heavy85 Posted February 2, 2005 Share Posted February 2, 2005 Just got my L28 crank back from the machine shop. They just polished it and mic'ed (sp?) it and said it should still use standard bearings. Now my delimna is that it's still got scratches in the journals that didn't polish out (previous owners had installed bearing caps in random order plus it looked like a lot of trash had gone through which resulted in scratched in the journals). The machine shop is not concerned with the scratches and say it'll be fine and doesn't need to be ground but they would grind it undersize it if I insist. Any more experienced builders out there have oppinions here? Should I leave it as is like the machine shop recommends or pay an additional $120 to have it ground undersized? The scratches or grooves as they are vary from journal to journal from none to several which can easily be felt. By the way I plan on beating on this engine most of the time (tripple mikuni's, shaved head, etc) so it's got to be reliable. Thanks Cameron Quote Link to comment Share on other sites More sharing options...
johnc Posted February 2, 2005 Share Posted February 2, 2005 Have it ground undersize by a different machine shop. Quote Link to comment Share on other sites More sharing options...
Guest Cronic Posted February 2, 2005 Share Posted February 2, 2005 Indeed, have the crank cut, for god's sake. Who is this machine shop? They should be put out of business! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 2, 2005 Share Posted February 2, 2005 Who is the freakin PO? He needs to be banned from using tools altogether! This isn't the only stupid problem Cameron's been having... Quote Link to comment Share on other sites More sharing options...
2126 Posted February 2, 2005 Share Posted February 2, 2005 Cameron, I have to agree with the other guys posting.....get it redone by a shop that has better judgment making capabilities. It sounds like the shop you mentioned knows how to insure they will have return business (as in a failed bottom end).....at least for the uninformed. Quote Link to comment Share on other sites More sharing options...
jaylude Posted February 2, 2005 Share Posted February 2, 2005 Indeed' date=' have the crank cut, for god's sake.Who is this machine shop? They should be put out of business![/quote'] No kidding. They fail not only on the technical side for offering you total **** for advice, but also on the business side for not making the extra money on the grinding of the crank. Before you have these jackasses gring the crank, ask them if they do the grinding in-house. Most machine shops don't have a crank grinder, and simply send them out to another house that does. Find that machine shop and start going there! Properly grinding a crank takes some skill, and I wouldn't trust these guys to do it if they do own their own machine. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted February 3, 2005 Author Share Posted February 3, 2005 Who is the freakin PO? He needs to be banned from using tools altogether! This isn't the only stupid problem Cameron's been having... Aint that the truth. One step forward followed by two or three back. Did I ever mention the one about the rear swaybar being installed upside down with a total of 6 (yes you would normally find 8) bushings - two of which were rubber the others poly, a rod end, a u bracket, and a couple extra nuts .... or the jet that wasn't even screwed in because it was cross threaded .... or the battery that was just sitting on the floor - not strapped down! .... or the cam tower shims that were different thicknesses .... or the 7 plus quarts of oil in it - which by the way makes a hell of a smoke cloud near 6 grand when it blows oil out the breather .... or .... dont get me started 'cause it'll take a while. I've had it just under one year and so far have taken what is 'fun to drive' and 'needs a tune up' and only been able to drive it around the block about 4 or 5 times and to work once This year it will see the autox track one way or another! To be fair to the machine shop they are nice guys and the parts department is really good. Also being in the midwest I assume they mostly taylor to farmers who tend to be cheap and only do absolute minimum (IMHO - so please dont take offense). I'll take it to another shop and have it ground properly. Thanks - so the saga continues. On the bright my LSD should be here tomorrow ... on second thought it's out of an '88 ZX so it'll probably need something too...I hope not. Cameron Quote Link to comment Share on other sites More sharing options...
jaylude Posted February 3, 2005 Share Posted February 3, 2005 To be fair to the machine shop they are nice guys and the parts department is really good. Also being in the midwest I assume they mostly taylor to farmers who tend to be cheap and only do absolute minimum (IMHO - so please dont take offense). I'll take it to another shop and have it ground properly. Very true about the "farmer" thing. I've heard an amazing amount of Farmer Brown stories in the few months I've been working at the shop here in Ct. My favorite is the one about the farmer who broke a con rod in his tractor, and instead of fixing the rod, or even removing the damn thing and the piston, he just simply welded what was left of the broken rod and piston to the crankshaft. This way he didn't have to pull the heads off or make any other costly repairs. The thing clanked and banged around like all hell but ran fine. Gotta love it! Quote Link to comment Share on other sites More sharing options...
datsunlover Posted February 3, 2005 Share Posted February 3, 2005 Yup, the farmers I've met are ALL like that. Bare minimum, patch it up, just make it work. It's amazing how long most old farm equipment will actually hold up to this kind of repair.. hell, I've see automotive stuff abused and still running, but the farm stuff allways blows me away.. We 'fixed' an old shaft of some sort (something that got towed behind a tractor to till I guess.. ?) and when it cam in, it was so worn that don't know how it was still spining at all.. The 'bearing' surface was about .050" smaller than it should have been, and wasn't even concentric to the rest of the shaft anymore! Some welding and a quick turning 'tune up' and it was good enough. If this shop does a lot of this kind of stuff, the crank from your Z probly looks to be in near mint shape to them.. having said that, I would look around for another shop to regrind it for you.. Anyone can use a micrometer (AKA; Mic) but if they are used to doing stuf "eh.. close enough.. ", that isn't really good enough for your needs.. Hell, if you don't have a good feel for it, a mic can read WAY off anyway.. and that 2-5 thousanths of mis-read diameter could mean a quick death for your engine.. Quote Link to comment Share on other sites More sharing options...
heavy85 Posted February 4, 2005 Author Share Posted February 4, 2005 Took it to a guy that was highly recommended today and he wasn't overly concerned with the scratches either but several of the journals measured under min specs so he's going to grind it .25 mm (~.01") under regardless. This guy seems to know what he's talking about. Builds race engines at least part of the time, wanted to know the brand of bearing because they tend to come in on the opposite ends of the tolerance band, etc so I'm optimistic and wish I would have taken the rest of the engine to him to begin with. Live and learn and spend more than you thought you would. Cameron Quote Link to comment Share on other sites More sharing options...
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