Aluminum ls6 trashed by machine shop
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Aluminum ls6 trashed by machine shop I have a 5.3 aluminum lc9 I had bored out to 3.905 at a local machine shop, I had low oil pressure issue. Pulled motor tore all back down. I put shop air to oil galley and it blew air out lifter bores bad. I tore engine completely apart found that my new ls7 lifters was loose in the bore. I snap gauged them and got. 004 to .005 clearance. After talking to machine shop about it they mentioned they normally run a hone down all lifter bores to clean any sharp edges in bore. I'm thinking they owe me a block! If I sent them an iron block I wouldn't be posting this today. I think they weren't thinking and ran a hone like they would an iron block and took off a few thousands of bore diameter. Has anyone had an issue with lifter bore issues on a stock block with 100k miles. Oil pressure was 6 to 7 psi idle on 10w30. Rods and mains .001 to .0015 and .002 .0025 on cam bearings.
Old days when machine shops would bake and shot tumble cast iron blocks it was necessary to run a home in the lifter bores in order to even get a new lifter to go on. IMO aluminum blocks need to be tight since they expand so much at operating temperature. It sounds like only part of the problem here though
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This machine shop doesn't see much aluminum blocks, I checked all 16 bores all loose. Before I sent block old lifters were tighter in the bore. Im just trying to figure all this out. Now I sent them my iron 5.3 to bore out . And I'm out 409$ in head gaskets answer bolts, new lifters ect to change out blocks. And my aluminium block. I hope they can compensate me something. I am going to send them the block so they can inspect also if needed. **** happens but it's costed me alot of money and time for a simple mistake.
Normally a shop will use a dingle ball type hone to clean up any sharp edges that could hurt the lifters. Those hones don't really remove that much material. You would probably have to hone for a full day to cause the issue you're describing.
A rigid hone would be a different story, they're normally used to hone the bores to size but the setup time involved would certainly make it an operstion that shows up on the invoice. You would not get that done for free.
A rigid hone would be a different story, they're normally used to hone the bores to size but the setup time involved would certainly make it an operstion that shows up on the invoice. You would not get that done for free.
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I can't say for certain the bore size before I took it to the machine shop ,just that it had good oil pressure before and you can see where a hone was used on lifter bores. They are paying half cost to machine my iron block so I'll just leave it at that and move on.
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From: Wilmington, De
Your aluminum block isn't trashed. Find a good machine shop and they can bush the lifter bores back to spec. Hell, you can even have it bushed for a lifter with a larger diameter wheel.
But it needs to be a GOOD machine shop to do this. A lot of set-up time is involved.
But it needs to be a GOOD machine shop to do this. A lot of set-up time is involved.
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I've thought about that, but what would the cost be for all 16 holes, I hear that's it's really expensive . And I'd have to pay truck freight to and from to get it done . I'd love to save this block and eventually build a 383 out of it .
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Verdad Gallardo TECH Fanatic
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From: Wilmington, De
It depends upon the machine shop. I had two or three lifter bores bushed in a block the lifters turned a couple years ago. I can look and see if I still have the invoice. I remember the total bill being something like $2500, but that included new custom forged pistons, piston coating, .005 hone, .010 crank turn, bushing the lifter bores, bearings, balancing, and the likes.
Why the truck freight? You can load that block in the trunk of a car and drive it to where ever.
Why the truck freight? You can load that block in the trunk of a car and drive it to where ever.
