infrared temp guns


Staff member
allen said:
hey grumpy I see you use an IR temp gun occasionally to tune and diagnose problems,I looked at the link to see how much the one you use costs and frankly was shocked at the price listed, you do know they can be found at less than 1/3 the cost right??

(I've used this one for years) and have had zero issues,its a great tool for finding a missing cylinder, or helping locate a vacuum leak, but Id point out the heat range its built too detect, and its accuracy and consistency and durability matter, be aware the the surface color and reflective surface index, has a much more noticeable effect on the less expensive tools , a flat black header will tend to read rather accurately, a chrome plated or ceramic coated header tends to read lower temps, lighter colors tend to read lower, so a silver or white ceramic coated header can very easily read 200F lower than a black header tube on a similar engine,
I'd also point out that its the differences in the exhaust port temps that is going to be usually your main indicator of a fuel/air distribution issue,
so that's what your looking for,not a specific temperature.
this requires accurate and repeatable test results.
thus inconsistency in the reading's can allow you to waste a great deal of time chasing an issue that might not really exist

but remember center and rear located header primary tubes don,t see the full cooling effect of air flow exiting the radiator the the #1 (driver front)and #2 (pass front) header tubes located on the front of the engine see so they tens to run a bit lower temps.

infrared thermometers are a very useful tool to track down issues with tuning, or mal functioning sensors , without verified facts your guessing.
this is the most consistently accurate I.R temp gun I've used for testing[/img]
42545.jpg Extech Products

Wide temperature range from -58 to 1832°F (-50 to 1000°C)
any time that your dealing with a potential temperature issue or a trouble issue where , knowing the exact temperature vs what a gauge might say, it helps to have a handy and accurate infrared temp gun handy to locate and confirm heat, levels.

yes there's other brands and models that provide accurate/consistent readings, but you obviously need to read the products heat range and accuracy limitations, most of the less expensive IR temp guns are both less accurate, and tend to have a lower upper heat limitation.

here's something similar too what I purchased
The non-contact Raytek Raynger ST81 infrared thermometer has a temperature range of -25 to 1400°F (-32 to 760°C).


yes they can be found much cheaper, under $40, testing both side by side , when Jack brought over his HF temp gun, made me appreciate the difference in accuracy, I could go back and check each tube write down the results be be fairly sure the temps would read rather consistently with mine once the engine was fully warmed up, that did not seem to be nearly the case with jacks it was rather inconsistent. yes it was far better than nothing , but it showed a noticeable and to me rather annoying inconsistency


