Large temp control

coooltroy

Has anyone experienced difficulty keeping the LBGE at 225 for a long cook... I recently did a pork butt and the last 4 hours of the cook the temp steadily climbed to 250-260 before settling.  My fan control was at 0% the whole time, top daisy wheel 1/4" open.  I am wondering if the fan allows enough air to make a 225 cook difficult or if I let the coals get too hot before closing it and letting it settle.

swordsmn

My cyberQ will do 225 easy.  Smokeware BARELY open ( or super narrow opening on DFMT). I think you need to barely get it going then turn it over to the 'puter... Might take a few to GET to 225 but I never overshoot but inserting the fan immediately after MAPP Lighting in the center only.. RO or BGE lump with a few random wood chunks..

stlcharcoal

Usually that's a gasket thing.  How's it looking (especially around the probe wires.)

Yes the BGE can pull air past the fan; however, if the daisy wheel is closed, it has nowhere to go.  

Also, if you light your fire from the bottom, the fire will light the charcoal above it.  Light it from the top so it burns from the top down.

Finally undershoot your temp for the first hour or two.  Shoot for 200F and see what happens.  The meat won't know the diff.....all you're trying to do is get as much smoke as possible inside before it starts leaching fat. 

If all else fails, put some water, beer, and/or apple juice in your drip pan.  That will help keep the temp down. 

coooltroy

@swordsmn and @stlcharcoalI think you nailed it... I torch lit and let it go till it was burning good... next time I will torch it and set up the fan.  Thanks for the input!  Much appreciated.  Had a feeling it was user error!

stlcharcoal

I wouldn't do that....... that fan will be feeding the fire shooting for 225F.  That's going to be a big fire ball by the time the ceramic hits 225F and the egg is ready to stabilize--you'll blow past the set point because you have a bigger fire than needed.

Fire up the top with a torch and let it spread for 5-10 minutes lid open.  Then get everything set up and close the lid.  Let it get up to temp normally, then put the fan on.  Or if you want to use the fan as soon as you close the lid, set it at 180 stabilize, 195 stabilize, 210 stabilize, then 225.   Starve the fire from early on.

swordsmn

Infinite props to sti,  I'm still a tenderfoot, but with my top almost shut and the sliding damper in my pit viper closed down by over a third, I just don't overshoot. YMMV

coooltroy

@stlcharcoal, I didn't mean as soon as I light, I will do as you say, 5-10 minutes then go to control.  
I have way more direct heat cooks so I usually light and let it get evenly going throughout before dropping the lid.  I am pretty sure that was the problem.  

swordsmn

I'm probably at 5-7 mins myself. 

swordsmn

Oh are we talking grilling. :-)

Photo Egg

The BBQ Guru has a slide dampner on the fan to slow down natual draft passing through even with the fan not running.
I missed the post on what controller you are using. 
Since your temp was steady for the early part of ypur cook I feel you started your fire perfect. As your PB started reaching temp it needed less fire and to much air flow would not let this happen.
Lower vent/fan air leak, gasket(slim), daisy still open a little much. The fan will push air even with daisy almost completly shut.

coooltroy

@swordsmn, no talking slow cook indirect, just mentioned I am more used to direct heat cooks 

Jeepster47

@stlcharcoal ... that's exactly what happened on my first cook with the Flame Boss. 


But, once I understood how to set the SW cap, I've not had that problem.  For a 250 degree cook, I still set a pit temperature of 225 degrees on start up ... I like the belt and suspenders concept.

Here's a graph of the results of starting the fire (centered and near the top of the lump) with a BGE electric starter.  I pulled the electric starter, installed the plate setter and grill, hooked up the Flame Boss, and closed the lid. 


The lid was closed at 11:27am and the egg was stabilized at 225 degrees 16 minutes later with negligible overshoot.  The meat was added about 15 minutes later when the exhaust began running clear ... used Rockwood 'cuz it clears quickly.

The electronics can only make the temperature go up ... the correct setting on the cap is what prevents overshoots and maintains a steady pit temp.

coooltroy

@Photo Egg Im using a flameboss 200.  

swordsmn

I was trying to do a bit o innuendo there...  I knew what we were discussing.

coooltroy

Ahh, sorry I can be way too literal when tired, my bad!

Begger

Long term or short term ups and downs would appear to be normal.    In industrial temp control of furnaces intended to go to 1100c or hotter, temp control was of critical importance.    The systems in use as shown in the graph, above are not all that bad.  The ONE temp spike (down) and fan spike (up) must have a reason.   Maybe flame spread in the firebox wasn't optimal?   But I'd expect the fan to ramp up slowly or have a series of SMALL spikes up as temp dropped from its peak about 0430 to large fan spike at nearly 0700.  

coooltroy

I think looking at my graph its obvious I let my fire get to hot before going to control... lesson learned.  Looking forward to the next cook to see the difference.

coooltroy

My eggs are less than a year old so the gasket isn't the issue.

coooltroy

@Jeepster47 great input!  Thanks so much.  Clearly that second cook was dialed.  Thats what I am looking for!

Photo Egg

coooltroy said:

My eggs are less than a year old so the gasket isn't the issue.

Just because your Egg is fairly new and gaskets are good does not mean you have air tight fit between base and dome. Not saying you do but slight alignement issues are common air leak problems.

Jeepster47

@coooltroy ... your Flame Boss didn't really contribute to the cook you posted above.  It was seldom in play ... from about 2:20 until the meat was removed, the fan only kicked on when you opened the dome.  Even then, the lid open algorithms kicked in and shut the fan down quickly.

You did not have your daisy wheel closed tight enough ... 1/4" open is most likely too much even for a manually controlled cook.  Next time close it until the fan usage looks more like the second graph that I posted above. 

Note that the pit temp in my graph was peaking at the set pit temp and oscillating downward.  I think that's the result of the correct cap vent setting.  If you coast much over set temp, then airflow isn't restricted sufficiently.

coooltroy

@Jeepster47 thanks for the help, wil try that for sure.

swordsmn

Great discussion, what the place is all about!