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How do you break in the rings correctly on a rebuild iwhen the engine will not be tuned right at first?

Doesn't there seem to be a good chance the engine will run very rough at first? It may take a few tries to get the engine running right.

I am rebuilding my carbs at the same time as the engine. I expect the engine to run rough while I sync the carbs, check mixture, set the timing..etc

Sorry for the 101 question
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Old 01-12-2005, 04:47 PM
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Splurge on a set of bore snap guages. These are T shaped tools with telescoping spring loaded ends. You place them in the bore, release the ends and lock them back in place when they contact the bore. You can then easily compare the top to bottom of the bore, the roundness of the bore and if you have a micrometer and measure the guage at this point the exact size of the bore.

Its easiest to compare. Just find the point where the bore is at its smallest, go to a place you wish to compare where the guage will be loose, add some paper or a feeler guage and wallah, the difference between the two points. Sometimes all you have to know is -is it smaller than one thousandth or bigger.

With lots of experience and care you can even get the same measurements that a bore guage makes, for much much less money.

Last edited by snowman; 01-12-2005 at 04:52 PM..
Old 01-12-2005, 04:49 PM
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HGP:

Did you measure the ring gap in 4-5 different heights of the cylinder to see how much it varies?

snowman:

Send us a webpage or a pic of bore snap gauges! I have never heard of them. Sounds like they are right up my alley.

VA914

Well yes, if your car runs rough, you will need a few minutes to get it going okay. But you know, even to get it to break in the cams correctly, you want to be over 2000 rpm. If you mess with it for many minutes at idle, that would be very bad.

When I rebuild an engine, I make sure the fuel delivery works well, before I take it all apart. Chances are that you put things together and you are close enough to break things in. Details like idle adjustment and mixture can be tended to later to match the new engine. I realize, this is probably too late for you, but why not rebuild the carbs before you do the engine?

Cheers,

George
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Old 01-12-2005, 05:24 PM
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See the following:http://forums.pelicanparts.com/uploads2/snap1075995272.jpg

photos of snap guages shown.
Old 01-12-2005, 09:31 PM
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Thanks Snowman!

I recognize these! Generally you are expected to measure them with a caliper after pulling them them out, correct? The method you described, where you just check for variation of course makes things much more direct!

George
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Old 01-12-2005, 10:55 PM
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Quote:
Originally posted by snowman
Its easiest to compare. Just find the point where the bore is at its smallest, go to a place you wish to compare where the guage will be loose, add some paper or a feeler guage and wallah, the difference between the two points. Sometimes all you have to know is -is it smaller than one thousandth or bigger.

With lots of experience and care you can even get the same measurements that a bore guage makes, for much much less money.
That's what I'm basically trying to do. I measure, (sometimes with paper as you mention above) comparing the one new in spec cylinder (which I purchased from a reputable supplier)......

but I have to with very extreme care, as these Biral cylinders are extremely hard to come by. But I'm having fun for the most part

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Old 01-12-2005, 10:56 PM
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Quote:
Originally posted by Va914
How do you break in the rings correctly on a rebuild iwhen the engine will not be tuned right at first?

Doesn't there seem to be a good chance the engine will run very rough at first? It may take a few tries to get the engine running right.

I am rebuilding my carbs at the same time as the engine. I expect the engine to run rough while I sync the carbs, check mixture, set the timing..etc

Sorry for the 101 question
Do a search on this forum for engine break in, also see Waynes book.
Old 01-14-2005, 06:19 PM
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