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The elusive 224/3.7 MerCruiser banger

Discussion in 'The Hokey Ass Message Board' started by tjm73, Apr 9, 2008.

  1. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    These holes are drilled through the side of the block and then on through the siamese portion where each cylinder is common. Maybe start and inch or so above the oil pan rail and move upward in 1/2" to 3/4" inch increments until you are maybe an inch or so from the deck. Then drill and tap the outside holes in the block to plug them. The holes that go between the cylinders are maybe .060" to .090" in diameter. Whatever you can find that are that long.
     
    dennis g likes this.
  2. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    Not sure but I think Mercruiser accomplished the same thing by cutting a grove in the deck between the cylinders. At least on the block I have has a slot in the siamesed portion of the deck that I assume is to allow air / steam to escape so there are no air pockets in the cooling system
     
  3. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    That's true, but the common modification that Dennis and a few others are seeking is to make the blocks deck flat and a "non-open" style eliminating that feature in the block. So he's thinking of a way to get around the new closed deck and create a new path for water circulation.
     
  4. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    After screwing around with the local laser guy since Dec. I saw our fearless leader Ryan posted a article on his other site Garage Journal about Send Cut Send a online laser cut service. so 5 days ago sent an email and this showed up today IMG_1215.JPG
     
  5. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

  6. Thanks, that clears it up nicely and makes great sense.
    foot long 1/8" bits are easy to find.
     
    Last edited: Mar 2, 2021
  7. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

    Three Widow's
    That's what we've been trying to nail down for months.
    I'm curious as to what you sent them.
    Are you planning to sell these?
    If not, can we purchase them directly from Send Cut Send?
    What's a ball park price?
     
  8. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    I want to check the fit when I get home tonight, This is set up to be welded in so not a super tight fit. Send Cut Send looks to be a real good resource. It cost just under $80.00 delivered. If it fits right I will post the .dxf file here if I can so anyone can order one. If the site won't let me upload a .dxf file I will email it to whoever wants it directly.
     
  9. SR100
    Joined: Nov 26, 2013
    Posts: 967

    SR100
    Member

    If it won't let you post a .dxf, you can zip it and post the zip file.
     
  10. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    Pretty happy with how this came out, it will need a little cleanup on the block to fit in place as I didn't draw in the lumps on the sides of the cylinder casting. I,m guessing 15 - 20 mins with a carbide burr and will be good to go. This is cut from 1/4" thick material, I think it will be plenty thick as most of the areas of the block that it will be welded to aren't any thicker, additionally it will require less heat to weld so less warping Slammed with work right now so it will be a few weeks before i get a chance to play with it. Thanks SR100 the .dxf file is in a zip folder hopefully someone can open it and see if it comes through right, it wont let me upload a .dxf directly. If needed I can email it direct as well. You can take this to a local shop or use it to order online, Ryan has a post on Garage Journal looks like there are several companies offering this service. Will update once I get it welded in place. IMG_1225.JPG
     

    Attached Files:

  11. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    I've posted .dwg and .dfx files here before so it should be an acceptable file extension the forum recognizes.
     
  12. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    You need a program that can open it. I use Sheet Cam to convert .dxf files to g-code for my plasma table, there are a bunch of free .dxf viewer programs you can download. Google is your friend.
     
  13. Jiminy
    Joined: Oct 25, 2012
    Posts: 409

    Jiminy
    Member

    DXF Viewer is a free viewer for DXF files. https://www.dxfviewer.com/

    I was able to download and unzip the DXF and view it.
     
  14. I think the problem is that I use Linux.
     
  15. Jiminy
    Joined: Oct 25, 2012
    Posts: 409

    Jiminy
    Member

  16. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    Three Widow's Garage - Great work on getting the filler plate done. If welding the plate like you plan to do, I think the 1/4" thickness is great. It looks like a nice piece. It does take longer than anticipated to get a nice fit around the cylinders. The 1/4" will be easier than the 3/8" that I used. I recommend getting a cutter designed for aluminum since the steel cutting versions do plug up pretty quickly.
     
  17. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    This is an update on my progress of the motor that I had the head gasket leakage on. I originally posted on page 79, post 2341, about the leak with photos. Discussion continued on it through page 81,

    When I took the head off I found no reason for the leak. The head gasket had impressions completely surrounding the block areas. I checked the block and head with a machinist straight edge. Everything checked out good.

    I reassembled using a MerCruiser gasket. I know they are supposed to go on dry, but I put a small bead of Halomar on both sides of the gasket. Then I put the head back on and torqued to factory specs. I pressure checked the coolant system with 5 psi of air pressure. It still leaks. It wasn’t as bad, but I was using less pressure this time.

    My plan it to run the motor like this. I will use the wafers of coolant sealant similar to what GM had recommended in some of their motors. It will be some time before I have the motor up and running, so it will be a while before I can update this.
     
