1-pipe steam riser slow to heat

Requesting help from the gurus

Each of my 1-pipe steam mains (L) and (R) are vented with (1) Gorton 2. At the end of my (R) main which heats slightly slower than my (L) main is a 1 1/4 in. riser that feeds 2 radiators.

Radiator #1 - 2nd floor / 35 EDR - 1 1/4 in.

Radiator #2 - 3rd floor / 24 EDR - 1 in.

These radiators are the last to heat in the house, with the one on the third floor being by far the worst and never really heating that great even with long run times.

I've removed the radiator and checked the radiator valve to make sure that it is actually fully open and I've tried removing the radiator vent temporarily to see if that made a difference, but it didn't. Presently I am using one heat-timer vent on each of these radiators set to max-open and I've also tried Gorton D's on these radiators, although they shouldn't need vents this big. I do not hear the vent needing to work that hard.

Besides ripping apart the walls to see what is going on with the pipe in there, is there anything more basic that I should be doing?

From the reading I've done, perhaps I need to be putting a Gorton 1 on the top of the riser, but I've never seen a picture of what something like this would look like. Given that it's just the pipe connected to the radiator valve, where would the riser (main) vent go? Is there any good way to know if this would make a difference and if so, does anyone have a picture of what something like this looks like? Would this go at the top of the 1 in. (3rd floor) or the 1 1/4 in. (2nd floor)?

Any help is greatly appreciated.

steamer

Thanks for the quick reply Mad Dog.

Yes, the boiler is sized properly and it's definitely putting out enough steam / not underfired.

The 3rd floor radiator does begin to get hot in well under 30-40 minutes, but while the other radiators in the house are getting hot way across like it's the coldest day of the winter after this long run time, this one struggles to get hot beyond 2 sections (and it's a tiny 24 EDR radiator in the coldest part of the house).

This is why I was really wondering if maybe the radiator valve wasn't open all the way, but I ruled that out. One of the other radiators in the house faked me out with that problem and had me ripping my hair out for a few weeks.

If taking the radiator vent off doesn't improve anything, does that tell me that specifically venting the riser wouldn't do much of anything for me?

slow other rads to test

Ok, i'll experiment with that. Unfortunately our local supply house doesn't carry any Gorton 6s, so the only vents I have with a lower venting capacity than Gorton Cs are Ventrites 1A's and I haven't been pleased with their venting ability.

However, the other thing you guys made me think of in this is that perhaps I'm redirecting all of the steam to the first (lower) radiator on the riser with the huge vent that I tried to put on it (Wide open heat-timer) to get it to heat up faster as well. One thing I may try is at least slowing down the venting of that radiator, although unfortunately that one heats a little slower than I'd like as well, although much better than the one on the 3rd floor.

mains

Gorton 2s (1) on each main. The far radiators (cold ones) each have a Heat-Timer which vents as much (actually more) than the D. I have tried a D on them as well. I think that I need to look at venting the riser to try to get the steam there faster since it's not only the far end of the colder main, but also up to the top floor. I haven't seen any pictures of where actually I'd vent this given the fact that it's just a radiator valve coming off of the line.