read links

Surface Material Emissivity Coefficient 1.0 is 100% heat transfer
- ε -
Alloy 24ST Polished 0.09
Alumina, Flame sprayed 0.8
Aluminum Commercial sheet 0.09
Aluminum Foil 0.04
Aluminum Commercial Sheet 0.09
Aluminum Heavily Oxidized 0.2 - 0.31
Aluminum Highly Polished 0.039 - 0.057
Aluminum Anodized 0.77
Aluminum Rough 0.07
Aluminum paint 0.27 - 0.67
Antimony, polished 0.28 - 0.31
Asbestos board 0.96
Asbestos paper 0.93 - 0.945
Asphalt 0.93
Basalt 0.72
Beryllium 0.18
Beryllium, Anodized 0.9
Bismuth, bright 0.34
Black Body Matt 1.00
Black lacquer on iron 0.875
Black Parson Optical 0.95
Black Silicone Paint 0.93
Black Epoxy Paint 0.89
Black Enamel Paint 0.80
Brass Dull Plate 0.22
Brass Rolled Plate Natural Surface 0.06
Brass Polished 0.03
Brass Oxidized 600oC 0.6
Brick, red rough 0.93
Brick, fireclay 0.75
Cadmium 0.02
Carbon, not oxidized 0.81
Carbon filament 0.77
Carbon pressed filled surface 0.98
Cast Iron, newly turned 0.44
Cast Iron, turned and heated 0.60 - 0.70
Chromium polished 0.058
Clay 0.91
Coal 0.80
Concrete 0.85
Concrete, rough 0.94
Concrete tiles 0.63
Cotton cloth 0.77
Copper electroplated 0.03
Copper heated and covered with thick oxide layer 0.78
Copper Polished 0.023 - 0.052
Copper Nickel Alloy, polished 0.059
Glass smooth 0.92 - 0.94
Glass, pyrex 0.85 - 0.95
Gold not polished 0.47
Gold polished 0.025
Granite 0.45
Gypsum 0.85
Ice smooth 0.966
Ice rough 0.985
Inconel X Oxidized 0.71
Iron polished 0.14 - 0.38
Iron, plate rusted red 0.61
Iron, dark gray surface 0.31
Iron, rough ingot 0.87 - 0.95
Lampblack paint 0.96
Lead pure unoxidized 0.057 - 0.075
Lead Oxidized 0.43
Limestone 0.90 - 0.93
Lime wash 0.91
Magnesia 0.72
Magnesite 0.38
Magnesium Oxide 0.20 - 0.55
Magnesium Polished 0.07 - 0.13
Marble White 0.95
Masonry Plastered 0.93
Mercury liquid 0.1
Mild Steel 0.20 - 0.32
Molybdenum polished 0.05 - 0.18
Nickel, elctroplated 0.03
Nickel, polished 0.072
Nickel, oxidized 0.59 - 0.86
Nichrome wire, bright 0.65 - 0.79
Oak, planed 0.89
Oil paints, all colors 0.92 - 0.96
Paper offset 0.55
Plaster 0.98
Platinum, polished plate 0.054 - 0.104
Pine 0.84
Plaster board 0.91
Porcelain, glazed 0.92
Paint 0.96
Paper 0.93
Plaster, rough 0.91
Plastics 0.91
Porcelain glazed 0.93
Pyrex 0.92
Quartz glass 0.93
Roofing paper 0.91
Rubber, foam 0.90
Rubber, hard glossy plate 0.94
Rubber, natural hard 0.91
Rubber, natural oft 0.86
Salt 0.34
Sand 0.76
Sandstone 0.59
Sapphire 0.48
Sawdust 0.75
Silica 0.79
Silicon Carbide 0.83 - 0.96
Silver Polished 0.02 - 0.03
Soil 0.38
Steel Oxidized 0.79
Steel Polished 0.07
Stainless Steel, weathered 0.85
Stainless Steel, polished 0.075
Stainless Steel, type 301 0.54 - 0.63
Steel Galvanized Old 0.88
Steel Galvanized New 0.23
Teflon 0.92
Thoria 0.28
Tile 0.97
Tin unoxidized 0.04
Titanium polished 0.19
Tungsten polished 0.04
Tungsten aged filament 0.032 - 0.35
Water 0.95 - 0.963
Wood Beech, planned 0.935
Wood Oak, planned 0.885
Wood, Pine 0.95
Wrought Iron 0.94
Zink Tarnished 0.25
Zink polished 0.045
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at times having an inspection tools handy when you can't get a good look at a problem any other way

if your going to buy a used short block or a bare block from an un-known private source or most salvage yards, obviously you'll need to do BOTH a close inspection, WITH some measuring tools
AND get some idea of the blocks physical condition
this is also a good inspection tool ... pv618.aspx

GOOGLE PV-618 and PV-636

High resolution lens provides a clear image of objects as close as 3/4 inch and over one foot away while providing a wide 40 degree field of view.
Powerful lamp illuminates dark crevices on-demand with the push of a button conveniently located on the handle.
Ergonomically designed handle is comfortable to hold and allows one-handed focusing and light activation.
Rugged and water resistant, ProVision is made of high impact ABS and flexible cable sheathing. (Note: Shaft is water resistant, not the handle.)
PV-618 and PV-636 models have .23” diameter, flexible, non-obedient cable. Durable carrying case included.
Accessories available to optimize ProVision for specialized applications.
Made in the USA

Cable Length: 18" (457.2mm)
Cable Diameter: .23"
Handle Length: 6" (152.4mm)
Handle Width: 1.43" (36.2mm)Overall Length: 24" (609.6mm)
Weight of Scope w/ Carrying Case: 1 lb. 5.7 oz (615 g)
Field of View: 40°
Optimal Viewing Distance: Min. .8" (20mm); Max. is dependent upon ambient lighting conditions.
Lamp Volts: 2.7 volts (Halogen)
Power Source: 2 AA batteries (not included)
Pressure Necessary to Operate Lamp: 2.9 avg. p/psi; 3.2 max. p/psi

heres a cheaper version that works with a lap top computer


GCA 5.5mm Diameter USB Waterproof 6 Led Endoscope Borescope Inspection Wire Camera (5m)

Price: $18.50 & FREE Shipping on orders over $49. Details

    • Waterproof wire endoscope
    • Diameter:5.5mm head, 5 meters long flexible tube
    • High resolution 1.3MP with 1/12" VGA CMO
    • 6 LED lighting adjustable, can be inspected the hard-to-see areas.
    • Waterproof : IP67, 60°Viewable Angle. Can take photo & video and save in your computer
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That's the Cheapest Low Cost Boroscope of all time.
Under $20.