When should Turbos kick in?

[Bill Karmis]

HI All,

I have been a boater a long time but new to diesels.
I recently purchased a 2000 3100 Tiara Open with 6BTA59 Cummins engines with 950 hours . Before hauling from Florida to Wisconsin I had a diesel mechanic friend of mine go through the boat and we did the following:

New Turbos
All new Hoses
New Injectors
Changed all fluids and filters

On a side note my Tachometers work sporadically so please excuse the lack of info on that side.

Currently after warming up I begin to accelerate the engines come up to about 1500 RPM and seem to hang for up to 20 -30 seconds until the turbos kick in. Once they are kicking in everything seems to be fine.
My guy thinks I might have old fuel.
Is this possible? Also I am less than 1/2 full (70 gallons a side) Is it better to burn some of this and then refresh? Or just add now?

Any insights would be appreciated.

Topic

[Rob Schepis]

When coming out of the harbor bring her up to 1,000, 1,200, etc for some light load and get the temps to settle in for a bit at thermostat opening temperature before pushing the throttles forward..

Salt air/mist in engine room = air side of turbo damage

Poor exhaust design = exhaust outlet side turbo damage

There’s more to it but that covers the lion’s share….

1 user thanked author for this post.

Bill Desmarais

[Bill Karmis]

Things are better

After running my old fuel from the previous owner down to under a quarter on each side I added 50 Gallons a side of fresh diesel and the lag I thought I was feeling is pretty much gone .As our season is getting short I do not want to fill just yet, My plan is to run this fuel add a bit more and put away. My thought is that is there is any grime in the tank I am trying to flush now. ( currently no sign of this) I will change filters in

Also I think my lack of experience was a huge factor. I have come to observe that the lag goes away after the engines reach at least 150 degrees. In my first test runs I am sure I rushed this and due to the cold Lake Michigan water they take a few minutes to come up to temp.
I will post Speeds and RPM etc… after my tachs come back from rebuild I have tracked that issue the guages themselves.

[Bill Karmis]

Salt Damage to turbos

Hi Tony,

After questioning the previous owner and my mechanic the salt water damage on the turbos was due to leaky drip-less prop shaft seals that sprayed salt water all over the engine bay. The boat was kept in a rack and the previous owner would only use the boat occasionally Like once a quarter and just didn’t pay attention.
So the turbos got salted and dried probably more than several times.
I stil wil get the pics of my exhaust just have not had the time.

[Rob Schepis]

Good to hear she’s in freshwater. In the 6BTA powered 35 Open Tiara did a very nice exhaust install with high and dry risers. In the 31 Open they simply used the OEM wet elbows which leaves a lot of room for improvement…. Remember – builders create many issues, they don’t solve them, that’s why we are all here trying to make things right.

[Bill Karmis]

Will Do

I am on the road until the weekend but will post when I return.
Currently boat is in fresh water but I understand what you are saying.

Just curious wouldn’t Tiara have addressed this issue if it were common?

Sincerley

Bill

[Rob Schepis]

Understood but what has been done to prevent salt water damage from happening again. Sounds like you need new risers to protect your turbos as the current configuration is obviously not safe. Turbos do not see salt water unless you have a poorly designed wet exhaust. . It makes sense that the port was damaged since the port riser and configuration is normally flat because it has to cross over the gear and run sideways. Post some good pictures of your engine room including the turbos and exhaust By rebuilding or replacing the turbos you have addressed the damage but not the cause So you are still traveling down that doomed road…..

[Bill Karmis]

End Play

Hi Tony
When I made the decision to change all the hoses we found we needed a new exhaust elbow as well.
The Starboard Turbo seemed fine the the port looked to have some saltwater damage and end play
I elected to have them both rebuilt as I was in Florida and it is easier to accomplish and less expensive than in Wisconsin where I live. The competition and long season in Florida makes for more competitive pricing as opposed to my 3 month season and diesel mechanics that are few and far between.

[Bill Karmis]

Thanks

Thank you Ill give it a shot

[Tony Athens]

Exactly why would you need new turbo at 950 engines hours?

Talk about a major RED flag..

Please tell me why? Trust me that is long term important..

Tony

1 user thanked author for this post.

Bill Desmarais

[Rob Schepis]

Front of engine on crank balancer. Here’s two pics, one with belt guard on shooting through a hole, other with belt guard off. Based on your vintage your belt guards should be the same unless they were already removed due to it being tight up front.

[Bill Karmis]

Thank you

I bought a photo tach from Harbor Freight.
Where do you attach the tape?
Based on my engine compartment this might be tough to accomplish.

[Rob Schepis]

Boost comes on in linear fashion, not instantaneous. At that rpm and with that hull type this sounds more like she’s struggling to get over the hump and on plane. Could be normal or could be an over propping issue. You need to post your fully loaded WOT rpms with ACCURATE rpms via a photo-tach.

[Author]

Replies