Monaco20

I wouldl like to change to tall pipes, to prevent reversation.

I wonder if it is space enough under the hatch ???

( my boat is indoor for winter, no access to measure before spring)

The total height is 17-1/16, 2-1/4 inches higher then my stock merc 454 with 3 inch spacer ???

I am ready to order just need to know if I have room enough

Please give me input 😀

Winter greetings from Norway

masi242

After re-reading your post, you are keeping the silent thunder platform you should be fine. I looked at post 9 with a pic it looks like all is good. Remember the platform blocks the water from going right to your pipes and your exhaust going into the platform sits a little higher in the platform. Or are you just looking for a more free flowing exhaust.

I hope some of this makes sense

mark

Monaco20

Hi Mark

Thank you for the reply 😀

The only reason for the change to tall pipes,are to avoid any reversation. The pipes that I have now is for silent choice, which I do not have.

My ST platform has to wholes under each chamber, water flow in and out. Out when engine is running. If I have understood the ST function correct are ther constant water in the chambers until you more or less
Reach planning speed, or? Also if I have understand the critical point of water reversation is when you turn of the engine or also possible when idle? I would be more then glad if the ST Platform also have the function
To prevent potential reversation, as I under stud was a issue with the Merc 500 blue racing engine. I would be pleased to save the money 😀

What du you think Mark?

masi242

I don`t know a lot about those engines but better to be safe than sorry. I know your ss will be one of the fastest out there,I`ll be following your progress.

FormulaSS

Reversion is the process by which water enters the cylinders. Typically, this happens because the cam in the engine has a large overlap which allows the pull of "air" back to the cylinder. If your risers are too short to where the water mixes with the exhaust gasses this vacuum will pull water in. You can ask around on here to find out if the cam you have will do so. If you are using the manifolds that come on that motor you shouldnt have a problem. Reversion typically isnt caused by water coming in from the back of the boat. I am unaware that anyone has had trouble with it. Not saying it isnt possible, just, I havent heard of it. If you go with exhaust tips make sure they have internal flappers and you shouldnt have any issues at all. I hope this helps. BTW currently have my 88 242 SS under the knife. Rebuilding 454 to 496 all eagle or scat forged internals with dart heads. Currently working on transom issues.