If they are constantly complaining about their lack of money, you could offer to help them come up with a budget and make suggestions for some of the books/blogs discussed on the forum, but don't offer help/advice unless they ask.
They do tend to whine to everyone. There seems to be a ripple effect because others are discussing the latest crisis.
I take some of the advice I'm giving you from the mouth of CaptainAwkward (another blog). Be direct, polite, and specific the next time this comes up in conversation with them, and follow the 2-attempt rule.
Broke Friends (BF): Oh, it's so hard living a life with 5 cars and a beautiful house and expensive luxury phones on 1 salary, whine whine, *hint hint give us money*
You: Friend(s), I want to be really honest with you. It seems you have been dealing with these financial problems for several years. While you have described these problems, it seems to me the root is that you buy expensive things that are beyond the means of the salary you are supporting your family with. You don't have to listen to my advice, but I am going to write down the [name of Dave Ramsays book]/[link for MMM]/[Your Money or Your Life]/[I Heart Budgets]/whatever. I really encourage you to read this. These people are smarter about money than I am, and instead of seeking advice from me, I encourage you to go learn from their wisdom.
BF: Oooh, but you are SO FRUGAL (aka we think you live like a dirty hermit) We could NEVER CHANGE, it would be SO HARD.
You: (hand them the paper) Well, this advice really helped me and spouse make a plan for our family. I hope maybe it could help you too ->(Subject change) So how are the kids doing in school?
Then, in all future conversations, if they bring it up use the 2-attempt rule. Try to change the conversation away from complaining about finances 2 times, and if they ignore your attempts, leave the conversation. This means that if they complain to you about finances again, you can say:
You: Did you get a chance to read that thing I recommended?
Them: (Any answer but Yes, I totally read it word for word)
You: That's too bad. ->change of subject. (This is attempt 1 to change convo away from complaints about money)
Them: Still complaining about how they're about to lose a truck/can't afford groceries/can't afford heat/etc.
You: Wow/Hmm./There you have it. -> Change of subject. (Attempt 2).
Them: More whining.
You: (Leave the conversation) Could be as simple as, "I have to go" -> hang up the phone. Could be "There's my spouse, he had a great story about BBQing/DIY home improvement/whatev he wanted to tell you" and a switch spots. Could be more direct, "I have given you all the advice I have on that topic, so if that's all you want to talk about, I think I'll go home for today/Maybe you should head home for the night. See you next time!"
They probably won't respond well to this tactic. Most people who are like this (borrow money from friends, never pay it back, complain to everyone they know, etc.) will respond really poorly to you sticking to a boundary about talking about finances. But you can have a friendship with them that minimizes this type of complaining - IF you choose your boundary and stick to it. You know better than I do the types of situations they are fun friends to spend time with - cultivate those situations, and limit the financial conversations.