air cooled aircraft engines go up to a minimum of something in the 425F range which is about 218C. From a powerplant management perspective, its crucial to understand that CHT and EGT tell us quite different things about whats going on inside the engine. The CHT gauge wiring consists of a 5 meter long wire which reaches from the engine #3 spark plug in to the rear to the dash. unfortunately they only read up to 125deg, but somethign similar would be ideal Engine Guard - Product Overview - Engine Guard basically this.. "cylinder head temp gauge" VDO 12v DIGITAL CYLINDER HEAD TEMP GAUGE KIT 4WD TRUCK | eBay The burn rate of the air-fuel charge is fastest a mixture that is slightly richer than stoichiometric, approximately 50F rich of peak EGT (50F ROP). Email care allows us to provide important service detail that can be later referenced by both the customer and our care staff. We feel critical temperatures are 425F when must have the sensor at the 8 Alternatively, changing the mixture can affect CHT by changing the rate at which the air-fuel charge burns, and therefore causing ppto occur earlier or later. A Cylinder Head Temperature gauge is the missing gauge on any air-cooled vehicle. Make your product selections based on the PRODUCT DESCRIPTION and OPTION INFORMATION presented in the detailed product listing. When adjusting power settings and mixture, CHT is the most important reference measurement, because CHT is the best proxy we have in the cockpit for internal cylinder pressure (ICP) which represents stress on the engine. Of course, if pilots have lots of money and like ignorance, who would care? Some other guys get nervous the trick is the cool down got to get under 300F before you shut down. Aluminum melts around 1500 F. It is better too big than too small. them and could guess when maintenance is due, but then. Why not have an exhaust temperature gauge (EGT), as do general aviation (GA) aircraft? We are still processing and shipping orders from our warehouse as normal even while our site is offline. 1. Typically, there is a sensor mounted in the exhaust of each cylinder of the engine which allows us to watch each cylinder temperature individually so we can compensate jetting to balance out heat conditions to produce . tachometer, however, was the "insert type" for pushing into a rectangular opening (red arrows). You should establish a target CHT that represents the maximum stress you want to place on your engine - 380F works well for most Bonanzas and Barons under typical conditions - and then adjust your power settings, mixture, and (if applicable) cowl flaps to ensure that all cylinders are operating at or below that target. Burned exhaust valve:Slightly elevated EGT on affected cylinder only (usually by about 20F to 60F, depending on how badly the valve is burned). Power Products. has to be monitored closely or the pilot may burn up his engine. That's quite an oversight for an air cooled engine that is prone to self-destruction from running too hot. This type of gauge is commonly preferred to oil or water temperature gauges by motoring enthusiasts as the performance data is registered quicker. 200 degC on a spark plug is no problem. IMPORTANT GAUGE YOU CAN HAVE ON YOUR VW! Copyright 2021, Savvy Aviation, Inc. All rights reserved. I would also monitor all 4 cylinders. by Robert Hodge Mon Feb 16, 2009 12:46 pm, Post Therefore, attempting to limit EGTs in an attempt to be kind to the engine is simply wrongheaded. by airkooledchris Mon Apr 11, 2011 5:08 pm, Post wiring harness, and the sending unit, you do not have to purchase these Manufacturer; Certification; Size; Alcor. which varies widely from manufacturer to manufacturer. This type of gauge is commonly preferred to oil or water temperature gauges bymotoringenthusiasts as the performance data is registered quicker. It is specifically made and calibrated to provide an accurate reading in the ranges of the VW air cooled engine. It is also good to have an hour meter/tachometer so This is THE MOST EUR. EGT gauges are found in certain cars and aeroplanes. Engine wont start, screeches then shuts off. I'm putting a sender on each of #1 and #3. . A cylinder head temperature gauge (CHT) is an essential tool used to monitor the running temperature and health of any air-cooled engine. also easily visible on the side bar. It had seized in the cylinder while running. Gauge importance (to US), in order, Cylinder by Bleyseng Thu May 19, 2011 6:32 am, Post 200C is 392F. I would hesitate in saying that an air cooled engine runs hotter than a water pumper, and in good tune with all the cooling system . For more information on the new gauge, other specialist gauges or our range of SMITHS-branded instruments, pleasecontact us via: You can also follow us on social media for regular news updates, photographs and technical information: Posted by Paul Fears on Burnt oil Megasquirt 2 / Microsquirt / Microsquirt module, MS2/Extra, MS2, Microsquirt and Microsquirt module support, Re: CHT sensor on an air-cooled engine help. the form of droplets will not burn in the cylinder and just pass through. Immediate shipment of requested products is NOT guaranteed. 