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  1. #1
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    Default Distributors rotating CCW? Opposite of normal

    Quick back-story: bought a '64 Hatteras 34 Sportfish with non-running engines. Engines are not original to the boat and appear to be ~1975 Pleasurecraft 454 big blocks (GM). Engines were partially dismantled when I got them with random parts missing...such as spark plug wires. Rebuilt starboard cylinder heads and was in the process of trying to fire up these old engines when I came across a bunch of things that don't seem to add up.

    My port engine is LH (CCW) rotation. The Pleasurecraft model/serial number tag states that it has a 1-2-7-5-6-3-4-8 firing order. This contradicts EVERYTHING I have ever read about a GM 454 engine - marine or automotive. Model number is PXLK-WR-R19.

    My starboard engine is RH (CW) rotation. The Pleasurecraft model/serial number tag states that it has a 1-8-4-3-6-5-7-2 firing order. Again, another contradiction. Model number is PXRK-WR-L19.

    The third contradiction is this, and I believe it makes the above two "issues" go away. My distributor rotates COUNTER-CLOCKWISE, which contradicts every service manual I have ever read on the GM 454 engine - marine or automotive. Since I have just about gone crazy with this I believe that since my distributor rotates in the opposite direction than it should, my LH and RH engines should have reverse firing orders (the ones I stated above) to what every manual and mechanic has told me.

    Does this seem accurate?

    Note: All rotations were viewed from the rear of the engine looking forward. Distributor rotation was viewed standing at the rear of the engines looking down.

  2. #2
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    Default Re: Distributors rotating CCW? Opposite of normal

    you have the oddball (output is opposite of input in FWD) BW gears....if you have the correct props, then you have the port and starboard designations backwards.

  3. #3
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    Default Re: Distributors rotating CCW? Opposite of normal

    Quote Originally Posted by makomark View Post
    you have the oddball (output is opposite of input in FWD) BW gears....if you have the correct props, then you have the port and starboard designations backwards.
    Port (left) and starboard (right) are accurately described in my original post. I do believe that my drives spin in the opposite direction as the engine when in FWD. I will double check that tomorrow and report back.

  4. #4
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    Default Re: Distributors rotating CCW? Opposite of normal

    Are these V-Drives?

    .
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  5. #5
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    Default Re: Distributors rotating CCW? Opposite of normal

    Quote Originally Posted by RicardoMarine View Post
    Are these V-Drives?

    .
    No, they are inboard drives. Borg Warner reversing with a 1.91:1 reduction according to the pleasurecraft model number.


  6. #6
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    Default Re: Distributors rotating CCW? Opposite of normal

    After looking at the picture in the post above, which was when I first purchased the boat, I remembered that the starters were not bolted to the engines and were just resting in place. I took both starters to get bench tested at a local shop and I made sure not to mix them up since I knew they spun in different directions, but they could have been mixed up from the get-go.

    Is it even possible to install a reverse rotation starter in a standard rotation motor (and vice versa)?

    Even though this theory would correct my seemingly backwards distributor rotation what it doesn't do is make sense of the engine rotation/firing order that is listed on the engine ID tags that are attached to the engine. Here is a photo of my port side engine:



    The 3rd digit in the model number defines the engine rotation. In this case, left-hand rotation, which is supposed to be the automotive standard for Chevrolet engines. If that's the case, then why does it have a reverse firing order?

  7. #7
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    Default Re: Distributors rotating CCW? Opposite of normal

    To the best of my knowledge, GM has always turned the oil pump and ignition distributor in a CW direction for this engine.

    When we Miranize this engine and make it into a REV RH rotation engine, we do not re-event the oil pump!
    Instead we:
    1...... redesign the camshaft "drive" gear and the distributor "driven" as to continue turning the GM oil pump in the normal direction. Consequently, the distributor rotation remains standard as well.
    2...... Use a twin gearset to turn the now REV RH camshaft in the std LH direction. Consequently, the distributor rotation remains standard as well.


    It may be possible that you have the starter motors installed on the wrong engines! Something like that would explain why you are seeing the distributors rotating CCW.


