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RTV instead of header gaskets?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Blazer79, Dec 19, 2001.

  1. Blazer79

    Blazer79 1/2 ton status

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    I'm currently swapping my 454 now. I'm going to use a set of used Thorley headers that came with the engine. The problem is that I don't have the gaskets, I would have to wait until next year for them to arrive from the US. Can I simply use high temp RTV sealer instead of gaskets just for a few months? Or is there a reason one MUST use gaskets?

    Thanks.

    <font color=purple>//////
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  2. Tybee

    Tybee 1/2 ton status

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    Do not use rtv, ever on a head!

    1984 GMC Jimmy 379 diesel, 700R4, 3.73s, 31x10.50 x 15
     
  3. Sparky87k5

    Sparky87k5 1/2 ton status

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    Can you locate any 396,402,427 or 454 stock exhaust manifold gaskets in your neck of the woods? Even used ones will work for now. They will work as well as any header gasket. Hi Temp RTV will NOT work with headers. Too much heat and will only burn away, fast.

    87 K5, 427BBC,D60 & 14BFF, NV4500, NP208, TSM disc's,
     
  4. Blazer79

    Blazer79 1/2 ton status

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    [​IMG] Allright then, I wont use RTV.

    According to Thorley Headers, only Thorley gaskets work with Thorley headers. This complicates things further, since the Thorley gaskets are out of stock at Summit Racing and the possible ship date is Jan 24!!

    Maybe if I order some cheap Summit gaskets and use them until the Thorleys are available. Do you think this is a good idea? Big blocks are scarce around here, so I don't think it would be easy to find the gaskets in junkyards. As a matter of fact, these Thorley headers had signs of RTV being used instead of gaskets. Any ideas?

    <font color=purple>//////
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  5. ImpalaSS

    ImpalaSS 1/2 ton status

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    RTV deffintly wont work, any header gasket should work, even ones for stock manifolds......... most header companys recomend only using their header gaskets and stuff because..... well it gets them more money :)

    68 SWB 4x4 1 of 1,449 made 327, 465 4 speed, rockwell tcase, dana44, 14 FF, <a target="_blank" href=http://communities.msn.com/68K10>http://communities.msn.com/68K10</a>
     
  6. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Every header gasket I've used has leaked. I started using factory manifold gaskets and haven't had a leak since...and they seem to last forever.[​IMG]

    Rene

    <font color=green>Dyslexics of the world...UNTIE!</font color=green>
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  7. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    I once had a exhaust leak coming from the headers. They guy I always go to at the local place here said that I was crazy for compaining about such a tiny leak, but it bothered me since it sounded like the engine was ticking!!! [​IMG]

    He suggested using RED HI-TEMP RTV in addition to the gaskets. Run a small bead right along the edge of the exhaust port holes in the gasket on both sides, then let it cure overnight. The RTV should be plyable, but no longer sticky when you install the gaskets.

    I tried this when I recently changed my cam. The BBC is quieter than it ever was. The RTV totally worked for me, and has been in place for a few months (even with leaky valve covers spilling oil on them), and they are still working with ZERO leaking.

    Just my .02 [​IMG]

    IN <font color=red>NO WAY</font color=red> WOULD I SUGGEST, HOWEVER, THAT YOU USE <font color=red>ONLY</font color=red> RTV TO SEAL YOUR HEADERS TO YOUR HEADS. YOU MUST USE SOME KIND OF GASKET!!! Had to include the disclaimer at the end!!! [​IMG][​IMG]

    <font color=red>GOT MUD???</font color=red>
    My license plate reads:<font color=blue> 8 YR SUV</font color=blue>
    454/TH400/NP205 - 14BFF/D60/w/ 4.10s - 36" TSLs
     
  8. 1bigk10

    1bigk10 1/2 ton status

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    I to had header gasket problems I used HITEMP RTV silicone and have ran the same for 2 years no leaks I ot a pinhole leaks around my collecter flange applied a liberal amount of silicone the problem was cured

    1982 K10 Silverado. [​IMG] 327 SHPE powerplant SM465/205,15"custom lift 38.5"TSL/SWAMPERS 12boltrearD44 front,3.73 gears.
     
  9. 1bigk10

    1bigk10 1/2 ton status

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    I to had header gasket problems I used HITEMP RTV silicone and have ran the same for 2 years no leaks I also got pinhole leaks around my collecter flange applied a liberal amount of silicone the problem was cured [​IMG]

    1982 K10 Silverado. [​IMG] 327 SHPE powerplant SM465/205,15"custom lift 38.5"TSL/SWAMPERS 12boltrearD44 front,3.73 gears.
     
  10. Lonnie

    Lonnie 1/2 ton status

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    As stated, you must use some type of gasket, but as I posted in a previous topic..... use Permatex Ultra Copper Silicone on the gaskets &amp; they will last an incredibly long time. This works both on the collector flanges as well as the head surfaces. This type of sealant works very well. Many other brands do not last. Almost every racer I know does this now &amp; I will not install a set of gaskets without it.
    Lonnie
     
  11. jaybird

    jaybird Registered Member

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    Here is a trick I got out of Hot Rod magazine many years ago. Buy 2 sets of the cheap Mr Gasket Header gaskets. Soak them in water overnight (both sets). Install 2 gaskets (wet) on each side, torque to spec, allow the vehicle to set until the gaskest are dry, torque again, drive (not idleing in the driveway) to reach operating temp, torque again. I used this method on 455 Pontiac's &amp; Oldsmobile, my 454, and a 5.0 Ford, never had a leak.

    Jay VT
    79 Jimmy 454, 700R4, NP208, D44, 14 bolt, 4.56:1, 38's
     

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