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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. US_Marshall
    Joined: Oct 26, 2011
    Posts: 85

    US_Marshall
    Member

    Dennis, you seam to be investing a lot of money into your project, maybe you should build your own front axle. I worked with a guy building two wheel drive pulling trucks, we made a couple front axles out of 2" solid steel plate. He had them cut out on a plasma table and I machined the the King pin holes so a standard chevy 2 ton spindle would fit on. Instead of trying to bend and weld the ranger split beam together, make a new one with the ends to fit the ranger spindles.
     
  2. You made a serious axle, overkill for my 1800 lb cars. I do like it being one piece. A tubular center has been suggested to me, but that would locate the weld near the point of greatest bending stress on the axle. As the point of my effort is to mount a caliper, I may simply try that before concocting an axle.
    Your suggestion is valuable in helping me think the decision through.
     
  3. dawford
    Joined: Apr 25, 2010
    Posts: 499

    dawford
    Member

    dennis,

    If you use 48 to 52 Ford F1 spindles you can use one of these kits for disk brakes.

    Don't use 53 to 56 F1 spindles they have a larger King Pin than the 48-52 spindles that will fit the early ford axles.

    Check it out. You can buy the basic kit and use Pick-A-Part or buy the complete package.

    http://www.f100central.com/catalog/...9_224&osCsid=c723668395d8c8f126b68bb1e077e1f8

    The only reason that I don't use this kit is that I want the look of drums on my Model A's and the 48-52 have good 11" drums with 5 on 5 1/2" lugs and Bendix self energizing 11 X 2" shoes.

    They will stop my 2300 lb Model A's, along with the 10" Ranger 8.8 rear end drums, just fine.

    Dick :) :) :)
     
    Last edited: Feb 23, 2012
  4. Thanks Dick, I did not know of the ready made adapters. I have 2 1956 axles one in use and one in pieces. so the kits will fit. My brakes, indifferent at best pull to one side, use lots of pedal and do not stop particularly well. I'd go to a larger master cylinder, but it is not easy to push the pedal now , so I hesitate to do that. Before self energizing brakes came into use, brakes were terrible, so our brakes are among the oldest reasonable brakes.
    I may resort to a remote booster if it is an issue more serious than linings or adjustment as I am out of room for the brake pedal.
    I do not object to a small disk, but big setups as on late 70's ford pickups appear massive and too heavy.
    On checking the site you referenced me to, I'm going to check some rotors and see how they fit my 1935 wheels (always a concern as they are so odd). The adapters seem to be simple flat plates.
    I'd not even thought of using older axles

    Dennis
     
    Last edited: Feb 23, 2012
  5. US_Marshall
    Joined: Oct 26, 2011
    Posts: 85

    US_Marshall
    Member

    What type of roller lifters did you use? How did you reseal the lifter cover?

    I picked up some lifters to see how they don't fit (couldn't get a clear answer from anybody). It looks like the boss for the bolts the side cover on will be milled down to the block, before hand I will drill and tap the block to hold the cover on with lots of small bolts (8x32?).

    The link will be on the other side when installed.

    [​IMG]

    [​IMG]
     
  6. jmayabb
    Joined: Nov 18, 2009
    Posts: 21

    jmayabb
    Member
    from Kentucky

    We don't run the roller lifters. That is in the plans for the future hopefully. You could possibly run the keyed lifters but that would be pretty expensive. I think your idea above would work too.
     
  7. A number 8 machine screw is the largest I'd try in the aluminum, it is not thick.
    A 6 may hold well enough to seal there.
     
  8. heronaircamper
    Joined: Feb 28, 2012
    Posts: 3

    heronaircamper
    Member
    from CT

    I just found this great thread. Thanks for all the info.

    Here's my question:
    With the right cam, pistons and head, will this motor make 175 HP at 3,500 RPM?
    3,500 RPM would be the maximum operating RPM.

    This would be for an airplane so the gas would be 100 octane. Typical usage would be 10 minutes WOT at 3,500 RPM then an hour at about 3,500 RPM but throttled back to make about 70% of full power.

    Would have intercooled turbo but only to make 1-2 psi boost at sea level but more up at high altitude just to maintain sea level power.

    Was looking up info on a modern Chevy 3.7L straight-5 but this motor looks much simpler and lighter.
     
  9. dawford
    Joined: Apr 25, 2010
    Posts: 499

    dawford
    Member

    I would leave the cam alone. A friend who makes cams for 4 cylinder Hill climb and lakes cars said that the Mercruiser cam is very good as it is and that it is a good torque cam which is what you want for an airplane.

    With 100 octane fuel the 8.8 to one compression could be retained with the turbo.

    With the turbo it probably would make 175 or more at 3500 rpm.

