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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. distributor guy:
    - I'm pleased that it is working well for you.

    -Trimming the block was just to fit Saganaw transmissions.

    - I think the international starter was identified here years ago.
    To help my memory would you identify it more precisely?
    It seems like a good option. Beck is having starter woes that it may solve.

    - as to the vibration, which motor mounts are you using?
    Are what rpm does the vibration begin?
    Are you using a harmonic dampener?
    How much weight was removed from your flywheel?
    It may be possible to do something with the mounts to absorb the vibration you experience.
     
    Last edited: Nov 11, 2021
  2. On this sort of engine, weight in the flywheel, crankshaft and dampener is your friend.
     
    Last edited: Nov 11, 2021
    CNC-Dude likes this.
  3. Flatrod17
    Joined: Apr 25, 2017
    Posts: 167

    Flatrod17
    Member

    I had also heard that I should keep the weight in the crank and flywheel. I was going to lighten the crank and did not, have a aluminum damper, and decided not to use it, but have switch to a steel flywheel that weighs the same as the stock one. Both flywheels weigh 23 pounds.
     
    Last edited: Nov 12, 2021
  4. I'm trying to find why distributor guy's engine vibrates. I don't notice vibration in my engine I normally operate it around 2000 rpm. At high rpm I have other much more pressing concerns than vibration. It has a full weight flywheel and crankshaft. Its steel vibration damper seems lighter than the stock alternator rotor. The Mercruiser rotor may be good to use just for dampening vibration if it is heavy.

    Distributor Guys engine is in a Land Rover.
     
  5. tjm73
    Joined: Feb 17, 2006
    Posts: 3,404

    tjm73
    Member

    What do you define as "higher rpms"?
     
  6. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    Yes, lightening the crank excessively can alter the harmonics of the crank making the harmonic frequencies appear at different RPM's than they do originally. Lightening the flywheel can have adverse effects if you do a lot of city driving, that coupled with a lightened crank can make it non-pleasureable to drive.
     
  7. There could be a resonance in his mirror or in his car body. I have a BMW R100pd which had its mirrors shake, They have plastic housings that I filled with a pound of steel shot, it did not prevent their vibration but did lower its frequency. I filled the mirrors with different amounts of shot so I'd have at least one clear mirror most of the time.
     
  8. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I expect I will have a shaky ride down the track. I removed the flywheel and installed a flexplate with a Very small & light racing clutch. I have also removed the stock heavy harmonic balancer and installed a SBF aftermarket piece. That is a lot of mass removed.
     
  9. The flywheel and pressure plate have sizeable mass, but I never thought to weigh them.
    Let's hope the resonance will be raised to a point above your operating rpm . I also use a small aftermarket harmonic dampener. It seems to be working, but I can't tell if it makes a difference without running with it removed. As oil would then be flying out around the crank nose, I will skip that test.
    My first merc engine ran to 4600 rpm with no bad vibration. The second idles smoothly but is not starting just now. I've had motorcycles with violent vibration that was intolerable after 20 minutes, but even vibration like that will not be a problem for you as you get down the track in seconds. Reducing mass as you did will help your engine get up to speed quickly. That matters for your racing, a smooth ride does not.
     
  10. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

  11. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

    Looks like they extended that pricing for cyber Monday.
     
  12. arse_sidewards
    Joined: Oct 12, 2021
    Posts: 4

    arse_sidewards

    Has anyone tried a combination of an MLS head gasket and aviation sealer (or yamabond or a similar product)? I don't think I saw this combination on the couple pages where various people's results so far were summarized.

    The expansion ratios of the materials involves are such that an aluminum block and aluminum head should be clamped tighter by steel bolts as it comes up to operating temp.
     
    dennis g likes this.
  13. You raise an excellent point. The increase in clamping force due to heating an aluminum head should be taken into consideration when tightening the head bolts or studs so that the threaded connection does not shear apart as the tension increases. The torque specified by ARP ,for example, is for clamping an all cast iron block and head. In my opinion it should be reduced for aluminum heads and blocks. The expansion of the cylinders is unclear in my mind as they are of aluminum cast onto iron. But it seems clear that the fasteners threaded into aluminum would pull out more easily than they would in cast iron ( because of the lesser strength of aluminum) so the fasteners should have less torque in aluminum than in iron. Ignoring the strength of ARP fasteners, this may explain why arp specifies something like 145 ft lbs for their studs and Mercruiser specifies 125 ft lbs for the head bolts.
     
