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Engine Swap

Discussion in 'Engine and Drivetrain/Mechanical' started by JonnybravoM3, May 26, 2018.

  1. JonnybravoM3

    JonnybravoM3 Member

    Hi all

    I'm still running the original 289 on my car and my Tech says the engine is really old and almost on its last legs even though she's running fine, but he did a compression and leak down test and told me that, depending on how much I drive the car, although it's hard to predict, I might get another year maybe out of it. My 289 leaks (not badly but it does) and I'm told even dropping the engine and changing the seals would be a temporary fix.

    I've spent a lot on the car already, upgrading ignition, distrubutor, radiator with electric fan, power steering, upgraded alternator, EFI (fiTech), new tank with in-tank pump, magnaflow exhaust, you name it I've done it...

    He's advising me to consider an upgraded transmission and a 302 crate engine which can just be plugged and played and will work with all my upgrades already done to the car.

    My question is, of those members who have swapped their 289s for 302 crate engine, is it worth it? Any regrets? I'm not a purist and don't care about matching numbers... But I do like to keep the original heart if I can, while I can!


    Sent from my HTC U11 using Tapatalk
  2. msell66

    msell66 Burning Fossil Fuels as Fast as Possible Donator

    Why not pull the motor and just do a complete rebuild? Unless the block is damaged or already bored out to far, no reason to go a crate engine route.

    rbohm likes this.
  3. JonnybravoM3

    JonnybravoM3 Member

    I could as an option but won't the seals and the gaskets be the same as those that are prone to leaks over time? I don't think they make more modern and robust ones for the 289, I'm not sure, just going by what I've been told.

    So doing so would be a fix albeit perhaps still a temporary one as opposed to going for a whole new engine?
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  4. msell66

    msell66 Burning Fossil Fuels as Fast as Possible Donator

    There’s no guarantee a crate motor won’t leak!
    Use the new Felpro rear seal and get the right oil pan gasket. Use sealer at the right places and you can get it leak free.

    When I built the recent motor last year, it still got a pan leak. I fixed that after talking to a guy at Canton by using the correct gasket. No more pan leak. The only leak I had in the old 289 was with the Canton oil pan. I was using the wrong gasket!
    rbohm and JonnybravoM3 like this.
  5. turq66

    turq66 Well-Known Member

    I'm still running the original 289 in my car. Have changed the seals with the engine in the car. Currently dry and still running strong. It might die soon, but it might run another 50 years, who knows. Anyway, my advice is if you're happy with the way it's running, keep it original. New seals should last quite a while.
    JonnybravoM3 likes this.
  6. jims6t6

    jims6t6 Well-Known Member

    I'm running the original 289 in my 66. Has closer to 300K on it. Been rebuilt twice. I agree with Gary. If it's running strong put new pan and valv cover gaskets in it and drive.
    JonnybravoM3 likes this.
  7. Horseplay

    Horseplay I Don't Care. Do you?

    The only difference with a swap to a 302 would be if you went with a new block that incorporated a roller camshaft. Other than that the 302 is the same as your 50 year old 289 engine. Crank, rods, pistons, heads...it's all the same tech.
    If it were me, I would rebuild the engine provided it needs nothing more than a .030 bore. Lots of the engine rebuilders who sell in bulk lack shall we say the best quality control. Minimum wagers bolting stuff together, for example. If you go with a bigger name you pay a lot more. You could have yours rebuilt for less and know it was done right if you do it yourself or employ the right builder. Stock rebuilds are cheap and easy.
    JonnybravoM3 likes this.
  8. Boom

    Boom Active Member

    I've swapped from 289s in both of the Mustangs I've had. No issues, I went with a roller cam 302 in the coupe and a roller cam 351w in the fastback. I wanted the ease and quickness of a engine swap vs pulling the engine and rebuilding it.

    A basic compression test only really shows piston ring, head gasket, and valve seat condition. You could narrow the issue down by squirting some oil into the cylinder and running a compression test again. That'll help tell you if its piston rings or a valve/gasket issue. If it's valve/gasket related you can pull the heads and have them rebuilt and put back on pretty easily.

    Plus if they're all original heads you might have issues with unleaded fuels, I believe it was a valve seat issue. Not sure on the specifics of that though, just something I read.

    Why are they wanting you to upgrade the transmission? Is there anything wrong with the one you have?
  9. JonnybravoM3

    JonnybravoM3 Member

    Still have the old 3 speed and that's leaking too. Was thinking of going 4spd AT.

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  10. Boom

    Boom Active Member

    There are lots of people that have done AOD swaps. The parts are out there to make it pretty simple, just have to set the TV cable properly. I always go auto to manual.
  11. msell66

    msell66 Burning Fossil Fuels as Fast as Possible Donator

    How many channels does the AOD get? Are they HD?
    tarafied1 and Boom like this.
  12. Horseplay

    Horseplay I Don't Care. Do you?

    I'm looking at a AOD for the '52 but after some research have some doubts. For a cruiser it is fine but for performance its not the best choice unless you do a valvebody swap. Stock it does some weak shifting and has issues with wanting to drop into OD way too often as lower speeds. A better option to find a middle ground might be to drop in a T5 5 speed. Simple to do, parts are readily available and you can cruise but always downshift for a bit of fun.
  13. JonnybravoM3

    JonnybravoM3 Member

    I've decided to go for a 4R70W like that off a Crown Victoria, used but rebuilt, won't cost much and I can find them locally which is good.

    By the way those 289s who swapped for 302s, did you change your 289 badges on the front fenders? Or leave them as they are.

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  14. msell66

    msell66 Burning Fossil Fuels as Fast as Possible Donator

    I still have all the 289 badging.
  15. Boom

    Boom Active Member

    The 289/302 are the same block and visually look exactly the same so there's no need to change it unless you personally want to.
    msell66 likes this.
  16. rbohm

    rbohm Active Member

    exactly right. new seals tend to not leak when properly installed, but even they can leak if the installer does something stupid. and seals and gaskets dont last forever, new or old. at some point they give up the ghost because they get old and brittle due to age, and the environment in which they operate.
  17. Horseplay

    Horseplay I Don't Care. Do you?

    I could have told you a valve cover gasket wouldn't work
  18. Midlife

    Midlife Well-Known Member Staff Member Moderator

    Mark uses gaskets? Since when???
  19. JonnybravoM3

    JonnybravoM3 Member

    I have a question, can our cars handle the swap? Say my 302 puts down 370hp. I've upgraded my brakes to discs, will get a new distributer and water pump etc... but will chassis/ body / system in general handle all that power?

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  20. msell66

    msell66 Burning Fossil Fuels as Fast as Possible Donator

    Lol, that and a lot more!

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