Dry compression test Ok -wet not so good. Rebuild???
tom wrote:pretty good dry compression
..approx 150 in all 6 cylinders. In a couple of cylinders the wet test shows 210 and 185. .... Tom, I'm thinking that the two cylinders that are high "wet" are OK, though the one at 210 sounds high. Probably due for a valve job as the other cylinders did not show a rise in pressure when wet. Normally I'd expect to see a moderate increase when doing a "wet" test. Actually the absolute numbers are less important (within reason) than the difference between cylinders anything over 10% or so is suspect. Good luck Mike |
Dry compression test Ok -wet not so good. Rebuild???
I think I understand. I will try that next time.
Thanks Gene. -- Bill Kiene Kiene's Fly Shop Sacramento, CA www.kiene.com "Gene Kearns" wrote in message ... On Tue, 09 Sep 2003 04:25:08 GMT, "Bill Kiene" wrote: Hi Tom, I have been working on reciprocating engines for over 40 years as a hobby. My grandfather, father and uncle were professionally trained mechanics. I have taken lots of compression tests in my day but have never heard of a "wet test"? If you have 150# in all 6 cylinders and it is not burning oil and goes pretty good, I don't think I would rebuild it unless you are going to do a real high-end rebuild or a brand new motor. Ever squirt a teaspoon or two of oil in a cylinder to sort out ring problems from valve problems? The rings are wet...... -- Grady-White Gulfstream, out of Southport, NC. http://myworkshop.idleplay.net/cavern/ Homepage http://www.southharbourvillage.com/directions.asp Where Southport,NC is located. http://www.southharbourvillage.com/autoupdater.htm Real Time Pictures at My Marina http://www.thebayguide.com/rec.boats Rec.boats at Lee Yeaton's Bayguide |
Dry compression test Ok -wet not so good. Rebuild???
Hi Tom,
I have been working on reciprocating engines for over 40 years as a hobby. My grandfather, father and uncle were professionally trained mechanics. I have taken lots of compression tests in my day but have never heard of a "wet test"? If you have 150# in all 6 cylinders and it is not burning oil and goes pretty good, I don't think I would rebuild it unless you are going to do a real high-end rebuild or a brand new motor. -- Bill Kiene Kiene's Fly Shop Sacramento, CA www.kiene.com "tom clark" wrote in message . com... My 1972 Mercruiser in-line 6 cyl. has pretty good dry compression ..approx 150 in all 6 cylinders. In a couple of cylinders the wet test shows 210 and 185. It doesn't burn much oil though ( can smell some blow by) and the oil pressure is still good. Top end RPM's are good too although top speed is not what it should be but still ok. Perhaps I screwed up the wet test but is this common... to have bad numbers on a wet test and good on the dry test? Should I be thinking of a rebuild? I agree with you Bill. I've never heard the "wet test" one either. I think any mechanic would know you squirt a couple drops of oil down a cylinder with low compression to tell you whether or not it's bad rings or a valve. A couple of squirts of oil in a high compression engine would certainly increase the compression. You'd be changing the compression ratio. A couple of more squirts and you could easily break something. In building a high performance engine you can increase the compression ratio just by going with a thinner head gasket. Can you imagine how much difference 3 or 4 squirts of oil will do? Barry |
Dry compression test Ok -wet not so good. Rebuild???
If the compression goes up when you put a little oil in the cylinder it
means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. I would not worry about it if you are happy with the performance and the oil consumption is not much. There is no good number, what you are looking for is all the cylinders to be about the same. My 350 has 65# in all the cylinders, think that is bad ? :-) It's not, I have a high overlap cam. "F330 GT" wrote in message ... Hi Tom, I have been working on reciprocating engines for over 40 years as a hobby. My grandfather, father and uncle were professionally trained mechanics. I have taken lots of compression tests in my day but have never heard of a "wet test"? If you have 150# in all 6 cylinders and it is not burning oil and goes pretty good, I don't think I would rebuild it unless you are going to do a real high-end rebuild or a brand new motor. -- Bill Kiene Kiene's Fly Shop Sacramento, CA www.kiene.com "tom clark" wrote in message . com... My 1972 Mercruiser in-line 6 cyl. has pretty good dry compression ..approx 150 in all 6 cylinders. In a couple of cylinders the wet test shows 210 and 185. It doesn't burn much oil though ( can smell some blow by) and the oil pressure is still good. Top end RPM's are good too although top speed is not what it should be but still ok. Perhaps I screwed up the wet test but is this common... to have bad numbers on a wet test and good on the dry test? Should I be thinking of a rebuild? I agree with you Bill. I've never heard the "wet test" one either. I think any mechanic would know you squirt a couple drops of oil down a cylinder with low compression to tell you whether or not it's bad rings or a valve. A couple of squirts of oil in a high compression engine would certainly increase the compression. You'd be changing the compression ratio. A couple of more squirts and you could easily break something. In building a high performance engine you can increase the compression ratio just by going with a thinner head gasket. Can you imagine how much difference 3 or 4 squirts of oil will do? Barry |
Dry compression test Ok -wet not so good. Rebuild???
What is the purpose of a high overlap cam?
Ron |
Dry compression test Ok -wet not so good. Rebuild???
Better breathing at very high RPMs.
Mark Browne "Ron Thornton" wrote in message ... What is the purpose of a high overlap cam? Ron |
Dry compression test Ok -wet not so good. Rebuild???
