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Newbie - 1972 Valiant

Discussion in 'A Body: Duster, Valiant, Dart, etc' started by Nebraskaorville, Aug 10, 2017.

  1. Nebraskaorville

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    Hey Guys,
    Just picked up a 72 Valiant, 318 - don't know the trans yet, but 99% sure its stock. Block is cracked (catastrophic oil/coolant mixing) and I'm looking for engines. Is there a definitive guide to what will bolt in and mate to the trans/exhaust/electricals with minimal mods?

    Thanks for your help,

    Green Dragon
     
  2. Best Answer:
    Post #50 by 68RT, Sep 21, 2017
  3. Scrounge

    Scrounge Well-Known Member

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    If your trans is automatic, it's probably a TorqueFlite 904. Look at the pan; if it's generally square, it's a 904, but if it has a rounded extension in one corner, it's a 727. Plenty of 318 engines are out there. The 340 might fit, but it's much more rare and expensive. The 360 replaced the 340, and should be fairly common. The 273 was used through the '69 model year, though you won't find many of them. The slant 6 was the base engine, if you want good fuel economy.
     
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  4. geraldg

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    Just remember the 360 is externally balanced unlike the 318 and 340.
     
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  5. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
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    Make sure it's not a head gasket failure causing the fluids to mix. Far easier to deal with.
     
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  6. dana44

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    When some kind of catastrophic failure like this happens, it is best to pull things apart before making assessments as to the cause. It makes repairs simpler so you don't waste time and money catching up on things you didn't prepare for, or parts you need or don't need. As far as the engine itself goes, any 318 LA block will replace the existing one with your bolt-on accessories, and brackets, and the 318 is a very common engine so not a problem or fear it won't fit or need any special parts whatsoever, truck or car, doesn't matter, a 318 LA engine is a 318 LA engine (not to be confused with the newer Magnum engine, there are some differences when you go that route). As far as the 360 goes, changes include the passenger side engine mount, torque converter for the transmission (for external balance, but the actual balancing weight can actually be welded to the 318 torque converter or a B&M counter balance flex plate can simplify that job), and exhaust manifolds are needed. All the brackets and accessories should bolt up otherwise.
    My suggestion is tearing the engine apart first, then decide the next course of action.
     
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  7. chuzz

    chuzz Well-Known Member

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    I agree with a tear down and examination. And the ONLY difference I ran into in changing a 318 car engine into a truck was the oil pan and pickup screen. I had to swap them as they're in a different position. Other than that and a possible exhaust manifold change, you should be good to go with most any 318 of that era.
     
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  8. valiant67

    valiant67 Rich Corinthian Leather
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    Physically, the LA 273, 318, 340 and 360 are basically the same. Only real external difference is the one mount on the 360 (and maybe 340) which can be swapped or shimmed. You likely won't find a 273 or an affordable 340, so that leaves 318/360. You need a car oil pan (318 and 360 oil pans are different). You also want to make sure the front of the motor has the same radiator hose orientation or you'll be swapping water pump and such. For a 360 you either need to swap to a property weighted torque converter or s weighted flex plate.

    You can go with a Magnum 5.2 or 5.9, but need the proper oil pan. You'd need a carb intake and electronic ignition for the simplest install.
     
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  9. Nebraskaorville

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    Thanks guys! I'm fairly certain it's a cracked block, PO was topping off a leaky rad w/water for 6mos or so and it sat through a cold winter- had chocolate mayo in the crankcase after he started it in the spring. I've tried some K&W block sealer with no success.

    I do intend to tear it down and am pretty sure I'll be at least be doing mains and rod bearings, probably just clean the topend and reassemble. What would really help me is to know where my compatibility cutoff is for a 318, can I just pick up a modern (80s? 90s?) used 318 shortblock and bolt all my stuff to it?

    Thanks again. I love this funky old ride.
     
  10. Nebraskaorville

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    Thanks! So- any 318 block will work- even up into the 2000s!? If so, that certainly simplifies things!
     
  11. chuzz

    chuzz Well-Known Member

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    Let us know what you do with it. Inquiring minds want to know! LOL
     
  12. Nebraskaorville

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    Oh you guys will hear about it! I'm prepping shop space this weekend and will likely start teardown after the dust settles on the start of the school year.
     