  14. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I have a new MLS gasket here waiting for me to get that far along again. The MFG says to put it on dry. The claim is that the gasket is coated with a sealant.
     
  15. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    That is really a non-issue. Thousands of aftermarket aluminum race blocks like Rodeck and Donovan use aluminum heads with ARP fasteners for over 30 years with steel studs and it's not a problem. They also have steel main caps and the different expansion rates doesn't affect anything. So rest assured that won't affect anything....
     
    ottoman likes this.
  16. arse_sidewards
    Joined: Oct 12, 2021
    Posts: 4

    arse_sidewards

    I mostly do Subaru shitboxes. I'm unfortunately well versed in the tech behind various types of head gaskets.

    I should have probably left off the bit about expansion rates. My question was more about the troublesome water/oil interface. I was wondering if a non-curing sealer combined with a metallic gasket that doesn't crush as substantially as a traditional fiber gasket with steel rings might perform better in that region. Those non-curing sealers do just fine sealing coolant pressure in more demanding locations (like a two piece engine block) but they do have the benefit of much fatter flanges to work with. I think using an MLS gasket instead of a traditional fiber gasket may give a sealer a better chance of working since those sealers are designed and tested with the expectation of a metal-metal joint since those are the applications in which they're used.
     
  17. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

    If you look back a way on this thread, there is quite a bit of discussion on closing in the deck surface. I have one I'm putzing with now,
     
  18. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    That seems to be the most practical solution for gaining real estate on the deck surface for better sealing and more run of the mill gasket choices.
     
  19. arse_sidewards
    Joined: Oct 12, 2021
    Posts: 4

    arse_sidewards

    I read the whole thread (over several days). I saw the pictures of the closed deck. I have a block that's not tapered enough to need boring. If the block were already going to the machine shop this wouldn't be a question and I would strongly consider closing the deck but as it stands I'm just looking to do a cheap stock rebuild with an aluminum head on top.

    Since the head bolts aren't TTY I guess I could just try everything with no expense other than the gaskets and sealants themselves until I find a combo that will pass a pressure test.
     
  20. oj
    Joined: Jul 27, 2008
    Posts: 6,281

    oj
    Member

    I happen to have one of these engines if anybody needs one, I wanted to build a tank but decided to go a different way. Shoot me a PM.
    Merry Christmas, Oj
     
  21. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

    @arse_sidewards,
    I see your dilemma. My guess is that you will be fine with a stock Fel Pro gasket. If the deck and head are flat and you are not upping the pressure, the stock parts will likely work. I purchased a relatively cheap aluminum head and plan to use it in a mild build. I am more concerned with the need for studs to avoid pulling the threads in the aluminum block.
     
    CNC-Dude likes this.
  22. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I have my motor reassembled. Now I need to install the clutch and trans again. Then it will go back into the chassis, followed by rewiring. After that I will again test my cranking pressures. Hopefully they will be low enough to allow the motor to live and the starter to do its job. arse-sidewards this is the motor that the MLS gasket went into. Hopefully, next week I will have a follow up.
     
  23. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I purchased another sealant, ThreeBond 1184 that was supposed to be comparable to Yamabond 4. The ThreeBond 1184 that I received is thinner than Yamabond 4. It is runny. It seems to dry a bit faster. Depending on your usage it could be better or worse. I did use some on the rear main cap.
     
  24. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    My motor keeps fighting me. It seems I have to do everything 2 or 3 times.

    It is on its 3rd head gasket and never has run. This last time was to increase its thickness.

    The pistons have been taken out for a top trim.