    .
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  8. #8
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    Default Re: Distributors rotating CCW? Opposite of normal

    Quote Originally Posted by RicardoMarine View Post
    To the best of my knowledge, GM has always turned the oil pump and ignition distributor in a CW direction for this engine.

    When we Miranize this engine and make it into a REV RH rotation engine, we do not re-event the oil pump!
    Instead we:
    1...... redesign the camshaft "drive" gear and the distributor "driven" as to continue turning the GM oil pump in the normal direction. Consequently, the distributor rotation remains standard as well.
    2...... Use a twin gearset to turn the now REV RH camshaft in the std LH direction. Consequently, the distributor rotation remains standard as well.


    It may be possible that you have the starter motors installed on the wrong engines! Something like that would explain why you are seeing the distributors rotating CCW.


    .
    This still does not explain why my engine nameplate clearly shows a LH rotating engine with a reverse firing order. I have also physically and visually confirmed that my LH rotating engine is, in fact rotating in a LH direction. I have also confirmed that my RH rotating engine is, in fact, rotating in a RH direction.

  9. #9
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    Default Re: Distributors rotating CCW? Opposite of normal

    Quote Originally Posted by RicardoMarine View Post
    To the best of my knowledge, GM has always turned the oil pump and ignition distributor in a CW direction for this engine.

    When we Miranize this engine and make it into a REV RH rotation engine, we do not re-event the oil pump!
    Instead we:
    1...... redesign the camshaft "drive" gear and the distributor "driven" as to continue turning the GM oil pump in the normal direction. Consequently, the distributor rotation remains standard as well.
    2...... Use a twin gearset to turn the now REV RH camshaft in the std LH direction. Consequently, the distributor rotation remains standard as well.


    It may be possible that you have the starter motors installed on the wrong engines! Something like that would explain why you are seeing the distributors rotating CCW.


    .
    I'll disagree with number 1 as the distributors will interchange.

    Have you ever had this boat running? if no, then the ID plates could have been swapped or the engines pulled and reinstalled backwards....

    Are the props "normal" - RH wheel on STBD and LH on PORT - so they turn "outward from the top" in FWD? I'd make sure that is straight and then verify the engines are on the correct side.

    The LH and RH firing orders are what they are...can't view pic on this PC but would be amazed if the ID plate was made incorrectly...

  10. #10
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    Default Re: Distributors rotating CCW? Opposite of normal

    I have not personally had these engines running, but I spoke to the previous-previous owner and he had them running, out of the boat. It is entirely possible that the engines were reinstalled in their incorrect position and that the ID tags were swapped. They are only held on with a 3/8" hex hex bolt in the cylinder head.

    Since you can't see the photo I'll list what the nameplate says for my LH rotating engine:
    Model number: PXLK-WR-R19
    Firing order: 12756348

    Received confirmation from PCM that the engines are from 1988. Working with their customer service now to figure out why the conflicting information on the ID tag.

  11. #11
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    Default Re: Distributors rotating CCW? Opposite of normal

    Also, I'll check prop rotation this evening and update this thread.

  12. #12
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    Default Re: Distributors rotating CCW? Opposite of normal

    ......................

    Copied from other thread:

    Quote Originally Posted by terrawombat View Post
    Sorry - you are both correct. I mixed up my CW and CCW.

    Port engine CCW/LH. This matches up with the engine model number.

    Starboard engine CW/RH. This matches up with the engine model number.

    BOTH distributors rotate counter-clockwise. No clue if the distributors are original to the engine or not. All I know is that they're electronic (no points) Prestolite-type.
    In order for that to be true, someone, at some point in time, had to re-design the GM oil pumps as to turn CCW, and to then install them into these two engines.


    Started a new thread in the Pleasurecraft forum: http://www.marineengine.com/boat-for...453#post531453
    .................................................. ...........

    OK.... back to this new thread:

    Quote Originally Posted by makomark View Post
    I'll disagree with number 1 as the distributors will interchange.
    Not necessarily so.
    The Std LH rotation engine distributor gear cut causes an "up-lift" on the gear/shaft. This is "checked" between the upper gear face and the bottom of the aluminum distributor housing.

