Another 4bt overheating issue

[Shannon Ritzert]

I just took my boat out for a test run after upgrading the cooling system.  I’m having overheating issues, and looking for suggestions.  I installed: larger expansion tanks, new heat exchangers, new impellers, all new hoses. in the lower elbow that attaches to to the water tube, that attaches to the expansion tank, I installed a 3/4 elbow that goes to the expansion tank, and a 1” elbow with a 1” hose that goes to the rear of the block at the casting/freeze plug.  Much like Francis did on his post.  This 1” hose runs under the engine to the next fitting in the back of the block. a couple of years ago, I installed the SBMAR 165 T-stats, and rebuilt the raw water pumps.  I have great raw water flow.  I’m wondering if the hose running under the engine is an issue, if the expansion tank is to high above the engine, or maybe the expansion tank caps are too hight psi?  These are rated at 15psi.   any suggestions are appreciated, Im on the coast for the rest of the day, and tomorrow morning, I’d love to solve it, plus I can answer any questions easily.  I will include pictures, though they may not be attached to this first post, for some reason I have issues getting pictures uploaded.  

Topic

[Francis Valerio]

I am propped at 17X16 with a slight cup.  I hit 3000RPM  “EASILY”

I played around for a few seasons and 17X17 was close but they were originally 18X18  but would not give me what I needed.  Going with new props for me was the way to go

[Tony Athens]

An accurate 3100 or a tad over,  vessel  Loaded for bear, is  the target number for this engine.

 

 

[Shannon Ritzert]

Awesome, thank you Tony.  I was worried that maybe I had something messed up again.  <br /><br />

The tachs were accurate when I tested them 2-3 years ago.  I strobed them.  I will check them again just to be certain.

 I purchased the boat with 18×18 props installed.  I purchased a set of 16×16’s that I felt were underproped.  I had the 18×18’s cut and pitched to 17×17’s.  I will get the props worked out.

 

thanks a bunch!!

[Tony Athens]

Cruising at 175F is a great temp.. However, IMO  you are close 200RPM Over propped if your tach is accurate

[Shannon Ritzert]

Test run today

I got my hoses re-routed and went out for another test run today

I have a 3/4 inch hose from the lower cast elbow and routed that to the exhaust manifold plate, like it was original from the factory.

 I purchased the 1” banjos from SBMAR, and used 1” hose from the turbo banjo, to the rear of the block.

 I put a temp sender in the head where the original return was from the turbo.

I am a consistent 175 degrees  on both engines.  Speed or load does not effect temp.  I do have the 165 high flow t-stats from SBMAR.  Should I be concerned with the 175 degrees, or is that more than likely the temperature where the sender is located?

WOT:  175 degrees   

              2875 rpm

              Egt 950 degrees

              Boost 9 psi

               Speed 23 mph.<br />               

[Francis Valerio]

Yes, that is the Banjo.

17X17 will prob be OK.  Even tho we have same boat the weight could be different.  Those props should be real close but you wont know till you run it.

I would think you will be 2400-2500RPM range and should be doing +/- 20-21mph (17 to 18 knots)

 

You can cruise ALL DAY long at that RPM

[Shannon Ritzert]

That’s my goal is to be able to run closer to WOT to get on plane. I run about 50 to 60 miles out which is about a 3 to 3 1/2 hour run.

I played with prop sizes last year, and ended up with 17×17 props. I purchased this boat with 18×18’s

I am stoked to get her running!

I appreciate yalls help. If you ever land in POC Texas, shoot me a message, I’ll take you fishing

1 user thanked author for this post.

Francis Valerio

[Shannon Ritzert]

Is this the proper banjo bolt for my application?

Complete Holset Turbo Banjo Fitting Replacement Kit with 2 x Copper Annealed Washers & Includes Bolt

[Francis Valerio]

YES that should work.  I have had success so far with this setup.  Maybe a few hundred hours.  I always run the boat WOT on the way in for about a minute or two and the temp never really moves.

The cooling system in the early days on this and the 210hp were minimal at best and the upgrades help

[Shannon Ritzert]

Francis,

I understand that part, thats the mistake I made. I’m going to order a 1″ banjo kit from sbmar.

