Added: 4 months ago
From: Jafromobile
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  • You should make a few calls to engine bearing manufaturers and ask to speak to guys from technical assistance.They will explain the reason why all shell bearings are manufactured with increased clearance at the parting line.They will confirm that the reasons for this are the same as I have explained to you.Your bearings aren't outside spec there.I showed this to a few collegues who are also professional engine assemblers and they thought it was funny.The internet can be vey misleading.

  • God Bless DSM master! your vids are by far the best and your speaking skills are excellent please keep up the good work

  • hi in this video for checking connecting rod journal u used digital caliper, is it possible to use bore guage for this, please note i am new, if my question is stupid, pls advise accordingly

  • Connecting rod bearings have greater clearance in the area of the rod parting line.They are manufactured this way.It's there to offset the effects of extreme load,mostly from detonation,that cause the bearing shell to distort inwards and wipe the oil film off the crank journal. This is rudimentary stuff. Engine reconditioning 101. You have given the viewers of this clip incorrect advice regarding the connecting rod bearing clearances and their relationship to the manufacturers specification.

  • @rcfirdy Did you even read all the replies? I stated it's cut wider on a DSM to reduce friction. There is no parting line spec on a 4g63. I own the '97 service manual, a '92 and '94 issue Haynes manual, have been through AllData, asked mechanics & machine shops and nobody can provide me with a parting line spec for a 4g63. If you could do that, that would be fantastic!

    I stated in the video to measure by the centerline, and to measure the parting lines only to make sure they're consistent.

  • It would seem odd that your connecting rod bearings are within specification at the area of highest load/wear[12-2 o'clock position] but well outside specifications in the area of least load/wear[connecting rod parting line]. P.S-I think you should double check the measurement on conncting rod number three]

  • @rcfirdy #3 was wrong. It should be .003". I just checked it, although it's much colder right now. Your point about the parting line I can't find any information on. I thought it was odd, too, but was told I won't find a specification anywhere for it. The added gap is indeed a friction-reducer by design. You only need to meet the oil clearance spec for about 20-30° off-centerline, on both sides. Even on the mains of in-line series engines. Of course, this doesn't work at all on V8's.

  • @rcfirdy The good news is I'm not re-using these rods. (ツ) b

  • What are the standard specifications for the connecting rod bearing at the parting line for this particular engine? I ask this as most manufacturers of connecting rod bearings engineer a larger clearance at/and around the parting line to counter the effects of detonation and excess load that cause the bearing to pinch-in at this location.Engine designers and bearing design engineers have been doing this for fifty years or more.

  • @rcfirdy I just want you to know that I encountered this and wasn't expecting to find it-AS I was shooting this video.

    I began immediately scouring the web and asking machinists for answers or specs. I'm terrified that more than half the ones I asked didn't know, and all the mechanics I talked to said "It's wrong, it should be perfectly round, you need to get it machined".

    Well, it's not on a 6-bolt 4g63. Both the mains and rods are a little egg-shaped. Load angles are what you go by.

  • whens the next video coming out, im tired of waiting!

  • @fckurvtc I'm trying to finish the edits. It's about 15 minutes at this point and covers over 3 hours of work. All of the footage for this series was previously lost after I upped the second video, so I actually had to reassemble the engine and re-shoot the whole thing. I promise you I'm not trolling, I'm just double-checking my facts to ensure I'm not leaving anything out or delivering bad info. I promise you the delay is caused by an effort to produce a quality video.

  • @Jafromobile hahaha You're good man, I was just messing with you. I want you to know that I sincerely appreciate the effort & work you put into your videos. That being said, take as much time as you need! We've got nothing but time. :)

  • @fckurvtc But thank you. I appreciate the fact that there are people that like my videos enough for the technical difficulties I experience to create anxiety from their interest in it. :) I really don't want anyone to suffer and I won't disappoint.

  • I went by the machine shop today and they still haven’t found reasonable ones for sale and I fund some 6 bolt rods for a reasonable price and I’m thinking of just telling the machine shop to buy them or if they buy off of me to order them and covert them to fit my 7 bolt crank and pistons since 6 bolt rods are stronger.

  • Well I wish I can tell u the measurements but the machine shop has them. They told me they where going to replace them and incase they couldn’t find use one’s they where going to buy them off of me. See I have this project that I’m working on and I need to shave at least 1.5 mm off of the each side of the small rod ends to make them fit the piston I’m using but like I said previously mention the guy from the machine shop started shaving off the big bore ends of all my rods.

