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Topic Review (Newest First)

  • 06-19-2016, 11:22 AM
    Does anyone have the photos and instructions on how to check shoe depth , nozzle to keel angles , ride plate , etc, etc
    MikeF posted this up several years ago on an old thread on here but photos are no longer available
    This would really be great to know !
  • 04-11-2016, 08:55 PM
    piston in the wind

    Plug reading 101 by Mike Canter

    Spark Plug Reading 101 by Mike Canter - Dragstuff

    Blown alcohol at the bottom of the page.
  • 03-05-2015, 02:54 PM
  • 10-23-2012, 10:55 PM
  • 07-11-2012, 09:23 AM
  • 09-27-2011, 06:25 PM
    Small block Chevy

  • 08-11-2011, 05:30 PM
    Engineering/dimensional drawings for BBC courtesy of Wizbang

    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
  • 11-08-2010, 08:20 PM
    sanger rat
    Blown Alcohol Motor Spark Plug Reading 101

    by Mike Canter

    Reading a blown alcohol tune-up using spark plugs is a very different than reading a gasoline tune-up on spark plugs. First major difference for alcohol is that you do not read the color off the porcelain around the center electrode. Air to fuel ratios within the combustion chamber are going to be read by the appearance of the metal base ring at the end of the threaded area of the plugs and the color of the first three threads of the spark plugs. The amount of ignition advance is still read as with gasoline plugs by the blue line on the plugs ground strap or sometimes referred to as the ground electrode.

    An important note is that the spark plugs only reflect the tune-up that was in the motor just prior to finish line engine shutdown. In a ¼ mile this is normally just the last 300 feet in high gear but it takes 1000 feet to develop the correct appearance. It is possible for the plugs to indicate a good tune-up at this point but to have run too rich or too lean in first or second gear or at a lower rpm. This makes it possible to damage the engine due to incorrect fuel mixture in the first part of the run and actually be correct at the finish line. It is highly recommended that the initial tune-up runs be limited to 1/8th mile plug readings before proceeding on to the ¼ mile run. Most the damage to an engine is done in the last 300 feet.

    The fuel mixture and the ignition timing are totally intertwined as to the effecting the appearance of the spark plug ring at the of the threads and the EGT values. Changing the fuel to air ratio and changing the ignition will both change the combustion chamber temperature. The leaner the mixture or the more advanced the ignition the higher the combustion chamber temperature and the richer the mixture or the more retarded the ignition the lower the combustion chamber temperature. Remember the EGT sensor is outside the combustion chamber so it is only reading the exhaust gas/flame temperature. The more the ignition advance the lower the EGT and more the ignition is retarded the higher the EGT. This opposite effect is caused moving the heat or the flame out of the chamber into the exhaust with a retarded ignition and raising the temperature of the EGT. So having a high EGT because of retarded ignition can and will show less heat in the spark plugs.

    It is highly recommended to pick a maximum ignition timing point that is known to be good for your particular engine setup and tune the mixture for that point. This way the tune-up is safe and you can retard the ignition to pull out power without drastically changing your fuel tune-up. You can always go back to the maximum power ignition point without damaging the engine.

    Reading For Air Fuel Mixture

    An important step first is to degrease the plugs by spraying the threaded end with brake cleaner to remove any deposits of oil that may have been put on the plug during shutdown or when the plug was removed from the head.

    Most of the spark plug manufactures that make plugs used for racing plate the spark plug shell with cadmium or zinc which oxidizes at a temperatures that corresponds to the correct operating range of the temperatures within the combustion chamber of a racing engine.

    As one is tuning the motor and leaning the fuel system out the first part of the plating to start oxidizing will be the ground strap. This oxidation (burning) is uneven in progression around the ring at the end of the threaded part of the plug because the side of the plug ring that was closest to the exhaust valve seat gets hotter faster than the side of the plug ring that is closest to the intake valve seat. The result is a crescent of unburned cadmium that gets smaller as the engine is leaned out. When the cadmium is oxidized and has turned white across the entire face of the plug ring or countersink area just inside the ring the increased temperature then progresses down the side of the plug into the threaded area.