More Power! Basically a racing cam. Is a source for real bad damage in a
boat, as the high overlap can cause negative pressure in the exhaust and suck water into the cylinder. Most likely used on Dry Stacks, or stacks where a little water is injected near the exit to meet the exhaust laws. e.g. V drive ski boats (Mandella, etc.) Or jetdrive low profile ski boats Bill "Ron Thornton" wrote in message ... What is the purpose of a high overlap cam? Ron |
Dry compression test Ok -wet not so good. Rebuild???
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Dry compression test Ok -wet not so good. Rebuild???
Mark, Bill and Gene,
Thanks for the replies. I understand now. Asskisser and jerkoff, Why don't you guys take your personal bull **** to e-mail. Ron |
Dry compression test Ok -wet not so good. Rebuild???
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Dry compression test Ok -wet not so good. Rebuild???
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Dry compression test Ok -wet not so good. Rebuild???
On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote:
(Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. Steve |
Dry compression test Ok -wet not so good. Rebuild???
(Steven Shelikoff) wrote in message ...
On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. Steve So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. |
Dry compression test Ok -wet not so good. Rebuild???
On 18 Sep 2003 04:25:28 -0700, (basskisser) wrote:
(Steven Shelikoff) wrote in message ... On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. You've already proven you're to dumb to understand anything. Steve |
Dry compression test Ok -wet not so good. Rebuild???
(Steven Shelikoff) wrote in message ...
On 18 Sep 2003 04:25:28 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. You've already proven you're to dumb to understand anything. Steve Just what I expected. As usual, when you are too dumbfounded to give an intelligent answer, you start name calling. Typical. |
Dry compression test Ok -wet not so good. Rebuild???
basskisser--
So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. Steve-- You've already proven you're to dumb to understand anything. Steve df-- I really want to put basskisser in my kill file (all that political crap), but damn if he doesn't seem logical and helpful now and then. Anyone want to defend Steve? |
Dry compression test Ok -wet not so good. Rebuild???
On 19 Sep 2003 03:45:02 -0700, (basskisser) wrote:
(Steven Shelikoff) wrote in message ... On 18 Sep 2003 04:25:28 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. You've already proven you're to dumb to understand anything. Just what I expected. As usual, when you are too dumbfounded to give an intelligent answer, you start name calling. Typical. I'll give you an answer when you answer the following two part question: Do you think NONE of the oil vapor that leaves the crankcase and gets routed to the intake via the PCV valve and breather actually makes it to the intake? And if you think some of it does make it to the intake, do you think NONE of it gets burned? Steve |
Dry compression test Ok -wet not so good. Rebuild???
(Steven Shelikoff) wrote in message ...
On 19 Sep 2003 03:45:02 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 18 Sep 2003 04:25:28 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. You've already proven you're to dumb to understand anything. Just what I expected. As usual, when you are too dumbfounded to give an intelligent answer, you start name calling. Typical. I'll give you an answer when you answer the following two part question: Do you think NONE of the oil vapor that leaves the crankcase and gets routed to the intake via the PCV valve and breather actually makes it to the intake? And if you think some of it does make it to the intake, do you think NONE of it gets burned? Steve Yep, as expected. Typical, and expected. |
Dry compression test Ok -wet not so good. Rebuild???
On 22 Sep 2003 06:46:22 -0700, (basskisser) wrote:
(Steven Shelikoff) wrote in message ... On 19 Sep 2003 03:45:02 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 18 Sep 2003 04:25:28 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 17 Sep 2003 04:44:35 -0700, (basskisser) wrote: (Steven Shelikoff) wrote in message ... On 11 Sep 2003 04:15:23 -0700, (basskisser) wrote: "Lawrence James" wrote in message ink.net... If the compression goes up when you put a little oil in the cylinder it means the rings are leaking. Too much oil could change the compression some I suppose. Make sure you crank each cylinder until the gauge stops rising. According to Shelikoff, and his boy wonder, JoeTechnician, leaking rings is normal, and acceptable. Really, they think that all four stroke engines should burn oil, getting past rings. I see that you're STILL trying to prove that you're too stupid to understand the difference between "none", "a little bit" and "too much". If SOME got by the rings, then how in the world would compression increase? I'll tell you how. The oil actually makes a better seal than dry. Good. At least now you realize that the rings/cylinder interface isn't dry and has some oil between. Part of that oil layer gets burned during combustion. So, let's see, a wet compression test tells us that the rings are worn, if the compression comes up from wet to dry. WORN, as in needs to be rebuilt. Now, if the test stays the same, decent compression wet or dry, the rings and or cylinder wall are good. So, using your above analogy, if the rings are getting oil by them, they are bad. If the ring to cylinder fit is good, the compression doesn't change from wet to dry. SO, please explain how this could possibly be. You've already proven you're to dumb to understand anything. Just what I expected. As usual, when you are too dumbfounded to give an intelligent answer, you start name calling. Typical. I'll give you an answer when you answer the following two part question: Do you think NONE of the oil vapor that leaves the crankcase and gets routed to the intake via the PCV valve and breather actually makes it to the intake? And if you think some of it does make it to the intake, do you think NONE of it gets burned? Yep, as expected. Typical, and expected. It's pretty easy to expect yourself not to be able to answer a simple question that has been posed to you many times. Steve |
Dry compression test Ok -wet not so good. Rebuild???
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