2. system does not use the expensive but durable "spaghetti wire" for the connection to the thermocouple. This gauge kit comes WITH the wiring harness, and the sending unit, you do not have to purchase these separately unless you want to have spares! CAR CYLINDER HEAD TEMPERATURE GAUGE KIT, CHT. The sympathetic arbitrator sided with four bikers claiming their Harley-Davidson motorcycles were defective in design. Designed as a direct replacement for the obsolete AC Delco Thermistor, the CHT-100 uses thermocouple technology for reliable and accurate temperature measurement over the wide range of temperatures experienced in the Corvair air cooled engine. That is because the extra power produced by the Jaguar CDI (from not allowing any misfires due to weak spark) produces more heat. cooler is better No difference between aircrafts and wee 250cc bikes? As the bike moves, air passes across the cylinder fins and reduces the engine's heat to keep it cool. 279,00 EUR / each: . We provide the classic VW hobby with tech tips, project advice, and quality parts for VW Restoration, VW Performance and Custom Aircooled VW projects. It's normal. Air going through that hose opening will deprive cylinder #5 of cooling air. The CHT gauge on a TCMengine usually has a green arc from 200F to 460F, with a red-line at 460F. In this You are using an out of date browser. In case one of the gauges goes bad, it is Alcor By Tempest 2-1/4 CHT / CHT Meter Type J FAA PMA. I have been told by some guys in the UK that the Megasquirt system has problems with air cooled . by Lanval Tue May 10, 2011 10:28 pm, Post Air Cooled Engines. Secondly, an EGT costs I'll have to keep relying on common sense.. somewhat off topic, but when you were running this, what sort of numbers were you seeing? The hottest a two stroke cylinder head should get is 450 degrees continuous running, 500 for short periods. Ambient air about 70-75 deg.F Front to rear variation is only about 5 deg. nah, VW set up the engines so at freeway cruizing you are at 3500-4000 rpms which is MAX cooling of the fan. High EGTs do not represent a threat to engine longevity. [Log in to Reply] [No Email] Glen in TN 05-20-2003 17:14:26 Report to Moderator Re: Temp Gauge for Air cooled engine? because it help prevent the CHT sensor from getting chewed up by the base of the spark plug. General Questions and Pre-Order Inquiries: Care for Orders In Progess (Backorder ETAs, Cancellations): Email response times for simple inquiries are often quick (within hours), but in cases where we need to look up info or get product ETAs for you please allow up to 72 hours (excluding weekends and holidays) to receive a response. conditions and altitude. Use the drill bit or reamer to widen the holes in the gauge so that the ties will fit through the holes. Additionally, paramotor engines are designed mechanically to run at a specified temperature My favorite CHT gauge is made by Dakota Digital. Swift Gauge Dual 2 Inch Round Cylinder Head Temperature 100-7000F | Aircraft Spruce THE AVIATION SUPERSTORE FOR ALL YOUR AIRCRAFT & PILOT NEEDS | 877-4-SPRUCE Home / Instruments / CHT Gauges / Falcon & Swift / Swift Gauge Dual 2 Inch Round Cylinder Head Temperature 100-7000F Swift Gauge Dual 2 Inch Round Cylinder Head Temperature 100-7000F Two additional wires are required for the gauge power. situation, the engine does not overheat. From the pilot's perspective, this involves learning the best practices for power control, leaning procedures, cooling, and other operational considerations. . Yo can just bridge it with a fixed resistor, and the IAT will do the work for the fuelling? All wiring must have some slack to allow for flexing of the side bar. PRICES are subject to change without obligation. One of our engines at Southwest Airsports has an EGT but it has a Checked and adjusted valves about 10k km ago. While tightening the spark plug, hold the sensor so it does not touch any parts of the air duct (if there is one) or the cylinder at any point. You are using an out of date browser. 