    Conversely, the REV RH rotation engine distributor gear cut causes a "down-force" on the gear/shaft. This is checked via a small thrust bearing at the upper area within the distributor housing.

    IOW, even though both distributors operate in the CW direction, there is a distributor for the LH engine, and one for the RH engine.
    Example: (BBC and/or SBC)
    Mallory YLM 624 AV is for the Std LH engine.
    Mallory YLM 624 BV is for the REV RH engine.
    Either operates in a CW direction so that the GM oil pump will function correctly.


    Have you ever had this boat running? if no, then the ID plates could have been swapped or the engines pulled and reinstalled backwards....
    Good points!

    Are the props "normal" - RH wheel on STBD and LH on PORT - so they turn "outward from the top" in FWD? I'd make sure that is straight and then verify the engines are on the correct side.
    Another great point!


    The LH and RH firing orders are what they are... can't view pic on this PC but would be amazed if the ID plate was made incorrectly...
    The LH engine firing order is 1-8-4-3-6-5-7-2.
    The REV RH engine firing order is just opposite, but still begins from #1...... 1-2-7-5-6-3-4-8.


    Just for fun, look at both of these firing arrangements from this perspective>>>>>>
    >>>>
    1-8-4-3-6-5-7-2.....2-7-5-6-3-4-8-1
    Quote Originally Posted by terrawombat View Post
    I have not personally had these engines running,
    Ah.... then you do not know if the starter motors have been installed correctly... I.E., installed on the correct rotation engines.
    Something like this would explain why you are seeing the distributors turning CCW instead of CW!!!!!!!!!!


    but I spoke to the previous-previous owner and he had them running, out of the boat. It is entirely possible that the engines were reinstalled in their incorrect position and that the ID tags were swapped. They are only held on with a 3/8" hex hex bolt in the cylinder head.
    (See below)

    Since you can't see the photo I'll list what the nameplate says for my LH rotating engine:
    Model number: PXLK-WR-R19 Does "R" indicate Right Hand?
    Firing order: 12756348 That is incorrect for a LH engine.

    Received confirmation from PCM that the engines are from 1988. Working with their customer service now to figure out why the conflicting information on the ID tag.
    Could be as simple as a mistake being made by the ghopher who installed the tags!

    Quote Originally Posted by terrawombat View Post
    Also, I'll check prop rotation this evening and update this thread.
    Suggestion:
    do a search on your transmission models. You may have what is refered to as "opposite of engine rotation" transmissions.

    This type of transmission is fully capable of turning the propeller opposite of engine rotation while in FWD gear.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  13. #13
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    Default Re: Distributors rotating CCW? Opposite of normal

    Thanks fellas for the help - I appreciate the insight and steps to take to get this situation figured out. I'll try to address the previous posts in order.

    The whole reason I stopped trying to start the engines and registered on this forum is because of the rotation of my distributor and, consequently, my oil pump. It conflicted with every service manual I have ever read for both marine and automotive applications. The problem is that my engine ID tags are telling me that the motors are spinning the correct way!

    It is entirely possible that the ID tags got swapped. It is also entirely possible that my engine ID tags are flat out wrong. I am working with a PCM rep to sort this out.

    The prop rotation is an excellent point. If my props are running in reverse with the drives in FWD then that pretty much solves this dilemma and tells me that my engines are running backwards - likely because my starters got swapped. This will be the first thing I look at when I visit the boat after work today.

    On the model number PXLK-WR-R19, the 3rd digit 'L' defines LH motor rotation. The 6th digit 'R' defines that my drive is a reduction or reverse gear and the 7th digit 'R' defines that my props are RH rotation.

    I do not know if my props are "normal", but I will check on this tonight when I get to the boat. I will also obtain the drive model number. I do recall during my engine compression testing that the drive was in forward and was spinning OPPOSITE of the engine, but I will absolutely verify that tonight.

