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Discussion Starter #1
I have a 4BT on the bench that I am tearing down for rebuild. I was surprised to see the cross hatch hone pattern still on the cylinder walls, and no ridge at the top of the cylinder.

Anyone with experience rebuilding these engines have a idea roughly how many 1000's of miles are required before the cross hatch hone pattern is worn smooth and there is a cylinder ridge ?

Just trying to develope a feel for these engines, wear vs miles

Paul
 

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Paul,

I tore down a 6bta 2 years ago do to a oil pressure problem it had 87,xxx and there was still cross hatch with no top ridge.

Maintance play's a big roll too.

Thanks
Crewcab59
 

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Yes, maintenance plays a big factor. I wish there was a way, a gimick to get a ball park millage figure. Like, count the rings in a tree, look at the horses teeth LOL.

Paul
 

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paul, if there is a ridge in the top of the cylinder its high milage or very poor maintence; build it and be done with it.
 

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Two problems with determining accumulated miles by condition of bore: was it plain iron, chrome or plasma-moly rings? Each material wears differently and has a different effect on the bore. A second factor is the grit of stones used to hone. Obviously a coarse grit will leave score marks for a longer time than fine grit.

I would expect to start seeing a ridge by at least 100,000 miles, maybe a bit sooner, depending on what rings were used.

O/T: is that Moose Creek Maple Syrup ready yet...? I'm running low!
 

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Discussion Starter #8
JimmieD, That makes sense. Its like trying to guess a girls age. The guess will never be right, and its a dangerous game to play LOL

Paul (MCMP Standing by
 

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You're so right, Paul. The first can cause an unexpected rebuild but the second can cause an unexpected trip to the local Emergency Room Trauma Unit!
 
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