monitoring cylinder head temperatures
#1
monitoring cylinder head temperatures
Is it worth doing?
I know that it's done a lot on airplane engines, but a significant portion of those are air cooled and thus don't have coolant sensors.
But I was wondering if it might be a good way of indirectly keeping track of piston temperatures to run 4x CHT probes under the spark plugs with a 4 way gauge. That way if one cylinder is running lean, it will show higher temperatures than the others and you can go "oh **** I have a problem I need to address" instead of melting a piston. Or am I completely misunderstanding what CHT probes can be used for?
I know that it's done a lot on airplane engines, but a significant portion of those are air cooled and thus don't have coolant sensors.
But I was wondering if it might be a good way of indirectly keeping track of piston temperatures to run 4x CHT probes under the spark plugs with a 4 way gauge. That way if one cylinder is running lean, it will show higher temperatures than the others and you can go "oh **** I have a problem I need to address" instead of melting a piston. Or am I completely misunderstanding what CHT probes can be used for?
#4
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Monitoring watercooled cylinders with four oxygen sensors: "Oh ****, I'm about to have a problem I should address"
Monitoring watercooled cylinders with four EGT sensors: "Oh ****, I'm now having a problem I should address"
Monitoring watercooled cylinders with four CHT sensors: "Oh ****, I had a problem I should have addressed and now my motor is blown up"
Monitoring watercooled cylinders with four EGT sensors: "Oh ****, I'm now having a problem I should address"
Monitoring watercooled cylinders with four CHT sensors: "Oh ****, I had a problem I should have addressed and now my motor is blown up"
#13
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To be fair, the sensors don't last long sitting in a turbo manifold. It's really meant to dial in per-cylinder trims and then get removed afterwards. EGT sensors are a better option if you want something that lasts a while and still provides more data than a single sensor.
#14
Monitoring watercooled cylinders with four oxygen sensors: "Oh ****, I'm about to have a problem I should address"
Monitoring watercooled cylinders with four EGT sensors: "Oh ****, I'm now having a problem I should address"
Monitoring watercooled cylinders with four CHT sensors: "Oh ****, I had a problem I should have addressed and now my motor is blown up"
Monitoring watercooled cylinders with four EGT sensors: "Oh ****, I'm now having a problem I should address"
Monitoring watercooled cylinders with four CHT sensors: "Oh ****, I had a problem I should have addressed and now my motor is blown up"
Also if you're wanting it perfect, I'd put some higher-octane-than-normal fuel and get a well-established baseline for your knock sensor and set fairly tight buffer so that say, 8% to 10% more knock activity than the base the per-cylinder knock detection pulls timing. Of course you already have that if you think you need 4x O2's or EGTs.
#17
Google found some numbers
Source: https://www.rbracing-rsr.com/rsrgauge.htm
Megamanual mentions it too.
Source: https://www.rbracing-rsr.com/rsrgauge.htm
Megamanual mentions it too.
Last edited by sparkybean; 01-15-2016 at 06:18 PM.
#20
True, but why would you do that when you could do it for 1/5th cost with EGT sensors?
You can leave them permanatly fitted as they last forever, are cheap, and are simpler to wire. Drive one with an AD595 with no external parts, unlike an 02 which needs a complex controller.
02's per cylinder are only worth the effort if you are pressure compensating, thus getting absolute values.
You can leave them permanatly fitted as they last forever, are cheap, and are simpler to wire. Drive one with an AD595 with no external parts, unlike an 02 which needs a complex controller.
02's per cylinder are only worth the effort if you are pressure compensating, thus getting absolute values.