    Speaking of my compression testing (which tested within spec, by the way) I'm wondering if my engines are, in fact, spinning in the wrong direction if that would have any effect on engine compression. I'm thinking no since there will still be a time at which both valves are closed and the piston is still creating pressure and engine rotation will not matter for that.

  14. #14
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    Default Re: Distributors rotating CCW? Opposite of normal

    ...........................

    Quote Originally Posted by terrawombat View Post
    Thanks fellas for the help - I appreciate the insight and steps to take to get this situation figured out. I'll try to address the previous posts in order.

    The whole reason I stopped trying to start the engines and registered on this forum is because of the rotation of my distributor and, consequently, my oil pump. It conflicted with every service manual I have ever read for both marine and automotive applications. The problem is that my engine ID tags are telling me that the motors are spinning the correct way!
    Unless something was done to these two engines that is very much out-of-the-ordinary, this is very easy and simple:
    Be they RH or LH engines, the camshafts will turn the ignition distributors CW (when viewed from over-head), and consequently your oil pumps will also turn CW (when viewed from over-head).
    This is fact.... not speculation!

    It is entirely possible that the ID tags got swapped. It is also entirely possible that my engine ID tags are flat out wrong. I am working with a PCM rep to sort this out.
    I would not waste any time on this.
    I would test for correct rotation, and move on!
    You can switch the tags around later on!

    The prop rotation is an excellent point.
    Yes, but only after you have determined the correct Engine Rotation.

    If my props are running in reverse with the drives in FWD then that pretty much solves this dilemma and tells me that my engines are running backwards - likely because my starters got swapped. This will be the first thing I look at when I visit the boat after work today.

    Your Engines are not capable of running (operating) backwards. The 4 stroke engine must run in the direction of the build.


    1. Pull the valve covers.
    2. Crank one engine over to #1 cylinder TDC C/S
    3. Now bump the engine 90 degrees further.



    • If #8 cylinder intake valve has just cycled and is now fully closed, this cylinder is next in-line to fire, thus indicating that this is your Std LH Rotation Engine.
    • If #2 cylinder intake valve has just cycled and is now fully closed, this cylinder is next in-line to fire, thus indicating that this is your REV RH Rotation Engine.


    To further this, continue down the firing order stopping every 90 degrees.
    For the Std LH Engine, #4 will follow #8.
    For the REV RH Engine, #7 will follow # 2.

    It's just that simple.



    And BTW, a typical twin engine boat with straight drive transmissions, will spin a LH prop on the Port side, and will spin a RH prop on the Stdb side. This will also typically mean that the Port side engine is Std LH Rotation, and that the Stbd side engine will be REV RH Rotation.




    Speaking of my compression testing (which tested within spec, by the way) I'm wondering if my engines are, in fact, spinning in the wrong direction if that would have any effect on engine compression.
    Due to valve timing relative to crankshaft angle, YES..... it would certainly affect your cylinder pressure readings!

    I'm thinking no since there will still be a time at which both valves are closed and the piston is still creating pressure and engine rotation will not matter for that.
    Correct, and that will be during the Compression Stroke.


    Imagine this running backwards!

    (being viewed from flywheel end)
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  15. #15
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    Default Re: Distributors rotating CCW? Opposite of normal

    The Mallory B distributors won't work with a production RH GM engine; only the A versions work - just look up the OEM distributors for any crusader or mercrusier - same part number for either rotation....

    They are the 'oddball gears, assuming they are the original ones - from the ID tag. verification from the BW ID plates would be prudent and eliminate another variable.

    And to answer the previous question on the starters - yes, either one will bolt up to either engine - put the wrong one in and it will crank away but never run.

    I see the ID plate with the firing order isn't correct - that one is puzzling....unless PCM used a different convention back when they were made. I'd suspect human error...

  16. #16
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    Default Re: Distributors rotating CCW? Opposite of normal

    I just got back from working on the boat and I have good news - I got the engines up and running!

    The starters were reversed. Swapped starters and reversed by firing order and she fired right up. First time in many, many years. I even dumped a few pounds of seaweed, muscles and barnacles all over the boatyard - hope the owner doesn't mind.

    So, here are the two issues that had me completely thrown for a loop:

    1) The engine ID tags were just flat out WRONG! I guess I should have ignored them from the beginning, but I'd like to think the manufacturer would check this...and then double check this through a quality control system. I don't believe that the tags were swapped since the firing order on each tag is correct, it's the LH and RH engine rotation designations that are incorrect. The prop rotations are correct.

    2) As Rick mentioned, it's common for the port side engine to be standard LH rotation and the starboard to be reverse RH rotation so that is what I was wrestling with this whole time and assumed that's how my boat was set up. WRONG, again. My starboard engine is standard LH rotation and my port is reverse RH rotation because.....

    my drives are reverse rotation!

    Just typing this is giving me a headache.

    Both drives are Borg Warner model 10-18-106 and spin in the opposite direction as the engine when in FWD.

    Again, thanks for the assistance and walking me through this. This is my first boat (I'm a glutton for punishment) and it's been an interesting journey so far. I have a lot to learn, but I'm learning every day.

    Bad news of getting my engines running - the clutch on my starboard drive is shot and it's making a horrible, horrible noise. Guess I get to learn how to rebuild drives!

  17. #17
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    Default Re: Distributors rotating CCW? Opposite of normal

    Being aft entry starters(bell housing mounted) the rotation is just the opposite of what you think. A standard rotation motor uses a reverse rotation starter and a reverse rotation motor uses a standard starter.
    Plenty of online sources for the BW manaul

  18. #18
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    Default Re: Distributors rotating CCW? Opposite of normal

    ................................


    Quote Originally Posted by terrawombat View Post
    .......................................
    2) As Rick mentioned, it's common for the port side engine to be standard LH rotation and the starboard to be reverse RH rotation so that is what I was wrestling with this whole time and assumed that's how my boat was set up. WRONG, again. My starboard engine is standard LH rotation and my port is reverse RH rotation because.....
    That is rather ODD. Most straight shaft drive Port Engines are STD LH Rotation, with the Stbd Engines being REV RH Rotation.
    I could see this if you had V-Drives!!!!!!

    my drives are reverse rotation!
    This is what I've refered to as "Opposite of Engine Rotation" capable.
    Quote Originally Posted by Bt Doctur View Post
    Being aft entry starters(bell housing mounted) the rotation is just the opposite of what you think.
    A standard rotation motor uses a reverse rotation starter and a reverse rotation motor uses a standard starter.
    Plenty of online sources for the BW manaul
    I guess that I'm not following your thoughts on this.
    A standard Marine Starter motor will not work in an In-Board Borg Warner AFT mount flywheel cover scenario.

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	starter motor CW vs CCW direction explained.jpg 
Views:	25 
Size:	55.4 KB 
ID:	13037  
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  19. #19
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    Default Re: Distributors rotating CCW? Opposite of normal

    what happened to the edit button?
    and a reverse rotation motor uses a standard rotation starter.

  20. #20
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    Default Re: Distributors rotating CCW? Opposite of normal

    Quote Originally Posted by Bt Doctur View Post
    and a reverse rotation motor uses a standard rotation starter.
    I will need to respectively disagree with you.

    The Marine Industry designates starter motor direction (as per Engine rotation) in terms of CW and CCW (when viewed from the pinion gear) for both I/O applications (I.E., Engine mounted starter motors), and I/B applications (I.E., Borg Warner flywheel cover mounted starter motors) as illustrated below.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	starter motor CW vs CCW direction explained.jpg 
Views:	23 
Size:	55.4 KB 
ID:	13051  
    Last edited by RicardoMarine; 04-04-2016 at 10:43 AM.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

    Please... no PMs! Post your questions on the forum.

  21. #21
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    Default Re: Distributors rotating CCW? Opposite of normal

    using the left hand motor you need a CW turning starter motor if it is mounted to the block. That same engine with a aft mounted starter will need a CCW rotating starter.
    When I said a reverse rotation starter for a standard engine I was refering to the rotation of the starter.

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