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bcal
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2.5L bore tolerances

Post by bcal »

After pricing a set of new liners and pistons for my 2.5 (1600 AUD :shock: :shock: ) I thought I'd try honing my 3 most crappy liners to see what the results would be.

They are class C green, 3.4648 to 3.4651 inch.
After honing they measure 3.4655 to 3.4660.
A net gain of about a thou.

Is this good enough for a reringer?

If these measurement are ok I'll go ahead and hone my 3 good liners and then look around for 3 more.
I have a supposedly good block to pick up along with some other bits in a couple of weeks so hopefully I get some good liners from that.
Brett
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Re: 2.5L bore tolerances

Post by MR2 Zig »

They "should be" fine....most important is if they are round. They tend to wear on the exhaust and inlet axis. If they are within about .005inch of being round you can reuse them. Put them in with the larger bore measurement running fore and aft. I've heard of good success by honing and turning the sleeves 90 deg as long as the sleeves aren't beyond the .005in out of round.

hth
zig
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bcal
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Re: 2.5L bore tolerances

Post by bcal »

Thanks zig.
Actually I'm measuring <0.5 thou difference round and taper.

Ring gap using an old ring is 22 thou in the honed liners and 20 thou in the virgin section of an untouched one. Maximum in the manual is 18 thou.
So I guess with a new set of rings this would be well within tolerance.
Brett
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Re: 2.5L bore tolerances

Post by MR2 Zig »

I think you will be fine with the new rings, but do turn the liners so that the bigger dimension lays front to back (along crankshaft axis)

Greg Gordon knows more on this...maybe he will chime in.

zig
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Re: 2.5L bore tolerances

Post by Greg Gordon »

We took a set that was worn to .004", turned the liners 90 deg and put in new Total Seal rings. It was a complete success. The car was powerfull (still is!) and burned very little oil. I doubt it would have been any better with new pistons and liners.

Greg Gordon,
www.hiperformancestore.com
bcal
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Re: 2.5L bore tolerances

Post by bcal »

Thanks for that Greg.
I now feel much more at ease abut what I'm doing.

I was told years ago to always use plain cast iron rings in a reringer, especially if there is a bit of ovality in the bores. The theory being that because they are soft they will form up easier.

Given that the car probably won't do more that 40 thousand K in it's lifetime cast iron might be the go.
Brett
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