Page 1 of 151 1234567891011121314151617181920212223242551101 ... LastLast
Results 1 to 10 of 1502

Thread: Mercury Mark 40-H

  1. #1
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Mercury Mark 40-H

    Well it all started by buying a whole bunch of engines from Charlie Miller up in Canada. My brother David and I drove up to his place to pick up a truck load of engines. In the lot was a Mark 40-H that really needed to be restored. Well we stopped at Doug Kays in Detroit on the way back and dropped the 4 four bangers off for restoration. All the engines were appart except for the 40-H and Doug asked what do you want done with them. Well I just told him to put them together. About a month later Doug called and said I would like to start on the 40-H also and being he had a all of the 44's in the works for me I told him to go ahead with it also. Well before I knew what happened and a lot of discussion we now have this wild red engine. I think its might be the only 44 cubic inch Mark 40-H with power dome heads. Yes that right its now 44 cubic inches with mercury 500 cylinder heads and a Brinkmen style port job. Hope you like the photos. We ran it last Saturday and hope to be on the water the first warm day in Detroit. Oh through in some others that are compete and some in works.

    Alan
    Attached Images Attached Images        
    Last edited by Ron Hill; 01-18-2013 at 12:18 PM.

  2. #2
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default 49 cubic inch seems impossible.

    As you can see the bore size for the 44 cubic inch mod came right up to the pins so it seems impossible to get 49 cubic inches unless the stroke is changed. Don't think the crankcase will let this happen.

    Alan

  3. #3
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Red machine

    As soon as it gets warm we will break the engine in on a hydro. I will give you the speeds as we go throught the testing. I expect that we will see close to 80 mph , hopefully more, if all goes well. Doug Kay dose all my 4 cylinder work and I have to say I have found no one better. I hope to make a few D's wonder how an old mark 40-H could run like that,

    Alan
    Attached Images Attached Images    

  4. #4
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default How fast will it run

    The engine is setup with KC6A cards and big read blocks to help it on the induction side. Then the interior of the block has been opened up to increase the flow to the intake ports. Both intake and exhaust ports have been reworked to allow for more flow. These are done to the Harry Brinkman specification. I have to note that the block had been ported with a file before we started the conversion. The largest changes have been making the engine into a 44 cubic inch engine using current flat top pistons. The cylinder domes were replaced from a Mercury power dome engine. The compression was also increased during this operation by installing them lower. The engines has 190 psi on a check of the compression after its first tank run. I expect this to come up a little. We are intrested in how the segmented exhaust is going to work in that the devider was left in from the standard 40H block. I beleive the engine is more capable than the current 44XS engine, but I guess we will see when we do some on water testing. The photos show some before and after shots of the build process. Have added some closeups of the ports.
    Attached Images Attached Images   

  5. #5
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Now the photos

    Hope you like them
    Attached Images Attached Images      

  6. #6
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Motor showing

    We hope to show them a few times this year. We just showed three engines at the Mount Dora show which moved acrossed the lake. Attached are a 30-H, 55-H and a 58-H.
    Alan
    Attached Images Attached Images   

  7. #7
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Merc 58-H

    Even though Mercury never made a 58-H I beleive that its a legal APBA "D" engine now to run with the 44XS engines. We have a pair of these engines that my brother and I hope to run this summer if we finish the two "D" boats we have under construction.

    Alan

  8. #8
    Sam Cullis Mark75H's Avatar
    Join Date
    Nov 2004
    Location
    Annapolis, MD USA
    Posts
    2,467
    Post Thanks / Like

    Default

    44 cubic inch motors are legal as of last year, but that does not make them "58H's"

    KG4H, KG7H, KG9H, 20H, 30H, 40H, 55H and 75H are actual Merc model names from the 1950's, not "generic" terms; for instance ... a KG9 powerhead on a Mark 40H tower and foot does not become a KG9H ... it is still a KG9 powerhead over a Mark 40H tower and foot, a Mark 15 powerhead on a KG4H tower does not become a Mark 15H either ... Merc never made it that way, even though it was legal to put the pieces together and race them that way.

    Like I said, showing a "Mark 58H" decreases your clout, no matter how shiny it is
    Since 1925, about 150 different racing outboards have been made.


  9. #9
    BoatRacingFacts VIP Aeroliner's Avatar
    Join Date
    Mar 2008
    Location
    Lake Charles, Louisiana 70611
    Posts
    924
    Post Thanks / Like

    Default Question of order

    I do beleive that Mercury sold the "Q" and "H" towers as a complete seperate package and a KG-9 became a KG-9Q. Likewise for the A and B motors had a hydroshort unit that could be acquired for the two cylinder engines. So if you bought a quicksilver "H" lower unit package from mercury and installed it on a Mark 15 it became a mark 15-H. Likewise for the KG-4 and KG-7 engines which used the same tower and foot. So if you put a Mark 58 on a H tower it becomes a Mark 58-H. Now don't confuse these engines with there name tag versions in that Mercury promoted both as racing engines and the use of quicksilver equipted engines was very common in APBA racing.

    Alan
    Attached Images Attached Images  

  10. #10
    Sam Cullis Mark75H's Avatar
    Join Date
    Nov 2004
    Location
    Annapolis, MD USA
    Posts
    2,467
    Post Thanks / Like

    Default 1950 Advertisement

    No, it did not completely work like that after the year 1950.

    You could put a "Q" under the original motors ... but not for the "H's" the only exceptions were the Mark 15 over the AB H tower and the Mark 30 over the "salvaged" Mark 30H towers. Even though you could race the motors that way, it did not make the motor a "Mark15 H" or a Mark 30H"

    There are actual known serial number groups for most of the "Q" and "H" motors ... other pieces put together are just parts that fit together, not 55H's 58H's, 15H's or Merc 28AH's. Where would the line be drawn? Is a 2 cylinder Merc 350 with a 55H tower and foot a Merc 350H? Is a Mark 75 adapted to a Mark40H tower and foot a Mark75H? Is a Chevy Caprice with a Corvette motor a Corvette or a Caprice?

    Racing rules were and still are very strict. A Mark55 fishing powerhead would not have been legal before they changed the rule in the late 1960's ... it would be out of spec on the ports and if you changed the ports to meet spec, the machine work would be obvious. Russ Hill or Edgar Rose would throw you out, no apology. If there was any doubt, they would have consulted the serial number lists.

    Merc did sell loose Q and H towers, but they went into use as alky conversions, replacements for damaged racing parts or cottage racers. Outside the 2 exceptions I noted above ... H's could not be "made" outside the factory doors.
    Last edited by Mark75H; 04-02-2008 at 12:44 PM.
    Since 1925, about 150 different racing outboards have been made.


Thread Information

Users Browsing this Thread

There are currently 10 users browsing this thread. (0 members and 10 guests)

Similar Threads

  1. Mercury Outboard Motors
    By Skoontz in forum Outboard Racing History
    Replies: 0
    Last Post: 10-23-2006, 08:10 PM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •