Help me solve intake mods on my UDS

BriGreentea · Posted: Aug 05 2010 Post subject: Help me solve intake mods on my UDS

Hello, after talking with a member on here that has a similar design on his UDS as mine, I'm thinking about making changes on the intakes(pic is in my sig)
Right now using 3 3/4 intakes. Two are 1.5 inch nipples with caps (left and center). The one on the right is an elbow with a 3 foot 3/4 pipe and ball valve. My plan was to only use the caps at the start to get the heat going and use the ball valve to adjust but for a couple of reasons cannot be done. For grilling on my lower rack cannot get it past 225 without taking off a couple intakes and even then the temp goes up and down too much. Last weekened smoked on the upper rack a pork butt and could not get it to stay at 225 without opening an intake.

I don't feel there is much of any air going down the vertical pipe and think it's just because it's too small. It didn't matter if I closed it or opened it or left it halfway open I never saw a temp drop or rise because of adjusting that.

So my choices are to take off the pipe and could use the existing elbow and place the ball valve verically on it. I'm not sure it that would be any better or not.
Or take off the elbow and put a nipple on it then put the ball valve. Or just get two more ball valves to have 3 total and wouldn't have to worry about uncapping or capping ever again but the size in the hole of the valve while fits a 3/4 pipe would be smaller.
The other minor problem taking off the vertical pipe would have a "U" bar on the side of the drum that helped hold the pipe in place. I guess I could just leave it there and could find a use for it but I'm not sure if JB Weld could fill the holes where not only would it look ok but hold also.
Suggestions?
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Old Country model: flagstone - vertical offset
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k.a.m. · Posted: Aug 06 2010 Post subject:

BriGreentea, I would do a few things to your cooker.
#1 Take off the long pipe.

#2 replace the street ell with a nipple to have the valve horizontal instead of vertical.

#3 I would increase the exhaust ID to 2''

#4 Good idea day_trippr, or replace the u-bolt with a couple of stove bolts. The hole is filled and hardly noticeable if you paint them. I would not use the J-B weld.
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Hybrid Cooker

day_trippr · Posted: Aug 06 2010 Post subject:

Depending on where that hole is located, you could use it to support something like this:

which I think is the coolest UDS mod I've seen yet...

Cheers!
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Char-Broil Commercial Gasser

BriGreentea · Posted: Aug 06 2010 Post subject:

Ya I've seen that before from another guy that built one and placed pics...

What is that part though that goes into that valve and where can you buy it or is just a customized rod assembly?

I think I'll go with kam's idea which I was leaning towards and will then move the valve to the middle one and should work fine. The exhaust though is 1 1/2 in diameter and works great and isn't too small at all. Other then that I've been enjoying this uds.
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Old Country model: flagstone - vertical offset
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SNN · Joined: 30 Jan 2010 Posts: 11 Location: NH

day_trippr · Posted: Aug 06 2010 Post subject:

cityevader · Posted: Aug 06 2010 Post subject:

In my humble opinion, a single 3/4" ball valve isn't quite sufficient.My 1" ball valve at 90% open gets it to 240. There is almost no "headroom" in terms of adjustment with a 3/4". Ideally, you'd want your most used temp to be somewhere in the middle of the ball valve's travel. That way you can have room to go up and down for temp control. If the valve is wide open to get the temp desired, why bother with a valve.

The most cost effective solution would be to remove one of the caps and put a reducer on it, or even two reducers (you can experiment with 3/4-1/2, and then a 1/2 to 3/8 ) so that it's always open but only a little bit. That way your valve will take up the slack and allow a larger range of temps with the easy twist valve.
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k.a.m. · Posted: Aug 06 2010 Post subject:

Smokenstein · BBQ Fan Joined: 07 Jul 2010 Posts: 157

I'm fairly new to UDS but the ones I have built have been easily to stabilize the temps.

I use (3) 1" ball valves about 3" above the bottom lip of the drum.

I've had used a couple of lids. The original flat top lid with (2) 2.5" diam x 6" h exhausts the other (1) 3.5" diam x 6" exhaust.

cityevader · Posted: Aug 06 2010 Post subject:

Your three 1" are vastly bigger than the OP's three 3/4".

A nominal 1" hole compared to a 3/4" (actual diameter, not pipe diameter which I haven't measured) will be almost twice the surface area. Increasing/decreasing diameter has a huge effect. Very rough calculations are .7 sq. in. to .4 sq. in. for a single hole 1" and 3/4" respectively.

And the exhaust surface area 1.5" compared to 2" is roughly 1.7 sq. in. to 3.1 sq. in. Again, huge difference for a "small" change in diameter.
_________________
Since Christ DIED for us, we should LIVE for Him!

To make the ° temperature symbol, hold the Alt key while typing 248 on keypad.
.

