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Suburban Project- Need Help!

Discussion in 'Tech Discussion' started by scenic760, Feb 10, 2021.

  1. scenic760

    scenic760 Full Access Member

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    I got it free!

    My neighbor came over and held a 3lb sledge against the #7 and we broke the cardinal sin of smacking two hammers together while I whacked it with a 5lb sledge. I put a 3 1/2" hole saw upside down against the piston to somewhat distribute the weight to the edges.

    Now at this point am I obligated to strip it down and take it to the machine shop or can I just hone the cylinders and re-ring?

    Thanks again all!
     
  2. Salty Crusty

    Salty Crusty Full Access Member

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    That rusty cylinder looked rough. Tear it completely down and take it to the machine shop and have them give it a good once-over. Tell them your situation and ask what options you have. A good machinist will spend your money as though it were his and he were on your budget. They're plenty busy with good, honest business and don't have time to play games. If he thinks it'll be fine with 7 "freshened" cylinders and one honed an additional .010, you should end up with an engine that will have plenty of miles left in it. I wouldn't hesitate to have it honed to .040 over but wouldn't even consider putting a sleeve in a .030 over 2-bolt block. If there's a good sized ledge a few mm down from the tops of the cylinders, it's probably worn far enough that you won't get very good ring seal. If there's no ledge, you're in luck!

    Clean it up as best you can and post a few pics.
     
  3. scenic760

    scenic760 Full Access Member

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    Thanks my man...yeah I'm coming to the realization I am going to need to do just that! I should probably just have them bore all cylinders

    It wasn't rust in the cylinder, it was like a carbon build up...as I started cleaning it off I noticed that cylinder wall is scored all the way. You think some kind of oil blowback that caused the carbon on the cylinder wall? I wonder if only honing it another .010 would get rid of it? I think the rest of the cylinders look ok?

    So when I tear this down, is there anything I need to mark? I think I need to mark connecting rods?

    Also should I Plastigauge the crank?

    20210221_160841.jpg 20210221_161758.jpg
     
  4. Salty Crusty

    Salty Crusty Full Access Member

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    Keep the rods and caps together, you can't swap them around. And yes, mark each with the cylinder it's out of. Pushrods can all go together. When it's time to pull the cam, flip it on it's top and rotate the cam a few times to get all the lifters up. Chances of saving this cam are close to nil, I wouldn't worry about it, plan to get a new one. This will give you the chance to step up to an "RV cam) that'll give you more torque and hp.
     
  5. Dave M

    Dave M Full Access Member

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    How did the bore end up in that state? Is there a crack in the bore or the head.
     
  6. Bextreme04

    Bextreme04 Full Access Member

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    The cleanliness of that piston top, combined with the nasty carbon sludge on the cylinder walls makes me think head gasket leak or intake gasket leak that was allowing oil and/or water into that cylinder. Coolant getting turned into steam in the combustion chamber will clean a piston top just like that. At the very least I'd tear it down and take it in for a thorough cleaning and inspection. Those cylinder walls look hammered to me, I'd expect to have them all honed at least another .010 and new pistons/rings. The oil sludge says you probably need the heads rebuilt with new guides as well. New cam, main, and rod bearings. New cam and lifters. Pushrods and rockers are probably fine to reuse with a thorough cleaning. New oil pump, water pump and harmonic balancer. That would be a whole new reliable engine. With careful inspection you can probably roll the dice on quite a few of those items. I wouldn't skimp on the bearings or oil/water pumps.

    Edit: fixed my nonsense grammar/spelling errors
     
    Last edited: Feb 22, 2021
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  7. Salty Crusty

    Salty Crusty Full Access Member

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    Ask your machinist for an estimate of what it would cost to do all this machine work and parts. Might be within a few hundred of a crate engine. Best to learn now before you're into it for a stack.
     
  8. scenic760

    scenic760 Full Access Member

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    You called it... called around today and machine shops 'round here are quoting $500 to bore, hone, cam bearing the block... clean as well but that's it

    Not sure I see the value in it as I honestly dont need much more than 10k out of the motor until I can LS swap it.. really thinking about a driveway hone/rering and keeping some oil on hand to burn..

    The only thing I worry about in that scenario is passing a smog test
     
  9. Salty Crusty

    Salty Crusty Full Access Member

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    How deep is that score and what caused it? Busted ring? Trash? Can you clean it up and post a pic? Is there a ledge near the tops of the bores that can you can catch your fingernail on?
    Scotch Brite has abrasives in it , I think the red is about 400 grit, similar to a hone. Don't scrub a small area with your finger, use full hand pressure to spread the load, you don't want to dig a hole, just clean it up. Wrap it around a length of 2x2 and use it like a sanding block but go around the bore, not up and down - again, don't want to dig a groove and screw up ring seal. Don't use it in any bores that don't need it, leave the clean ones alone.
    How do the rod and main bearings look? Post pics if you can. Is the cam still in it? Do all the lobes look pretty similar - none ground down or anything like that? When you remove it - if you haven't already - make sure you keep the lifters in the correct spots. They can wear differently but the only problems I have ever seen were when a used cam and lifters were swapped from one block to another, all your lifter bores are indexed the same, so it shouldn't be a problem if you've already pulled 'em and mixed them up. You don't want to mess with a cam swap if you don't have to.
    If it cleans up OK, there's no reason not to reassemble it and run it. So what if it has a little blowby and/or smokes a little? As long as it's a runner, it'll get you by which is what you are looking for, right? BE
    MAKE SURE YOU PRESSURE WASH IT REALLY GOOD PRIOR TO REASSEMBLY. Blow it dry with air and hose it down with WD-40, it'll cling to the metal and displace the water. Don't leave it sitting around, get it reassembled and closed up before it rusts in spots you can't get to.
     
