Natural Gas Conversion Q's

G Schafer

TVWBB Fan
I'm running a 3/4" gas line out to supply my grills. I have a NG manifold ordered and I have a second one for the second grill. So the grill conversion is taken care of.
I will reduce to 1/2" pipe for the two grills.
So, is there any preference for quick disconnects, flexible line from the pipe to the grill, or any other fittings that I should know about?
These will be connected to Genesis 2s

Thanks
Gerry
 

G Schafer

TVWBB Fan
Hopefully not too busy. Just looking for good parts and parts to avoid. It looks like it should be simple enough, but I'd like to avoid the "gotchas".

Gerry
 

Bruce

TVWBB Olympian
Either PM LMichaels or wait for him to reply to this thread. He is pretty active, so it probably won't be long. He has a good working knowledge of gas and propane connections and converstions.
 

G Schafer

TVWBB Fan
Either PM LMichaels or wait for him to reply to this thread. He is pretty active, so it probably won't be long. He has a good working knowledge of gas and propane connections and converstions.
Yeah, I noticed that he is in on pretty much all of the conversion threads talking about the valves and orifices (orifi?). I'm sure he'll be here soon. I'm more wondering which gas hose to buy, and do I use a quick connect or not. My grills pretty much stay in place, so a quick connect might be a waste?
I haven't researched the fittings I'll need between the 1/2" gas pipe and hose but I want to make sure I get the right stuff.

Gerry
 

LMichaels

TVWBB Hall of Fame
This is really all you need https://www.amazon.com/exec/obidos/ASIN/B07CZCZVXT/tvwb-20
They have them in 3/8" or 1/2". 1/2" is perhaps over kill for a Genesis but certainly won't hurt anything. You can also get various lengths.
One other thing you need to check on though is this. If you have a newer Genesis II design I believe those manifolds are jetted to run with a regulator. Something like this https://www.amazon.com/exec/obidos/ASIN/B008CPQMNO/tvwb-20
This is an important thing if they are as it will regulate your grill pressure down to 3"WC from the 7-8" WC line pressure. You may want to research that as I don't know if it is or not.
 

G Schafer

TVWBB Fan
I received the NG manifold. It's not like the original. The manifold is square stock and the valves look like a compression against a gasket fitting. So I'm not going to use it. I'm kind of a stickler for OEM style parts.

So, what drill size do I use for natural gas orifices?
The orifices on this one seem to be #54.

Thanks
Gerry
 

John Ford

TVWBB Pro
Just finished my conversation.
ill tell you that Larry Michaels IS the resident expert.
The hose has all the correct connections!
get some pipe dope to use on all connections.
I redrilled my propane jets.
used a little trial & error. Didn't use manifold, unsure of WC, & I know with hand twist drill you tend to wallow out the opening.

Drilled to 1.0 mm reinstalled . Lite well, stayed lite at low ( very important) temperature maxed at 575 F
Redrilled to 1.2 mm temp maxed at 675F , 1 burner on low ran 250F QUIT WHILE I WAS AHEAD 🙄
 

G Schafer

TVWBB Fan
Good to know. I sometimes smoke ribs and I have trouble getting down to 225f. A staggered drilling of the orifices might make it easier to get there. Nice to have a starting point. Thanks!

Gerry
 

LMichaels

TVWBB Hall of Fame
I received the NG manifold. It's not like the original. The manifold is square stock and the valves look like a compression against a gasket fitting. So I'm not going to use it. I'm kind of a stickler for OEM style parts.

So, what drill size do I use for natural gas orifices?
The orifices on this one seem to be #54.

Thanks
Gerry
It's not as simple as just drilling orifices on those old style grills. The valves were different between fuels as well. If you take an old style LP grill and change orifice openings to NG size you will see that medium will run VERY low and low will flicker and not always stay lit. Now here is the dangerous part. There is still gas flowing (even though you don't see a flame). This gas is collecting under that lid turning into a "bomb". So now you simply lift the lid and a sudden rush of air and you can have a huge fireball, or it can collect under the hood and a flame flicker on another burner can cause it to ignite under the lid blowing the lid clean off. You're messing in places here you better be far more careful of
 

G Schafer

TVWBB Fan
It's not as simple as just drilling orifices on those old style grills. The valves were different between fuels as well. If you take an old style LP grill and change orifice openings to NG size you will see that medium will run VERY low and low will flicker and not always stay lit. Now here is the dangerous part. There is still gas flowing (even though you don't see a flame). This gas is collecting under that lid turning into a "bomb". So now you simply lift the lid and a sudden rush of air and you can have a huge fireball, or it can collect under the hood and a flame flicker on another burner can cause it to ignite under the lid blowing the lid clean off. You're messing in places here you better be far more careful of
I understand your point. I watched my dad almost blow the lid off the grill once. He thought it lit, but when he checked it a bit later, the temp wasn't going up. He hit the igniter, and boy did it light off that time! No damage or injury, but a lesson learned.
I have an old manifold on the grill I brought to work. That one was originally NG that I changed over to LP by swapping orifices. I can't find the orifices now, but I can grab that manifold back and drill out some LP orifices.
I'll do a valve cleaning on that one and try to see how the valves differ.

Thanks
Gerry
 

LMichaels

TVWBB Hall of Fame
Most important is that burner stays lit when on lowest setting , not how hot the grill gets
Well actually both are true. You can over size the main orifice and allow the burners to somewhat stay lit, but then you will have a dangerously hot grill at higher settings. Which is why I emphasized the importance of the correct valves
 

G Schafer

TVWBB Fan
Well actually both are true. You can over size the main orifice and allow the burners to somewhat stay lit, but then you will have a dangerously hot grill at higher settings. Which is why I emphasized the importance of the correct valves
That statement has me puzzled. I thought that at low settings it was the spools in the valves that limit the gas flow, and not the main orifice size. Isn't that why you need NG specific valves? I'm not going to oversize the main orifices, but I am going to drill out a set of LP orifices to match the orifices in the new NG manifold I bought. Those will be installed into a set of known NG valves that I have on another grill. If memory serves, it's a #54 drill bit.

Can anyone confirm the #54 bit size?

Thanks,
Gerry
 

LMichaels

TVWBB Hall of Fame
For giggles and grins I tried it once with a spare orifice on my own grill. It seems they work in conjunction (up to a point) as at some point there is no change. Sorry I never recorded it but suffice to say I tried it just to prove it to myself. And confirm #54 for what?
 

Bruce

TVWBB Olympian
And this is why I simply swap manifolds on grills rather than trying to modify them. Unless you have the knowledge of someone like Larry, modifications are fraught with too many pitfalls. Just easier to find a donor grill IMO. Or call the support line at 1-800-lary.
 

G Schafer

TVWBB Fan
For giggles and grins I tried it once with a spare orifice on my own grill. It seems they work in conjunction (up to a point) as at some point there is no change. Sorry I never recorded it but suffice to say I tried it just to prove it to myself. And confirm #54 for what?
I wanted confirmation that the #54 bit would be the correct size to use to drill out the main orifices for use with natural gas.

Thanks,
Gerry
 

Top