    The peak performance is at the point where the cadmium or zinc plating oxidizes and turns white over about 90% of the plug ring and a small crescent of unburned plating is left on the ring. Burning 100% of the plating off the ring all the way down to the first thread will not result in any damage but will also not result in any increase in engine performance. There is a fairly large tuning range between the burned area being at 90% and being burned all the way down to the first thread. Using this large area will ensure that no damage is done to the engine. The next stage from this safe appearance is when the cadmium is burned down to the second thread and the ring loses its white appearance and picks up a greenish tint with small visible bubbles and the ground strap picks up rainbow colors (blues and green when held in the bright sunlight). The strap getting hot enough to exhibit rainbow colors is hot enough to start igniting the fuel mixture too soon and causes pre-ignition/detonation. As the plug gets hotter then sooner the mixture will ignite and this will result in the melting of the ground strap and possible breaking of the plugs porcelain and damage to the upper rod bearings.

    By keeping good records of actual performance this peak performance point should be readily seen and matched to the indication on the spark plug ring. When the 90% white ring is obtained with the fastest MPH noted you are now ready to move on to adjusting the ignition timing.

    Reading for Ignition Timing

    Once the fuel mixture has been adjusted so that 90% of the plug ring is white and all the cylinders have been adjusted so that the white area are the same on all plugs the ignition timing can be now checked by reading the blue line on the ground strap of the plug.

    Ignition timing is also directly responsible for the heat in the combustion chamber and therefore the color of the plug’s ground strap is a tattletale sign of this temperature because it is thinner than anything else on the plugs and sits right out in the combustion chamber. The ignition timing can be checked by looking at the color of the plug’s ground strap and the position of the "blue line" on the strap. The blue line really indicates the point at which the strap has reached annealing temperature of the metal. To help to understand this think of a bar of steel (ground strap) on a table that is being super heated with an acetylene torch at one of the tip ends. As the end heats up and the heat starts moving down the bar you will see a blue line across the bar at some point down the bar away from tip with the torch. This blue line reflects the temperature that is the annealing point of the metal. As the temperature increases the blue line moves further down the bar away from the torch. Similarly, the blue line moves down the spark plug ground strap as you put more heat in the engine.
    Assuming that you have adjusted the alcohol fuel mixture correctly and if you are using gold colored ground strap like with an NGK spark plug then not enough timing will show the ground strap as still gold or going light gray maybe with a few bubbles on it after a run. As you advance the ignition and put heat in the engine the plug ground strap will turn darker gray. As the metal turns medium to dark gray you should start looking for the blue line (band) around the ground strap. Ideally, you want this blue line to be just above where the ground strap makes the sharp bend and above the weld. If you advance the ignition too far the blue will disappear off the strap and the strap will pick up rainbow colors (blues and greens). The next step beyond that is to start melting the strap from the tip end and detonation. When you are close to the correct timing then only change the timing by half a degree at a time. If you ignition system has the capability of adjusting the timing of each cylinder independently (ICT) then you can use that feature to have the blue line in the same position on all the plugs. First, adjust the basic timing to get as many of the plugs to have the blue line just at the sharp bend in the strap. Now adjust the ICT to move the blue line to the same point on the remaining plugs. Once all the plugs read the same you can advance the ignition a little at a time to put the blue line just above the weld on the strap or whatever point gives you the best performance.
    If your timing is too far retarded then it maybe necessary as you adjust the timing to add a little more fuel to keep the crescent on the end of the plugs white for 90% of the area. Be very careful on adjusting timing because it does not take much change to make a lot of difference. I recommend limiting the changes to half a degree at a time. It is easier to set the timing at a known good degree for the type of engine and adjust and individual cylinder timing (MSD ICT) to balance out all the cylinders and then adjust the mixture to show the correct amount of white area on the metal ring of the plugs as explained above.
  • 09-06-2010, 03:39 PM
  • 05-07-2010, 03:44 AM
    Boat Tech

    General Information About Mercruisers Warning System Horns On EFI Engines.

    Here's some general information I have put together about the warning horn systems on Mercruiser EFI engines.

    I hope this information will be able to help out the members of performance boats forums someday.

