What temp should a 440 IC gas run at? I recently got the machine back together and the temp runs a little hotter when I put an aftermarket car glass pack muffler on it so I am sort afraid to run it with this restricting it.
Any thoughts?
Thnaks in advance,
Cliff
440 IC Temp?
Glasspack should not cause any extra heat, less if anything due to less restriction in the exhaust. Two things to check, make sure your timing is not off, and that the engine heat shield is in place, this will cause false readings.
I run 180 degree thermostats in all of mine, and using an infrared thermometer, they run right about at that, Winter or Summer.
Lavoy
I run 180 degree thermostats in all of mine, and using an infrared thermometer, they run right about at that, Winter or Summer.
Lavoy
Call me silly but I'm wondering if it might not be a bit the other way around than the way you're thinking on the muffler. If you went to more restriction on the muffler, wouldn't it tend to make the engine draw less air on the intake and run richer making it run cooler rather than warmer? Less restriction would mean less back pressure so leaner and probably hotter. Of course, it all depends on where you started in terms of how well tuned it was before you replaced the muffler. Without a heat shield the exhaust gas temperature is going to change as a function of the mixture with peak EGT occurring at perfect balance of fuel to air. Hotter exhaust manifold less heat shield equals higher reading on the gauge.
Bill Wattson
And I'll say I could be more wrong than you Lavoy but here's my reasoning based only on limited experience.
One of the tests that you do if you think that you might have a plugged exhaust is to connect a vacuum gauge to the intake and run the engine at mid-rev RPMs. An exhaust restriction is indicated by a drop in vacuum as the back pressure of the restricted exhaust causes the engine not to be able to pull in more air to keep the cycle going. The engine overall looses power and the temperature of the engine goes down as a result of power loss.
In an airplane with a carburated engine you have a mixture control that you use to "tune" the engine for peak efficiency at any altitude. The normal procedure is to lean the mixture to peak Exhaust Gas Temperature or EGT and then back off 25 degrees. One of the things that pilots are taught to help manage engine temperature in high power situations, such as climb outs, is to richen the mixture to reduce engine temperature. The gasoline itself has a slight cooling effect but the reduction in power helps maintain the engine below redline.
Or I'm completely full of #%$^$ and have no idea what I'm talking about. Could be the later. Wouldn't be the first time.
I might do a like experimenting with a small gas engine to try this out. Seems like I had an old Mustang that had restricted exhaust due to a catalytic converter issue that exhibited this behavior but it was 20 years ago and my memory is failing fast.
Well, that probably way more than enough on this topic and I'm going to shut up now. In any case, I think the missing heat shield needs to be replaced.
One of the tests that you do if you think that you might have a plugged exhaust is to connect a vacuum gauge to the intake and run the engine at mid-rev RPMs. An exhaust restriction is indicated by a drop in vacuum as the back pressure of the restricted exhaust causes the engine not to be able to pull in more air to keep the cycle going. The engine overall looses power and the temperature of the engine goes down as a result of power loss.
In an airplane with a carburated engine you have a mixture control that you use to "tune" the engine for peak efficiency at any altitude. The normal procedure is to lean the mixture to peak Exhaust Gas Temperature or EGT and then back off 25 degrees. One of the things that pilots are taught to help manage engine temperature in high power situations, such as climb outs, is to richen the mixture to reduce engine temperature. The gasoline itself has a slight cooling effect but the reduction in power helps maintain the engine below redline.
Or I'm completely full of #%$^$ and have no idea what I'm talking about. Could be the later. Wouldn't be the first time.
I might do a like experimenting with a small gas engine to try this out. Seems like I had an old Mustang that had restricted exhaust due to a catalytic converter issue that exhibited this behavior but it was 20 years ago and my memory is failing fast.
Well, that probably way more than enough on this topic and I'm going to shut up now. In any case, I think the missing heat shield needs to be replaced.
Bill Wattson
I know what you mean on planes, I think it is different, but can't tell you why, only gues is you do not have mixture control on a car engine. Using your catallytic converter example, back in my automotive days, we would have people come in with a complaint of whatever type on their car. I remember opening one guys hood, and starting the engine, revving it up slightly, and in about 5 seconds, the exhaust manifold was glowing. Needless to say, kind of a WOW type experience. The problem was a plugged converter which was causing restriction in the exhaust. Remove the restriction, problem solved. From then on, that was always our dead give away for that type of problem.
Lavoy
Lavoy
-
Stan Disbrow
- 350 crawler
- Posts: 2898
- Joined: Fri Jul 15, 2005 3:13 pm
- Location: Raleigh, NC
Hi,
Some combustion chamber shapes and valve types are designed to scavenge the cylinder of exhaust gases with a specific about of backpressure. Note the operative word here: Some.
As in the things have to be designed with malice aforethought to having that backpressure.
Most 4-cycle recriprocating engines are not designed with such thinking, though. And, I'll go out on an extended hydraulic ram here and say that Deere never thought this way during the design phase of any of our old iron.
So, in our case, I'd say that anything that lets the nasty old burned gases out of, or new charge mixture into, these poor old things would be considered a good thing.
