the stuff which car nose bras are constructed, with magnet strips sewn in to seal it to the nose. With a BIG MGA logo on it. Or a graphic that looks like an MGA grille.

OK, I'l stop now and take my medication.

Frank
Frank Nocera

Hi Dominic, Do you have a thermostat on your oil cooler ? The general recommendation is not to fit the cooler unless you have a thermostat as well. You obviously have no need for the oil cooler so removing it should increase the engine running temperature - I have not got an oil cooler fitted and use it in summer temperatures over in UK without too much problem. Recommendation for cold climates is for the hot thermostat in the water (82C) - Cheers Cam
C Cunningham

The heat shield doesn't fit with the Judson, at least mine didn't. I had the opposite problem with it, though - too much heat. My BGT, however, has the over-cooling problem. My only solution was to cover the oil cooler and to make a radiator cover. I made it out of clear lexan. It completely covers the rad, save for a six inch hole in the middle. My old midget (even sans oil cooler) ran too cool in the winter as well. Again, I covered the rad. I'm interested to find if it's a mechanical/tuning issue. I never found the problem, if there was one. Keep us posted
Kemper

Thanks to all for the inputs so far (certainly makes a change from talking about overheating issues!)

The cold air hose to the carbs is non-existent in this installation - the drive pulleys for the Judson sit where the metal cuff comes through the radiator firewall, so this could be blanked off. In a normal car, having these hoses missing causes a decrease in the effectiveness of the colling system, so I don't think that this is the problem,

As for a radiator muff, this is something I also have thought about, hence the use of a piece of plywood to block 80% of the rad area from the front in the hope that this would reduce airflow enough to make a difference. It did, but still not enough, and I am a bit reluctant to block 100% and go without any flow at all through the rad.....but who knows. I do have a radiator blind on the way from the USA.

Frank, I am familiar with Carb heat (I did a fair bit of flying when I lived in Altamonte Springs), but it's so tight around the carb and exhaust and steering that I think this would be difficult if not impossible to fabricate. I do like your idea of removing the heat shield (I noticed even in the summer that the inlet mainfold was very cold, so this should not be a problem).

I am deeply puzzled by the fact that the thermostat does not seem to be having any effect. This would imply that the problem is completely unrelated to the cooling system (hey it can't be doing even 30% of it's normal work with what I have so far covered up !).

The icing on the carb manifold suggests that the air in the manifold is super cool as it comes out of the carb. (and it's pretty cold here right now anyway).

The car is stuttering a bit on first take up and needs choke for a long while till it reaches 60C, then it runs like a rocket.

Keep the suhhestions flowing, please.
dominic clancy

Dominic,
So how cold has it been in Europe this winter? I have read about the extreme cold weather in Russia and Eastern Europe. Ditto with Western Europe? Or is it just another Alpine winter?
Frank Nocera

Could the supercharger be the culprit in the sense that it is blowing extremely cold fresh air into the system? I am assuming that the outside temperature is very cold, well below freezing, and that the engine is getting a far faster dose of cold intake than with standard carbs.

I'm thinking that the car was designed for more moderate outside temperatures and that the blower is forcing an induction of frozen air. If the car were sitting still and just idleing does it tend to warm up, but when revving and driving does it then cool off?

I'll bet a radiator shield would be easy to make, the magnets or snaps would do the trick to hold it on to the front of the radiator. But the problem may persist until the outside temp warms enough so the air being forced into the carb and manifold is above freezing.

I have the Moss supercharger on my car and I have noticed this winter that it warms up more slowly than before I installed it. But I am not driving at all in very cold weather, we have been spared that so far this winter.

just two more cents worth. preheat the air going into the supercharger?? good grief, can you imagine a tube from the heater to the supercharger intake?

Ted

Ted

We have had temps of -8C here, nothing like as bad as in Germany or Russia, but we have had no rain worth speaking of in the north of the country since September, and have been in high pressure for weeks, so we have really bad air quality right now.
dominic clancy

Car doesn't heat up any faster sitting, and even when sitting in traffic it doesn't get any warmer than when on the move.
dominic clancy

then I think that completely closing off the radiator air flow with a shroud like you have ordered would help warm the engine itself, but that may not help the temp of the air being forced into the carb and manifold.

how about when the car is inside a garage, in from the frozen air, does it tend to warm up then?

could be a combination of factors too efficient cooling of the radiator, very cold temps outside, and forced air induction through the supercharger.
Ted

Dominic

You haven't answered Cam's question regarding a thermostat on the oil cooler. If you indeed do have an oil cooler and it either does not have a cover blocking air flow, or it has a thermostat that is not functioning (always open), you will get significant engine cooling from the oil cooler.