    The 2 beeps per minute can be generated by quite a few things. Some of the error conditions will limit the available power the engine produces. The 2 beeps/minute can be generated by: cam sensor open or shorted, engine cooling temperature circuit open or shorted, coil harness wire (EST) open or shorted, fuel injector open or shorted, IAC output, knock sensor, MAP sensor, MAT sensor, oil pressure circuit open or shorted, port/starboard exhaust manifold cooling temperature circuit open or shorted, sea pump circuit open or shorted, fuel pump relay, throttle position sensor circuit open or shorted, low 5 volt power supply as well as other errors.

    Best suggestion for the 2 beeps per minute is to have the dealer/shop read out the error log to see what is generating the error condition.

    This table below is a guick guide, showing what warning horn output will accompany a fault for the Sterndrive (MCM) Model Serial Number 496 MAG HO 0M000000 and Above/496 MAG 0M000000 and Above.

    PS, for all the non 496/8.1 EFI engines, Your particular EFI engine may not not have every one of these Warning horn Fault sensors, But most of the newer style EFI engines from Mercruiser now has a lot of these sensors that are listed below. The best thing to do is to have a service manual from mercruiser for your engine to help you know what your engine really has as far as sensors go.

    Also it highly recommended that if you could buy a marine scan tool from Rinda technologies, it will help aid you with diagnosing your warning horns, if your going to be working on your own EFI engines this is a must have tool.

    Warning system Faults, SC1000 Yes/No, Audio Alarm, Available Power %, Description.

    (1) Cam Sensor Yes 2 Bp/min 90% Open or short, engine must be cranking to set this fault code.
    (2) ECT CKT HI Yes 2 Bp/min 90% Open
    (3) ECT CKT LO Yes 2 Bp/min 90% Short
    (4) ECT Coolant Overheat Yes Constant 6-100 % Engine guardian overheat condition
    (5) EST 1-8 Open Yes 2 Bp/min NA Coil harness wire open
    (6) EST 1-8 Short Yes 2 Bp/min NA Coil harness wire short
    (7) Fuel Injector 1-8 Open Yes 2 Bp/min NA Fuel injector wire open.
    (8) Fuel Injector 1-8 Short Yes 2 Bp/min NA Fuel injector wire short
    (9) IAC Output Yes 2 Bp/min 90% Only with rpm
    (10) Knock Sensor 1 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear.
    (11) Knock Sensor 2 Yes 2 Bp/min 90% Alarm sounds for 20 seconds in NEUTRAL and indefinitely in gear.
    (12) Low Drive Lube Strategy Yes Steady Bp 0-100% Low oil in sterndrive.
    (13) Low Oil Pressure Strategy Yes Constant 0-100% Low oil pressure strategy.
    (14) MAP Sensor 1 Input High No 2 Bp/min 90% Short, no visual on SC1000.
    (15) MAP Sensor 1 Input Low No 2 Bp/min 90% Open, no visual on SC1000.
    (16) MAT Sensor Yes 2 Bp/min 90% Open or short in MAT circuit.
    (17) Oil PSI CKT Hi Yes 2 Bp/min 90% Short, defaults to 51.7 psi.
    (18) Oil PSI CKT Lo Yes 2 Bp/min 90% Open, zero oil pressure.
    (19) Overspeed Yes Constant RPM Limit Engine over rpm limit
    (20) Port EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F.
    (21) Port EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F.
    (22) Port EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212
    degreesF(100 degrees C) limit.
    (23) Sea Pump PSI Lo Yes Constant 6-100% Low water pressure strategy, defaults to 43.4 psi.
    (24) Sea Pump CKT Hi Yes 2 Bp/min 90% Open.
    (25)Sea Pump CKT Lo Yes 2 Bp/min 90% Short.
    (26) STB EMCT CKT Hi Yes 2 Bp/min 90% Open, defaults to 32 degrees F.
    (27) STB EMCT CKT Lo Yes 2 Bp/min 90% Short, defaults to 32 degrees F.
    (28) STB EMCT CKT Overheat Yes Constant 6-100% Overheat condition, 212 degrees (100 degrees C) limit.
    (29) Steer CKT Hi Yes No No Open and short.
    (30) TPS1 CKT Hi Yes 2 Bp/min 90% Short, signal to 5v+, engine will not start. Refer to data monitor screen.
    (31) TPS1 CKT Lo Yes 2 Bp/min 90% Open.
    (32) TPS 1 Range Hi Yes 2 Bp/min 90% Above 4.8v, 994 counts.
    (33) TPS 1 Range Lo Yes 2 Bp/min 90% Below 0.5v, 35 counts.
    (34) Trim CKT Hi Yes No No Short, high range, visual warning on SC1000 only.
    (35) Trim CKT Lo Yes No No Open, low range, visual warning on SC1000 only.
    (36) 5 VDC PWR Low Yes 2 Bp/min varies Short any 5v+ to ground.

