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Ray Newport

Exhaust Manifold Question

9 posts in this topic

Installing a new gasket. I was told i wouldn't need any adhesive on the the gasket, just put it on. I have a bad feeling about that. What's the best way to do this? Also i couldn't find the torque and boltdown sequence in my shop manual. This is for a 49 roady. Any help would be appreciated. Thanks in advance. smile.gif" border="0

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I don't know if there is a specified torque-down procedure. I just bolted mine on (51 Super), I tightened the ends (not all the way) and moved to a couple of bolts in toward the middle. Basically, I tried to space them out so it would tighten evenly.<P>As far as the gasket goes, you don't need any adhesive on an exhaust gasket. It would most likely burn off anyway. I placed the gaskets on the block (they just hung on the studs) and eased the exhaust manifold onto them. Eased is a genle way of putting about a half hour of kicking, screaming and yelling. That thing is heavy!<P>Good luck.

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Hi, <BR> 48-49 shop manual page 23 section 2-1.<BR> manifold studs 25-30ft-lbs (clean and lightly lubricated threads)page 90-91 section3-14 how to install.<p>[ 05-01-2002: Message edited by: Scott W. Taylor ]

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when you do your final tightening on long metal engine parts like exhaust manifolds and heads you usually tighten from the inside to the outside. This keeps the gasket from getting bunched up in the middle.

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yeah, i wanted to reply to this post very early on but hesitated to do so because of my lack of streight-8 experience. HOWEVER, many engines i've built (Chev V8) i used NO exhaust manifold gaskets at all. i believe even the factory quit using them at one point. IF the exhaust is coupled to the intake then u need a gasket at that point. BUT, probably not against the block.<BR>DISCLAIMER: i DID use gaskets on my 56 Packard V8 exhaust manifold recently only because the gaskets were real handy. the next job i will try it without them.

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I can tell you from experience that after you run this engine a few miles, It will need to be checked. I have had to tighten mine 2 times, but now it is good. Good luck Mark Sanders<P>39 Century (same engine as a Roadmaster)

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Thanks to all who responded. The gasket is on without any adhesive. Engine is running better. Doesn't sound like a tractor anymore. Next will try boltup metal to metal. BTW noticed all the bolts were loose when i went to change gasket. Never did go back to retighten the last time. Will check and retighten this time.

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A bulletin in the 1940 year stated that Buick was to use 4 coated gaskets on INTAKE ports only.They ar coated with a thermal- setting compound.Use of additional sealer of any kind was a no-no. Suppliers will sell you gaskets involving ALL ports.I tried these on my 37 but every time I got into a race,the expansion of the exhaust manifold would destroy the gaskets. I think Buicks are to DRIVE.It wasnt uncommon for me to get the manifold so hot,that it would actually expand so far I would break the end studs off(the ones which hold the exhaust manifold on). People who designed straight 8's saw the need for the 4-ring deal in mid 1940.Put the exhaust manifold on metal-to-metal like the people who know Buicks do!

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To add to above,dont tighten the manifold above the specified torque. The manifold expands and contracts a lot,and too tight cracks manifolds (especially on the 248 & 263 engines) Years ago in the "Bugle",some novice suggested you take off the splash aprons,said the car would run cooler.Dont do it! If you do,the next puddle you hit could cost you an exhaust manifold. Have you priced the repro manifolds? Look them up in your "Bugle" ads,and you will slow down the next puddle you come to !

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