Infrared broiler burner in gas pizza grill -What's wrong with my design?

[jgame]

The manufacture had vents below the IR burner in my gas grill as noted in picture. Once I removed the IR I was left with a large hole. I covered that up with a piece of thin sheet metal and keep it closed. The back of pizza oven is open and sits tight against the rear wall of the grill, forming the rear wall of pizza oven. I take back my post about an upper vent. My vents are pizza stone level and my IR works fine.
jgame

[Tampa]

Thanks Jeff.  I'm still open to naysayers, especially since I have not seen all the different placements and designs of gas-fired IR burners.  It seems to me that the ceramics should hold up facing sideways (like mine), facing down (like Jeff's, Creation's, and a few others) or facing up.  However, the "up" implementations I've seen use a different element design, probably so they can handle grease drippings.  Ceramic still might work facing up in pizza ovens, although I'm out on a limb here.

We should all be careful with propane.  Remember it is heavier than air and tends to pool in unvented areas so don't let it build up before igniting.

Recently I've "hogged out" the underside burner holes with a slightly larger drill on my rotisserie pizza grill.  The result has been a pie in 3.5 - 4 minutes.  The attached photo is my attempt to replicate Tony's New Yorker (in SF).  Tony's menu says he throws in a coal-fired oven at 900F and I'm figuring he is on a VPN clock.  I'm certainly not that, but I'm getting a light crispy crumb and light crunch on the underside; it tastes good to us.

Here's a link to a more recent pie than the picture below: http://www.pizzamaking.com/forum/index.php/topic,10241.msg197609.html#msg197609

Dave

[jgame]

Here's another photo showing (very hard to see ) IR burner and vents at pizza stone level.
jgame

[creaton]

Jgame- did you modify the top back vents on your grill? If not, then it seems that the hot air would exist your setup through those original vents top back. Do you have any pix of your grill back vents?

[creaton]

@Tampa - that New Yorker looks incredible. Any special dough recipe here?  How much hotter is your grill after the bore out?

[jgame]

Only modification I did was cover up the hole left by IR burner with sheet metal. For some reason my top mounted IR works fine. I'm sure my pizza oven is not airtight or the gas grill. Your modification might be to airtight. Try raising your oven off the grill a little at a time. Might be easier than guessing and cutting holes in the oven.

[Tampa]

Jgame – good pics.  Thx.  I think the reason your IR burner works and creaton’s doesn’t is because his IR burner is up higher in a more sealed lid than yours is.  My IR burner is in the same place as yours was before you relocated it; I don’t have vents directly underneath the way you do; and still I get plenty of O2 in my hood.

Creaton – thanks for the kind words.  There are lots of great pizza makers on this site.  All I was trying to say with the pic was that “I’m in the ballpark”.  No special recipe here.  Just Kyrol HG flour w/ 60% hydration.  There is no way to say “how much hotter” – all I can do is measure the stone temp and it is whatever I want so I throw at 675F to 700F.  The real issue is the heat flow.  Given the larger flame because of the slightly oversized holes, I think the heatflow is greater over the top of the pie making 4 minutes crispy all over.

Dave

[Tampa]

Creation, is it too late to say that I thought again about your stainless beauty and have a different opinion about why the IR burner doesn't work?  If not, then read on.

Fresh air draw is important to proper function of IR burners as well as regular underside burners.  On convential grill-style IR burners, fresh air is drawn from the backside of the burner box.  On jgame's innovative design, the burner is horizontal over the top of the pie, but the nozzle area is still open to allow fresh air from outside the burner area.  You want that - a fresh air source supply just before the gas nozzle sprays into the IR burner.  That spray draws fresh air along and allows the gas/air mixture to flame in the IR burner.

FWIIW, I've been noodling on the overhead IR design for some time.  But after more thought and some experiments in my grill, I have reservations about the effectiveness.  My main concern is that the center of the pie will be continuously exposed to the IR heat, but a given section of the rim of the pizza will only be periodically exposed to the head as the rotisserie rotates the section into "view" by the above burner.  Initially I figured I would address this concern by slanting the IR burner so it is closer to the rim of the pie and farther away from the center of the pie - but I don't think this will be enough.  Maybe jgame has commented on this and I just haven't seen the post yet.

Dave