Don't skip a year - TEST THOSE HEADERS
 

I had never tested because they were only a couple years old when I bought the boat with almost no time. Thought about skipping this year as well, but it was a rainy day so I spent a few minutes pressure testing. Starboard header on Port motor leaking.

Only reason I thought about skipping was because they are Big Tube headers with very little run time, this one is leaking at the Top, not down at the bottom where it bolts to the head. Strange.

A good reminder for sure.

I added 1/4 turn 316 stainless valves at the end of the water distribution tubes on all 4 of my headers, so that after flushing and cooling down to ambient temp, I can drain the headers, at least avoiding filling a cylinder while sitting.

Would a good internal ceramic coating as a heat barrier help guard against cracking? To me, keeping the heat away from the stainless would be a good thing. Anyone here tried this?

Are they on a stag motor setup?

I install -4 drains on all tube headers for just this reason. They tie together and dump out of a common thru-hull fitting (one per motor). The amount of water dumping off is not enough to negatively impact water pressure, but it's piece of mind for me knowing that if a header does develop an internal crack, it's not going to fill a cylinder with water.

Mine are on a side by side setup.

Skater, can you post a picture of your drains..?

Haven’t tested my CMIs since they went back in the boat. I’m afraid to say how old they are - not leaking.

But….

I also installed ball-valve drains at the junction from the heat exchanger to the distribution tube. After she cools down, she gets drained.

Interesting… when running, the valves can be open but will not drop water until they shut down. Have throught about converting to drains out of the transom using a similar setup to Skater’s.

When you say top do you mean at the collector?

As for drains I were going to put small 12V SS valves in wired to a switch so I could just drain, but it took 20 years for my E-tops to leak.

Skater, are you saying you dump a little water even when running?

Just get a nice set of stainless marine manifolds and never have headeraches again.

For me that would me no plug changes, PITA for a lot of other work. I am good with 20 years out of exhaust.

How come no plug changes?
Super easy and accessible on my manifolds, no header tubes in the way to get at spark plugs.
Installation takes 1/4 of the time , no header botls against tubes to fight with and more room in the bilge


https://cimg9.ibsrv.net/gimg/www.off...c9307ed7f3.jpg

Guys,

Is this a saltwater thing?

I do find the idea of a single dump valve (per side, if need be) on a solenoid that would allow for everything to drain at the flip of a momentary switch.

Thanks. Brad.
(937)545-8991

Just for what it's worth-
ALL headers are susceptible to cracking/rotting/leaking.
We replaced a set of 5in Stainless Manifolds and elbows on a really well maintained raceboat last year. They just rotted out. It happens to all of them eventually.
Flex flange helps a lot on CMI stuff. IMO that was some of the problem with the Merc sweepers. The GenX Sweepers with a flex flange don't have anywhere near the same amount of issues. We test the headers on just about every engine that comes through the shop. The only set I think I've never seen leak are CMI E-Tops. If maintained they really seem bulletproof.
We also have a 30 year old set of full stellings on the bench right now which miraculously don't leak...so it's all a crap shoot lol.

Saris,

Yes the E-tops seem to last (20 years for me) and flex I agree hurt the long tubes, why I asked if it is a stag setup. Seems Very few have a brace, think of all the SS hanging there AND I see guys stand on the tubes! But for a stag setup if I had one and it needs replaced, the old Kieth black cast manifolds that are pretty much long tube headers sure seem to be the way to go.

Dead people,

Look at a Fountain that has manifolds, the dam things touch each other in the center, I am a 58 year old fat guy with a 32, no way I can get my arms between the two motors. I would have to call the Good Doc feelgood every time. :drink:

...And I'm only slightly less fat and less old.

I just can’t figure out why people are still buying headers,if you have to test them every year. Buy Stainless Marine and you don’t have to worry about pressure testing exhaust every year,I have better thing’s to do with my time.

I don't disagree, but jeez are they pretty.

I think it's worth it to me to spend an hour or two on a rainy winter day to get to look at them all summer. My perspective will probably change as I get older

For me, I wasn’t willing to give up 25-30 hp per side.

This was done years ago on a HP 500 motor, I would assume as you go up in HP on a NA motor the more pronounced change there would be. The Eickerts I would think should be the closest to long tube headers.

How do you upload a .pdf?

I don't think you can. I'd do a screenshot of it and upload it in jpeg format.

When my engine was pulled last year, there was some rust in one of the cylinders. It was honed, new rings, etc. What I don't know is if the headers were ever checked or if it was just assummed the water was due to reversion. Now you guys have me all worried.