    Fuel injection would solve the problems that automotive type carburetors experience in airplanes.

    An oversize oil pan similar to those used in race cars would supply oil in more of less level flight. (Non inverted)

    I am sure that those who make experimental aircraft will have better information on how to convert automotive engines for aircraft.

    The basic engine when properly converted would provide a lot of torque and Hp. per pound however the radiator is an added complication to be considered.

    I would think that an inter cooler might be a problem at altitude where the air is already cold.

    All of this is said noting that what I don't know about aircraft engines would fill a whorehouse.

    Dick :) :) :)
    .
     
  10. As most engines go, a Mercruiser 470 is light, has good torque and often runs for hours at high power output. Being a marine engine, it is closer to your application than an automotive engine. And it normally drives a prop so the load curve on the engine would be the same.

    In aircraft engines, an O-320, with its 30% displacement advantage, weighs the same as the mercruiser. Because of its displacement, O-320 output is at a rpm more appropriate for a prop and provides the output you request.
    An O-200, much closer in size, with its 100 Hp output, would be a fairer comparison in the direct drive mode to a merc 470.

    I think a merc 470 would be a viable aircraft engine provided:

    1. that it was built specifically with that in mind. Ie. a lower compression ratio to prevent detonation which is so common to them. The factory engine is rated at from 170 to 190 hp. But lacking an output graph I can't say more than that.
    (Running it on avgas will probably reduce its power.)


    2. that it is not expected to do more than it reasonably can.
    It is probably easier to design an airframe to require less power than to redesign an engine to make more power.

    3. A redrive would allow better prop efficency, but a narrower operation speed range.

    In considering it, realize that unlike Chevrolet car engines, it is not an inexpensive engine to buy parts for.

    I feel it is superior to some engines I see friends sticking in aircraft.
     
  11. heronaircamper
    Joined: Feb 28, 2012
    Posts: 3

    heronaircamper
    Member
    from CT

    It looks like if it was a "normal" airplane configuration it would be a very good engine if used with a reduction unit like this: www.classicairboats.com/ROTATOR-REDUCTION-Rotator-Reduction-1-71-19919.Item.html
    Then it could run up above 4,000 RPM with a prop speed around 2,500. Typically the bigger the prop the better for efficiency. 6-7 feet diameter is common modern length. Older slower engines used 8 feet or more. Need to keep tip speed down to around 900 feet/second maximum.

    I happen to need to use small (5 foot) props which lets me spin up to 3,500 RPM without using a redrive. There's other thrust bearing and crankshaft bending issues with using direct drive, but this crankshaft looks tough enough to deal with such a small prop.

    Feb 2006 Car Craft dynoed a Ford 460 and it showed 350 HP at 3,500 RPM without anything too exotic, so I would hope the Merc could do half of that without too much trouble.
     
  12. The merc 470 is close to being half of a ford 460. I say close as although it has the head, pistons and rods of a 460, it has a British Leyland tractor crankshaft which approximates the Ford 460 crankshaft in stroke and as far as I know, duplicates its bearing dimensions.
    I have read in this forum that Mercruisers came with either forged or cast crankshafts.
    As is normal, there is a thrust bearing, I do not know if it is adequate for your intended use.

    The redrive you refer to might even bolt onto a merc 470 [ one stud , top right position, will not match]. I have been told by a manufacturer that geared redrives often have gear lash problems.

    I wish you luck in your experiment. Be advised that this engine has been out of production for some time and some parts are only available used and can be expensive. Carry a parachute.
     
    Last edited: Feb 28, 2012
  13. res0wc18
    Joined: Feb 2, 2012
    Posts: 14

    res0wc18
    Member

    ha! now that is funny. although believable
     
  14. Phil1934
    Joined: Jun 24, 2001
    Posts: 2,640

    Phil1934
    Member

    First i had heard this. Explains why the crank weighs as much as the rest of the engine.
     
  15. flacoman
    Joined: Oct 5, 2006
    Posts: 75

    flacoman
    Member
    from Sunrise FL

    I remember the the Ford 3.8 V-6 being used in such a capacity ; I'd rather walk
     
  16. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    That was a light engine. It was originally intended for the block to be iron. For cost reasons the lightest possible iron block was done instead. The earliest versions were the least capable. To achieve adequate durability and head sealing the Supercoupe required a dedicated block. Over the years the engine has been upgraded numerous times. It eventually became something better than the POS it started out as, but it's probably my least favorite modern Ford engine. Block issues aside, ports in most of the heads are terrible and the engine has minimal built-in reserve. At one time there were good Motorsport blocks, heads, and misc pieces, but those haven't been available for quite a while.
     
  17. I am searching for a 470 Mercruiser ready to drop in a GM product. Are any for sale?
     
  18. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    Not true at all. I am not sure where you heard this but it is incorrect.
     
