Head gaskets.
in [Aussie Drivers]
|
From: Jason James on 9 Aug 2010 02:42 "atec77" <atec77(a)hotmail.com> wrote in message news:i3o5b4$9d8$3(a)news.eternal-september.org... > On 9/08/2010 9:27 AM, Jason James wrote: >> "Noddy"<me(a)home.com> wrote in message >> news:4c5eacdf$0$34570$c30e37c6(a)exi-reader.telstra.net... >>> >>> "F Murtz"<haggisz(a)hotmail.com> wrote in message >>> news:4c5e955d$1(a)dnews.tpgi.com.au... >>> >>>> What are current day thoughts on head gasket coating? (none, plain >>>> grease, copper coat grease or spray,nickel anti seize,etc? >>>> The old man 60 years ago swore by grease as he was trained by the air >>>> force. >>> >>> Grease would be one of the best things to use on any head gasket that >>> you >>> *didn't* want to seal, as would any other non adhesive, non compressible >>> solid that's main purpose in life is to act as a lubricant. >>> >>> I used to know an old guy, who was pretty old school, and he also swore >>> by >>> grease for use on head gaskets. When I shook my head and asked him why, >>> he >>> said "because it made the gaskets easy to remove". He used to be into >>> Valiants, and not surprisingly he used to go through head gaskets on a >>> pretty regular basis and could never put two and two together despite me >>> and a few other people telling him that the use of grease is what was >>> actually causing his problems. >>> >>> Still, he was one of those guys who had his "ways", and couldn't be >>> told. >>> His idea of a good valve job was to remove the head, take off the >>> springs, >>> coat the underside of the valve head in heavy lapping paste and stick it >>> back in the head and then place the part of the stem protruding from the >>> top of the guide in an electric drill chuck and give it a decent spin >>> while pulling on the drill as hard as he could :) >>> >>> The best thing to use on any gasket, including head gaskets, is what the >>> engine and/or gasket manufacturer recommends. >>> >>> Most head gaskets these days are of a composite material that come >>> pre-coated with an adhesive which requires nothing other than the mating >>> surfaces to be in a suitable condition for a new gasket to be used >>> (clean >>> and free from damage or blemishes in other words) and the parts >>> assembled >>> and tightened in the correct manner (which the gasket manufacturer >>> usually >>> advises). For gaskets that don't come with an adhesive bonding agent, >>> which these days would be limited to old stock items or plain copper >>> sheet, there are specific head gasket sealants such as Hylomar or VHT's >>> Copper Coat which are aerosol based that work particularly well with a >>> *light* even coat that will promote an effective seal. >>> >>> The most important part of any head gasket seal, apart from the gasket >>> itself, is the finish of the mating surfaces on the block and head. If >>> they're not clean and smooth, then the best gaskets and glue that money >>> can buy isn't going to do diddly squat. >> >> At work, the mechanic used to use "Rolls Royce" which came in hardening >> and >> non-hardening bottles. I cant remember which one he used for >> head-gaskets. >> In the POS Passat engine, I used non-hardening "Gasket Goo" which worked >> OK. >> There was also a gasket cement made by Ford. >> >> Jason >> >> > That was the blue Hylimar ? > looked like the blue used in machine shops but very thick ? Yep,..that's the beast. Wasn't a bad product from all accounts. Jason
From: Clocky on 9 Aug 2010 03:27 Jason James wrote: > "Clocky" <notgonn(a)happen.com> wrote in message > news:4c5f8873$0$11126$c3e8da3(a)news.astraweb.com... >> Jason James wrote: >>> >>> In every case I've found the head-bolts will retorque after as >>> little as 300 ks. >> >> In every case where the headbolts are NOT torque to yield you mean, >> which excludes just about every engine made in the last decade. >> >> You don't want to retorque torque-to-yield bolts so if the tightening >> procedure involves torqueing in stages of angles rather then just a >> tension wrench you shouldn't touch them again. > > Yeah,..I'm talking about re-usuable head-bolt situations. However,..I > cant see how torque to yield h/bolts installations are going to be > any different. I know you cant retorque them, otherwise they might > snap. They are tensioned so that their elasticity tends to compensate for the different expansion rates and materials I think. > So why do headbolts lose tension? Dirty threads and perhaps the > gasket loses it squash? > Thermal cycling and the different expansion characteristics of the varying materials used, probably.
From: atec77 on 9 Aug 2010 04:28 On 9/08/2010 4:42 PM, Jason James wrote: > "atec77"<atec77(a)hotmail.com> wrote in message > news:i3o5b4$9d8$3(a)news.eternal-september.org... >> On 9/08/2010 9:27 AM, Jason James wrote: > >>> >> That was the blue Hylimar ? >> looked like the blue used in machine shops but very thick ? > > Yep,..that's the beast. Wasn't a bad product from all accounts. > > Jason > > I still use it occasionally used it yesterday to seal the rocker cover on the 300E -- X-No-Archive: Yes
From: Jordan on 9 Aug 2010 04:32 F Murtz wrote: > 7M-GE, notorious for head and gasket problems, Bugattis never had head gasket problems, like ever. They didn't have removable heads - extreme way to get reliability! Jordan
From: Noddy on 9 Aug 2010 06:24
"Jordan" <jprincic(a)yooha.com.au> wrote in message news:D2P7o.3058$Yv.1904(a)viwinnwfe01.internal.bigpond.com... > Bugattis never had head gasket problems, like ever. They didn't have > removable heads - extreme way to get reliability! Back in the old, old *old* days a great many engines didn't have removable heads. Not for any belief that it was a better way to make a more reliable engine, but because no one had figured out how to make a removable head with a gasket that would effectively seal. -- Regards, Noddy. |