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Amc 304 Oil Out Exhaust( Now Re-building)

Discussion in 'Intermediate CJ-5/6/7/8' started by B-Rad, Jun 16, 2017.

  1. Jun 20, 2017
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    And so it starts...
     
  2. Jun 21, 2017
    Desert Runner

    Desert Runner Member 2024 Sponsor 2022 Sponsor

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    Push rods can be cleaned and reused, Lifters....... your choice, I would check each lifter by pushing on the seat with a Phillips screw driver and feel how stiff it is, and compare one to another if all are about equal, then reuse them. Or let project creep have it's way and replace :)

    Jay
     
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  3. Jun 21, 2017
    B-Rad

    B-Rad Member

    Dayton
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    Also, I see Bulltear has rockers and pushrods with different size oil holes for better oiling is that the way to go? I have also seen the oil line modification in the motor valley, is that worthwhile? I have not talked to the local machine shop if he has ever done any AMC stuff. Thanks
     
  4. Jun 21, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Stay on target. First thing to do is fix what's broken. You will have plenty of oil pressure if 1) the main and rod bearings are not worn out 2) the cam bearings are not coming apart and 3) your oil pump is assembled properly and measures to factory spec. The oiling mods are of questionable benefit on anything but a full-race engine. IMO there is way more risk from the added oil lines breaking or your not executing the new oil lines properly than any possible benefit from better oiling.

    Read the TSM thoroughly and do everything carefully and to factory specification. Measure everything you can, and then re-check your measurements. Measure, measure, measure.

    The Tom Monroe book linked in my PSA about TSMs will give you some good background about engine rebuilding in general. That and study the TSM. PSA - Which Manual Should I Buy?

    Your main problem is not which mods to do, but deciding which might-as-wells are important, and which you can skip. This is a really hard and important question. You are very likely to cut some corners that shouldn't be cut, or to do too much and end up spending more than a rebuilt replacement engine would cost.
     
    Last edited: Jun 21, 2017
  5. Jun 21, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Quick rule of thumb - if you start taking things apart and find something obviously broken, stop.

    Fix the broken rockers or bridges, put it back together, and check the compression. Most of these heads have rocker bridges - though the earlier ones do not. I'm not sure which rocker bridges you need - it would be good to post a pic of the broken rockers/bridges or whatever. The guys on the Wagoneer sites know which rockers and bridges you need. I believe if you have aluminum bridges you should replace them all with the aftermarket steel bridges. If you have the OEM steel bridges, those are the best. If it's the rocker that's broken, post up a pic and we can evaluate.
     
  6. Jun 21, 2017
    B-Rad

    B-Rad Member

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    I will have to get a picture when I get home. Thanks guys

    Another thing I just thought about. I did the leakdown test on one of the better cylinders making sure on tdc, and could feel air coming out of the oiler filler. Is that not rings? Or could it be a valve issue?
     
    Last edited: Jun 21, 2017
  7. Jun 21, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Unless you have a hole in a piston (actually not uncommon) or some other strange occurrence, air coming out of the oil filler would indicate leaky rings. Oil on top of the rings would lessen the leakdown here, just like with a compression test. The only way a leaky valve could leak to the crankcase is through the guide, and that would be way less than through the intake or exhaust. The pressure has to go past the valve to get to the guide, and from there the intake or exhaust tract is a wide-open highway compared to even the most worn guides.
     
    Last edited: Jun 21, 2017
  8. Jun 22, 2017
    Keys5a

    Keys5a Sponsor

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    I have built several AMC 304 and 360 engines, and have done the priority oil modification on all of them. This simply taps into the main oil gallery at the front top of the block, and runs a 3/8" flexible hose back to the rear of the lifter gallery on the right side. The key here is to use a braided high pressure hose with swaged ends; think of a ss braided brake line, only larger diameter. A hard line can fatigue and break as Tim alluded to.
    The need for this modification is that AMC feeds the crank main journals via the lifter gallery. There can be significant internal oil loss as these engines wear, especially in the lifter area. These V8's are kind of notorious for severe ticking lifters that don't stay fully pumped up.
    I also open up the drain-back holes above the cam to make sure oil gets back down to the pan. I have seen a couple blocks with significant casting flash restricting return flow.
    -Donny
     
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  9. Jun 24, 2017
    B-Rad

    B-Rad Member

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    Update time. I ended up pulling the motor to do a rebuild. Good thing because one of the lobes on the cam is still egg shaped but has some pretty good flat marks on it, more than the others. So it looks like a new cam is on the menu, stock or should i get an rv cam? worth it over stock?

