6 inline temp question

[i_build]

Just purchased a 66 Anacapri Newport. Previous owner repowered with a crate engine inline 6. Up on a plane at 3500 rpm she stays at 175* but when I throttle back the temp goes up to about 195* until she cruises for about 5 mins at idle. Is this normal?

 

[Bt Doctur]

If its caused by "heat soak" a few minutes at reduced rpm after a hi speed run traps the hot water in the block for a few minutes

 

[alldodge]

The gauge may not be accurate, might suggest an IR temp gun to check thermostat temps. When was the last time the impeller was replaced

 

[Alumarine]

Is 175 not a bit on the warm side for that motor?
I thought they had either a 140 or 165 degree thermostat depending on cooling method.

Are you seawater cooled or closed cooled?

 

[Bondo]

Just purchased

Ayuh,.... Bein' an unknown,.... I'd change out the impeller, just so ya Know it's in good shape, then do it every other year,...

 

[i_build]

It's sea water cooled. Is 175 high?

The impeller age is unknown so I will replace it. Just in discovery mode right now to address anything before I get her to a high and dry to fix everything at once. But if that is indeed too high a temp I will pull her straight away.

 

[alldodge]

For sea water cooled 175 is to high

 

[i_build]

Found the belt had over 1/4 inch play so I replaced that. Temp seemed to stay at 175* ( dash gauge ) still need to get ir gun. Now I noticed a small trickle of water from underneath the exhaust manifold. Engine and manifold are supposed to have less than 100 hours and I have the receipts. Not sure what would cause this slow drip. I tightened the bolts to the manifold but it still is dripping as shown in this video. Not sure if it could be a gasket or what? Can I pull this manifold while the boat is in the water? Also any ideas what could cause this leak would be appreciated. Thank you in advance.

https://youtu.be/vj0njOk-4qg

 

[alldodge]

You have receipts for exhaust manifolds but in my opinion it isn't for the ones on your motor. I'm seeing some major rust on there

 

[i_build]

Yeah... I take it with a grain of salt as well. Can I pull this while it's in the water? If so I'll pull it to get a closer inspection.

 

[alldodge]

Yeah... I take it with a grain of salt as well. Can I pull this while it's in the water? If so I'll pull it to get a closer inspection.

You should be able to, but before doing, loosen the boot on the exhaust riser to manifold. If no water starts coming in then your good. The intake hose coming from the drive just gets tied up

 

[i_build]

While the manifold surely doesn't look 20 hours old it looks better than many I have seen. I filled it with water for 24 hours and the level did not drop. Will buy some acetone to fill and test again. The riser on the other hand looks very bad. I can see where there is a line of rust from where the riser joins with the exhaust manifold. Provided the acetone test proves good from what you see in the pics would you replace the riser and put the manifold back on for a season?

 

[alldodge]

Your call, I'm not seeing what you are, same with the riser. A leaking riser gasket can cause same issue. Can also take a flat file across matting surfaces to clean them up if not in bad shape