Cold heater!!

[perkins2.0]

Listening for that gurgle of hgf it is a sad day when that noise reappears!

Sam it is more the nature of a direct injection diesel that doesn't make a huge amount of heat. The heater on a diesel engine can be lacking from a petrol. Also advising someone to up the fueling on a car suspected of hgf is not the best advice.

sorry, but acctually a direct injection diesel engine runs a hell of a lot hotter than a petrol or infact an indirect diesel,
they run by igniting their fuel with their own compresion heat, they do not even need the use of heater plugs!

[H48HPE]

sorry, but acctually a direct injection diesel engine runs a hell of a lot hotter than a petrol or infact an indirect diesel,
they run by igniting their fuel with their own compresion heat, they do not even need the use of heater plugs!

I think you might find countrydude is correct - a petrol engine runs hotter than a diesel. And maestro / montego diesel engines run cooler than most diesel engines.

I understand its the exhast gas temperature of a petrol that makes them hotter than the cooler exhaust gas from a diesel. don't think its anything to do with the ignition method just the temperature of the burn...

[E_T_V]

Peak combustion temp of a diesel is higher than a petrol

However,

Cylinder temperature and exhaust gas temperature of a diesel is much lower than a petrol generally giving lower thermal transfer to the engine and thus in our engines a cooler heater.

[perkins2.0]

The leaving exhaust gasses from a diesel are still a hell of a lot hotter than a petrol its only beacuse the burn continues out of the exhaust in a petrol (much less efficient) that people think its hotter but in acctuall fact if you rev out a diesel maestro or any diesel on stand-still it will melt bottles out its tailpipe because the gasses are that hot! where as a petrol engine will not even touch the bottle in terms of heat.
so with a working heater matrix and a clean, clear cooling system, the heater should be "burn ya face hot".
diesel maestro's are generally cooled very well so they may take a couple minutes longer than any other petrol maestro to heat up to its normal working temperature but when it does.. it should get a lot hotter providing everythings okay.
i would not personally go down the root of putting a higher opening temp termostat in a diesel especially as this is putting unessesary stress on its internals when it reaches this temp even though its only a few degrees more.

[Chris Y]

You should have no problem getting 1200bhp out of a diesel then.

[E_T_V]

The leaving exhaust gasses from a diesel are still a hell of a lot hotter than a petrol its only beacuse the burn continues out of the exhaust in a petrol (much less efficient) that people think its hotter but in acctuall fact if you rev out a diesel maestro or any diesel on stand-still it will melt bottles out its tailpipe because the gasses are that hot! where as a petrol engine will not even touch the bottle in terms of heat.
so with a working heater matrix and a clean, clear cooling system, the heater should be "burn ya face hot".
diesel maestro's are generally cooled very well so they may take a couple minutes longer than any other petrol maestro to heat up to its normal working temperature but when it does.. it should get a lot hotter providing everythings okay.
i would not personally go down the root of putting a higher opening temp termostat in a diesel especially as this is putting unessesary stress on its internals when it reaches this temp even though its only a few degrees more.

Err what a load of carp.

EGT's in diesels are FAR lower than that of petrol engines.

Lets face it when did you last see a diesel turbo glow red hot, yet it is quite routine to get petrol turbos this hot.

Oh and why are VNT turbos common on diesels and not petrols? Because the VNT mechanisms can't cope with the heat from the petrol engines!

All cars will melt bottles from the tailpipe under the right load conditions, that is hardly a scientific test! The melting point of plastics generally being under 200 deg C and the EGT's being 700+ under load.

A diesel maestro heater will never burn your face off for several reasons.
1. The heat generated by the diesel engine isn't that great, and when not under load the heat is extracted by the heater quicker than the engine can replace it so the coolant temp will decrease.
2. There are no face level vents capable of blowing hot air out of!

[perkins2.0]

You should have no problem getting 1200bhp out of a diesel then.

a smart awnser.. YES all you need to acheive this, is amazing V.E. and strong engine!

[perkins2.0]

Err what a load of carp.

EGT's in diesels are FAR lower than that of petrol engines.

Lets face it when did you last see a diesel turbo glow red hot, yet it is quite routine to get petrol turbos this hot.

Oh and why are VNT turbos common on diesels and not petrols? Because the VNT mechanisms can't cope with the heat from the petrol engines!

All cars will melt bottles from the tailpipe under the right load conditions, that is hardly a scientific test! The melting point of plastics generally being under 200 deg C and the EGT's being 700+ under load.

A diesel maestro heater will never burn your face off for several reasons.
1. The heat generated by the diesel engine isn't that great, and when not under load the heat is extracted by the heater quicker than the engine can replace it so the coolant temp will decrease.
2. There are no face level vents capable of blowing hot air out of!

As i said in my last message about the exhaust gasses...
the only reason you would think the gasses from a petrol are hotter (glowing manifols etc.) is beacuse they are much less efficient and they don not burn all their combustable material in their cylinders and the combustion continues out of the mainfold.
the gasses how ever after the combustion has taken place is a lot cooler than a diesel.
I can tell you this for a 100% fact!
i said on stand still.. not under load!
the reason that petrols heat up quicker(but still not as hot jus get to their normal operating temp quicker) is because they are built a hell of a lot less materials than a diesel lump because they are not put under as much stress.
hope that helps ...

[H48HPE]

this is getting really tedious.

