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Bottom end rebuild discussion, help needed; Want to discuss about bottom end rebuild
Topic Started: Sep 8 2011, 08:27 PM (838 Views)
vikasintl
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I bought bore gauge set look at this

http://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html

and when I checked the mm it was showing 73.8 mm

is this ok? or it should be at least 74 mm

This is how I checked I pushed, one of gauge inside the each cylinder and let it expand inside the cylinder and than tight the screw and than measured this with digital micrometer...

Correct me if I did it wrong..I did this while block is still in the car...have not removed..it..

Now I checked pistons size? I checked it with digital caliper, I bought

here is the link http://www.harborfreight.com/6-inch-composite-digital-caliper-93293.html

Where exactly I should put the caliper? I am not too sure so I put it 15 mm above lowest part of piston

and measurement was again 73.7

so there is clearance of 0.1 mm

starscream5000 mentioned from book, tolerance should be 0.02 to 0.04

I think I bought wrong tool because resolution is 0.1 mm and not 0.01mm

anyway I measured from bottom of the head and this is what I found
exhaust valve was 31.2 mm
and intake valve was 24.0 mm

Edited by vikasintl, Sep 8 2011, 09:23 PM.
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Hugothegrunt
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Uncle Sam's Metro Club
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vikasintl
Sep 8 2011, 08:27 PM
and when I checked the mm it was showing 73.8 mm


and measurement was again 73.7

so there is clearance of only 0.01 mm


You have a decimal in the wrong place somewhere.
73.8-73.7=0.1 not 0.01

Just saying it's a big differance.
Edited by Hugothegrunt, Sep 8 2011, 09:04 PM.
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Coche Blanco
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Troll Certified

What is the mileage on your engine? are there any ridges on the cylinder walls?

99% of the time, the first rebuild can use just STD rings.
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vikasintl
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Hugothegrunt
Sep 8 2011, 09:01 PM
vikasintl
Sep 8 2011, 08:27 PM
and when I checked the mm it was showing 73.8 mm


and measurement was again 73.7

so there is clearance of only 0.01 mm


You have a decimal in the wrong place somewhere.
73.8-73.7=0.1 not 0.01

Just saying it's a big differance.
Thanks for correcting me...I think I bought a improper tool ...I have edited the post..
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Coche Blanco
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Troll Certified

Stop worrying about it. Buy a hone, hone the walls, drop in rings. :)
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vikasintl
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Coche Blanco
Sep 8 2011, 09:53 PM
Stop worrying about it. Buy a hone, hone the walls, drop in rings. :)
You are right...but rather worried I like to learn in details and that's why asking too many questions ....

I know some people might get impatient with my persistent questions...but my intention is to learn as much as I can...

Btw I found that O'reilly and autozone both loan hone as well as ring compressor ...just for others to know...
Edited by vikasintl, Sep 8 2011, 09:58 PM.
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starscream5000
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Got 70 MPG?

This is a prime example of why you should let the machinist use their high dollar equipment instead if you are insistent on knowing if your tolerances are within spec.
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vikasintl
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starscream5000
Sep 8 2011, 10:06 PM
This is a prime example of why you should let the machinist use their high dollar equipment instead if you are insistent on knowing if your tolerances are within spec.
Well lesson learned vs 120$ machine shop charge, just to check this...
I am still working on it...I should have bought this item which is 30$ (not much high)

http://www.harborfreight.com/3-piece-micrometer-set-66512.html

where increment/resolution is 0.001" and not 0.01"


thanks for taking time to scan that page and sharing tolerance range ...it helps..
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Coche Blanco
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I, by no means, mean to insult you or say you are doing it wrong. I am simply saying, if you are going to spend 120 to get it checked...go ahead and spend 200 and get a .020 over bore with new pistons. Otherwise, use STD sized rings and pistons.
Edited by Coche Blanco, Sep 8 2011, 10:53 PM.
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vikasintl
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Coche Blanco
Sep 8 2011, 10:53 PM
I, by no means, mean to insult you or say you are doing it wrong. I am simply saying, if you are going to spend 120 to get it checked...go ahead and spend 200 and get a .020 over bore with new pistons. Otherwise, use STD sized rings and pistons.
I don't feel insulted...I know you are expressing your views...but just to let you know ...am trying to avoid machine shop charges and that's why am trying to do it myself and I will buy right tool next time..
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