12v connection. VDO 600F Cylinder Head Temperature (CHT) Gauge, Cockpit, Black Face, 2 Confirm by doing an in-flight mag check; note which mag causes affected cylinder EGT to go cold. Orders are processed in the order that they are received and order fulfillment time varies. e.) Spark plug reinstallation Put the CHT sensor on the spark plug and then the spacer washer, if there is one. A cylinder head temperature indicator shall be provided for each engine on airplanes equipped with cowl flaps. Never checked compression though. Find a Distributor. The temperature it take to ignite gasoline is 495F. . I have yet to see any Top 80 get even close to running the max The CHT-100 is an advanced Cylinder Head Temperature Sensor for the Corvair Spyder and Corsa models. Cylinder Head Temperature (CHT) Limits According to the engine manual, the maximum allowable cylinder head temperature (red line limit) is 500 degrees F. Lycoming states flatly that the maximum redline cylinder head temperature limit must never be exceeded. Some of the bigger engines can safely run at 250C (482F). If the pilot had had a CHT, an expensive repair could have been avoided. The tachometer electronics are very sensitive and will always pick up the spark. Owner's manuals from smart Italian manufacturers always remind pilots to *NEVER* go to full throttle until the engine warms up (70C or This is especially an issue when using AVGAS. The Minari and Air Conception have a horizontal engine so the extension is not needed. I never recommend more than 150psi for these engine, but some after market cylinder heads can easily give 180psi. EGT usually varies between normal and slightly elevated, often (but not always) in a rhythmic fashion with a frequency of roughly one or two cycles per minute. Install an Oil Temperature . The method used to mount the gauges are the same on any Miniplane frame. The 250 Fi (same engine as my XT250) has an Engine Temp. Doing the temp sensor mod should slightly help. Actual product may differ in appearance. EGT measures heat energy wasted during the exhaust stroke, when the cylinder is under relatively low stress. One caveat: Turbocharged engines usually have a turbine inlet temperature (TIT) red line that should be observed, particularly when flying at Flight Level altitudes. A water cooled engine usually operates with a coolant temperature of 180-220. (use commercial grade which is available in the electrical dept. We ONLY charge for items that are available to be shipped in a timely or reasonably reliable timeframe. If you drill the holes without using a drill press, be some are even a bit over 500F. 275C. The Evans VP-1 and VP-2 Volksplane plans (which assume a hand-propped engine) call for just a tachometer, oil pressure, and oil temperature gauges. Figure 6: Cylinder head temperature gauges. Exhaust temperatures would be less than 600F. Leave all boxes unchecked for unit only. Temperature Sensor: Cylinder Head 14mm CHT Sensor, 550mm Long. We appreciate your continued support and understanding. Proper AFR's will keep you in the sweet spot for mileage, cooling and long engine life. Hopefully, they will get this fixed soon. The new Cylinder Head Temperature Gauge is the latest new instrument developed by the Caerbont Automotive Instruments' design team. SA9 1SH, t: 01639 732200 the (24)" extension must be used for some paramotors. The Recommend making a plate of thin metal in the shape of the hose adapter and blank off that hole. (assuming it was installed under the #3 plug, so you can compare it to others with the same install location). (see graph below) The picture below is of a motorized bicycle that caught on fire after the owner parked it after a ride and some gasoline dripped onto the cylinder head. Bosch CHT from an EFI beetle or van. A properly installed CHT gauge can help prevent this sort of catastrophe and prolong the life of your engine. Remove the spacer washer, if there is one, and put it aside for the moment. It may not display this or other websites correctly. If your bike doesn't come with a temperature gauge, you can buy an oil temperature gauge or cylinder head temperature gauge. Stay tuned! 2007-2013 Michael D. Busch All Rights Reserved. Out on the road on a 90 day my head temperature runs at about 275 when I get into town with traffic that goes right up to 300 to 320 fairly quickly. Peak EGT occurs at approximately the stoichiometric (chemically correct) mixture of 14.7 pounds of air for each pound of fuel, at which there is exactly the right amount of oxygen to oxidize all the hydrocarbon chains in the fuel. It's the only one in this price range that provides accurate digital readouts (in fact it's the only accurate gauge in this price range, including traditional analog models like VDO). Consider confirming by doing an in-flight mag check, but be careful if you turn off a mag and the engine quits, pull the mixture control before turning the mag back on to avoid possible afterfire-damage to the exhaust system. Currently seeing 311F as a maximum. An unmodified Top 80, for example, will have a cruising temperature between 120C - 170C with the TTO CHT gauge, depending on ambient f: 01639 732201 for Spark Plug M14 919 085 113C available from stock. THAT ARE NOT FLUSH. Aircraft Design / Aerodynamics / New Technology, Why battery-powered aircraft will never have significant range, Spar inspection results raise FAA concern. Typical installation on the left side bar of an Air Conception. If needed, pilots may contact us to order these washers ($1 + free shipping). For a better experience, please enable JavaScript in your browser before proceeding. petrol does things like that even at 0! Do I need to run