  10. scenic760

    scenic760 Full Access Member

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    Yep Salty, just looking to get by for right now and put the time, effort and cash in the LS swap. It seems like the only shops around here who are working on Gen I stuff are the high $$ speedshops... one guy I called was almost appalled that I would even cross the threshold of his shop with a rickety 2 bolt main out of an '81 Suburban.

    I think that groove was caused by a splinter coming off the piston, it lines up in the exact spot in the pic. Also pulled off the center main cap and it looks pretty worn to me? I would assume other bearings look similar..? Also the harmonic balancer looks like it exploded?

    So my thought at this point is maybe change out the bearings, oil pump, timing chain, harmonic balancer, water pump and put it back together?

    When I go to clean it should I just spray it down with Purple Power or something and then go to town with a pressure washer inside and out? And then like you said spray the heck out of it with WD40?

    20210223_103300.jpg 20210223_105548.jpg 20210223_105723.jpg 20210223_111827.jpg
     
  11. Bextreme04

    Bextreme04 Full Access Member

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    Man, that is trashed. I don't know that I would even touch the bore or rings with it looking like that. I'd throw some new main and rod bearings in it and a new balancer and maybe a water pump. I wouldn't worry about oil pump or timing chain unless they look damaged or worn. You likely don't have enough crosshatch to seat new rings anyways, and you wont fix that gouge without a bore and hone. Get a new engine gasket set and clean/degrease the heck out of it with the pressure washer, blow it dry and spray some basic black engine enamel paint on the outside of the block/heads and send it.
     
  12. Salty Crusty

    Salty Crusty Full Access Member

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    Before you do anything else, at least pull every main and rod cap and look for damage. A turned crank may put this out of budget, especially if you have to swap a rod. If none look worse than the one you showed, I think you're probably fine.

    I've never seen a production oil pump wear out. Low pressure is due to increased clearance in the bearings as this one would certainly have shown!
    I'd probably clean it up and add a timing chain if the one in it is loose. When you pop the bearing shells out, you'll see if they're standard or if the crank has been turned and oversize bearings are used, you don't want to assemble with standard and find out it's been cut .010.....presto, low oil pressure and trashed bearings.
    Clean the pistons in a parts washer and make sure the rings spin freely and that none are broken. Don't worry about the missing chip on that one.
    Big concern is the camshaft - need to see how the lobes look. If there's any rust on the bottom of the lifters or cam lobes, it could screw with the surface hardness of either or both. At this point, I'd leave the cam in place and pull each lifter. Make up a rack for them so you can make sure each goes back into the exact same spot. Shoot pics of the lifters, especially if you see any that have major cups on the bottom. Same with any cam lobes that you can see through the lifter valley drains - they should all look pretty much the same, both intake and exhaust. Fairly sharp edges on the lobes, not rounded/ground down. If they all look good, clean 'em as best you can. I would probably get some cam break in paste and put it on the lifters to protect them at fire-up if it takes a little while for the oil to get to them. Cheap insurance since you're going to be out gaskets, bearings, etc., no reason to waste that money. Get a replacement Pioneer balancer, don't get cheap ebay Chinese here, it's false "savings", yours is junk.

    And what caused that one hole to carbon up so bad - head looks the same. Bad valve seal or guide leaking oil?
     
  13. scenic760

    scenic760 Full Access Member

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    Thanks for the replies gentlemen!

    I will carve out a place to lay all the stuff out in order and start cleaning stuff... and putting together a parts order

    Thanks again!
     
  14. Salty Crusty

    Salty Crusty Full Access Member

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    "And I will not purchase any parts or make any plans until I am confident that my efforts will result in a running engine, capable of filling the gap until I have time and resources to complete a more powerful and reliable engine"

    Too many people get excited at this stage and start buying parts - pistons, bearings, cam, etc.
    WAIT until you have had time to calculate the cost of repairing this one and getting it back together and running.
    Make sure everything is clean enough to determine if it's usable.
    No problem with getting a list together, but don't order anything until you know for sure that you'll be rebuilding this one.
     
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  15. Matt69olds

    Matt69olds Full Access Member

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    If all your doing is trying to get it running until you can swing a LS swap, I don’t think I would even consider messing with that engine. Find a running engine, who cares if it burns some oil, or makes a little noise? Unless you have lots of of the parts you need sitting around, I seriously doubt you could reasonably fix that engine for less than 500-600 bucks. Or, just let it sit until you can scrap the funds together for the LS swap. Why waste a bunch of time and money on a temporary fix?
     

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