The original poster was wondering what he could do to make his heater run hotter.

a couple of suggestions came back to say that diesels don't heat up as hot as a petrol. That is a fact. more waste heat is generated in a petrol engine - that heat has to go somewhere - it is absorbed by the metal head and block. that heat then heats the coolant in turn this is used to heat the car up. because there is less waste heat in a diesel it doesnt get the engine as hot.

the suggestion to put a higher temp thermostat in is a good one as it will allow a greater accumulation of waste heat in the diesel engine before the radiator operates to cool it down. therefore the heater will be hotter. there was good advice about cleaning out the matrix too.

the only issue i can see with a higher temperature stat is that an inrush of cool water into a hotter engine could cause some stress - however it is a well proven and reliable idea that has been used extensively.

Can we have an end to this now?

[Guest]

Stick a good hose or pressure washer through both pipes on the heater matrix and also the pipe on the inlet manifold to loosen all the debris, keep going till it runs clear. This should help improve matters.

The dramatic way I managed a suberb heater in the diesels is by flushing the cooling system, fitting a good 88 deg stat, replacing the heater foam seals, and lastly for super performance the HG.

When new the HG has small holes in for the water to pass from the block to the head. Smaller holes nearer the water pump and larger ones further away. The galleries around these holes however are much larger. As the gasket wears and corrodes, the holes open up to the shape of the gallery letting more water through and preventing quick warm up and constant heat.

When I replaced the HG warm up time was so much quicker, heat was constistant, and temperature was hotter

Bit extreme to do tho if it's not needed!

Rich

[perkins2.0]

well no because i know as a FACT that diesels run hotter!
but you believe watever crap you want.


Yes all that work to your engine sounds nice, bet the heater is a lot hotter ayy?

[countrydude]

That cleared that up then. What I like best is how you proved they run hotter, without just blindly repeating what you have already said. If you know as a fact then surely you must be able to prove it?

well no because i know as a FACT that diesels run hotter!

[E_T_V]

As i said in my last message about the exhaust gasses...
the only reason you would think the gasses from a petrol are hotter (glowing manifols etc.) is beacuse they are much less efficient and they don not burn all their combustable material in their cylinders and the combustion continues out of the mainfold.
the gasses how ever after the combustion has taken place is a lot cooler than a diesel.
I can tell you this for a 100% fact!
i said on stand still.. not under load!
the reason that petrols heat up quicker(but still not as hot jus get to their normal operating temp quicker) is because they are built a hell of a lot less materials than a diesel lump because they are not put under as much stress.
hope that helps ...

EGT = EXhaust Gas Temperature. Diesels have lower temps than petrols. There is no way you can argue different sensibly.

The peak combustion temp is indeed higher for diesels as I said earlier on, however this does not equate to how much heat is transfered to the cylinder wall, head or piston crown. Also as diesels work with excess air this air cools the combustion temp further as there is large volume of gas that is just well pretty inert really.

The reason petrols heat up faster is that they transfer more heat to the cylinder walls, piston crowns and cylinder head. The O series and prima share a pretty much identical block, both have an alloy head and both are two litre. Your living in another world if you think they heat up at the same rate! The petrol gets hotter a lot faster.

[G Force]

well no because i know as a FACT that diesels run hotter!

Its a shame really, it is like you have seen the pictures from space but you still believe the earth is flat.

I don't understand why you have come to the conclusion about EGT, maybe you have compared a diesel engines exhaust temperature running at 4500rpm on its governer while doing a smoke test for an MOT, and a petrol engines exhaust temperature running at 4500rpm on light throttle and mistakenly thought they were both under the same load.

Diesel engines have long been proven to have a superior thermal efficiency to a petrol engine. They achieve this by making better use of the energy in the fuel through the increased pressure on the combustion stroke.

All engines convert the stored energy in the fuel into heat on the combustion stroke, if an engine makes better use of its fuel, its thermal efficiency is increased. Thermal efficiency can be shown by calculating the losses incurred in an engine.

Petrol engine:
Losses to coolant 33%
Losses to friction 10%
Losses to exhaust 33%
Total losses 76%
Thermal efficiency 24%

Diesel engine:
Losses to coolant 31%
Losses to friction 11%
Losses to exhaust 24%
Total losses 66%
Thermal efficiency 34%

The major saving in a diesel engine is in the loss to the exhaust.


Some generic temprature and pressure figures during the combustion cycle but for engines of the same era as the Maestro diesel.

Petrol engine.

Induction stroke: Temperature: 15 degrees C. Pressure: 14.7 lb/in
Compression stroke: Temperature: 350 degrees C. Pressure: 150 lb/in
Power stroke: Temperature: 2500 degrees C. Pressure: 550 lb/in
Exhaust stroke: Temperature: 700 - 1200 degrees C. Pressure: 60 lb/in

Diesel engine.

Induction stroke: Temperature: 15 degrees C. Pressure: 14.7 lb/in
Compression stroke: Temperature: 700 degrees C. Pressure: 500 lb/in
Power stroke: Temperature: 2500 degrees C. Pressure: 1200 lb/in
Exhaust stroke: Temperature: 550 - 650 degrees C. Pressure: 60 lb/in

[cybernaughthippo]

Just to add to the argument... Does it matter what fuel you use... Surely the heat comes from the water entering the heater matrix right?? Then surely whoever has the highest temp valve will be hottest as it will try and maintain the engine and thus the water around it at the opening temp of the valve.

In other words a car with an 88deg will have cooler water and less heat then one with a 92deg valve.... What ever the fuel is and assuming its upto temp?

On a different note my Ledbury is way hotter than my rover... Colder in bulgeria maybe? Also my rover doesnt give any heat until its upto temp at all, has anyone come across this?