    Here's some other information that what will sound the alarm on a mercruiser Engine.
    Constant tone alarms are for:
    1.) engine coolant temp overheat,
    2.) low engine oil pressure,
    3.) engine overspeed,
    4.) exhaust manifold cooling temp overheat
    5.) sea pump PSI low.
    Note #5 is known to be a common problem, It's been said that this fault might not show up in the fault history section of the scan tool.
    If that is the case then the only other way to know if this is your problem, is to watch this sensor live as it happens out on the water with the scan tool hooked up to the engine.
    Also make sure all the Battery cables are clean & tight plus a fully charged Battery is very important.
    Check the water pressure sensor threads for any paint, Also check the sensor to see if it has come loose or Has a blockage of some kind.
    If any sensor has lost it's ground it could sound the alarm. As an additional test, try adding a ground wire to the sensor threads to possibly stop the warning horn.
    There is also a chance that you could have picked up or created some air bubble for a short time, until the boat slowed down, possibly due to the brass water pump impeller Housing could be failing due to deep grooves inside housing creating a disturbance with the water flow.

    Constant beep alarms are for:
    1.) low outdrive lube level.

    Two Alarm beeps every 60 seconds are for:
    1.) Faulty cam,
    2.) IAC,
    3.) MAP,
    4.) MAT,
    5.) knock sensors.
    6.) open/short in the engine cooling temp circuit
    7.) open/short in fuel injector wiring circuit,
    8.) open/short in oil PSI circuit,
    9.) open/short in exhaust manifold cooling temp circuit,
    10.) open/short in sea pump circuit,
    11.) open/short in throttle position circuit.

    Good luck to you all.
    Happy Boating
  • 04-20-2008, 08:44 AM

    Holley Jet size vs drill size

  • 04-20-2008, 03:17 AM

    Courtesy of Chris Struab

    Calculating Timing Events:

    Intake Opening
    Duration/2 = Sum - Intake Centerline = Intake Opening

    Intake Closing
    (Intake Opening + Centerline) / 2 = Intake Closing

    To figure exhaust, Opposite of Intake.

    Overlap is IO + EC.


    Calculating Oil Pan Capacity:

    Multiply the sump length x width x depth x .0172 = qt volume. Add 1 qt for std merc remote filter location and filter capacity.
  • 04-20-2008, 03:15 AM

    Courtesy of Infomaniac

    Standard Boat Wiring color Codes.

