Newbie experiment

Discussion in 'General Discussion' started by gonavy, Jul 4, 2015.

  1. gonavy

    gonavy Smoke Blower

    Ok don't know where to put this, so here we go.  I have an Oklahoma Joe Highlander, did all the mods sealed the firebox etc...two things I need to point out, the temp probe that came with it on the lid was way off, by 50 60 degrees higher then at grate surprise everyone knows this, and the temp difference at grate level was 60 degrees higher on the firebox side, again no surprise.  So I got a deflector plate from BBQmodders.  I did a burn in today to season it in...and there were a few surprises, and I thought I would let you'll know about them.  

    1)  it takes a good 45 mins longer to get up to temp with this plate in.  Granted I didn't use a full charcoal load because I just wanted to do a fews hour burn in, but I did use the normal chimney start up, just took a really long time to get it up over 200 degrees.

    2)  Prior to the deflector I got temps 50 to 70 degrees higher on the firebox side at grate level, too be expected.  I thought the deflector would fix that, and it did, but it over did it.  I got 20 to 30 degree cooler on the firebox side.  Then I tried something radical, I removed the elbow I had on the stack to grate level and went back to stock setup.  Oddly this made it  only 5 degree difference  from firebox side to exhaust side, very happy with this...  I used a mav 733 temp probe set 3 inch from the left side in the middle and the other probe 3 inch from the right side (near firebox).  lol...why it is a lower temp on the firebox side is a mystery. But the bottom line is if you have a deflector plate, you don't need the elbow on the stack to grate level, just makes things worst.

    3)  here is the kicker, now my useless stock temp probe, works great, it is within 5 degrees of what my mav at grate level is reading, why...I have no idea.
  2. oddball

    oddball Smoke Blower

    Having the stack at grate level, traps heat and smoke in the top of the chamber.  As heat rises, that is why the stock probes are usually "hot".  This also allows the smoke to collect in the top of the chamber and remain at grate level which keeps the meat "in the smoke".

    As for the deflector, when I had my old offset, I built my own deflector.  It was basically several pieces (as noted in one of the many topics here).  When placing them in the grill, the gaps between the plates were smaller on the firebox side and wider as they moved to the cool side.  It was a matter of trial and error to adjust the gaps and get an even temp across the pit.  I've also seen one piece models where there were simply holes drilled (as opposed to the gaps between pieces in mine) to allow heat through.  With a one piece plate, I've seen them use different sized holes and/or just more/less holes to adjust the heat.  If I haven't explained it well enough, just let me know and maybe I can dig up the topics to reference. 

    The bottom line here is that the deflector just needs to be adjusted to get an even temp.  Or you can leave it be.  Personally, I'd want the smoke/heat at grill level, not the top of the lid and out the stack.

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