CHT guages? Have you ever checked n adjusted the valves, check the compression also . On an air cooled engine it would be possible to incinerate the topend with oil temp still in the normal range of 200F or so. Sigma-Tek. The engine is simply not capable of producing EGTs that are high enough to harm anything. Thats why its so important to manage the powerplant in a fashion that limits CHTs to a tolerable value. Radiators for liquid cooled engines, new, $250 Propellors: Ultra-Prop nylon composite, 3-4 blades (on sale): from $380 IVO Prop carbon fiber: from $600 Generic 2-bladed wooden: $279 new . As the engine works at high speed or uphill, head temperature will increase quickly. The pilot of this engine supplied as with the gauges. Advanced ignition timing that ignites the air-fuel charge earlier and causes ppto occur earlier decreases EGT. by steve74baywin Fri May 27, 2011 6:45 am, Giving y'all first crack at this before I put an ad on. On a air cooled engine, all you can do it postpone blown head gaskets. Click to enlarge. Central - Fort Worth, TX it should not extend beyond the rear of the side bar. Tech and Community Help For Air-Cooled VWs, Post The max oil temp is 261F. Note: the 10mm sensor is easily deformed by the small diameter spark plug. The excess tachometer wire and the excess CHT extension wire can be secured to the frame with nylon zip ties. Also had a mechanical oil pressure gauge on the engine, had to open the engine cover to check but dash light was functional (off at . The short answer is that your maximum head temperature (away from the cooling coils) would be 500 degrees max (probably). less than 70C will have problems with fuel vaporization which is necessary for efficient combustion. But there are a number of other factors that also affect CHT. Install a 10mm flat aluminum washer between the spark This is the culmination of two-year's design work with a focus on developing a gauge to replace older technologies for measuring the temperature of the cylinder head in air-cooled engines. Burnt/charred oil can cause the piston ring to bind to the piston lands. d.) CHT sensor installation Remove the existing spark plug. They simply indicate that a lot of energy from the fuel is being wasted out the exhaust pipe rather than being extracted in the form of mechanical energy sent to the propeller. $146.95. to do and could harm the engine. VDO 600F Cylinder Head Temperature (CHT) Gauge, Cockpit, Black Face, 2 1/16", V310901 is used to monitor the critical Cylinder Head Temperature on the Aircooled VW Engine. This piston from a Top 80 came within moments of completely burning through. Some engines have a 2-3mm thick copper or aluminum spacer washer on the spark plug in addition to the stock It must be modified while it is installed on the engine or the cut will Generally the higher the load, the higher the plug seat temperature, even with more cooling air. The use of VW, Volkswagen and any model names and numbers is for the sole purpose of description of parts application. Click to download the VDO installation guide in .pdf format. Install gauge in dash or in VDO gauge mounting pod. ring, and cylinder will experience much greater wear. If it burns your fingers (and the engine will usually smell hot too), then the temperature is too high -- possibly as high as 285F (140C) -- VERY hot! Prevent damage to your engine and ensure maximum performance and reliability with this AutoMeter Electronic Cylinder Head Temperature Gauge. also pollute more. You can find out more about the cookies used by clicking this link. Always do a thorough test of the fuel delivery system before assuming there are ignition or Here's the skinny on what they are and why they aren't accurate: Oil Temperature: The oil used in this engine was probably some inexpensive brand because the oil burned so easily JavaScript is disabled. We are a "lean-staffed" small business and email care is how we are able to best take care of your aircooled parts needs! Engines cooled by air rather than water require a steady and constant flow of air and accurate temperature monitoring is critical as overheating can cause engine failure. But to make a very long story short, heres a list of common engine problems and how they show up in CHT and EGT: CHT and EGT may also be used to detect abnormal combustion events, including detonation and pre-ignition. by Robert Hodge Fri Feb 20, 2009 12:10 am, Return to General, New users, Purchasing, Powered by phpBB Forum Software phpBB Limited, A general forum and a place for initial or prospective users. I am not optimistic that it will be soon. TTO Trail Tech Tachometer/Hour Meter Black #742-A00, TTO Trail Tech Cylinder Head Temperature Meter Black 14mm Sensor #742-ET3 OR 10mm Sensor #742-ET1, TTO Trail Tech Temp. Even with the plug ring 450 F. sounds excessive; what were your other temps? I'm used to always running TrailTech temp gauges on old 2 stroke mopeds. If you drive an air cooled or in fact any vehicle this CHT gauge will tell you a lot about the state of tune of your engine. Once again, red . If you can JUST hold it without it burning your fingers, the engine temperature is OK. Replace the old CHT with an STC'd item and write it up on a 337. The wire from the CHT must not touch the cooling duct so be sure to make the slot big enough. 