What I am trying to figure out, is from the lower elbow to the exhaust manifold plate. Did you keep that 1/2″ pipe to 3/4″ nipple for 3/4″ hose, or did you route that differently? Am I making sense?

[Francis Valerio]

The rear “plate” that mounts in the freeze out plug hole is plumbed with a 1″ nipple that I drilled and tapped a 3/4″ threaded hole.

 

The hose is 1″ and goes to the rear of the Turbo. 

 

This allows maximum flow of coolant to circulate at the rear of the system.  I installed my coolant Alarm in the side rear threaded hole that I eliminated from the system as that is a perfect location to monitor heat

[Shannon Ritzert]

Francis, did you keep the hose from the elbow to the exhaust manifold plate 3/4” or did you change that to 1”?

 

thank ya sir!

[Francis Valerio]

That 1″ line goes from the back of the Turbo to the Back of the Block.

The hose that goes to the back of the Head (on the side and NOT the REAR) gets eliminated in my case.  I installed a coolant ALARM in the threaded hole.

 

Look at my thread again,  I am running out now and will check later to see if I have better pics.  I will try and reply this evening

 

FV

[Shannon Ritzert]

Tony
I totally pulled a stupid move on that one. I was going off of another post in here that was started by Francis Velerio. He has the same boat, and engines that I have. I went back this morning and re-read that whole thread, and realized when he put that plate on the back of his block, that he ran that hose to his turbo banjo, and not the way that I ran it.

I have seen where it is mentioned here to upgrade the turbo banjo for 1″. I had asked the question before if I should follow the same procedure for the 4bt, but I never got a reply back on that question.

Just to clarify:

Should I replace the 1″ on the aluminum elbow back to 3/4″ and run that back to the exhaust manifold plate the way it was originally? I do not there is enough meat in the exhaust manifold plate to enlarge that to a 1″ hose. I am assuming that 3/4″ hose is acceptable for this application.

Is there any advantage to using the 1″ banjo at the back of the turbo on a 4bt? Should I just use the 3/4″ the way that it was originally?

[Tony Athens]

Not sure how you came up with that, BUT the plumbing is 100% wrong.. Certainly nothing from us. Remove the hose and plug the back of the block. You are bypassing way too much  coolant flow that needs to go thru the turbo and the exhaust manifold BEFORE it returning to the inlet of the coolant pump thru that cast aluminum elbow under the alternator.  100% of the coolant from the engine must go thru the turbo in this case FIRST. The feed to the turbo and manifold comes from  rear left side of the block &  needs to be  3/4″ hose  being sure that the threaded port in the head is open and not clogged with rust or crud.  1″ hose would be ok there too and better for 6 cyl engines. The turbo banjo  needs to match the hose size…. This is shown on this web site.  

Or you could, maybe use the your custom rear block hose and go direct to the rear of the turbo and plug or  eliminate the side block hose 

1 user thanked author for this post.

Francis Valerio

[Shannon Ritzert]

Yessir, that is one hose.

[Tony Athens]

At this time, I ‘ll let you deal with your electrical issues.. What is important is your overheating issues.. Look at the attached picture.. Do these two hoses connect to each other–I.E .is this ONE HOSE?    

[Shannon Ritzert]

Maybe this is important to know.

I wanted to check a few things before I left the coast to head home.  Home is 6 hours away from the boat.

 

my redundant alarm did not sound yesterday, which I didn’t think anything about, because I rewired a few things on it.  I just assumed that I did something wrong wiring it.  I was testing out the overheat side of it.  I know this isn’t the best way to test this, not knowing the temperature of the sender to trip the alarm, but it’s what I have available.  I pulled the sender, and held a lighter to it, to see if the system would sound, and it did.

 

the sender for the alarm is by the thermostat, and the sender for the gauge is in the turbo.  <br /><br /><br />Is it possible that the coolant at the turbo is not flowing well, but the coolant at the alarm sender isn’t getting hot enough to trip the alarm?  Like there’s good flow there?

 

[Shannon Ritzert]

Actually not that low of a spot, but it is slightly low.  I just jumped in the bot to look

[Shannon Ritzert]

Yes thats a low spot.

the 1” hose  goes to the back of the block.  I removed the freeze plug at the back of the block and installed a 1” elbow for that hose.

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