Intake Manifold Heater

[bsevans]

Well, I'll start this and it can serve to get me motivated to develop the documentation. I'm also very interested in feedback from all of you.

I've designed a manifold heater that will improve cold weather starts and idle which equates to lower emissions.


Here are two photos of the adapter plate.

 

[IDave]

Does that warm air intake just rest on those good looking headers, Ed? Or does it attach somehow?

 

[bsevans]

Where are the photos?

I run a header and use a fluid heat rise and fabbed a warm air intake for the 2F aircleaner that warms off the header.


Ed

NOW I see the pics....

The issue I have with using the coolant as a preheat is that when the carburetor needs it the most the coolant does not offer any where near the temperature that the stock exhaust manifold does. What I've used is a new generation of Instant-Heat dual element ceramic glow plug that is self regulating. The hotter it gets the more its regulating coil increases the resistance to the heater coil. This keeps the glow plug from burning itself up. In ten seconds this glow plug is not red hot but bright white hot. I also have a relay that shuts power to the momentary switch when the ignition is on. Even self regulating glow plugs do not like 14v. This type of glow plug can do this all day.

 

[bsevans]

That seems to be well thought out and I compliment you. However the coolant coming off the head gets hot very quickly, assuming a functioning thermostat. I was amazed at how quickly it heats. As important is the air going into the carb, that's why I use the "warm air intake"...it also prevents icing at operating temps.

Ed

I also have a warm air intake. I don't see how there is any comparison of the coolant temperature at what, maybe 180 to 190 degrees vs. the temperature of the exhaust striking the intake on a factory setup. The exhaust gasses are at least 600 degrees minimum. My goal was to come as close as I could to mimicking the initial environment as far as intake manifold temperature under the carburetor to vastly improve the cold weather starting characteristics. I've had long talks with Tim Hill in Avra Valley (an FJ40 guru and legend) about the use of a coolant system. It is better than no preheat. I just question how much. I would like to instrument a 2F with the coolant heat and with my heater and one with no heater at all. Then we could base our conversations on graphs that show the temperature rise in all three configurations. Sometimes it is best to analyze and not base our assumptions on anecdotal opinions. We all do it.

 

[bsevans]

"Sometimes it is best to analyze and not base our assumptions on anecdotal opinions. We all do it."


You could have said it all without saying that. I think you have over engineered the whole thing (especially for "Southern Arizona"), but then again, that seems to be your nature. I have no doubt that your glow plug gets hotter than my coolant. You seem to be trying very hard to insult people and pick a fight. Well, you won't get one from me. I improve my s*** to suit my own situation and enviornment. Could I let off the choke sooner with your system? Probably. Do I want another system(glow plugs, management systems, etc) to worry about? Nope. I embrace the simplicity of the Landcruiser, at least the older ones. That is a fine looking piece you made, or had made, but it's complexity does not suit me. You are not wrong and neither am I.
Just play nice... you might learn something and not piss everyone off here.
And although I am not one, there are several "Guru Landcruiser guys/gals" on the MudBoard.
Good luck and good cruising to you. You have a great looking rig there and I am impressed with it! Just tone down your acerbic wit just a little.



Ed

First off, I'm not interested in picking a fight with anyone. I like to come up with solutions to a problem that other may not have thought about. Is there only one solution to a problem - no - there are any number of solutions that work. As far as designing it for southern AZ. No, I don't need one. I rarely need to use my choke in this climate. I designed it for a cruiser friend who lives in Nashua NH. If you took offense from my posts then I apologize. There was none intended.

 

[4x4Poet]

Degnol, from my perspective, you took offense to bsevans' matter-of-fact style, not any actual insulting comments. So he doesn't sugar coat his opinions. Big whoop. My guess is, his to-the-point writing style comes from his mech engineer training and perhaps his personality we don't yet know.
Who cares? He has something valuable to say regarding the improvment of our Cruisers. As long as he presents good tips, he can cuss my name all through his posts, for all I care. Actually, he can insult me without bringing good tips. As Butch (Texican) once posted, internet bitch slaps don't hurt.

