CTA Blow By

[Jim Miller]

I am under contract to purchase a 2006 Meridian 411 with CTA 8.3 diamonds. Engines have 2400 Hours. Up until one year ago boat was owned by a charter operator who took passengers around San Diego Bay at 8 to 10 knots for 13 years. He said to me he Performed all scheduled maintenance and never “stressed” The engines. He said he probably only Ran at planning speeds about three times he could remember. During the last year the boat was owned by another gentleman who could not use it due to health reasons. It has been run seven hours in the last year, has been up to planing speed three times and otherwise been run at the dock once a month.
Gary Record from Coleman marine did an engine survey a week ago and found quote blow by above normal starboard engine and slightly above normal port engine. Otherwise the engines run fine Turn 2700 RPM starboard and 2600 RPM port at WOT boat fully loaded fuel tanks full into 12 knot headwind. Gary was on the boat when it was run at WOT .
1. I was assuming that the these engines would be good for 5 to 10,000 hours but given their current status is that realistic?
2. Gary said he has had good luck using “pro one oil additive by Bardol”to clean up carbon deposits if that’s the issue. He also said there are other additives out there to do the same thing. do you have an opinion as to whether this will work?
3. Could the blow by be The result of worn rings or valves And only be fixed by a engine rebuild at some point in the future?

Topic

[Jim Miller]

Thank you tony

Sounds like a neat trick, I will do it. I also am pulling the Aftercoolers and sending to you for service.

Regarding supplements I have always felt the same as you so that’s why I am floundering a bit.

The interesting thing about this one is some Aerospace Lab Guys tested the chemistry of the active
ingredient which is apparently commonly used in Spacecraft bearings. The results are surprising.
Here is the link:
/bobistheoilguy.com/forums/threads/bardahl-1-ingredient-what-is-it-and-what-does-it-do.22569/

The above is real news to me if true. At least some thing to think about…..

[Tony Athens]

If you really think carbon build up is an issue——————————-Do this..

Have a 1-2 Qt spray bottle– add a few drops of Dawn (any dish soap really) to each quart of plain water– Get to up high cruise power/good weather, pull the air cleaner and spray away (1 trigger pull per second until all the water is gone ……………………………………..Old trucker trick and 100% it cleans things up from a lot of low speed running.. Cleans up the air side of the turbo too.

I have zero use for any commercial additives –all “snake oil” from what I have seen..

[Jim Miller]

Thank you Francis

I had given up waiting for a reply and quit checking. Thank you. I ended up having few discussions with
My Cummings Mechanic Who is the San Diego Expert recommended by Tony in the past. My Mechanic believes this is Carbon Build up keeping the rings from seating and not excessively worn vales or rings.
He has a treatment plan for the engines involving Pro 1 and many hours at cruising speed of at least 2000
rpm. I did use this to negotiate and received a price concession and to night just signed to proceed with purchase. I am taking some risk but its something I can tolerate. thank you again,

Jimmy

[Francis Valerio]

The blow-by issue is honestly something that you will not get a definitive answer on I think. Blow-by is in many cases caused by worn rings allowing compression gases to enter the crankcase (past the rings obviously).

She could run another 2000 hrs like that or more…hard to say. I would probably use it as a negotiating tactic if you really want the boat.

The piston tops can get excessive carbon build up which can get to the rings as well and not allow them to seal also.

You did mention the boat was run at 8 to 10 knots for 13 years….how much RPM is 8 to 10 knots? If that is lugging the engines and keeping her from getting over the hump that could lead to carbon build up.

It is possible running her at her rated “cruise rpm” could burn off some carbon….possibly but who knows.

I dont have a cut and dry answer for you and I think that is why there has not been any activity on this thread. I am just giving you some thoughts…

Good luck

[Jim Miller]

more info

Should have mentioned normal white smoke at cold start. clear exhaust when warmed up. underwater exhaust system. Blow by not like a pump. no black exhaust.

[Author]

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