    I had to wait 2 months to have my crank polished and the timing chain gear and harmonic balancer bores honed. I had to use a pry bar behind the crank sprocket to remove it. I had been having issues with it when previously degreeing the cam. Naturally I got the cam right on the 1st try this time.

    I had to replace rod bearings again. I needed to order rod bearings 3 times before I got the right parts. Once was my stupidity. Don’t buy 460 Ford rod bearings, they are wider. 2 rods run on a journal in a 460 so there is no need for a chamfer on one side. In the 470 each side of the rod rides on a crank chamfer so the bearing is narrower.

    I messed up my custom intake gasket when I set the head/exhaust/intake down as a single piece. My head requires something special. This required taking the intake off for reassembly. When I put it back together the last bolt hole, the one at the top rear of the block stripped. I removed the intake again and installed an insert. After installing the intake again I see the lower front part of the gasket has split and is squished out of place. It will be good enough for me to check cranking pressures. In fact I should have just left it off. I should send my gasket drawing out to have some commercially cut.

    I need to install larger battery cables. There is a possibility that the current flow is limiting starter performance.

    My buddies that I compete against are razzing me that this thing will never run. I will have to look back on this thread to see when I started it. WAY to long ago.

    Am I this stupid or are others having similar problems? I cannot blame it on thinking my motor is higher performance than others. It is not. I am probably putting more electronic control on it than others, but I haven’t even started fighting that battle yet.
     
  25. GearheadsQCE
    Joined: Mar 23, 2011
    Posts: 2,843

    GearheadsQCE
    Alliance Vendor

    I hate having to do things over. You would think the second or third time thru it would get easier but that never seems to be the case.
    Good luck on this round! :)
     
  26. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    I did have to make a minor modification to the MLS head gasket. The gasket overhung the block and head at the ends. See the 2 white arrows. I cut off the offending protrusions with a Dremel and cut off wheels after putting the head on. The center of the gasket didn't stick out.
    Build 2 pistons gasket 1 w arrows.jpg
    I had talked about the piston & rod balancing issues. If you look close on my #2 & #4 pistons you can see how close I got it. Those 2 are 987.76 and 987.83 grams. Building the rod balancing fixture and getting that consistent was a pain.
     
    Last edited: Dec 27, 2021
  27. arse_sidewards
    Joined: Oct 12, 2021
    Posts: 4

    arse_sidewards

    Are you gonna pressure test the cooling system before you install it in the vehicle?

    Then again, it's not like it's hard to remove a head from an inline four in the vehicle.
     
  28. CNC-Dude
    Joined: Nov 23, 2007
    Posts: 977

    CNC-Dude
    Member

    Here is a tidbit regarding MLS gaskets you may or may not realize. Because by design, they dont compress like a composition head gasket or copper head gasket, MLS gaskets require a much smoother surface finish in both the block and cylinder head to seal. Otherwise, compression pressure will escape under and above the gasket in the low spots created by rougher finishes because the gasket can't fill in those low spots. Many older machine shops don't have equipment capable of producing the finer finishes required in case you happen to be using one. And you will only be relying on sealer that oozes into those low spots to bear the brunt of those pressures and may not end with success.
     
    Last edited: Dec 28, 2021
  29. beck
    Joined: Sep 20, 2008
    Posts: 272

    beck
    Member

    No, I am not. My motor is completely exposed in my application so it is easily done in the chassis.
     
  30. Flatrod17
    Joined: Apr 25, 2017
    Posts: 167

    Flatrod17
    Member

    Beck, Good luck on getting it to run this time around. Larger battery cables may be what you needed. I know you worry about weight, but I have run into this problem before. To small of cables.
    Are those oil return holes I see in your picture? Did you add them, or were they there? Drain out into the lifter area?
    I have run Cometic head gaskets before on small blocks, they are said to be reusable. I did reuse them up to twice then I got afraid of them and replaced them. And as CNC dude has said, they do need a smoother finish!
    As for my project, everything I do to it fights me! Its still not assembled yet. But I am mocking it up in the car to get things right before I assemble it. Making headers now, what size tubes did you go with?
     

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