As you recognized, Degnol, bsevans does give well thought out rationale to support his opinions. This was very evident with his skid plate thread. I suffer from a similar attention to detail, as well. Some folks take offense, however minor.

BTW, this was a self-deprecating remark:
"Sometimes it is best to analyze and not base our assumptions on anecdotal opinions. We all do it."
What part of "we" doesn't also include bsevans? He's admitting to not having solid analysis to support the advantages of his glow plug set up. That, alone, proves he doesn't consider his opinion the last word. No doubt that attitude also comes from his mech eng training where fact must always rule over anecdotal opinion.

So, lighten up, Degnol.

And bsevans, FWIW, keep the tips threads coming. I enjoy them very much. (So far, the skid plate, solid state VR, and this glow plug set up.)

 

[HappyGilmore]

This interests me, since I live in Iowa and drive mine daily. Secondly, Cost???

 

[Mace]

One of the main reasons for a heater on a 2F with a header is icing of the carb.


Does the glow plug always stay hot??

And, how is the cast AL going to deal with such a localized heat source?

 

[PabloCruise]

I'm interested - tell us more...

 

[bsevans]

This interests me, since I live in Iowa and drive mine daily. Secondly, Cost???

Well, off the top of my head the prototype circuit to control the glow plug was under $90 dollars. The glow plug will run in the neighborhood of $11 to $15 depending on which series (instant heat is more). I'm confident that with a little digging the component cost could be reduced by $25 to $45. The piece of Aluminum plate which yielded two prototypes was in the neighborhood of $25 to $35. Yes, I've built a couple so far. The M10-1.25 inserts were from McMaster-Carr (p/n 90245A174) and were $3.22 each. They are key locking inserts and require either an insertion tool to drive the key locks in or a steady hand and a flat punch. Or you can take a dowel pin that will slip into the threaded insert. Drill out a piece of steel or aluminum to slip over the dowel pin. Make it long enough so you can drive the key locks flush with the plate without hitting the end of the dowel pin. The labor to do this was, well free. I did all the electrical and milling myself. If you have access to a Bridgeport and the heat riser gasket, you could make one from that. The holes in the gasket are spot on for the bolt pattern. If you need a drawing, I could put it into AutoCAD. Having given this info, I would prefer that you not make one until I can test this enough times to develop a thermal profile based on cold soaking a manifold with a carburetor attached and instrumented with a number of thermocouples. I also want to see how a 10 to 20 second on cycle affects the aluminum casting (the manifold) and the 6061-T651 aluminum plate. If it has repeatable data over an extended period of testing (at least 250 cycles) without a H/W failure, then I will start failure testing to see if I can damage either chamber or the glow plug by running the glow plug system longer than what I would consider to be necessary (accelerated life cycle). Correct me if I’m mistaken about this. My understanding is that carburetor icing only occurs, if it is going to occur, during the initial phases of starting, until the intake manifold is sufficiently heated, which brings the carburetor to a temperature where icing is unlikely. As a side note, can someone please explain to me how I can quote multiple posts in a single reply. Thanks

 

[Poser]

As a side note, can someone please explain to me how I can quote multiple posts in a single reply. Thanks

open multiple windows....who only has one browser open on Mudd...


Keenserts....those are the best threaded insert, hands down.


control C- copy the text you want quoted from the other post

control V- paste the text into the main post box that you are working on...


good luck!


-Steve

 

[Degnol]

[ My understanding is that carburetor icing only occurs, if it is going to occur, during the initial phases of starting, until the intake manifold is sufficiently heated, which brings the carburetor to a temperature where icing is unlikely. As a side note, can someone please explain to me how I can quote multiple posts in a single reply. Thanks[/QUOTE]


Although I am no automotive OR mechanical engineer, I have had carburetor icing occur on the highway, where I was at operating temps for well more than an hour. It is a combination of dew point (temp and humidity). In that particular case it was in my old 3.0CS, carburetted, and the foil hose from the warm air(exhaust manifold heated) intake was "off." Condesate in the fuel might have been a problem, too.

Ed

EDIT: I think it used to be a problem (maybe still is) in small planes with carburetted engines, and I think the remedy is something very similar to what you have designed. An electric heater anyway. With all your gu'vment work, was that a source for your idea?