  19. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    Done quite a bit of research on cooling system routing. Some of the newest engine designs, like the Audi V6 turbo, are using some very complicated and unique routings. I feel that's one of the major ways they can run combo's like 10.3:1 Cr/89Oct/14-17+ Psi boost... and run 180,000 miles on average.

    So I got to looking at a head gasket, and the fact that I will not be using the factory casting which incorporates the thermostat housing..and I will be using a heater core, unlike most on here.

    I'm a little hesitant to be put this up on line for opinions, because I am not sure I'm done researching this, but I have a quick Paint drawing of what I believe is the ultimate cooling routing.
    I've checked that the rear crossover port can be opened up to basically whatever area I want- for sure the equivalent of a 1.5" hose.
    Thoughts?
    This would be using the factory water pump design.
     

    Attached Files:

  20. BuiltFerComfort
    Joined: Jan 24, 2007
    Posts: 1,620

    BuiltFerComfort
    Member


    I found the pics promising but a little confusing. Can you draw up a pencil-and-paper block diagram of how this would work? If you can show radiator, block, deck, head (etc, all water passages on engine itself), water pump, thermostat, heater; and then the hose or passage sizes and all the in and out and flow direction, I think you'd get better opinions.
     
  21. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    rad cooled water is blue, hot water is orange. Arrows indicate direction. Not sure how it's confusing.
    Oh. You did expand it to be able to read the text? I know the thumbnails don't allow you to do this...
     
  22. dawford
    Joined: Apr 25, 2010
    Posts: 499

    dawford
    Member

    iadr,

    I have also given the cooling system a lot of thought and also plan to introduce the cool radiator water from the bottom of the radiator into the front of the block where the original water pump pumped water into the block.

    I am not using the original Mercruiser water pump because of the sealing problems associated with that design. I will use an aluminum Toyota Cilica pump similar the the one Dennis is using.

    I am putting a pipe plug into the Mercruiser intake manifold at the rear of the head where you indicate that your return will be.

    The return line is going to be a 5/8" hose. If I find that inadequate I will also run a return from the front of the head.

    My very experienced Marine Mechanic assures me that he has run big blocks with no more flow than that and had no problems.

    I am using Walker Radiators that are good to over 450 hp so I do not expect any problems.

    I plan to run the hot water return through the Mercruiser intake to help with start up. I may use a cable operated heater valve to bypass the intake after warm up if that works better.

    None of my cooling system plans are set in stone and because I have so much room around the engine to work with almost any system can be developed if my initial system has some surprises.

    Dick :) :) :)
     
    Last edited: Mar 11, 2012
  23. tjm73
    Joined: Feb 17, 2006
    Posts: 3,315

    tjm73
    Member

    Someplace in this thread is the answer to this question, but I can't find it. I think I want to hook a S10 T5 to one of these Mercury engines.

    I know a Ford flywheel is used along with a Ford Mustang 10.5" clutch and some Chevy clutch disc (which?). Which bell housing from what car/truck should I look for? Am I correct, I take 5/8" off the bell mount of the block? Do I use the throwout setup from the S10 tranny? And I have to have the crank machined for a throwout bearing. Am I missing anything?
     
  24. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    There is a pair of T5 applications with an ideally 0.6" long input shaft-
    They were used in Mustangs after the restyle away from the traditional "Fox body"... so mid 94 & newer. In that application you could get 5.0's or 3.8 V6's.
    The V8 5.0 was used for only about 18 months production before being superceded by the 4.6 which also replaced the T5 with a newer trans design. With those, some insist the ratios are better than the v6.
    The 3.8 V6 used the T5 with long input shaft, and what I feel are even better ratios- less gap from 3 to 4th, and way less gap from 4 to 5th than the v8 gear set. It uses a middle of the road 1st gear @ 3.35. Certainly not stupid short like some 4 cyl applications, and most other v6's, like s10...but not as tall as 2.95 of the v8. Could you even tell the difference??

    Anyway, in any case, whatever T5 model you run, bellhousings are then *anything* with the SBC to T5/T4/Ford pattern... as follows:

    1- Jeep & AMC Eagle T4 to iron Duke circa 80-83. Being 4x4 has no effect on the bellhousing, but you are looking for parts (clutch fork!) for a totally orphaned make/model of car.
    2- Chevy Astro 5spd and a very few fullsize trucks (probably less than a years production). Also very very rare.
    3- Camaro- by far by far easiest to find. but it runs the trans at 17 degrees leaned over. To me that was a problem.
    4- Aftermarket scattershields are made by the main names in those things- Lakewood, Macleod, TCI, etc. with the correct patterns front and back.