FWIW

Larry
58A
Larry Hallanger

I like Ted's idea. You could engineer a system involving an AC converter, a small electric heater, and a hot air intake box.

Since a 50/50 water-antifreeze mix has the best cooling efficiency, what if you switched over to straight antifreeze? That should get you a few more degrees.

If you eliminate the plumbing for the heater core (just pipe it back over to the other side of the enigne) it might also help, the downside of that being you'll still be freezing your berries off even if the engine gets warm.

A question: Would advancing the timing a bit help, or is that too dangerous with your very high compression?
Mark

Dominic,
A stupid question ,perhaps but you did mention that all things were new "except" the water pump. One possibilty here would be that althought the pump is turning , perhaps the impellers inside the pump are not. This could be a result of a broken shaft etc, or the impellers may be loose on their mounting and not supplying full water circulation. In this case would not the circulation of the heated water be reduced therefore a lower temp in the engine? Maybe the pump is supplying just enough circulation to prevent over heating but not enough to heat the engine properly.If the pump is defective by replacing it you would then have proper circulation of the heated water and no icing. PS: Rad blind should be there soon . They told 2/3 weeks delievery. let me know. Gord
Gordon Harrison

Dominic, your first entry stated that the radiaotr covered vs uncovered gave you a 20 deg C difference. This would indicate that there is some flow thru the radiator and the thermostat is not shutting off completely. Some thermostats have a bypass hole this may be your case. Try a different style thermostat or solder your bypass hole shut.

Secondly, I have not seen where you have tried shutting off your heater. This may be the root cause. If there is enough coolant and airflow thru the heater, it may be cooling off the engine too much. If the 80 degree thermostat made no change and there is no bypass hole in it, then I would suggest focusing on the heater system rather than the cooling system. Try bypassing the heater core.

Chuck


Chuck Schaefer

The answere is easy, drive something else! Leave your 'A' indoors during the winter months. My GTi Golf doesn't seem to mind the cold temperatures

Regards

Terry
Terry Drinkwater

I agree with those of you who said it's the thermostat (still passing some coolant when closed). If your water pump wasn't pumping, you'd have coolant blowing out all over from the boiling. I do think it would heat the engine more with the cabin heater off.
Tom

Again, thanks for the comments and helpful suggestions.

Cam, Larry, The oil cooler is completely covered (both sides) -I made a simple cover from cardboard and Gaffer tape that just sits on top of it. There is no oil thermostat fitted, but as there's no cooling going on, I don't think that should be an issue.

Kemper, The heat shield did fit. I have to remove the head to fit the compression-reducing copper gasket, so when I refit the manifolds, I will try and leave this off. I am a bit worried that this will cause problems in aggressive driving in the summer, but what the hell...

Gord, the water pump is fine. If the impeller was not turning, I would quickly have overheating problems locally in the head, and the laser temp device is telling me that the head temp is more or less uniform. The radiator blind is going to be a swine to fit, as there is so little space at the front of the rad to get hands down there. It may have to be a grille-off job to get it in. At the moment I am using a piece of plywood.

Chuck, I leave the heater off till I get to 70C on the gauge, and as the temp never goes any higher, I switch on and am just grateful for whatever I can get as background warmth. Switching it on (electrically and for water flow) does not seem to cause more than a 1-2 degree drop in temp. The heater core is original, so I suspect it is not very efficient anyway (I rinsed a large amount of radiator sealant and gunge out of it a few years ago).

Ted, I can't comment about how the car warms up in the garage away from the cold air as I am not yet at the point of being suicidal about this!!!!

Terry, I am still looking for a rich friend to give me a second car to drive - can you help? The A is my only car.......