 

[Degnol]

One of the main reasons for a heater on a 2F with a header is icing of the carb.


Does the glow plug always stay hot??

And, how is the cast AL going to deal with such a localized heat source?

Mace, I think icing of the carb occurs well above the base, where the heater is located. The icing occurs in the venturi....I believe, where the air(and moisture) is accellerated and cooled. Ice bulds up in almost molecular layers until it chokes the carb. To prevent icing, the preheat needs to be in the air intake....there again, I ASSuME the aforementioned statement, based on common sense and experience...not a science fair project.

BTW, when my carb iced up, it was not below freezing, just above, but it was very humid.

Dunno for fact.

Ed

EDIT:And as how the aliminum intake will handle the heat...I think BSevans has stated that his idea will heat to 250* in 45 seconds, far below the 600* that he states the exhaust temps that "bathe" the bottom of the intake with a stock intake/exhaust/bimetal/ flapper setup. There again, horse sense says it will be OK.

 

[Mace]

Yes, icing typically occurs in the venturis, but heat from the baseplate will aid in keeping the venturis clean.. The worst case of icing I have happened was with a 460 in a F350 driving from Mammoth to Bishop, Ca. It was cold that morning..

The carb ices due to humidity and the quasi "swamp cooler" effect that air undergoes while flowing into the carb.

The "white hot" temp is what had me concerned.. But if it is only for a short period of time I kinda doubt that it will do much of anything for the startup. Much less wile the motor is running..


Doing this mod where Bstevens lives is like boosting the heated seats for a long daytime drive across the Sahara..

 

[bsevans]

The "white hot" temp is what had me concerned.. But if it is only for a short period of time I kinda doubt that it will do much of anything for the startup. Much less wile the motor is running..


Doing this mod where Bstevens lives is like boosting the heated seats for a long daytime drive across the Sahara..

I hear that. We had a cold front come through these parts last weekend. A chilly 106, 106 and 105 today; had me looking for a coat. I understand that this icing can occur with the factory exhaust system under the right conditions with an engine at running temperature. Then my little mod will obviously do no more than what I intended it for, which is, to preheat the flow coming through the carburetor and into the cylinders resulting in a reduction in the time to achieve better combustion, a smoother idle, and reducing the time needed for the choke. The problem with icing is obviously not one the factory setup, the coolant heater or this glow plug heater has or will resolve. Nor are they intended too. I would think this only occurs on carbureted engines. I do appreciate the posts explaining the process and it makes sense. I've seen a similar effect on thermal chambers using LN2 on high humidity days. The orifice on the solenoid valve would ice up during the transition from an ambient condition to cold cycle. I personally have never had the pleasure of experiencing the phenomena. I have experience more than my share of vapor locks here during the high heat holy days. That caused me to determine what the problem was with that damn blower (cold solder joints on the circuit board, redid all the discreet component joints and it has worked for 15 years now).

I know that some complain about my writing style being a little too matter of fact. Like I think I know everything or it's my way or the highway - I do not. But I do have an approach to life that is based on the fact that I realized years ago that the more I thought I knew, the more I realized just how much I don't know. It has made life worth getting out of bed each morning; because I just don't know what life will teach me and who the professor will be. Not to be morbid, but when I suck that last breathe of air, I just hope that a light goes on and my last thoughts are "damn, that’s how you do it". I really can not think of a better way to take that big staircase in the sky.

 

[Mark W]

Carb Icing: This occurs at normal engine operating temps, usually during a cruise condition. Not during startup. It is cause by a combination of ambient air temps, high moisture content of the air and cooling of the incoming air as it passes through the venturi.
A heated intake manifold (by whatever means) can largely prevent this because the heat in the intake (and therefore carb and any fuel contained therein) is enough to prevent the formation of ice. It is normally more of a problem in engines (such as a straight six) where the intake it relatively isolated from the rest of the engine (the opposite example would be a V8 which has the manifold in the middle, surronded by heat generating combustion chambers and usually with an exhausty and/or fluid passage through the manifold).


