Header drain???
 

As I'm learning more & more about my "new to me" Prowler, & the in's & out's with it...It brings me to a question I have about the headers on the 525SC (I'm assuming they are CMI's)...
I've read & heard about the "issues" with the late model header systems on the 525EFI, & I do realize they are different headers, & it seems that there is advice about draing the headers after each use. So, I started looking at my headers. I do in-fact, have a tube running along the bottom & there is a plug at the end of it. Is this where folks are installing petcocks for draining?
Second part of the question....
I've also heard of folks installing dump fittings in the transom & connecting them to the headers for this purpose. With that set-up, do the headers drain constantly, or is there a petcock that controls this?
Thanks for the input...Again, just trying to learn bout my "new to me" boat...:D

525SC headers are standard CMI E tops. The don't have the issues of 525EFI headers and half the price. Treat them as any other HP exhaust.
If you're in salt water, flush the engine VERY well. The intake is aluminum and salt will eat away around the water passages. My 525SC was in salt for about 200hrs before I got it and when I pulled it apart at 350hrs, the intake needed to be welded up. It was close to major failure.

Any more info on this drain through transom job

Natural gas petcocks on the water feeder tube is cheap insurance. .if the header leaks it goes in the cylinder. .drained no problem. ..just educated opinion on the matter. .it's not If they are going to fail..just when...

I have them on my boat and they have worked flawlessly for many years. When the engines are running there is enough pressure that the water doesn't go down the drains but as soon as you shut down, it just trickles all the trapped water right out so there is a huge reduction in the chance of reversion or leaks into the motors.

You can see them just above the waterline by the tabs.

My CMI's (525efi) had the blue thumb screws at the end of the rails. I just unscrewed and left them out after I flushed. I have Stainless marine now and just disconnect the hoses at the bottom of the manifolds when the boat is not in use.

I have ball valves at the end of the distribution rails of each of my headers. When I'm done flushing and the headers are cool, I open the valves and let all of the water out. CMI recommends against a full time open drain system as the risk is there that it may bleed off cooling water. I'm not disputing Tom A's success with his system; just reiterating what I was told from CMI. I do think though that the lack of bleed on Tom's system is due to the fittings he's used... might be helpful to see a picture of your setup Tom from the inside...

I found a pic that shows the drain tube set up (ignore the dirty bilge!).
I am not sure of the size fittings as Ron Potter set it all up, but it is reduced to something smaller than the factory outlet.

I was skeptical about it at first but trusting Ron and after seeing it not bleed a drop (even on a hose), I was convinced.
Once the engines are shut off, it takes a a minute or two before anything starts dripping out of them but it definitely works.

Here is a link to an idling video but you can't really see the drains.
https://www.youtube.com/watch?v=fQmNI20NSCU

Anyone know of any electrically operated valves? I have drains on mine but it's a pain crawling around the engines to reach them.

Id rather have all my parts under water then let oxygen at em to start the rust process.

Mine all have solenoid valves on them. Hit the switch and they drain. I'll be in the boat this weekend, I'll try to remember to get a pic with a part number.

That would be great.

Any info or pics of your setup would be great. That's the way I'm going to go.

That is the way to do it.. I started doing that the same way years ago. any stainless header system should have drains ..

Sorry guys, I didn't get pics this weekend like I hoped. I never made it to the boat. I haven't forgot about it, but I'm traveling for business the next 7 days. I will be winterizing when I get back, and will get all the info posted when I get back.

Ok thanks. Try to get a part # or manufacturer. Lots of solenoid valves available online, but tough to telll how well they'd fit without putting hands on them.

Finally made it out to the boat...

One of these on each engine. [ATTACH=CONFIG]547689[/ATTACH]

Thanks for the info

I know its an old thread but I am in process of figuring out how I want to set up a drain system for my cmi headers. I have made some fittings with a 3/16" hole to fit where the blue drain plugs are, rather than putting a fitting through the transom, how about draining into one of the unused the sea strainer ports? When boat is under way additional water could go up through the fitting rather than loose water through the open line at transom? When the motors are off and no pressure in the strainer the headers would drain into the strainer? Thoughts????

I never really saw a good reason to drain headers…are you really going to go into your bilge everytime you shutdown the engine and drain the headers? If the answer is no, then you are wasting your time. In the event of a leak; even if you prevent a hydro lock situation; small amounts of water will be making its way into the engine every time you shut down.

salt water will make quick work of your valves, pistons, and cylinder walls. What’s the point?

anyways I know I didn’t help…but you may be wasting your time.

good luck.

my plan is to have the headers drain after every use either from me doing it manually or preferably have it done automatic every time i shut down. That is what the line does if it is going out the transom as is being done by some on this thread.

Drain
 

drain

D
 

Like t hat ,always wondered about header being hot and no water in it ,your way would drain header slowly