    The other way to go is machine the back of the block by 5/8 inch. I dunno. Maybe that would have been the better way to go, but I've mocked everything up, and what I have works...


    The only downside is that if I pop a trans... I have to track down one either exactly the same or switch the long input shaft onto whatever other t5 I buy. On the other hand, I find the V6 Mustang application is not desired by many, and usually when found is in un-abused condition. Big bonus over v8 applications. :)

    Your last option is what Phil did and have a flywheel with a bit of a dished center made up.
     
    Last edited: Mar 13, 2012
  25. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    Ok, I'm in discussions with ARP, noted maker of fasteners, to make up head studs to my specifications, mainly full thread lengths for maximum contact in the block, and cut down to .500 on the shank, so that they don't need crazy torque figures to get the appropriate fastener stretch into them & torque up "correctly".
    Problem is, They are talking serious coin: $850+ for one 10pce set, dropping to around $535 each for three sets.
    Is anyone but me serious enough about this to spend that kind of money?

    Also, my build is based around a Boss reproduction head. If you are interested in going in with me, please post or PM me measurments of your head's thickness at the bolt holes. My Kaase Boss9 head is exactly 3.0" along one side, and is 3.22" along the other.
     
  26. heronaircamper
    Joined: Feb 28, 2012
    Posts: 3

    heronaircamper
    Member
    from CT

    A long time ago a friend of mine had a set of titanium main bearing bolts made up for his 1960s 427 Ford aluminum block for a Cobra restore. The stiffness of the Ti is about half of steel so the vibratory bolt force they put into the aluminum block threads was about half of what the original steel bolts did. He was counting on that because most of the threaded bolt holes were cracked before he had them welded up.

    Smaller diameter steel bolts will do the same but they will obviously be weaker than original, but they don't need to be any stronger than the aluminum threads anyway. (I don't know why he didn't do this instead of using titanium, maybe a brain fart...) He paid more than $1K in the early 1990s.

    Studs or inserts in the aluminum should be stronger than bolts.

    Need to match original preload tension force in bolts and not original bolt tightening torque.
     
  27. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    the problem as I see it, is that these engines used a head (iron) and headbolt (9/16-12) designed around a much beefier iron block- the ford 460.

    ARP recommends something around 170 ft-lbs tq to properly tension a full diameter 9/16 stud made of their alloy. That tq level would create enough clamping force to twist the block up in a very unhealthy way, and would definitely require threadserts. Trust me, I have emails from the engineer at Time-sert Inc, but that ended up not being a productive path.

    Modern engines use bolts stretched a great deal. That's done because it works. It tracks the growth of the block with heat, keeps tension in the interface ... even if the gasket flattens, etc.
    I maintain the the 9/16 dimension was something that Mercruiser engineers inherited that they would have liked to change- there just wasn't a practical way, having commited to using bolts and production-line Ford heads.
    The ideal way is a cut down stud, it seems to be the best of all worlds.

    There may be a stud already in greater volume production for a specific use in Top Alcohol & Pro Mod that is almost as good as custom. I'm inquiring what price I can buy those for, and if they are perfect or if I should have one sent as a trial. That should take place this coming week. I also have what is supposed to be Mr Frum's home number. He was the engine builder for the NHRA comp roadster with the 7sec 1/4 miles (featured about p 39 in this thread). I might ask him what he has done... I don't know how receptive he'll be so I am collecting questions, so it won't be a waste of time for him.
     
  28. BuiltFerComfort
    Joined: Jan 24, 2007
    Posts: 1,620

    BuiltFerComfort
    Member

    Just a shot in the dark here - if the block threads are too big (too much force for the aluminum), could you use a helicoil in the stock hole to bush it down to a smaller size? Then use 1/2 or whatever studs or head bolts you need?

    As I say, just guessing.
     
  29. [QUOTE=iadr;7551 I think it was on a H.A.M.B. thread. I t was some time ago.
     
  30. iadr
    Joined: Apr 14, 2007
    Posts: 147

    iadr
    Member

    That would work, but the block threads are very deep. It would require a thread insert with 9/6-12 outside and 1/2-13 inside, and almost 2" long. Or as that would end up impossibly thin (threads are not in sync, so low's of one meet highs of the other) - You'd end up drilling the block even bigger and threading that hole to 3/4-11 or whatever to make it all work. Completely custom thread insert.
    And then you'd want at least 1.5" threaded on the bottom of the stud, and that stud would make the stud custom, too.
    I am not worried about "locating" the head by the bolts, but some are thinking that the head will shift around with a small bolt through the bolt holes. To my mind, you have the two little collars to align during assembly, and then more importantly the total clamping force once it's together... really makes it unlikely. If your head ends up 3/16" cross ways on the block, you'd detonated or hydraulic-ed it so bad the pistons are done anyway...lol
     

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