    Also look like a new timing chain, lots of slack but I figured that.

    The timing cover where the water pump bolts on get ate up pretty good by a previously failed water pump i am guessing, the blade must of went and made its mark in the cover. So looks a new cover is probably a good idea.

    Glad I pulled it all. Thanks
     
  10. Jun 24, 2017
    Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Good part is you will know what you are putting back in as an engine.
     
  11. Jun 24, 2017
    Keys5a

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    If you have to get a new cam, I would highly recommend an aftermarket grind over stock. Be sure to get new lifters. Check the pushrods for wear, as they may be reused if in good shape. There are aftermarket timing covers available, so this might be an option for your damaged one. I prefer a double roller timing chain over the stock design as they last a lot longer before going slack.
    -Donny
     
  12. Jun 25, 2017
    B-Rad

    B-Rad Member

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    Any recommendations on a cam? Just street driven and taken off road some. Does not rev very high so probably looking for something torque related. Thanks
     
  13. Jun 25, 2017
    Desert Runner

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    When I rebuilt mine i put in a RV cam. The stock curve is typically 1500 - 5500 the rv cam lowers that to 1000 - 5000
    Having the power band kick in earlier can be very advantageous. I used a cam dynamics RV cam, but Crane bought them out. I'm told The Crane Energizer series are the old Cam dynamics grinds.
    Jay
     
  14. Jun 25, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Melling cams are sold through parts stores as an aftermarket RV grind for many different engines. The Melling for the 360 is well regarded by the Wagoneer guys. Melling is a respected name that's been around forever.

    There are quite a few threads on cams at JeepForum.com - you might look there. That seems to be the most popular forum for 304 CJs.
     
    Last edited: Jun 25, 2017
  15. Jun 25, 2017
    Keys5a

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    I have used the Melling MTA-1 in a couple 360's along with an Edelbrock Performer 4 bbl intake. It really wakes up the 360, but could be a bit much for the 304, depending on your use. I think I used a Melling MTC-1 in a 304 that pulled really well, but its been so long, I can't be sure if it was the MTC or MTA that I used. They are both classified as RV/torque cams, whatever that really means.
    -Donny
     
  16. Jun 26, 2017
    B-Rad

    B-Rad Member

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    Took the block to the machine shop today. He is a little behind but it is just a one man show. He measured the crank and said it was pretty good and to just use standard size bearings along with the crank bearings. Cam is done for so I am getting a crane cam, nothing crazy.

    I said previously that the timing cover looks like it got in a fight with a water pump fan at one time. I was going to get a new one but does that really hurt anything? I can make sure the oil pump is within spec. Just trying to save some money, those covers are not to cheap. THanks
     
  17. Jun 26, 2017
    Desert Runner

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    And not always very good there are several threads on here and FSJ boards about timing covers being worst than the one's that came off.
    Jay
     
  18. Jun 26, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Your best option is to refurbish your used cover, or another used OEM cover if you can find a good one. The clearance between the gears and the oil filter adapter is critical; there are several ways to address this, including steel mid-plates, thinner gaskets, and abrasive lapping of the oil pump adapter and cover.

    There were quite a few badly machined import replacement covers several years back. If you use a new cover, I suggest you look at it very carefully and measure the clearances. Procedure for measurement is in the TSM. Checking the clearance with careful measurement is essential for any cover replacement, new or old. If you are willing to pay a premium price, BullTear sells a replacement cover that they have measured and checked for manufacturing defects.
     
  19. Jun 26, 2017
    OleBlue

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    A few years ago I found and bought a new cover that had been checked by an eBay seller. It came with gaskets and seal. Just looked and don't see them now. I also purchased a mid plate. Mine holds pressure in spec with what 73 CJ5 states the TSM states.
    My opinion, but Bulltear doesn't get my business. I've tried a couple of times but had to get PayPal to refund me both times after several weeks of no response.
     
  20. Jul 6, 2017
    B-Rad

    B-Rad Member

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    Hey everyone, I have gathered up most of the new parts to put it back together when it comes back from machine work except head bolts. I am looking at arp website and none of them state they are for an AMC 304 just a 343-401. I believe there are 14 bolts in each head with the one on the outside of the valve cover being shorter. They have a few head bolt kits that appear to have the shorter and longer bolts but they do not give any specs( thread size and length) Maybe I should just call them up? Or maybe I do not need ARP?
     
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