1999 6BTA blow by

Thomas,

Pulling off #6 valve cover on an in-line drive with a 6BT /BTA 5.9 is the absolute worst place to vent this engine.. #1 is OK but the timing cover is superior except in V-drive applications..

You could move that cover back to #1 and put this at #6:

If you keep up with Tony and it sounds like now,  Victor, since he has been through this with the same model,  you will get some help.

I also strongly suggest that you look through Tony’s Tips on this site and read all of his exhaust articles and you will begin to understand what he, and Victor,  are  getting at.

And reread my post about how to figure out how much height above the outside water level your turbo has.

It is important.

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Tony Athens

Why go to 4 blade props?
Unless there’s a specific reason to run them, I’d stick with the 3 blades, modify existing props to get sorted out before purchasing new ones.
Regarding the exhaust geometry, you’ve got to let go of the notion that anything that comes out of the factory is perfect!
You most definitely need some dry risers to protect your motors from ingesting raw water.

Thomas,

There’s no doubt your waterline is higher than you think, the engine rebuilds at very low hours, seized turbo’s are telling the story, it looks like you have room the fix the problem – post pics of the entire E/R .

If in doubt, to get an accurate measurement of your waterline you could close the seacock, remove the hose, attach a short length of hose to the seacock and hold it above he exhaust hose on your engine and mark where the waterline is, be careful, when you open the valve there will be a lot of water, only open it a little bit.

You would be mistaken to presume that because Tiara put the boat together they got the exhaust system correct.

With the envirovent it cant work properly if not plumbed correctly, have a close look at the hoses and see if there is any dips in the hose that can fill with oil and block the suction, post some pics of that install.

Thomas, not sure where/what you measured as related to this comment: “Wet exhaust water entry hose is more than 12″ above waterline”

The requirement is that highest point of the exhaust system is dry and at least 12 in above the loaded waterline.

No way that engine room with OEM wet elbows meets that spec. Looks like Victor has been there..

*******Engine room blower barely keeps up with smoke at low speed ops. Once turbos kick in it iOS OK.***********
Not clear what you mean. Is there smoke inside the boat, the engine compartment??

FOr checking the exhaust system in comparison to the water level a clear vinyl tube can be used.
Adapt it to a nearby seacock. Install a small ball valve on the other end. THe valve can be quite small as can the hose, maybe 1/2″ OD.
Take the B.V. hose end with you as you check the heights of various components.
When you want to check something hold the hose end somewhat above the part you want to check and then open the ball valve.
THe water will rise untill it reaches the same level as the seawater outside.
Take your measurement which will be from the seawater level outside.
Then once these points are measured you can measure the points for distance around the E.R., clearances distances from one part to another and so on.

This is not my idea. I just though it very good.

Look at this picture –Do you think your engine installation qualfies?

There is a reason for that 12″ spill over heigth and you are experiencing exactly why.. I’d bet you are less tha 6″..