Valve clearance adjustment
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From: Scotty on 22 Apr 2010 05:30 "John_H" <john4721(a)inbox.com> wrote in message news:ih20t51fndaeagc0om46rknckjn07q2okq(a)4ax.com... : Scotty wrote: : > : >Blow by is through the rings or valve stem seals? : : Blow by is the combustion pressure (gas) that gets past the rings : (unless there happens to be a hole in a piston). : : -- : John H Excuse my ignorance but would it also come past the stem seals? Thats why I commented on if you put oil down the bore and it still shitty compression that it may be valve seals? Tell me if Im wrong so I can learn a bit here.............. after all aint that why this NG is here.
From: atec7 7 ""atec77 " on 22 Apr 2010 05:38 Scotty wrote: > "John_H" <john4721(a)inbox.com> wrote in message news:ih20t51fndaeagc0om46rknckjn07q2okq(a)4ax.com... > : Scotty wrote: > : > > : >Blow by is through the rings or valve stem seals? > : > : Blow by is the combustion pressure (gas) that gets past the rings > : (unless there happens to be a hole in a piston). > : > : -- > : John H > > Excuse my ignorance but would it also come past the stem seals? > > Thats why I commented on if you put oil down the bore and it still shitty compression that it may be > valve seals? > > Tell me if Im wrong so I can learn a bit here.............. after all aint that why this NG is here. > > ring will still sorta function with quite a gap , they do allow gas and oil past though indicated by smoke and or low compression , the stems/guide and seals have a much closer tolerance which when exceeded allow oil past and the valve to rock knocking the guides and seats about but the amount of gas allowed past the stems would be minimal predicated mostly by oil puffs on over run and sometimes low cylinder preasuers someone else can finish it off
From: Noddy on 22 Apr 2010 06:08 " Scotty" <scoter1(a)warmmail.com> wrote in message news:4bd002bc$0$6094$afc38c87(a)news.optusnet.com.au... > Blow by is through the rings or valve stem seals? Rings. If it was through the valve stem seals the engine would be in *very* serious trouble. -- Regards, Noddy.
From: Noddy on 22 Apr 2010 06:18 " Scotty" <scoter1(a)warmmail.com> wrote in message news:4bd01730$0$12142$afc38c87(a)news.optusnet.com.au... > Excuse my ignorance but would it also come past the stem seals? In short, no. > Thats why I commented on if you put oil down the bore and it still shitty > compression that it may be > valve seals? It'd be the *valves* themselves, or a head gasket or damaged piston or some other fault. > Tell me if Im wrong so I can learn a bit here.............. after all aint > that why this NG is here. Valve stem seals aren't designed to do anything other than limit the amount of oil that finds it's way up to the top of the engine to lubricate the rocker hear from travelling down the valve guide and entering the combustion chamber. They don't completely eliminate oil from getting inside the valve guide, as some oil is necessary to keep the valve stems lubricated, but they're generally intended to prevent bucket loads of oil running down the valve stem. The sealing of the cylinder is done in three key areas: The piston rings, the head gasket and the valves themselves, and all three can fail causing a compression loss. It would actually be impossible for compression gas to be lost through valve stem seals in a conventional engine, as they would first have to get past the valve seats and the minute they do they'd be vented into either the inlet or exhaust manifold. -- Regards, Noddy.
From: The Raven on 22 Apr 2010 07:36
" Scotty" <scoter1(a)warmmail.com> wrote in message news:4bd01730$0$12142$afc38c87(a)news.optusnet.com.au... > > "John_H" <john4721(a)inbox.com> wrote in message > news:ih20t51fndaeagc0om46rknckjn07q2okq(a)4ax.com... > : Scotty wrote: > : > > : >Blow by is through the rings or valve stem seals? > : > : Blow by is the combustion pressure (gas) that gets past the rings > : (unless there happens to be a hole in a piston). > : > : -- > : John H > > Excuse my ignorance but would it also come past the stem seals? > > Thats why I commented on if you put oil down the bore and it still shitty > compression that it may be > valve seals? The valve seal (as in the sealing effectiveness) could be poor, which you should be able to hear when the engine is running. As for the valve stem seals, they are separated from the compression gasses by the valve itself (if it's sealing). Even if the valves themselves are leaking (aka burnt valves) any gasses that make it past the valve stem seals are the least of your problems. > Tell me if Im wrong so I can learn a bit here.............. after all aint > that why this NG is here. Trying to be helpful. |