Dominic



dominic clancy

Hi Dominic - the fact that the oil is being taken away from the engine means that it will be cooled - the pipes feeding it will still be in very cold air as well - blanking it off will keep the radiator from cooling it further but the oil will still be colder than if a thermostat was fitted .I would think that the super charger is your main problem though. Cheers Cam
C Cunningham

Dominic, hope we have been of some help. I'm still wondering about the ice on the intake manifold after a strong run. Most superchargers generate heat as they compress the air. I would think the intake would be warm from that, instead you see ice. Can't get that sorted out in my head. My first thought is that the supercharger would warm things up, not cause it to run cool. Anyway, thanks for asking for our ideas, it's not often we see an MGA that doesn't run hot! ;-)
Bill Young

Dominic,
I agree with what Bill just said. The supercharger should be compressing air at the manifold resulting in a slightly higher temperature. I would think that you'd experience icing upstream of the blower, at the carb. Are you sure your supercharger is working properly?
I just rebuilt my 1500 and I'm amazed at how cool it runs. I have a 160 deg. thermostat and the temp gauge doesn't go a hair above 160 any more. Before the overhaul it used to fluctuate between 160 and 200 depending on how hard I was pushing it. If I let it idle with the radiator covered I can get it to heat up, but as soon as I remove the cover the temp goes right back down.
Bill
Bill Boorse

Hi again

I think there's a slight confusion in terminology wrt the inlet manifold here, as with the SC there are effectively two - one between the Carb and the SC, and one between the SC and the cylinder head. The ice is forming on the first one between the carb and SC, which is experiencing a significant pressure drop. The SC itself is hot to touch, and the boost gauge is showing 4-5lb of boost when the foot goes down. The second stage inlet is at the same temp as the engine.

In the Judson setup, the Holley carb sits at the rear of the engine bay, just in front of the pedal box. The first manifold runs underneath the SC, parallel to the head, and is therefore about where the bottom of the SU carbs would normally sit, or maybe just a fraction lower. The second inlet manifold (ie the outlet from the SC) is in the position where the normal inlet is found. It just has a big SC bolted onto it instead of two small SUs.

You can see some pictures of an installation here

www.infostuff.com/carstuff/ mgacbc/mgajudson.htm

Dominic
dominic clancy

Dominic,
Sorry, I misunderstood. That's where I expected you would be getting icing.
Bill
Bill Boorse

Dominic, is your fuel pure gasoline, or does it have
alcohol in it?
gil

Hi Domonic

I've looked at my stock, unfortunatly I have no spare cars, I could send you a diecast model. Are you running fan blades? If so, take them off, an 82 or 88 degree thermostat should help. If none of this works move to a warmer climate, don't bother with the UK its freezing!

Terry
Terry Drinkwater

Dominic,

I live in Mississippi and have a supercharged TC. I had to install an offset manifold between the carburetor and the supercharger intake manifold so I could close the bonnet, and this small manifold will ice up in 50 degree (F) weather when I'm pushing it. I think that's just a fact of life due to the flow through it.

I doubt it has anything to do with engine temperature.

Gene
Gene Gillam

Gil, it's just standard premium gas.

Terry - like the idea of removing the fan blades - inspired! This will also bring a smidgeon more power!!!!!!

Die cast models are always appreciated....

dominic clancy

Back in the days when I drove my Sprite year around. [foolishly] I would completely block off the radiator with cardboard, remove the fan blades and run the heater fan full tilt.
I also added a Oldsmobile fan to the heater, which really blew much faster than the stock item.
When it started to warm up outside, I would either cut a hole in the center of the cardboard, or remove it entirely.
As as it gradually became warmer, I'd re-install the blades.
I have done this with several cars over the years, including a Datsun 510 , and a '76 Plymouth volare. [blush]
And many cars I've owned, if they ran a bit hot in summer, would run the heater fan on hot/high to cool the engine and save it.
But the passenger compartment does get hot.
LOL

SF
Dwight
Dwight

Dominic,
Do you happen to have an infrared thermometer? What I am thinking might help you is to map the temps through your engine system AND also your engine compartment. Altho the supercharger should heat the air by compression, there should also be a cooling effect from evaporation as the fuel atomizes in the air stream.

If it were my problem, I would very much like to have an independent reading of coolant temp, air temp, radiator temp, block temp at key points, and spot temps along the induction system. Mapping things out like this might point up a discrepency in the readings of your temp gauge (not overly likely) and give you an idea where the icing begins.

In the US, you can pick up an adequete handheld infrared thermometer with laser aiming for about $75US or so. It might be the best way to see where things are happening and certainly cheaper than damage to your engine.
Bob Muenchausen

This thread was discussed between 02/02/2006 and 06/02/2006

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