Well after talking this over with a bunch of people, and a couple of well known engine builders in the area, I've decided to yank the manifolds back off the motors when Gusman gets back from Minnesota and have water jackets milled into the manifold flanges.

One of those deals where common sense tells me it "should" be okay just to bolt them up and go, but when did common sense ever enter the world of boating. Hell if we had any common sense we wouldn't own these resin bucket money eaters. I don't want to have spent this much time, effort, and money to take a chance, so I'm going to do it in a manner I feel comfortable with. Sucks because I'll miss the New Year's Day Fun Run and have 372 more days of listening to Cuda ride my azz.

Anyway there are some things I can do to get it finished up, but the exhaust is just going to have to wait until Gusman gets back. I know my luck and I'm not going to chance it.

Outlaw, what made you choose the Eddie Marine exhaust? I plan on using Lighning headers for my new motors. I am just curious what you know.

Russ,

I ran 454 mag 365hp with those same EMI exhausts you have. No problems at all. Not sure if I am missing something here...

You also talk about building new motors, or upping your HP, and those EMI's won't do for that - well at least the risers anyways, so you are looking at new exhaust then as well.

What's the problem / fear that you think you need water jackets milled? I could run my setup WOT for 1/2 hr, no problems.

I keep waffling back and forth on this issue and it's driving me up a wall. Jay I need some help here. Just to be sure we're on the same page, your set up was that you had water jackets in BOTH the risers and spacers but no water jackets in the flange of the manifolds, correct? That is my set up. The concerns have been (not mine, I'm not qualified which is why I'm asking so many people and questions), that if that by water not circulating through the spacer, that the water/spacer might get hot enough to burn a gasket and allow water to get into the engine. As Cuda stated, one would think that if steam was created it would follow the easiest way out, via the risers. If there were no water jackets in the spacers I can see where they would get extremely hot being "dry" and all. It would make sense to me that if there is ANY water in those jackets that they would transfer heat, steam would be created, steam would rise and exit through the riser, only to be replaced by more water. Now does that make sense to you guys? If you guys have the same situation I have, and are not having any problems with it, I don't see why I would. It's one of those situations I don't trust my own knowledge enough which again is why I'm asking. Do I WANT to take those manifolds off and mill them? Hell no. I want to bolt my boat back together and run it. If you guys are running the EXACT same situation, and are not having any problems, then I'm ready to say screw it and take the chance. I mean I am tired of having the neighborhoods largest lawn ornament. I want to enjoy my boat. Cuda told me to talk to Ray Heinke at Force 10 Marine in Clearwater this afternoon. Cuda swears by him, I know him slightly through OPBA. Ray has been building, working on hi po motors for as long as there's been motors. He advised against bolting the water jacketed risers and spacers up to an "un" jacketed manifold flange, for fear heat would burn the gasket out. I honestly don't see that much heat building up there but I DON'T KNOW THAT IT WON'T. Again, if you guys are running that type of system and not having problems, I'd say that a strong case to bolt it together. Just remember, I have the risers AND the three inch spacers above the manifold. The hose would run from the manifold up to the riser, bypassing the spacer. I can't run a hose to the spacer because the four water jackets, being milled from solid aluminum billet, are independent of each other, whereas the stock Merc risers, being cast, the water jackets connect to each other. On that thought, it would make sense that the "inside" water jacket would be the hottest.

I'm telling you this has just got me so perplexed it's not even funny anymore.

Dustin: I have basic 454 motors and don't need something as potent at the Lighting Headers, although if I go to bigger power I would certainly use them. For my current purpose, the Eddie Marine units serve the purpose just fine. Plus Too Old aka Trick Marine gave me a deal on them. I have also talked to others who ran these systems and like them. So that is the reasoning behind the Eddie Marine units.

Jay: The Eddie Marine manifolds USED to have water jackets milled in them but they discontinued that practice and went strictly the "hose" route about three years ago. Not to sound repetitive but are you sure your EMI manifolds DO NOT have water passages in them?

This is a very big decision because if I guess wrong I'm going to blow my motors up.

Thanks guys for the input. I DO appreciate it. Russ

Do you have pics of your machined 3" risers. You should run water through them. I would not mill the manifolds. You might be able to cross drill and pipe plug unwanted ports where you cannot see the plugs to run water from manifold via hose to bottom of spacer, out top of spacer to pipes. Dry spacers won't work with out melt down. As for removing the manifolds, if you decide to mill water holes, why not just drill them bolted up to the motors. If you are worried about chips just run about 10-15 PSI air in the water inlet hole with the outlet plugged and let the air PSI keep the chips out of the water jacket of the manifolds.

here is the way I am seeing it, if you didnt have the spacers, you would just be bolting it to manifold anyhow, and it would act as a block off plate. So the water in theory would end there anyhow. How much difference would the 3 inch spacers make, just another 3 inches of hole to hold water, it is going to be blocked off none the less. Secondly, could you use copper or aluminum gasket material to make the gaskets? Same as headers on a car exhaust? I know that certain things on cars dont work on marine apps, but just food for thought...Rob

THANK YOU ROB, that is exactly the way I am seeing it, I just couldn't put it in those exact words. Every set of manifolds/risers being sold for the last three years have had water jacketed risers being bolted to unjacketed manifolds. Eddie Marine reports no problems in that application. And the gaskets they sent me, according to them, are adequete for the job, something Gusman (my mechanic) agrees with.

You are the second person to suggest just drilling them in place. I've probably drilled about a gazillion holes in my life but I'm scared to death to start drilling on my new manifolds. BUT it would save some time and money not having to pay a machine shop to do it. I'll just down a bottle of "Jack" and get out the drill.

My old and current setups had the jacketed manifolds with the slots in them, so that is different than what you have. However, my mechanic just welded the slots closed in mine as I have stainless risers that only use the hose connection. Now I never will have any leaks! The reason EMI probably stopped using the slotted manifold design is that tons of people including myself were experiencing leaks (I know of 3 personally). Mine were leaking from the previously owner's poor installation, but thank god he only ran the motors for about 2 hrs and the leaks were minor.

I do not have spacers, and I will claim that I am NO EXPERT, but here's my 2 cents worth (probably all it's worth!) If the manifold is being cooled, and the riser is being cooled, I don't think that the spacer is going to get overly hot on a normal engine. When the cooling systems is working normal you can grab these parts with your hands under operation. I would use a high heat Permatex gasket sealer on the surfaces when installing -something like this
http://www.permatex.com/selector_cha...&item_no=81160
I have used this stuff before with great success. It says it holds up to 650 degrees, and if your exhaust parts are that hot you have bigger problems!!

You could always throw it together, and measure the spacer temps with an infrared heat gun. Add the additional cooling later if needed...

Again, just my thoughts. Good luck!

Russ, after more thought.................. The spacer will be bolted to the manifolds and risers, which are both cooled. By being bolted together, both sides would conduct heat off the spacer. Just food for thought.