My Header dilema continues
 

I am really struggling with the fact of buying these used headers (cmi big tubes)for my new motors, they come off of the boat I have bought and supposedly only have approx 150 hours of use. He will let me take them and have them checked and if I'm not happy will refund me my money, It will probably be the difference in boating this year or not. I am already on a tight budget for this project. What do you guys think? I'll post some pixs if I figure how to.

What's the delima? The cost of the headers or testing them? You can test them yourself and save a little money. Pretty simple process with a water hose ,35-50 psi of water, there should not be more than that in them with the engine running full out. Hook the water hose to the pipe on the bottom (water hose fits inside the 1 inch hose, attach with hose clamp) plug off other ends of bottom pipe then put a short piece of hose on the top of the header (were the u shaped hose dumps into the tail pipes) and installed a 3/4 water spicket in the end of the hose then stand the header upright opened the upper spicket, turned on the water and let it run until all the air is pushed out the top spicket, then shut the top spicket and let it build pressure then checked inside for leaks. Let it sit with pressure for 1/2 hr or so.

Pressure checking it is the easy part, I guess the part that gets me is the fear of everybody I talk to saying steer clear of used headers, then there are some who would have no issue with used headers as long as they pressure checked them. Is there a life expectancy on these things, these particular headers have been sitting for 10-12 years, they are the big tube with the two piece flange. Would you feel comfortable with them after you tested them? He wants 3k for both sets and tailpipes.

I look at it like this if they don't leak they are good. I check mine every year. I have had newer headers spring a leak too. If you don't feel comfy with headers go with some manifolds thay have less problems than headers but less bling.

Trying to post a pix

I gotta agree with you. I really like these a. Because the price is right and b. They already fit the boat. Price includes tailpipes and everything.They could test good today and go bad tomorrow, so could new ones. New stainless marines will cost me about 6200. These would be half of that and I could still get the bling.

Those are CMI Split Tubes. Do the tails come with them???? If not, then you will have a hard time finding some tails.

They come with everything, they were on the boat I bought. He's just selling them seperately.

You are thinking too much..buy them..test them, install them, run them! problem solved!

Bajapred, you hit the nail on the head. I am seriously an overthinker/worry wart when it comes to this type of thing. The motors are a big investment, just wanna not regret it later.

Those early style two piece CMI headers had a reputation for being strong and leak free from what I have been told. Innovation used quite a few of those sets on the high speed special forces craft they built for the Navy on those big 632 cubic inch mills they produced. a I know they were beat on pretty badly in actual military use and I don't believe the military had a real problem with leaks in them. I think their shape and strong tube routing made them stronger than current tubular headers.
( Maybe less prone to vibration damage)
However that being said, testing before using is a smart way to go and I prefer to use compressed air and submerge the header underwater to find cracks and leaks. Seems to be a better way to find any possible weaknesses and leaks than using water.
Just my two cents.

Best Regards,
Ray @ Raylar

So if you tested them with compressed air and they passed you would feel comfortable using them on new motors? They've been sitting for 10-12 years and have approx. 150 hrs give or take a few the guy says. This guy keeps his stuff in tip top shape. He had 680 hp motors. He pretty much told me what you just said minus the military part. The engine builder was concerned with them being discontinued , if they were such a good design, he stated that there are many more welds to crack on those compard to the new style. but they seem to be built extremely well. He also uses compressed air to test his header in a tank opposed to the garden hose method.

If those headers were stored dry and they test good I would have no problem using them as long as you properly apply them to your boat with good tails and such and remember to flush after salt use and drain and store them dry and empty during winter layup. I would recommend testing them for leakage every two years or so depending on usage hours and boating conditions.
As for discontinued I don't see how that even matters as if in the future you need to replace the system you would probably opt to replace all and start fresh.

Best Regards,
Ray @ Raylar