Re: the intake heater that this thread is about. Just how much heat is actually produced by this glow plug? Regardless of how hot the central point gets, how much heat energy is actually produced and soaked up by the manifold? What is the current draw of the glow plug.? In the design application for the glow plug a point source for the heat is all that is needed to ignite the fuel/air mixture in a diesel engine. But the overall output is more of a concern in the application we are looking at here.
It takes a fair bit of heat to raise the temp of the entake and just as (probably more) importantly the carb and fuel in the carb. And it takes some time (in terms of how long a glow plug is normally energized).

Does this glow plug generate enough heat to do this? And how much electricity will it take? This has to come from the battery after all, and if it is cold enough to impact starting then the battery may not have a whole lot of power to spare.

While the fluid heaters do not approach the heat of the factory ehaust manifold, this amount of heat is unneccesary.

A fluid heater does not help during initial startup of a cold motor. Neither does the factory ehaust manifold (although to does come nto play much sooner than the standard fluid heater). But there is a simple and proven approach that changes this. Plug in block heaters. If the coolant is heated prior to the "cold" start of the engine the manifold is already heated. An additional step improves this even more. Either by itself or in addition to the freezeplug heaters, add an external tank heater with the intake feeding from the drain port on the block and the outflow plumbed into the"heater hose" side of the intake preheater plate. The other side of the intake heater is of course connected to the heater hose fitting on the head.
When the tank heater is energized, the convective flow generated pushes hot coolant through the intake heater before it flows into the head. Since the intake side of the heater is pullng fluid out of the drain port, a very effective circular pattern is generated which flows through the intake before going on to shed the rest of it's heat in the engine.

The proof is in the pudding as the saying goes. An 800 watt heater, with no additional heaters involved, turned on for about 15-20 minutes can bring the intake manifold to warmer than body temp (about 100-105 F at a guess) when the starting temp of the engine (and the continuing ambient temp) is -25F.


Mark...

 

[bsevans]

Great post and I hope to have answers for you as soon as I have enough testing. I quote here from one manufacture of glow plugs I'm looking at.
"Diesel starting is now quicker, more reliable and more environmentally friendly.
One example is the 2-coil heating technology: glow plugs of this type have not only a heating coil to maintain the optimal heating temperature, but also have a regulator coil that effectively protects the glow plug from overheating. In this way glow plugs are extremely reliable and durable.

Modern diesel trucks and cars are, in addition, equipped with the innovative three-phase heating system (pre-heating — heating during starting — post-heating). This means: the glow plug not only heats prior to and during the starting phase, but also up to 180 seconds after starting. This protects the environment and the engine.
I'm posting a gif that shows the temp vs time.
So you can see that with the right circuit and glow plug, you can run a glow plug after starting without damaging the glow plug.

Folks, this is an experiment that I'm going thru and letting everyone follow it. It may turn out that it is not practical, too expensive, or heaven forbid, damages the intake casting or the adapter plate. Current draw for a single glow plug is not a problem for vehicles with a good alternator and healthy battery. Weak charging systems need not apply. Let's just see where this takes us. The trail of discovery in many instances is more exciting than what is at the end.

 

[Mace]

. But there is a simple and proven approach that changes this. Plug in block heaters. Mark...

Ding ding

 

[Degnol]

I know that some complain about my writing style being a little too matter of fact. Like I think I know everything or it's my way or the highway - I do not. But I do have an approach to life that is based on the fact that I realized years ago that the more I thought I knew, the more I realized just how much I don't know. It has made life worth getting out of bed each morning; because I just don't know what life will teach me and who the professor will be. Not to be morbid, but when I suck that last breathe of air, I just hope that a light goes on and my last thoughts are "damn, that’s how you do it". I really can not think of a better way to take that big staircase in the sky.

Excellent philosophy

Additionally, I just did a second application of skin thickener to alleviate my symptoms

Ed

 

[bsevans]

Ding ding

I know from first hand experience with my turbo diesel that sometimes that 100 foot extension I carry for my block heater may as well be plugged into my a** for all the good it's doing me. If every where you go/park overnight in a cold climate has a readily available AC outlet then you are living a charmed life and have no need for a pre-heater of any design.