phoenix70
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| posted on 5/11/08 at 09:53 PM |
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Turning engine by hand
Hi
Just how easy should it be to turn an engine by hand (i.e. socket on the crank pulley nut). It's 2L pinto and it seems to turn without much
resistance, and makes a nice hissing noise as you approach TDC, does this sound normal, or is something worn?
Cheers
Scott
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Stuart_B
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| posted on 5/11/08 at 09:56 PM |
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i take it you are talking about with the plugs out, right?
stuart
black mk indy, 1.6pinto on cbr600 bike carb's.
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phoenix70
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| posted on 5/11/08 at 09:59 PM |
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quote:
Originally posted by Stuart_B
i take it you are talking about with the plugs out, right?
stuart
Nope, Plugs are still in
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Stuart_B
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| posted on 5/11/08 at 10:01 PM |
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have you done a compression test?
stuart
black mk indy, 1.6pinto on cbr600 bike carb's.
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ReMan
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| posted on 5/11/08 at 10:02 PM |
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In my experience they vary considerably.
Some as you describe , smooth and easy with the plugs in, others very tight even with the plugs out.
But in both cases run perfectly OK
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MikeR
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| posted on 5/11/08 at 10:09 PM |
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the hissing sounds normal - you've got lots of pressure pushing past the piston rings as you slowly turn the crank (or at least i'm sure
mine used to do that).
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AndyGT
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| posted on 5/11/08 at 10:12 PM |
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hissing is normal as the compression is coming back out through inlet ports and maybe the carb if it is fitted. Plus there is a percentage leakage on
anything mechanically sealed which could also explain the hissing.
I would think the more hissing the better as it compressing gasses even at such a low turn over speed.
[Edited on 5/11/08 by AndyGT]
nothing is impossible
everything is possible
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02GF74
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| posted on 6/11/08 at 08:17 AM |
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hissing is good - it shows you have compression, this is air getting past the rings as the valves should be shut. The slower you turn it, the more
time you let the air to escape - the rings aren't a perfect seal.
It is hard to quantify how hard it is to turn with a wrench since some people are stronger than others, may use differnet length lever, how fast your
turn it etc.
.... but generally you shouldn't be able to turn it without any tools but as each piston comes on the compression stroke, there should be
resistance.
Compare to turning over without plugs - if it feels the same, then you have poor compression = bad engine.
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DarrenW
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| posted on 6/11/08 at 10:19 AM |
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With a half metre bar on mine it turns over relatively easily by hand and hissing noise is observed. It wont fly round, you will notice compression
points where you have to apply more force and easy points in the cycle.
Yours sounds normal from your description.
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Michael
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| posted on 6/11/08 at 08:24 PM |
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Hissing noise on my crossflow is from the air coming out pas plugs, as mine are not fully tight.
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