I have a few questions

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74Bug
Posts: 21
Joined: Sun Dec 07, 2003 3:15 pm

I have a few questions

Post by 74Bug »

Ok I'm working on my 1641 rebuild and getting closer everyday. I'm ready to install the cylinders and pistons....so i have a brand new set and i'm used piston ring clamp to hold them down shot the inside of the cylinder with oil and and got it in...i'm a little worried because it doesn't move up and down the cylinder very well...is this normal? Once the motor starts running then does just work its self into play? TIA
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amskeptic
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Joined: Thu Oct 24, 2002 1:01 am

Post by amskeptic »

Expect a lot of friction with new rings and cylinder wall surfaces. It will slowly diminish as the rings seat. Be very aware that the engine will be running hot during this break-in time, so be sure to optimize your ignition timing and cooling system.
Colin
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A_67vdub
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Post by A_67vdub »

Also, don't forget to gap the rings, if you haven't already.


Steve
CHAZAVW
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Joined: Fri Nov 15, 2002 12:01 am

Post by CHAZAVW »

make sure that you stagger the ring gaps.....180 degrees.....

this is key.... if you dont when the motor will be together oil can pass right by the gap and in theory you now will have blow by on a new motor....
74Bug
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Joined: Sun Dec 07, 2003 3:15 pm

Post by 74Bug »

I'm sorry but what does the 180 degree thing mean? The rings were already installed on the pistons...and i just slapped them on my new cylinders...do i need to do something different?
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volksmann
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Post by volksmann »

180 degrees means, don't line up the gap on the first, second and oil rings.
I don't like to put the gap to the bottom of the cylinder or have the gap inline with the wrist pin because, when the engine stops and has been sitting awhile, oil that runs down the cylinder wall and will go through the gap into the combustion chamber and will smoke alittle when it is first started up.
I do it this way (most people will also do it this way). When looking at the piston and the arrow is pointing towards the flywheel, the top ring gap should point at 2 o'clock, second at 10 o'clock and the oil ring at 12 o'clock if it is a one piece ring, on the three piece oil ring, put the first rail at 2,the second rail at 10 and the expander at 12

Ken
Last edited by volksmann on Sun Mar 21, 2004 4:26 am, edited 1 time in total.
yumyumchoppers
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Joined: Sat Dec 07, 2002 12:01 am

Post by yumyumchoppers »

the best way to gap rings is to start with the three piece oil control ring.Do not line the gap in the middle ring up with the wrist pin. wherever you put it the top and bottom rings go 90 degrees from the gap in the middle one.if the gap int the middle ring is at 7 o clock the the top and bottom would be at 4 and10. then the second ring goes 180 degrees form the gap in the middle oil control ring(1 oclock). then the top ring lines up with thegap in the middle oil controlring (back to 7 oclock). Hope this helps.
74Bug
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Joined: Sun Dec 07, 2003 3:15 pm

Post by 74Bug »

well my rings came on my pistons when i bought the drop in kit
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Sharkey
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Joined: Sat Jul 22, 2000 12:01 am

Post by Sharkey »

74Bug wrote:well my rings came on my pistons when i bought the drop in kit
But you can still rotate them in relation to the piston before installing the piston into the cylinder. If you want to install them "properly", you will need to tear everything apart so that you can pull the pistons back out of their cylinders.

However, there is some debate as to exactly how critical ring gap positioning is. I can guarantee you that your ring gaps will not stay in the same clock position over the life of your engine, but perhaps someone that has torn down a number of used engines could confirm if this is the case.

PS: No offense, but this is a typical newbie mistake. I wouldn't be so concerned about the clock position of the ring gaps. Rather, I would be more concerned that the expansion ring for the two oil scraper rings isn't overlapped. I made that mistake on my first engine, even though I knew about ring gap clocking. My advice now would be to remove the pistons from their cylinders, clock the gaps of the various rings as others have suggested, and make absolutely sure that the ends of expansion ring for the oil scraper rings are butted up against each other and not overlapped! If you miss this, your engine will burn oil like there's no tomorrow and it will never stop.
Guest

Post by Guest »

I also think it's vitally important to make sure the ring gaps are correct. I don't think they usually gap them when you buy a piston/cylinder set.


Steve
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