I replaced the CMI's with SM on a single 525efi and didn't notice any difference.

I didn`t notice any difference either.
Actually thought I picked up some power .

This what you're thinking of?

https://cimg5.ibsrv.net/gimg/www.off...0d86480272.png

Yes I have that file, I could see if I can convert it to a jpeg.

On the 525's too SM I do not have the dyne curve but have seen it, ran back to back on the same dyno. You may not have felt it on the boat but the curve showed it as a great way to make a HP500.

Most of the loss was above 4600 rpm.

I would love to see a test like the one posted above but with a 540 that starts around 600HP or so. The best would be run it like some guys do, no water pump, no flame arrestor, no sea water pump, no alternator, no power steering pump with dyno headers.

Add all the acc run again.

Then start putting different marine headers/ manifolds on.

The other thing I always see is "its got a SC doesn't matter". Still takes power to turn those and if there are restrictions, going to take more.

How much does it matter on a heavy a$$ pleasure boat,,,,,, well until we see the dyno no way of knowing.

Lets see if this works, surprising results.
https://cimg2.ibsrv.net/gimg/www.off...b825e1a1d3.jpg

I think you just gave me glaucoma.

LOL, I could save each page, higher res. But I do have a day job!

I forgot there were 5 pages to that file. Went back and looked at the PDF.
Tried to attach the PDF.
I get an "issue processing the data" alert. Won't attach.

Any pictures of a drain plug on a header?

https://cimg6.ibsrv.net/gimg/www.off...efdd355565.png
The 520 and 525 are similar. The 520 manifolds are the same as the 496 manifolds, and similar in size and shape to a stainless marine gen 2. If a 520 can gain 48hp in the upper rpm a 525 can lose at least 20-30

That is close to what I seen, the long tubes start breathing better as rpm goes up. Its funny everyone is always talking about the best intakes but then when it comes to getting all that out slap whatever on. What goes in has to come out.

Many years with small motorcycle motors and exhaust was everything.

Thanks for the info. :thumbs

I would love to see how it was set up on the dyno.

Me too, I was ready to buy all new stainless marine or Hardin exhaust at half the price. When I found this sheet I sucked it up and bought new cmi headers. My boat runs 91-92 most days, not willing to drop onto the 80’s over 5-10k. Most on here would spend that to gain 3-5 mph. Why save it to give it up.

Sorry this took a while, the Skater is all covered up for Winter, but here's a pic of the drain system we installed on the 500EFI that's going in my Party Cat right now. The line off the bottom of the T attaches to a single thru-hull fitting mounted in the transom, below the height of the header drains.
https://cimg6.ibsrv.net/gimg/www.off...ec0bb42621.jpg
https://cimg7.ibsrv.net/gimg/www.off...67401d1a77.jpg
https://cimg0.ibsrv.net/gimg/www.off...139a4dcccf.jpg

Yes, they're constantly dumping water from both headers out of a single -4 line. I didn't notice any drop in water pressure on the 700s in my Skater when we installed them. It's such a small volume of water relative to the large volume being supplied by the pump that it wasn't noticeable on the gauges. As others that have posted mentioned, it's easy to put a ball-valve in the line going to the thru-hull fitting if you do see a drop in pressure.

Can someone explain me how do you pressure test them when they are on the Engines please?

I’ve done it with compressed air, regulator with air line fitting, then a header to tail pipe jumper cut in half on other end of regulator. Attach that to either the water in at the rail or out at the collector. Cap which ever one you don’t use. A rubber barstool foot with a hose clamp works fine as a cap. Apply air and watch the regulator and listen.

That’ll get you lost of the way there but it’s also recommended that you test with a heat source. You’ll have to pull the headers to do that, but then you’ll know for sure.

I have a large tank that I dump my etops into. They’re connected to air and a gauge. I use the rubber distribution tube and a rubber cap on the jumper. Pressurized to 35-40 lbs and in they go. I watch for bubbles and a drop in pressure. Once that test is good, I pull them and then apply heat via a propane torch to the flange welds where the pipes come into the collector.

The headers are twenty-two years old and no leaks so far. When the engines went back in this time, I added ball valves to drain them into the bilge. I sleep much easier now.

35-40 PSI? what pressure do you have when running. I like the heat idea. I tested mine off but with water, we have 35 lbs here so I used that but didn't go to 35, I think I stopped at 20-25.