    Blk -Grounds-General
    Blk/Brn -Pump Grounds
    Blk/Red -Voltmeter Grounds
    Blk/Org -Isolated Accessory Grounds
    Blk/Yel -ignition stop
    Blk/Grn -Water Level Sender Ground
    Blk/Blu -Lighting Grounds
    Blk/Gry -Nav Light Grounds
    Blk/Wht -Battery Parallel Solenoid
    Brown -Pumps-General, Bilge or Sump (Manually Switched)(Also alternator starter to Ign.)
    Brn/Red -Pumps, Bilge or Sump
    Brn/Org -Power feed to Auto Bilge Switches-Pumps, Fuel/Oil Tranfer or Priming
    Brn/Yel -Baitwell or Aerator
    Brn/Grn -Fresh Water Pump/Water Maker
    Brn/Blu -Head Pump
    Brn/Vio -Washdown Pump
    Brn/Wht -trim pos sender
    Red - Battery Feeds Unprotected
    Red/Vio -Misc. Accy. Main Feed Protected (fused) from batt to trim panel.
    Pink -Fuel Sender
    Org/Blk -Audio System Feed
    Org/Brn -Electric Head-Sanitation System
    Org/Red -Wiper Port
    Orange -Accessories common feed- Dist Panel to Acc switch-Anode Electrode-Mercathode
    Org/Yel -Diesel Pre-heat
    Org/Grn -Wiper Stbd
    Org/Blu -Communications Equipment
    Org/Vio -Navigation Equipment
    Org/Wht -Wiper Center
    Yel/Blk -Choke - Neutral saftey trans mounted
    Yel/Red -Start Solenoid(starting circut), Neutral Safety
    Yel/Org -Powered Ventilation, Fans
    Yellow -Bilge Blowers -(also alternator DC output)
    Yel/Wht -Rudder Angle Sender
    Grn/Red -Stop Solenoid/Kill Switch
    Grn/Yel -AC Grounding
    Green -Bonding
    Grn/Wht -Engine Trim in and or tilt down
    Grn/Org -Engine Independent Trim down
    Blu/Blk -Cabin Lights
    Blu/Brn -Oil Temp Send
    Blu/Red -Cabin or Cockpit Lights Port
    Blu/Org -Engine Independent Tilt Up
    Blu/Yel -Lighting Circuits to Remote Send
    Blu/Grn -Cabin or Cockpit Lights Stbd
    Blu -Instrument & General Lighting
    Blu/Vio -Courtesy, Boarding Lighting
    Blu/Wht -Engine Trim Outand/or Tilt Up
    Light Blue -Oil Pressure
    Vio/Red -Eng. or Generator B+ from Breaker
    Vio/Yel -I/O Trim Up (ballast bypass)
    Vio/Grn -I/O Trim Down
    Vio -12v Ignition-Generator or Engine
    Vio/Wht -Trim "Trailer" switch
    Gry/Blk -Mast Light
    Gry/Red -Spotlight Remote
    Gry/Org -Docking Lights
    Gry/Grn -Strobe or Beacon
    Gry/Blu -Spreader/Flood Lights
    Gry/Vio -Windlass/Winch
    Gray -Navigation (running) Lights, Tach. Send
    Gry/Wht -Anchor Light
    Wht/Brn -Temp. Alarm or Indicator
    Wht/Red -Fuel Alarm or Indicator -((Ignition module to Dist.)Mercury Thunderbolt Ignition)
    Wht/Org -Fire Alarm or Indicator
    Wht/Yel -Air Flow Alarm or Indicator
    Wht/Grn -Water Press/Flow Alarm or Indicator - ((Ignition module to Dist.)Mercury Thunderbolt Ignition)
    Wht/Blu -Oil Press Alarm or Indicator
    Wht/Vio -Voltage Alarm or Indicator
    White -General Alarm Usage, Yamaha Kill Switch
    Tan - Water Temp sender
    Tan/Blu -Warning system sense wire (Audio warning)
    Pink -Fuel sender
  • 04-20-2008, 03:04 AM
    This thread is only for Tech and Informational links. No questions... No chatter... start other thread for that please.

    I will consolodate the links into this top post and then delete the other posts as necessary. Please post any links you think should be considered.

    What I won't include in this pinned thread are links that are to companies that supply product (spam) or a bunch of spam links with a little tech teaser of some kind. I will make certain exceptions for some "manufacturers" like ARP for instance that have very useful info on their website and don't offer product directly for sale. What I don't want is a bunch of retail outlet links or banners on the tech links.

    Mortec (web archive)

    BRC Engine Calculators Compression Ratio, Engine CID and Piston Compression Distance Calculators

    Ford 460 Tech

    VIN # Decoding

    NGK Plug Heat Range Chart

    Tips on reading Spark Plugs

    More Spark Plug reading...

    And even more on plugs

    ARP Fastener Tech Info

    Driveline Angle, a Spicer guide to installation

    Basics of driveline angle and U-Joint function

    Barry Grant Jet & Nozzle Sizes

    VP Race Fuel Specs

    Racing Gas Octane

    Fuel info on How Stuff Works

    Deck heights, rod lengths, compression heights various engines:

    Oil Filter Comparison

    Basic Engine Timing Explained

    Free Virtual Engine Math Software

    Machine Tools Library - Good Resource

    AN (Army-Navy) Thread Size Chart

    Soldering and Splicing, How to do it right

    Another one on splicing and wire repair

    Propeller calculator

    NGK plug info

    Connecting Rod vs Stroke

    Holley Carb rebuilding and Tuning

    Turbo and Supercharger Maps

    Firing order info

    Holley Numerical Listing

    Understanding Relays

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