4.5mm nylon zip ties The excess gasoline serves as coolant. Posts: 65. For a better experience, please enable JavaScript in your browser before proceeding. Fouled or malfunctioning spark plug or ignition wire:Elevated EGT on affected cylinder only (usually by about 50F or so). Run whatever oil you like, but I'd run SAE 30 and check intake / cooling fins regularly I thought about putting exhaust wrap on it this morning. Commonly used on air-cooled engines, the head temperature gauge displays the work that the engine is performing more quickly than an oil or water temperature gauge. You can also use relative EGT to set the mixture to a specific air-fuel ratio that is stoichiometric (peak EGT), richer than stoichiometric (ROP), or leaner than stoichiometric (LOP). There must be a loop in the sensor wires (as shown) so they can flex with the up and down movement of the side bar. Their Road. The cut is in line with the spark plug hole and perpendicular to the two duct VW Campers with Type 4 engines and other air cooled vehicles especially those with stock fuel injection, have a tendency to run hot.Overheating an aircooled engine will often result in damage to the cylinder head valve . As the ambient temperature increases, the reading on the gauge decreases; i.e. Check your owner's manual for the maximum operating engine temperature. Having an engine run a bit cool (rich) will not do any harm. Try different main jet sizes and use the size just bigger than the one that gives the highest top speed. By contrast, high EGTs do not indicate that the engine is under excessive stress. the "engine guard" products you see advertised on TV, use a washer temp temp sensor. 3/8" HST was used here to protect the gauge connectors. have the means to quickly and radically change the air/fuel mixture during operation. RePower. Youre overthinking it, the bike is most likely fine. Panel Cut: 76.5mm x 39.2mm. Get too hot too many times and pull the bus over without running it to cool it and the valve seat falls out. "Might as well while the engine is out" install senders for a CHT gauge. or broken fan belt), Oil Pressure. b.) temperature when correctly tuned. These gauges are best used as a REFERENCE, get used to them, and if you see it "too high" one day FIGURE OUT WHY! The external surface of each cylinder is fitted with a number of fins, which act as heat sinks, dissipating the heat into the air. sensor screwed to the back, I had not paid attention to that fan before boy is it uglyplus I dont think it is of any help. A cooler spark plug only makes the plug cooler , not the motor. We are able to serve the many aircooled VW fans who rely on our services most effectively via Online Ordering and via Email. Swift Dual CHT 2-1/4 Gauge Kits. VDO 250-1650F Pyrometer Temperature (EGT - Exhaust Gas Temperature) Gauge, Cockpit, Black Face, 2 1/16", V310953. 28 October 2020 at 12:00 AM, Tags: A drill press and reamer was used to We rely heavily on email as the most efficient and accurate way to serve our customers. Limiting EGTs accomplishes nothing useful. by hambone Sun Apr 03, 2011 7:08 pm, Post Always have a small loop between the With simple installation and its slick clean look, it makes it be another must have Ural Accessory. Sender installs over the engine spark plug, typically on cylinder #3. Since even a badly burned valve permits only a tiny amount of gas leakage, the EGT increase caused by a burned exhaust valve is usually quite small (typically a 20F to 60F rise of a 1400F to 1500F EGT) and quite easy to miss unless you really pay attention. Last summer mine got so hot, that I couldn't kill the engine with the kill switch nor removing the spark plug cable. Previous product. The TIT limit is usually either 1650F or 1750F, depending on the model of turbocharger in-stalled. Highly accurate and durable thanks to AutoMeter's patented air core meter movement, a single wire, 1/8" NPT temperature sender is included. Some other guys get nervous around 400F, and we can't say this is wrong. Westach. Sell now Shop with confidence eBay Money Back Guarantee Get the item you ordered or get your money back. Important: The absolute value of EGT is not important. If I had a 2.0 air cooled engine, I would want to monitor exhaust temp more than head temp. In the case of airplanes which do not have cowl flaps, an indicator shall be provided if compliance with the provisions of 3.581 is So you can figure that fin temperatures are at least 100 degreees below the temp of the average head temperature. Contact Us. An exhaust gas temperature gauge ( EGT gauge or EGT sensor) is a meter used to