Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 

Thread: testing for burnt valves
          
   
   

Reply To Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 19
  1. #1
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    testing for burnt valves

     



    I got a dollar sucked in half by my exhaust so I think I have some burnt valves. Is a leak down test the best way to determine this?
    Also, is it measured over a specified time interval? because wouldn't any cylinder leak down 100% given enough time.

  2. #2
    shawnlee28's Avatar
    shawnlee28 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2004
    Location
    so.cal
    Car Year, Make, Model: 66 c 10 fleetside longbed
    Posts
    1,942

    Burnt exaust valve or valves,I ran a 300 straight 6 for years with the burnt exaust valve.A vaccume guage will tell the story.
    Its gunna take longer than u thought and its gunna cost more too(plan ahead!)

  3. #3
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    but I don't know what the vacuum should be without burnt valves.

  4. #4
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    if you don't have a burnt valve the gauge needle will stay study, if you have a burnt valve the needle will flicker real fast.
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  5. #5
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    but wouldn't that only tell me if the burnt valve is on the intake?

  6. #6
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    Quote Originally Posted by tcodi
    but wouldn't that only tell me if the burnt valve is on the intake?
    yes, then you would have to do a comp. check on ea. cylinder to find out which one was bad.
    Attached Images
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  7. #7
    chevy 37's Avatar
    chevy 37 is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2004
    Location
    Auburn
    Car Year, Make, Model: 1937 chevy truck& 33 fordtruck
    Posts
    3,017

    Mike thanks for that drawing. I'm sure it will help sometime down the line.
    Keep smiling, it only hurts when you think it does!

  8. #8
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    a vac. gauge can tell you a lot. i all ways run a vac. gauge in the dash of the race cars i built.
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  9. #9
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    yeah I wish I had one inside my car, I couldn't get a vacuum gauge in the style of the rest of my gauges though.

  10. #10
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    ok, used a leak down tester last night and every cylinder came out around 20%, +/- 5 or so. On each one I could detect a sound if I put my ear to the exhaust pipe, it was faint as hell so I don't know if it was something else I was hearing.

  11. #11
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    Quote Originally Posted by tcodi
    ok, used a leak down tester last night and every cylinder came out around 20%, +/- 5 or so. On each one I could detect a sound if I put my ear to the exhaust pipe, it was faint as hell so I don't know if it was something else I was hearing.
    sounds normal to me. did you use a vac. gauge?
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  12. #12
    tcodi's Avatar
    tcodi is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    parkesburg
    Car Year, Make, Model: 1950 chevy pickup
    Posts
    580

    no, I haven't run it yet with a vacuum gauge cause I don't have one, but I'm going to get one. Some things are still a little sketchy, like if I'm on the throttle real hard and then have to shift I sometimes get a pop out the exhaust. After taking all the plugs out last night I see that they are looking lean, which I don't understand because when I was warming it up before doing the test it was burning my eyes.

  13. #13
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    you can have a rich idle and a lean WOT. 2 dif. parts of the carb. what kind of carb. do you have?

    "but wouldn't that only tell me if the burnt valve is on the intake?"
    this is a ? you had before and no one answered it. this would tell you the burnt valve was on the exhaust, not the intake. if the intake valve was leaking then you would hear comp. blowing back up through the carb.
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  14. #14
    thesals's Avatar
    thesals is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2004
    Location
    san diego
    Car Year, Make, Model: 66 mustangFB, 69 econline Drag Van
    Posts
    1,527

    Quote Originally Posted by lt1s10
    a vac. gauge can tell you a lot. i all ways run a vac. gauge in the dash of the race cars i built.
    thats one thing i love about the after market restomod gauge cluster i bought for my mustang, it looks like the factory one but they added numbers, a tac, and a vac/boost gauge.... so helpful
    just because your car is faster, doesn't mean i cant outdrive you... give me a curvy mountain road and i'll beat you any day

  15. #15
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    Thumbs up

     



    Quote Originally Posted by thesals
    thats one thing i love about the after market restomod gauge cluster i bought for my mustang, it looks like the factory one but they added numbers, a tac, and a vac/boost gauge.... so helpful
    the gauge they put on some cars to help you with your gas mileage was a vac. gauge. light throttle good vac. WOT low vac. and if you watched the gauge you wouldn't mash the throttle as hard when taking off.
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




Reply To Thread
Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink