thats true, the compression rings seal the chamber, and the oil rings just scrape away the excess oil from the bores, and if these are worn will allow to much oil on the bores and get into the chamber.
mark k ----- Original Message ----- From: "andrew smith" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, January 27, 2003 11:25 AM Subject: Re: engine confusion... > Unfortunatly compression testing doesnt allways give a true indication of oil > consumption.Valve guides will just about allways give a puff of smoke on start > up if they are worn.Sounds like it might have weak oil control rings.(just a > guess).Runing better in hot wheather sounds like it is lean on cold days.It > must be nearly at the surge stage on cold days for you to notice the > difference.Not blowing smoke on hot days has me stumped. > On my mates drag car we would get it setup right during qualafying(hot > daytime) and then during eliminations(cold nights) it would run slower and > would be knocked out in the first round.If you cant run within a couple of > hundreths of your dial in then you get knocked out.We are now getting a much > better handle on the night time tune and let it run slower during qualifying. > > "GREENBURY, Andrew Robert" wrote: > > > Hi everyone, > > > > The condition of my L18 has seemed to be getting worse and worse - blowing > > more and more clouds of smoke predominantly after a closed throttle > > (taking off, after coasting down a hill etc). Its now doing it > > consistently after every coastdown. > > > > However a compression test revealed a consistent 176 psi (at WOT cold) in > > all cylinders, so I thought it might be the valve seals. > > > > Now the weird thing is in our hot Melbourne weather the car runs much much > > better (runs smoother, more responsive, less harsh). And the really weird > > thing is in 40+deg weather Saturday, the engine didnt blow any smoke at > > all, even after coasting down big hills that usually have bellowing clouds > > pumping out. > > > > So the reasons for all this have got me stumped. Something I thought may > > be a factor was that the atmospheric changes (temp, pressure) has the > > engine sucking less air for the same amount of fuel ie running richer in > > the hot weather, therefore the engine was running lean before. > > > > I also thought maybe for some reason the engine is sucking blowby in > > excessively, adversely affecting combustion performance, but how all this > > relates to better performance and very little smoke in hot weather > > compared to normal has got me stumped... > > > > Any thoughts on this would be greatly appreciated, > > Andrew > > > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