  • ok so if i get my hands on some 6 bolts rods all have to do grind 1.114 of the 6 bolt big end rods?? and bore the small end of the rod to a 22mm to fit the wrist pin of the piston.. im i correct?

  • @TheSuprasalas What were the rods that were shaved... shaved to? How thick are they right now?

    If they shaved the whole rod to 22mm... then they're definitely un-usable. That's .866" You'd need the rods machined about .004-.006" narrower than the outside journals of the fillet radius. I haven't popped my 7-bolt crank out yet to measure it, but if you have a 6-bolt crank, yes, 1.114" is a good width measurement if you want a .006-.007 rod gap like mine. :)

  • That be awesome man I can’t find any forum that has the measurements for the 6 and 7 bolt rods. Well I was thinking of just buying forged rods since must likely I’m not going to be able to use them I think there grind down to much to be reuse. But ill still keep those to measure them to see if they are really useless now. Thanks

    So what would be the difference between the 7 and 6 bolt rods?? I read a lot of forums saying the 7 bolts are weaker then the 6 bolt rods.

  • @TheSuprasalas The forums are correct. 6 bolt rods are the strongest. The 6 bolt rod is 1.114" thick. At least the ones I have with .006" rod gap clearance on a 6-bolt crank are. :)

  • well i was asking because im having a problem with mine.. see i send my rods to get machine from the small rod ends but i guess the guy was on something and he decided to machine the big rod ends and now my rods are thiner then what they supposed to be? the real question is how bad do they have to be to get new ones??

  • @TheSuprasalas Would you like for me to measure the 1g rod thickness so you can gauge what is removed?

    I would put new ones in it if it's machined past the service limit. A narrower-than-spec rod has less surface contact with the crank, so those surfaces will receive more force than they would at the standard thickness. 1g rods are tough, but part of what makes them that way is how huge they are.

    A 2g's crank is narrower, and the rod is the same length. They'd be an upgrade for a 7-bolt.

  • @Jafromobile ...wait... I might be wrong about that. With any luck, my 7-bolt will finally be on the stand today. I'll know soon enough.

  • @TheSuprasalas I'll show more details about them in the next video. :) Just because you've run into this.. it's already justified. I've got it all in pieces already. It's looking like the crankshaft video is going to possibly be 2 parts. It's complicated enough to be 3. You're playing with some critically important parts. You have to be willing to replace them if they're fubar'd. Fortunately they're a dime a dozen because everything with a 2.0 or 2.4 4g 6-bolt has the same rods. (ツ) b

  • how much can you shave off the big bore end of the rod to have a fatter gap??

  • @TheSuprasalas a few thousandths, not much is needed. I'd keep it below the service limit, but on the wider-side of the standard spec. (which is roughly .004"-.010") Mine were between .006-.007 and there's NO wear on either part. You might have to have the inner 45° radius regrind on the big bores if you take more than a few thousandths off. That's what makes room for the fillet radius.

  • @Jafromobile Excellent video. I actually did all this this week as well, putting a 6 bolt in a classmate's 97 that walked. Interestingly enough as I was disassembling both engines, I am becoming more and more convinced that the girdle is what is guilty of causing more cases of crankwalk in 7 bolts than 6 bolts.

  • I guess after you blow an engine you start becoming a lot more methodical with the tolerances. Love seeing you do your thing man. It's amazing to watch you work. It's art in motion.

  • @DJDevon3 Actually, a paid professional assembled the engine that blow'd up. So you're correct! Now I'm doing it myself in-house. :)

    Thanks for your vote of confidence, and for the compliment. If I save someone else the grief, then I've done my job on the internets.

  • @Jafromobile That right there is why you're awesome in a nutshell. You have the knowledge, the passion, and dedication to show the next guy the right way to do it.

  • @DJDevon3 That's the only reason I know anything. I listened. Someone else gave it to me, so if I want to keep it, I have to give it away.

    There's no other gearhead out there quite like a DSMer in that regard. Google anything about cars, and you'll get a dozen DSMtuner, DSMsource and DSMtalk threads before you find anything else. So either DSMs are just problematic POS's, or there's a MUCH larger following of capable self-sufficient and un-selfish do-it-yourself'ers in that crowd. :)

  • Haha you said slap the nuts.....lol Great video by the way...

  • I learn so much from your vids, I appreciate them, me and my 99 eclipse GS (yeah yeah...no X) will benefit.

