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Unbalanced Crank Symptoms

Discussion in 'Engine Building' started by jtornado, Dec 25, 2007.

  1. jtornado

    jtornado New Member

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    What are the symptoms if I dont balance my crank with my build I am currently doing. I already got the crank micropolished and all the journals are in very good shape and within spec. The guy at napa who micropolished it says the crank is balanced from factory and shouldn't need to be balanced but since I installed different rods and pistons, shouldn't I need to get it balanced???
     
  2. LS_VTEC

    LS_VTEC you get the BRAKE

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    its "safe" to have your rotating assembly balanced. but all you really need to do is take a really GOOD look at the crankshaft when you take it apart and look at the journals for discoloring. look for scored or worn spots and marks. clean it up a bit first. most likely, its not out of balance. IF you do infact change the crank pulley than you will have to make sure the crank pulley is balanced, I.E. CTR crank pulley... they say its balanced from honda, but not for nothing, everyone ive seen was out of balance. also, make sure you atleast hone the cylinders before installing the pistons/rods. make sure there are cross-hatch markings on the cylinder walls for it helps the rings seat faster and properly (most important). Just change the seals front/rear and you should be fine if the crank was only micro-polished. Good luck.
     
  3. jtornado

    jtornado New Member

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    Yes I had to get my block bored cause of corrosion in the cylinders walls. My setup that I have installed right now is 81.5mm 9:1 C/R CP Pistons with Eagles rods w/3/8 arp bolts, Micropolished crank and I even checked the oil clearance on all journals and they are exactly what Blanco wanted me to have them which was I think .015 main and .017 rod, well they are in the middle of the factory spec, so I know Im not too tight or too loose. All my journals did look really nice with no scoring or discoloring. Now I heard to use conventional oil for breaking in the motor because synthetic does not let the rings seat that well but once everything is seated then use synthetic to maximize life and performance?
     
  4. jtornado

    jtornado New Member

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    So why break in N/A first, because its too risky to run too lean or too rich with a turbo on it???? I heard pull the spark plugs and crank the motor with your starter for a maximum of 30 seconds or until you see the oil pressure gauge begin to register. This is just to be sure that everything is working properly because actually idle. Then after this if you do have a turbo, trailer it to get it tuned right away.
     
  5. LS_VTEC

    LS_VTEC you get the BRAKE

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    you dont have to bore to clean up the cylinders, you have to hone. as far as the break-in, use 5w30 and change the oil after 500 miles and check for broken pieces of metals and such in the oil when it comes out. if all is well, run 5w30 for another 500 miles to make sure those rings are seated. from there you can run your synthetic blend, but personally I would run a half synthetic blend with half non synthetic (after the break in). When breaking it in, try not to take it past 5k rpm and dont put too much load on lower gears... like... 5th gear, 50mph going uphill is a great way to break in the rings properly.

    There are plenty of machine shops that can balance a crankshaft, they all use pretty much similiar machines to balance them. Its all up to how lazy your engine builder really is.
     
  6. LS_VTEC

    LS_VTEC you get the BRAKE

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  7. jtornado

    jtornado New Member

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    So basically everything stock including the fuel pump. I actually wanna change my oil after 20 miles cause you could be surprised how much metals is coming off the rings in 20 miles. I dont wanna build them up into a pile and get into my oil pump. That would suck. I play it safe and probably do 3 oil changes before actually putting in synthetic. May I ask why you would use a half and half oil????
    I also heard from a honda master tech that I will need to get it balanced after I install new pistons and rods. Obviously its internally balanced but if ya think about it, if my crank is already balanced why bother do it again. How much does balancing a crank usually cost?????
     
  8. LS_VTEC

    LS_VTEC you get the BRAKE

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    1) fuel pump doesnt have to be stock, you can run your walbro it will not make a difference.

    2) you should def. NOT see pieces of your piston rings in your oil whatsover, especially after 20 miles.

    3) I use 1/2 and 1/2 oil because its what i run in all of my engines... just works out well for me in my area (climate).

    4) if your just swapping out pistons and rods just make sure you go with ARP products as far as the bolts go and always torque to spec from Honda Motor Co. specific for YOUR engine.

    5) dont balance it if its already balanced. its not a serious neccesity when just swapping out pistons/rods. Make sure you put the rings on properly though. always set a space between them about 90 degrees(the openings of the rings). And make sure your crankshaft pulley is balanced.
     
  9. LS_VTEC

    LS_VTEC you get the BRAKE

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    Sure it is. When you balance the reciprocating assembly, you weight each component to see the differences in their weights. You would use the lightest piece as the platform of what you want all other pieces to weigh. from there, you drill out peices until you get the desired weight for all 4 (pistons). Rods are the same thing, but they usually grind off the larger end (journal end) of the rod. If you fail to balance, it will most likely STILL run....but the engine will make noise after some time and the engine will not make power smoothly. Plus, it wont be as reliable especially when revving high.
     
