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#62029 06/22/2006 5:03 PM | Joined: Dec 2005 Posts: 19 Junior Member | | Junior Member Joined: Dec 2005 Posts: 19 | I have a newly rebuilt 235. After dropping it back in, hooking everything back up, and adjusting the timing and the carb, I noticed some carbon under the front most exhaust port... putting my hands under each port revealed significant leaks under each one.
I read all of the posts I could find on this in the engine & driveline forum, and as suggested in several, I pulled the manifolds (together) and had them ground at a machine shop. Using new gaskets (but no rtv) I reinstalled. NO DIFFERENCE, STILL LEAKING.
So... short of gooping some rtv in there with new gaskets (again) which is my next plan of attack... am I missing something here? The manifolds "look" like they are on there square and true to the head, they are tight (probably a little too tight)... Kind of hoping this is something simple & dumb... any experience would be appreciated. Thanks. | | |
#62030 06/22/2006 5:51 PM | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | sbtc,
From your research, you have probably determined that the proper procedure for the surfacing of the manifolds would be bolted together with a new gasket and machined as "one"! If it was done in this manner, it must be right.
If you can loosen the four bolts connecting intake to the exhaust, and re-tighten the exhaust manifold to the head and get rid of the leaks, then the machining was not done correctly.
This is a straight forward mechanical seal and no goop is necessary. Poke around and you will probably find the problem quite easily.
Stuart | | |
#62031 06/22/2006 7:08 PM | Joined: Jun 2006 Posts: 687 Shop Shark | | Shop Shark Joined: Jun 2006 Posts: 687 | The bolts you are using are they sholdered? If so is it possible that the sholder is to long and the bolt bottoms out before the manifold is tight? DONT USE RTV it wont work anyway.
I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"
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#62032 06/22/2006 7:23 PM | Joined: Dec 2005 Posts: 19 Junior Member | | Junior Member Joined: Dec 2005 Posts: 19 | I've been told by other people not to use RTV, but saw several posts here where people suggested "copper" RTV... picked some up, it says good to intermittent temps up to 700F...
How hot does the exhaust manifold get anyway? | | |
#62033 06/22/2006 9:24 PM | Joined: Jun 2006 Posts: 687 Shop Shark | | Shop Shark Joined: Jun 2006 Posts: 687 | About as hot as the fire in slide rock park.
I use to live in Holbrook.
I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"
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#62034 06/22/2006 10:59 PM | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | I,ve used the copper RTV on them & it seals them. When u take them off put a straight edge across & see if it is ground correctly. Do you put them on before hooking up the exhaust pipe? Could it be holding it back?
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
#62035 06/22/2006 11:06 PM | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | The rings are for the intake, not the exhaust. They should still be installed, however. Replacing the end dowells with bolts will help with curing exhaust leaks on the ends of the manifold. Also consider studs rather than bolts.
Bill Burmeister
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#62036 06/22/2006 11:10 PM | Joined: Jul 2005 Posts: 226 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Jul 2005 Posts: 226 | Uhhhhhh guess what, if its been leaking along time, the head itself can be eroded there. the head would need to be ground also to flat.... mine is that way.. i got it leaking and put on a different manifold that was flat only to find out the head itself on one port is gone, its a good 1/8th inch gone.... for a temp fix i put that silica woodstove chimney sealer in there with a gasket and thats been holding for about two months now.... so at least it stops the exhaust leak until i can get the head off and surfaced....
What it will say on my Tombstone: "Boy, that guy sure owed alotta people Money"
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#62037 06/22/2006 11:22 PM | Joined: Apr 2003 Posts: 608 Shop Shark | | Shop Shark Joined: Apr 2003 Posts: 608 | Longbox55
Thanks I realised that after I had posted
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