  18. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    My plan is to get it tacked in place about .020 above the deck then use a die grinder to V out the weld area jumping around with short welds. 8 -10 welds at a time letting it cool between sessions.
     
  19. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I wondered why those slots were between the cylinders. That makes sense. Unfortunately when I put the deck plate on mine I filled those with JB Weld. When putting the deck plates on those channels no longer do their job. I expect drilling vent holes like mentioned above is another thing on the "To Do" list.
     
  20. Three Widow's Garage
    Joined: Jan 18, 2010
    Posts: 228

    Three Widow's Garage
    Member

    Here is a screen shot of the .dxf file opened in Sheet Cam Screenshot (1).png
     
  21. Thanks for showing the image, the color is even nice. From it I see that our blocks have different contours around the head bolt holes and cylinders.

    1/4" or 5/16" takes less laser power than 3/8"
    When welded there should be no need for more than 1/4" and the weld will penetrate a higher % than thicker metal. Some aluminum alloys fracture immediately adjacent to laser cuts but welding may heal that. A deckplate has the added benefit of carrying more heat away from the very top of the cylinder.

    Thanks for going to the effort to show the illustration so I could see it.
     
  22. Lets pool our experiences on sealing the head gaskets:
    updated as post 2525
    Randy said:
    - adding Permatex failed to seal the headgasket edge
    - adding silver paint failed to seal at the edge of the headgasket
    + The Mercruiser (Mahle) gasket with the grey sealant bead seals ok
    Distributor guy:
    + used great stuff (both sides of gasket)and it has sealed
    Dennis (me)
    + used Locktite Flange Sealant #518 on both sides of a Sierra headgasket and so far (30 minutes running) it has sealed. Assembly was like the Brer Rabbit and the Tarbaby story.

    Beck found that:
    - a bare Felpro head gasket failed to seal at the edge
    - a bare Mercruiser (Mahle) headgasket with Hylomar added to both sides failed to seal at the edge
    + his engine deck does not leak so if drydecked, no coolant leaks are possible if both the bottom of the head and the top of the block are sealed

    Chris reports that:
    + a copper gasket with spray on copper seal works to seal the edge

    many people :
    + used the factory sealant bead gasket for several years and like many others had no leaks
     
    Last edited: Sep 23, 2021
  23. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    - a bare Felpro head gasket failed to seal at the edge
    -a MerCruiser headgasket with Halomar top and bottom failed to seal the edge
    - my dry-decked engine does not leak around the plate. No head has been installed.
     
  24. I had an intake leak too. It came about as I used a Ford head which was not machined down to match the side of the block. All that would seal it was a cork gasket that worked because it was thick enough to fill in the gap between the manifold and block and also seal the head to the manifold.
     
    Last edited: Mar 7, 2021
  25. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    If you can find someone with a smoke machine it will show you if and where it is leaking.

    Is that a Land Rover?
     
  26. randydupree
    Joined: May 19, 2005
    Posts: 665

    randydupree
    Member
    from archer fl

    I wish you guys had been around 20 years ago when i was messing with those engines..
     
  27. distributorguy
    Joined: Feb 15, 2013
    Posts: 45

    distributorguy
    Member
    from MN

    Randy, I wish I was around Bonneville when you were racing them! Now I just drag a Datsun pickup out there and go real slow.
    As far as the intake leak, I just haven't gotten around to looking yet. Its an aluminum Ebay head, taller so the intake doesn't interfere with the block. Plus it spent a little time on the flowbench. I think the gasket just compressed with heat. The upper bolts were a little loose - might be all the vibration???

    As a side not, has anyone gotten these big venturi 2GC carbs to run well on the street??? I feel like its starving for fuel, but the AFRs are 13-15. Stalls under load from time to time. I only have 10 minutes of drive time so far, so not enough data to solve the problem, using an Innovate LM-1 AFR meter with a long extension in the tailpipe.

    Yes, this is a '64 Series 2A Land Rover.
     
  28. Or pressurize the intake manifold with air and brush a lather of soap and water on the suspect joints and look for bubbles.
     
  29. One cylinder can be lean and another rich but as the AFR is an average when its sensor is located downstream from the individual header pipes it would not show the deviations of individual cylinders. The meter would only show the average.
    My LM-1 is the most entertaining thing on my car. I have it permanently mounted.
     
    Last edited: Mar 9, 2021
  30. https://www.underhoodservice.com/diagnosing-intermittent-stalling-issues/
    this is a good article on erratic stalling. I experienced odd stalling when I improperly used an 8 cylinder 1.5 ohm ignition coil instead of the correct 3 ohm one for a 4 or 6 cylinder engine. The 1.5 ohm coil drew too much current, overheated and would stop working at inconvenient places.
     
    Last edited: Mar 13, 2021

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