Hi; I wouldn't say that they have a poor record of leakage on the B/RB engines but with cork gaskets they do leak when they get old. I think that Mike Becker is right in that it does have something to do with the heat from the exhaust manifolds cooking the cork, that's why silicone is an improvement in that it is more heat resistant. However, back when my Newport was built, and most of the Imperials on this list, silicone was unheard of so the oil drip did happen at some point. Lets face it, the valve covers are stamped steel, hardly the ideal surface for sealing since they distort very easily from bolt tightening. I have noticed that one of the common upgrades on these engines is to go with cast aluminum covers, perhaps they are better to go with if you need to remove and install them to adjust valve lash and the like. It is probably for that purpose that the silicone gasket are on the market otherwise just a tube of RTV would suffice. Best Regards Arran Foster 1954 Imperial Newport Needs all gaskets replaced on rebuild and a left side tailight bezel. 1975 Chrysler Newport Needs the right side valve cover gasket replaced along with the valve guide seals. ----- Original Message ----- From: <staffel@xxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Friday, December 16, 2005 10:02 PM Subject: IML: B/RB Valve Covers-leaks ? Just to report I have NO valve cover leaks from my 413, and I've put 1,978 miles on the Imperial this year, much in 300-700 mile one day trips. I also have no leaks from the valve covers on my 440 in the Jensen Interceptor. On the Jensen, I do have a slight weep from the valley pan seal up front with brisk braking, but only in the hot summer temps. I've never heard that the R/RB engines have a 'history' of poor valve cover seals with proper installation. I would recommend using RTV top & bottom if the seals are not upgraded silicon. Sherman Taffel COlumbia MD ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm