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Removing carbon deposits

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Leinie, Jul 4, 2001.

  1. Leinie

    Leinie Registered Member

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    I have a 350 long block with 8,000 miles on it. Problem is the carb ran very, very rich for those 8k and the valves have lots of carbon on the top. Will it work to soften the carbon by filling the closed intake ports with Seafoam and rotating every few days until I run it?
    If I need to remove the heads I want to have the heads shaved .025" for a bit more compression ( they are 441 76cc)
    Are there any other mods neccessary if I have them shaved?
    Any Idea what it might cost to shave them? Thanks
    The motor is on a stand, not in a truck at this time so its easy to work on.

    72 K5 CST X 2
     
  2. rocko

    rocko 1/2 ton status

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    Try posting this in the other forum.. the 73-91... This question has been brought up before there.. someone I'm sure will answer this...
    Hope this helps a little.

    A well armed society is a polite society. <A target="_blank" HREF=http://www.rocko.rockcrawler.com>http://www.rocko.rockcrawler.com</A>
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    If you have them shaved, you'll have to have the intake shaved. A machine shop won't have a problem, probably cost $50-$100

    I'd have the block decked instead. By getting the quench distance in the good range (.039"-.043") you'll be able to curve your distributor for more advance and have better luck controlling detonation with a higher compression ratio.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  4. Steve_Chin

    Steve_Chin 1/2 ton status

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    If you're going to remove the heads, don't worry about the deposits on the valves, since you can easily take care of them when the heads are off. If you aren't, wait until it's running and use GM Top Cylinder Cleaner. I hear that it works GREAT on valve and chamber deposits.

    WRT milling, if you mill the heads, you have to mill the head face of the intake a like amount in order to make the ports match again. Once you do this, you will not be able to use this intake with any other heads unless they are also milled the same amount. I kinda-sorta agree with having the block zero-decked before going to the trouble of milling the heads, since that will set you up with a reasonable quench height and you will also have a known piston to deck clearance for compression calculations. Alternatively, you could simply measure your piston to deck clearance and run head gaskets with a thickness that will get you in the 0.038"-0.050" quench range and base your compression calculations off of that.
     
  5. k5blazerus

    k5blazerus 1/2 ton status

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    I have have had good luck with spraying a small stream or water into the carb. have the idle set high so you wont choke out spray a small stream like one squirt from a bottle. I had the same problem on my stroked 307 motor so I did a old mechanics trick and It works . But it dose take time. I did 6 squirts a day for a week and I did work. By the way what kind of carb are you running I am pretty good at carburator work so if your stumed let me know.
    Colin

    IF its not broke dont fix it
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Yep, water in the intake will work. So will tranny fluid.

    At Jiffy Lube they've got an intake cleaner that will make your motor smoke black for about an hour. I think it retails for $60.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     

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