The answer to your original question... Measure your manifold vacuum from the lowest point on the carburetor or anywhere in the intake manifold. A healthy engine should read a steady needle from 15 to 22 in/Hg - subtract 1 in/Hg per every 1000 ft above sea level. Long duration cams and late ignition timing will lower your idle vacuum too.
Thank you, Don Hoeschen CEO/Mechanical Engineer Granite City Performance Granite City Performance custom engineered competition components On Tue, 2007-08-14 at 21:27 -0500, Dale wrote: > Check the bottom of the lifter for abnormal wear with some others > nearby. It may indicate a bad lobe on the camshaft. Personally I > would not change all the lifters as they’ve already taken a seat on > their respective lobes; same with pushrods, no need to replace them if > they look alright. > > > > > Dale McIntosh > > ChevelleCD.com - 1966/67 Chevelle Reference CDs > > ChevelleStuff.com > > > > > > > > ______________________________________________________________________ > > From:[EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jim & Chris > Sent: Tuesday, August 14, 2007 9:12 PM > To: The Chevelle Mailing List > Subject: Re: [Chevelle-list] Vacum > > > > > > > I just found the problem .It seems the intake lifter on #7 must have > failed causing the push rod to bend like a slight "S" and break off . > so now I'm going to take the manifold off to retrieve the lifter and > bottom piece of the push rod and look for damage. is there anything > else I should do while I have it apart ie.change all the lifters and > pusrods ? Thanks again Guy's, Jimmy C. > > > ----- Original Message ----- > > > From: Rick Schaefer > > > To: The Chevelle Mailing List > > > Sent: Tuesday, August 14, 2007 9:20 PM > > > Subject: Re: [Chevelle-list] Vacum > > > > > > > I second the blown out header gasket theory. At least > check it before doing a lot of other work. Its easy to > check...Been there, done that, got the T-shirt. > > > On 8/14/07, Jim & Chris <[EMAIL PROTECTED]> wrote: > > > oil pressure is fine, the tapping noise is comming from what > seems to be driver side maybe #7. I'm going to drop the oil > and look for particles. thanks, Jimmy C. > > > ----- Original Message ----- > > > From: [EMAIL PROTECTED] > > > To: [email protected] > > > Sent: Tuesday, August 14, 2007 3:18 PM > > > Subject: Re: [Chevelle-list] Vacum > > > > > > > How is your oil pressure? > > > > > > I had a knock in my 454...Oil pressure was fine, so I > knew it wasnt a rod knock. LONG story short, it > flattened out the cam...which is notorious in BBC's > from what I hear. I would check your valve lash...if > one is really lose, there's your problem. It would > most likely be the number 7 or 8 cylinder. > > > -----Original Message----- > From: Jim & Chris <[EMAIL PROTECTED]> > To: The Chevelle Mailing List < > [email protected]> > Sent: Tue, 14 Aug 2007 11:59 am > Subject: [Chevelle-list] Vacum > > > > > I am finally getting back to my Chevelle , rookie > question but here goes. which is the best port > to measure the vacuum and what should the vacuum be ? > I have a knock and its not running on all cylinders . > The motor is a 454ci , with a stock rebuild with a > mild cam. 915 miles after rebuild..with a few hard > ones squeezed in. Thanks for any help, Jimmy C. > > > > ______________________________________________________ > > AOL now offers free email to everyone. Find out more > about what's free from AOL at AOL.com . > > > > > > > > -- > Rick Schaefer > 72 TPI El Camino > > > > > > ______________________________________________________________________ avast! Antivirus: Outbound message clean. Virus Database (VPS): 000765-1, 08/13/2007 Tested on: 8/14/2007 9:26:24 PM avast! - copyright (c) 1988-2007 ALWIL Software.