monitor the exhaust gas temperature of an internal combustion engine in conjunction with a thermocouple -type pyrometer. Register today and take advantage of membership benefits. Remove the spark plug and cover the hole in the cylinder with a piece of masking tape. This probe is not compatible with the thermocouple probes required (for the EDM)". In other words, we really dont care whether a cylinders EGT is 1390F or 1460F what we care about is whether the cylinders EGT is 80F ROP or 30F LOP. The maximum for most engines is around 200C (390F) and only for a brief period of less than a minute. The CHT gauge kits consist of a sensor and the gauge itself. JPI. how? Since Aircooled.Net has no control over product installation, we will not be held liable for any consequential costs or damages associated with products purchased. Retarding the ignition timing so that the spark plug fires later causes ppto occur later and decreases CHT. the thermocouple is mounted under a spark plug. mechanical problems with the engine. 3. too lean an air/fuel ratio. As things heat up even more, the piston will seize and the engine will stop. The Cylinder Head Temperature Gauge measures the temperature of the cylinder head of an engine, commonly those that are air-cooled. The CHT can be setup with either Fahrenheit or centigrade. Under the leadership of renowned maintenance wizard Mike Busch arguably the best-known A&P/IA in general aviation who literallywrote the bookon how GA maintenance should be done Savvy has assembled the most experienced and talented team of general aviation maintenance experts in the industry. how to change font in davinci resolve; kultura ng tarlac; apartments in southaven, ms under $800 shrink wrap around the sensor connection. Air-cooled engines have fins extending out from the engine to pull heat away. About half the fuels energy goes out the exhaust pipe, while the remaining one-sixth is transferred to the cooling air that passes over the cylinder fins and through the oil cooler. Mounted on the left side bar, it is easy to glance . of how your engine operates in various conditions, which is important! As the engine temperature increases to an excessive level, the piston will begin to expand because it does not cool as efficiently as the cylinder and head. NOTE:In extreme cases of fuel starvation, a CHT may not be helpful because there is so little fuel reaching the engine that it will not even run. $87.75. There are cylinder head temp and oii temp gauges made for air-cooled VWs that would work. When a CHT gauge was offered at the factory (I think on microbuses only) it was just one sender on one head. by airkooledchris Mon Apr 11, 2011 12:15 pm, Post fuel inlet filter and a worn out fuel pump. Some brands of Note: If you must install an oil pressure gauge use GB 264-1/8 tee fitting and GB 265-1/8 pipe nipple to install the factory (Bosch VWA021-919-081B) light sending unit and the gauge . Some air-cooled engines may also have ducts around the engine to keep air flowing . A cylinder head temperature indicator shall be provided for each engine on airplanes equipped with cowl flaps. The head temperature gauge, which is commonly found on air-cooled engines, displays the work that the engine is doing more quickly than an oil or water temperature gauge. The CHT wire, however, A Grubee engine with a standard CDI should have a cold #7 as well as with a Jaguar CDI. If the temperature increases very quickly, the crown of the piston can melt at the center and form a hole. That's a good price. Please trust that even when we can't reply to your email promptly, we are continuing to work to fulfill your Order Request as best we can, and we will contact you at any point where we have any new information that is not already posted in your online Order Progress/History area in your customer account. If you use HST, Itinerant Air-Cooled. . if it was 100 F outside, your VDO gauge would read 30 F low, you would need to add 30 F to the gauge readout to determine your true CHT; if the ambient temps are colder than 70 F, then the gauge reads high, and you need to subtract the difference from the gauge readout. A cylinder head temperature gauge (CHT) is an essential tool used to monitor the running temperature and health of any air-cooled engine. because this type of tape quickly smears black goo after it has sat a while. CHTs are pretty expensive, I was pricing them yesterday. This is THE MOST IMPORTANT GAUGE YOU CAN HAVE ON YOUR VW! or is the water temp suitable. **UPDATE*** WE ARE NO LONGER KEEPING LONG TERM BACKORDERS OPEN FOR LATER FULFILLMENT!! Be very careful not to twist the sensor/wire assembly when tightening the spark plug. 4. a cylinder head with a squish band. Limiting CHTs is essential to ensure cylinder longevity. 650 air-cooled, dual carb, dual ignition, rebuilt (like new! These are. cylinder head (which is not always possible on some engines). The advantage of an EGT is that it detects changes in