  13. dana44

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    Yes, all the bolts and mounting positions until they swapped to the Magnum are the same.
    Now, with that said, I had a 318 in my Barracuda freeze and the head cracked inside the valve cover, knocked a piece of metal out of the corner of a water jacket in the very front, so it doesn't have to be the block itself.
    Yeah, the oil pan is different, too. But my point was that all the pieces from your 318 will bolt to any 318 block and not have any bolt or bracket problems.
    Getting into the, I believe 318 in 1989 (check the engines page here, good write-up), the 318 went to a roller camshaft and 4bbl intake. Everything should line up still, but verify the year.
    318s in good condition are very inexpensive, mostly because Mopar never made any attempt to make it a performance engine or performance parts, so they are just a durable and common engine out there.
    Yes, I want to know what happened, too.
     
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  14. Scrounge

    Scrounge Well-Known Member

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    Agreed with examining first. If you can trace the leak, it might just mean the replacement of a hose (and it's probably best to replace all of them if one is bad). It could also be from the water pump or sending unit. But if oil is in the coolant (and/or coolant in the oil), then add me to the head gasket recommendations. Most head gaskets these days are composite, and I prefer the originals, which I think Summit and Jeg's still stock. Some chocolate was in my Dakota's cooling system. The leak was from a rear freeze plug; the rust and crud were bad in the heater core, and pretty much spread through the system. Someone had previously put some stop-leak in the system, and the shavings were everywhere. I flushed it quite a bit, including removing the block plugs, but still had to replace the radiator twice.

    I don't think the earliest 318 blocks will work. The engine was redesigned for the '67 model year, so any 318 from '67 to '89 should fit your car. After that, they were fuel-injected, and as previously reported, truck engines require minor changes. So long as the heads, manifolds, oil pan, and other externals on your current engine are undamaged and functional, they should easily swap to a 318 block.

    Count me as one more inquiring mind.
     
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  15. Nebraskaorville

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    IMG_3374.JPG
     
  16. dana44

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    904.

    727 has a definite bump on one corner.
     
  17. Scrounge

    Scrounge Well-Known Member

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    Agreed, 904. Most trans filter kits include a gasket for the 904 and 727. When you change trans fluid and filter, make sure you use the right gasket for your pan.
     
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  18. dana44

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    That, and also make sure the bolt holes are dimpled out so it doesn't leak. Years of overtightening the bolts tends to allow them to leak, a lot, so what I do is take a 2X4 and lay it on edge, sit the pan rail so the head side of the pan is against the 2X4, then take a bolt that is one size larger than the bolt holes and give a good wack so the hole is dimpled a little bit, allowing the bolts to then press more of the pan rail against the case and properly clamp the gasket instead of just at the bolt holes themselves. Make sure the surfaces are really clean, too. You can use a tiny smear, about paper thin, no thicker, of RTV number 1 or 2 for extra sealing, do NOT use a bead on the gasket surface, it's too much and if it gets inside and gets into passages it can cause shifting problems, so just a super thin smear to stick, not ooze when tightening.
     
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  19. valiant67

    valiant67 Rich Corinthian Leather
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    There is a really nice reusable rubber gasket available from Mopar.
     
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  20. Volunteer

    Volunteer Well-Known Member

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    And, other materials depending on company - - but don't neglect the integrity of the pan surface - as dana44/mr. k pointed out.
    I like to use Gaskacinch to attach gasket and seal it to the pan but with more flat surface available on tranny, it is perfectly fine to leave this portion (and gasket itself) clean and dry - as the 'entry-level' cork-rubber gaskets will seal well. Suggest to re-tighten after first 'test-drive' once everything well warmed-up.
     
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  21. Nebraskaorville

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    Hey Guys,
    Just updating - i have gravel down in my shop space with concrete going over it soon. Electrical is in process as well. Built a set of plug wires from an MSD universal set Saturday night over a couple beers - its a shame about the block, this is a pretty good running little engine. I've got the coolant system completely open and "dry" and i take it on short (1/2 mile- 2 mile) runs with my daughter just to feel out the brakes, trans etc. Its usually hot enough after that to see vapor from the top rad hose - i'm still hoping it is residual coolant burning off but am pretty sure its crankcase vapor. I replaced both sets of shoes in the front and bumped the torsion settings a little bit to bring the ride level. Also washed it and cleaned the inside of the windows.
    Makes it go faster! Anyway, here's some pics. Thanks for all your input! More news as it develops...
    image6.JPG image5.JPG image4.JPG image3.JPG image2.JPG image1.JPG
     

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