  • dude ur like the 4g63 God. Awesome work man. i started working on my car cause of you. ur videos helped me a lot on my gst

  • I own a modded Subaru Wrx so a transmission or motor rebuild will be happening one day.

  • glad there's people out there like you out there that know so much about 4g63's. i want my first car to be a 92 tsi or gsx but they are very rare around my area. I also want to be a car mechanic but dont know if it will pay off.... what do you think? BTW.... nice videos.

  • @numeroza It's important to do something you love. But if you really love doing it more than anything else, don't do it for a living. You'll ruin it.

    Something you'll notice about mechanics... They spend so much time working on everyone else's busted crap to make money... that they're usually the ones with their pride up on blocks, driving some pile of crap that's economical and easy to work on.

    It's a valuable skill, and one that can get you paid, but you're going to work hard to do it.

  • @Jafromobile you are so right with that man I have seen this all to much in my town + my frend is just like that his truck has been down a 2 year's no time he had the motor was rebuild 3 month after he pull it but still not in the truck my truck been up for 8 year's waiting on me to get a motor for it it like wen you have the time you don't have the money wen you have the money you don't have the time the story of my life

  • @Jafromobile Ah, this is so true, and the reason i drive a 20 yr old honda, because it rarely gives me trouble, which means i can devote more of my time to fixin other peoples "busted crap"! Im not sure i agree about not working at something you really love, mechanic is my trade and my hobby, and i feel i am not working when i am enjoying it, but there will always be bad days too! Love your videos, when im not working or tinkering at my own stuff, im watching stuff like this,cars are my passion!

  • I like it

  • This is unrelated to the rods, but in the future could you do an in depth video on how to tell if your crankshaft is balanced or not?

  • @iexploderacoons I don't really have a choice, so you can count on it! I have to balance it in order to assemble it correctly.

  • @Jafromobile Awesome, I have a pretty big deal coming up with an RB30 that may* go into the Z in about 5 years. I plan on building it up to handle a larger turbo and I haven't found many videos about balencing engine internals.

  • How did you learn all this Jafro? Or how did you start maybe a better question?

    Damn I need a GSX but they are as rare as....well, as rare as a GSX in the UK :s Ive seen 1 in london in my 24 years :(

    Great videos as usual :)

  • @RGTGAME I think you've given me topic for a video... but I absolutely hate VLOGgging. None of you come here to hear me bitch and moan about life or pop culture, that's for sure. You come hear for the icing and creme filling.

    I was once a poor college kid with a Toyota pickup and enough money for a torque wrench and a Chilton's manual... but not enough money to pay a mechanic. I started at step 1, did one at a time, then exclaimed...

    "Holy #%&$, anyone could do this".

    And so it began.

  • Fuck it I'll say it. He said slap the nuts and he also taped the nuts with a hammer. Ouch.

    Great vid. I'm learning a lot about a car I will never own.

  • @iconone5 Actually I shoved the handle right up its bore.

    But whatever car you own... building its engine will likely employ all the exact same techniques. ;) There's been very little innovation in the past 60 years of the combustion engine. The only thing to improve is fuel control and construction materials. Oil gaps are still oil gaps. :)

  • @iconone5 I came back to reply to you twice. Look up which cars have a 4g63. If there are Kia, Hyundai, Dodge, Eagle, Plymouth or even a few Chinese branded cars in your region, chances are you'll encounter one of these engines. There are millions upon millions of cars produced over a 25 year period using 4g-series Mitsubishi engines. Even several boats and lots of forklifts use them. You can buy factory propane injection kits for a 4g motor. 'just have to shop at Caterpillar. ;)

  • @Jafromobile

    So when you are measuring rod gap, you are measuring the distance between the rod and the fillet radius, correct?

  • @fckurvtc You guys are the best. You ask good questions! The fillet radius is 3 or 4 mm wide. Since the bearings don' go all the way to the fillet radius, that adds a little gap. The rods have a 45° tapered edge inside the big bore in order to clear it. The faces of the rods are supposed to prevent the bearing from touching down. I'll cover that a lot better in an upcoming crankshaft video. :)

    If you had to shave the rods, you just need to make sure you leave that radius room to breathe.

  • Why not use your bore gauge for the ID of the rod bore?

  • @DrJerryrigger GREAT question...

    Because it starts at 2". :(

  • @Jafromobile Damn, that's lame.

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