  10. LS_VTEC

    LS_VTEC you get the BRAKE

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    Master Technician just means he passed all 8 ASE exams to become a master certified technician. Doesnt mean he is an engine building specialist. =)
     
  11. LS_VTEC

    LS_VTEC you get the BRAKE

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    Ask any machinist and they will always tell you the same; always balance the assembly no matter what IF you want it to be reliable. I think you mis-understand what"piston slap" really is. Piston slap is when the pistons clearance to the cylinder wall is excessive which will cause it to go upwards and downwards angled causing the knocking noise. Has nothing to do with silica. please dont give out false information. Silica is a material they use in production of aluminum alloys among other things.
     
  12. jtornado

    jtornado New Member

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    Thanks for the info.
    One thing he argued with me is that he says every honda motor has a stock engine girdle. Im almost sure its just vtec or just the b16/18c series. He was trying to tell me my B18a LS Block comes stock with a girdle. I'm pretty sure that if I did have one, then my main bearing cap bolts would be different lengths for 2,3,4 mains, right???
     
  13. LS_VTEC

    LS_VTEC you get the BRAKE

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    That guy is a clown. Only B-series engines that came with a girdle that I know if, is the 1.8 gsr engines/itr. LS short blocks do not have girdles. you can buy aftermarket girdles, I think eagle makes one for a decent price.

    Z10 makes a girdle for all b-series. if you use a stock gsr girdle you have to use the gsr main bolts. the girdle just prevents crank walk. the mains should always be aligned with the girdle so you dont damage the bearings.
     
    Last edited: Dec 27, 2007
  14. LS_VTEC

    LS_VTEC you get the BRAKE

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    to check for crank walk, get a dial indicator, feeler gauge and a pry bar. put the dial indicator on the flywheel end inbetween the crank and the casting and slowing apply pressure back and forth while keeping your eye on the dial indicator. im not sure of the maximum play you can have safely, ask a machine shop. most engines are close to the same (4 cyl.) OHC engines that is.
     
  15. jtornado

    jtornado New Member

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    Is crank walk the same thing as crankshaft end play and I know I dont know everything and I never said I did, which is why I asked for help. The honda master tech I know is smart but also thinks he knows everything, which I bet he don't. So every honda block doesn't come with a girdle correct???
     
  16. LS_VTEC

    LS_VTEC you get the BRAKE

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    Are you on drugs? Give me the names and numbers to those "highly reputable" machinists because they should NOT be building engines.

    Expand from a cold state? What state are they in when they are fabricated bozo? Pistons do NOT expand, rods tend to "stretch" under heavy loads. And what manufacturer requires a larger clearance?? Last time I checked, an 81mm bore gets an 81mm piston. Your theory is completely trash. And for your information, "forged" components are built stronger to eliminate these problems. how many times do I have to prove you wrong? And silica... my god you need to get some serious help if you think the little amount of silica used in aluminum alloys will cause piston slap.

    lol you really need to do your homework. you do not build engines, I do. I have multiple ASE certifications, you do not.


    Ive built a dozen short blocks or more so far, and my friend YOU are the one giving out mis-information. Experience is what I have, the internet is what YOU have. You probably dont even know wtf plastigauge is or how to use it. Do us all a favor and save your own embarrassment once again, and just stfu already. you have been on my nuts ever since i joined this forum.

    The process of balancing a reciprocating assembly is easily understood Blanco. I'm not a machinist, I do not perform these tasks, THEY do. I'm a mechanic that builds honda engines for myself and friends. I am probably more reputable than your so called "machinists". So do us all a favor and pickup a book and read about engine building, not just use the google search for all your answers. I graduated school with a 3.9 GPA in automotive technology. Hence, "technology", more than just "turning a wrench". Those ppl are called "grease monkeys". Get your facts straight or else I will continue to expose you for the internet fraud that you are.
     
    Last edited: Dec 27, 2007
  17. LS_VTEC

    LS_VTEC you get the BRAKE

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    The only b-series engines that came with a factory girdle are the b18c engines. GSR/ITR engines. Crankshaft end play is similiar to crank walk, and is checked how I specified earlier. Crank walk is usually caused by bad crank bearings allowing the crank to "move" back and forth. (left to right), (crank to flywheel) direction.
     
  18. LS_VTEC

    LS_VTEC you get the BRAKE

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    a lot of mechanics look for this problem and usually think its a clutch/flywheel related problem when infact its not.
     
  19. LS_VTEC

    LS_VTEC you get the BRAKE

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    Your unreal Blanco. Names and numbers to those engine builders, thats it. Im finished here. PM me the Names and telephone numbers to those reputable engine builders.
     
  20. LS_VTEC

    LS_VTEC you get the BRAKE

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    Also, since YOU build your own shit, lets see a write-up on something you have built. Would like to see all clearances for ALL bearings, prior bearing wear (from what you see during disassembly, "allowable" clearances for all bearings (SINCE you know where to find them), and torque rating for the rod bolts as well as what engine you RnR'd. Oh yea, im SURE you took pictures since you have been on this forum for so long, so lets see those as well.
     
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