12TH AV SMOKERS · Posted: Aug 06 2010 Post subject:

My 2 cents......I agree with k.a.m 100%. Exhaust is the main problem. I would remove the vertical inlet pipe too . I've made enough of these for myself and friends and I've made them all the same way in regards to the inlets and exhaust. Everyone raves and no complaints yet. I've also used them many, many times. All you need is (3) 3/4" pipe nipples, that's a 1" hole. (1) with a ball valve and (2) with caps.
Teleking and others don't even use ball valves. He uses magnets to cover the holes. You just slide them over the hole for adjustment. Cheap too. He saves his money for Wusthofs Razz

peace
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FATTIE THROWDOWN CHAMP
(2) WBS- Wine Barrel Smokers
(2) BDS - Brick Drum Smokers
(1) UDS - Ugly Drum smoker
SMS - Vertical - wood / gasser

http://www.youngbergindustries.com/

BriGreentea · Posted: Aug 06 2010 Post subject:

My lid which when I bought it off a buy thought it had a bunghole but was mistaken and did not. If I could just find a lid that has a bunghole I would try a 2" pipe. Others have used electrical small tops only a a couple inches long on the bunghole to screw it on. I have also located a 2" 8 inch long electrical pipe at Lowes that would work.
If a wider exhaust would work I would try it but would be difficult to do with the lid I have since I already have the mounting holes on the one I have now...so would need a new lid with a bunghole. I could argue that some have used exhausts way too big on UDS's causing too much draw and could make the arguement some just drill some 1/2 holes in the lid. The only reason I didn't do that is because of rain in my area and with a stack would be harder for rain to get inside.

I switched the pipes around last night and now have my valve in the center and two nipples on each side. Will try it tonight when I make hamburgers.
_________________
Old Country model: flagstone - vertical offset
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Smokenstein · BBQ Fan Joined: 07 Jul 2010 Posts: 157

IMO, it's best practice to build a UDS that has more intake and exhaust than not enough.

At least you are able to choke it down if the intake or exhaust are too much.

If you don't have enough of one or the other, its remod and cutting time.

polishdon · Posted: Aug 07 2010 Post subject:

oldnndway · Posted: Aug 07 2010 Post subject:

For what it's worth this is how my UDS works ...

I drilled 4 each 3/4" holes evenly spaced a couple of inches up from the bottom of the drum.
I have found that when I leave one of these holes open and plug the other 3 with a piece of foil stuffed in them my cooker will stay rock-solid level temp for numerous hours.
The one open hole is enough intake to feed the fire.
I have a clamp on lid that has the screw bung in it.
I simply leave this open and get (I guess) near perfect draft.

Nothing I figured out, just the steps I followed after reading about it on here.
I don't find a need for the nipples, valves, smoke-stacks etc.

Just my .02 cents

cityevader · Posted: Aug 08 2010 Post subject:

Weber lids with four holes at 7/8" ea has a 2.4 sq. in. area, which puts it smack in the middle of a 1.5" and 2" exhaust. Many folks use that with great success.
Just sayin'.

There are such an enormous variety of factors that make temp control extremely variable. Newly built cooker on my porch with a 7/8" hole for intake with magnet cover, needed nearly wide open to maintain 240�. I then delivered it to my brother and in the sun/heat the intake was nearly fully closed to maintain 240�.

So while there are general "rules" to follow, they can almost be thrown out when it comes to an individual cooker in an individual location. So advice can't be "make it like what I've done" (which I admit to doing) it can only be adjust it this way or that.

That said, we all seem to be saying "give it more" and throttle back if needed.

Can't wait to hear what resolves OP's concern.
_________________
Since Christ DIED for us, we should LIVE for Him!

To make the ° temperature symbol, hold the Alt key while typing 248 on keypad.
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BriGreentea · Posted: Aug 09 2010 Post subject:

Here's my modified uds now.
modified one:

old one:

_________________
Old Country model: flagstone - vertical offset
http://img51.imageshack.us/img51/5237/dscn1024jg.jpg

12TH AV SMOKERS · Posted: Aug 10 2010 Post subject:

Allright then...fire that hooker up!

peace
_________________
FATTIE THROWDOWN CHAMP
(2) WBS- Wine Barrel Smokers
(2) BDS - Brick Drum Smokers
(1) UDS - Ugly Drum smoker
SMS - Vertical - wood / gasser

http://www.youngbergindustries.com/

cityevader · Posted: Aug 10 2010 Post subject:

Kinda looks like you started over with a new lid huh?

Sometimes it's just plain easier to start over than to keep reworking what you've got.

We've given you a few hours, now we want a full write-up review!!
Whaddaya mean you ain't cookin" yet!?!?
_________________
Since Christ DIED for us, we should LIVE for Him!

To make the ° temperature symbol, hold the Alt key while typing 248 on keypad.
.

BigMikeIA · Posted: Aug 11 2010 Post subject:

I have 4x 1" holes 2 1/2 inches up from the bottom on my uds, my lid also came with no bung, I used a 3" hole saw to drill a hole dead center. Right now it's just an open hole, and I use magnets over the intakes. I open them all until the coals catch, then close 3 off completely and leave the last one 3/8 open, and I get a rock-solid 275 (done lots of wings and moinks) or close it a little more and get 225 for ribs.
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UDS