The first thing we need to lose is that cast iron exhaust manifold. Let's make up some header pipes. Heck, let's even tune them such that when running at our favorite RPM we have it such that the last exhaust pulse is creating a partial vacuum at the exhaust valve.
Next, let's lose that intake manifild as well and make up an adapter for a couple motorcycle carbs. I haven't given it any thought until right this second, but there must be an old bike carb that is close enough to perfect for the intake charge volume we need for our favorite RPM.....
That ought to do it without getting into changing the valving, piston and combustion chamber shapes.
Just like tuning up a street engine for racing, actually. It'd be a hoot.
Maybe I'll pay with my old 'M' this spring. Heck, it already has a pair of homemade pistions in it. I'm sure it could use a little breathing work to go along with them.
I wonder what folks would say at the tractror shows if the 'M' showed up sporting a pair of side-draft bike carbs and a set of stainless steel header pipes???
Later!
Stan
Some combustion chamber shapes and valve types are designed to scavenge the cylinder of exhaust gases with a specific about of backpressure. Note the operative word here: Some.
As in the things have to be designed with malice aforethought to having that backpressure.
Most 4-cycle recriprocating engines are not designed with such thinking, though. And, I'll go out on an extended hydraulic ram here and say that Deere never thought this way during the design phase of any of our old iron.
So, in our case, I'd say that anything that lets the nasty old burned gases out of, or new charge mixture into, these poor old things would be considered a good thing.
The first thing we need to lose is that cast iron exhaust manifold. Let's make up some header pipes. Heck, let's even tune them such that when running at our favorite RPM we have it such that the last exhaust pulse is creating a partial vacuum at the exhaust valve.
Next, let's lose that intake manifild as well and make up an adapter for a couple motorcycle carbs. I haven't given it any thought until right this second, but there must be an old bike carb that is close enough to perfect for the intake charge volume we need for our favorite RPM.....
That ought to do it without getting into changing the valving, piston and combustion chamber shapes.
Just like tuning up a street engine for racing, actually. It'd be a hoot.
Maybe I'll pay with my old 'M' this spring. Heck, it already has a pair of homemade pistions in it. I'm sure it could use a little breathing work to go along with them.
I wonder what folks would say at the tractror shows if the 'M' showed up sporting a pair of side-draft bike carbs and a set of stainless steel header pipes???
Later!
Stan
There's No Such Thing As A Cheap Crawler!
Useta Have: '58 JD 420c 5-roller w/62 inside blade
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Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)
Useta Have: '58 JD 420c 5-roller w/62 inside blade
Useta Have: '78 JD350C w/6310 outside blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)
Lavoy,
Now I can't help myself. I'll bet you that the car was fuel injected and not carbureted and the reason that the catalytic converter was plugged was that it had been dumping fuel down the exhaust for some time and melted the insides of the converter causing a blockage.
In an injected engine the amount of fuel is regulated by the throttle position and things like a flow sensor on the intake as well as feedback from oxygen sensors in the exhaust to manage the problem you have to manage manually in an airplane with a carburetor.
I'm betting that if you put a valve on the exhaust of an old JD tractor engine and varied the amount of back pressure above what the engine was tuned for, the engine will lose power and the operating temperature of the engine will go down. You'd need to do this with an engine without a thermostat so that's why I'm thinking a small air-cooled engine would make for a better experiment.
Well, it's like we used to say in nuclear power; never preceed any major evolution with anything more predictive than "Hey, watch this!" If I get to trying it in the next week or so, I'll try to put it on youtube.
Now I can't help myself. I'll bet you that the car was fuel injected and not carbureted and the reason that the catalytic converter was plugged was that it had been dumping fuel down the exhaust for some time and melted the insides of the converter causing a blockage.
In an injected engine the amount of fuel is regulated by the throttle position and things like a flow sensor on the intake as well as feedback from oxygen sensors in the exhaust to manage the problem you have to manage manually in an airplane with a carburetor.
I'm betting that if you put a valve on the exhaust of an old JD tractor engine and varied the amount of back pressure above what the engine was tuned for, the engine will lose power and the operating temperature of the engine will go down. You'd need to do this with an engine without a thermostat so that's why I'm thinking a small air-cooled engine would make for a better experiment.
Well, it's like we used to say in nuclear power; never preceed any major evolution with anything more predictive than "Hey, watch this!" If I get to trying it in the next week or so, I'll try to put it on youtube.
Bill Wattson
Bill,
Could be, never thought of that, but at the time I was there, fuel injection was not in that wide of use. From what I recall, it was most likely the Iron Duke 2.5L in the early Citation/Skylark chassis, and they used a little staged two barrel. I don't think they got fuel injection until they changed them to the Tech4 in the late 80's. I remember a place I worked at in the later 80's had an S10 with one in it.
Lavoy
Could be, never thought of that, but at the time I was there, fuel injection was not in that wide of use. From what I recall, it was most likely the Iron Duke 2.5L in the early Citation/Skylark chassis, and they used a little staged two barrel. I don't think they got fuel injection until they changed them to the Tech4 in the late 80's. I remember a place I worked at in the later 80's had an S10 with one in it.
Lavoy
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