Baffled by apparent reversion issues with Lightning headers and mild cam
#91
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From: chicago
#92
SM was just an example of a manifold vs. header. Not a fan of headers unless you are leaving a ton of HP on the table by not running them. In this build I'd run manifolds vs. headers. Funny sight at the LOTO Harbor Hop back in May. At Larry's I saw a 46 Cig with 1075's and SM manifolds. Must have gotten tired of the CMI blues!
#93
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From: chicago
I agree, headers can be leaky. My stellings 18 years old and they needed a leak fixed last year. Cost me about 75 bucks having my local welder fix it. A friend of mine has stainless marine manifolds and the risers needed repairs as they were leaking badly at the welds. I have a few buddies running the lightning headers for years in fresh water with no leaks . I wouldn't be afraid to run a set .
#94
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From: chicago
Besides the cmi crap mercury specd, I think a lot of header issues are caused by improper tailpipe support, esp on staggered boats that run in rough waters. You just can't put all that stress on the collector. Stainless doesn't like being flexed repeatedly from all the twisting and vibrating.
With that being said my next exhaust will prob be stainless marine GEN I I I with 5" tails .
With that being said my next exhaust will prob be stainless marine GEN I I I with 5" tails .
#96
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I really like the Eickerts, and if I had room I would be looking for a set. It would probably require extensive transom surgery to run anything with a fixed tailpipe, unless I had a set of custom tails made for it.
#97
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I'd ditch the silent choice diverters and get the right collector setup going on them.
If money is a concern along with noise , you can temporarily make some home made turn downs for the exhaust at the back of the boat. I think your pissingg right into the wind with that exhaust setup you have there. It's not the cam.
If money is a concern along with noise , you can temporarily make some home made turn downs for the exhaust at the back of the boat. I think your pissingg right into the wind with that exhaust setup you have there. It's not the cam.
#98
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Plan right now is to run it one more time with the standard collectors sealed up with silicon like Lightning advised, and keep the idle at or above 900 to be safe. I'll be interested to see if that is where it was pulling water. This winter I might explore some changes to the way the water is fed into those collectors.
Appreciate all the help, and the razzing too.
Hell, at least I'm not one of those guys who throws a "3/4 race cam" in there and tries to run stock Merc exhaust, and then comes on here bashing everyone. Have fun everyone, and thanks for the suggestions. I'll try not to start any more threads on here.
Appreciate all the help, and the razzing too.
Hell, at least I'm not one of those guys who throws a "3/4 race cam" in there and tries to run stock Merc exhaust, and then comes on here bashing everyone. Have fun everyone, and thanks for the suggestions. I'll try not to start any more threads on here.
#99
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back from the dead........this is basically what I had to say in my 2 paragraph delete. Dump water into pipes just before transom and add mufflers switchable or not to the outside of transom= no more concerns except for future leaks with the headers......but thats a 300 page thread by itself.
And thanks for the advice.
#100
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From: Tampa, FL
Please run it!!! My combo is similar to yours except that I am running about 10.2-1 compression and I am running silent choice with no issues..... Keep in mind that when the engine is installed, the hoses that connect to the Y pipe will be used and they exit straight down in front of the diverter valves...... I bet half the water goes down there and the other half goes out the back. That has to help prevent reversion by allowing gravity to help pull that water down........As I said before, on the stand with cold hose water, your engine never got up to temp and a cold engine will create condensation bad in high humidity. I also had aluminum heads with no heat crossover and an air gap inake as well and I could keep my hand on the heads after it had run for an hour.... The intake was cool to the touch and it was sweating like crazy so keep that in mind. I bet you will have no problem as long as you get your engine up to normal operating temps.....



