Should I be concerned?

[browntw.79]

I have been working on my 1987 Albin 36 trawler for the past year.  I spent considerable time and money on the 6BT engine getting it cleaned up and refitting all the hoses, clamps, accessory belt, new Dayco belt tensioner, and new alternator (145A Delco 19si from SBM).  On Sunday we ran the boat from our house to a boat yard for haul out.  As we started out we smelled burning rubber.  My wife took the helm and I went below to check the engine and the pulley belt.  All looked fine and the smell went away.  It was a little over a five-hour trip.  Today I was down below and noticed several “spray” patterns of rubber particles.  Is this normal or something I should be concerned about? Also, my pulley configuration is not one that I have seen on another 6BT.  Is this a standard configuration or one that has been altered by a prior owner? As always, all insights are welcomed.

Tom Brown

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[JimmyK]

The amount of contact between the belt & alternator is poor on that belt wrap design, which is going to limit the amount of power the alternator will be able to produce without belt slip, especially at low/idle rpms.

Look at Tony’s picture…old belt wrap (yours) only has about 120° of contact, new belt wrap has about 270°.  Amount of torque the belt can apply before slipping is directly proportional to this angle due to something referred to as the capstan effect.

The burning rubber smell at startup may have had to due with something (?) on the belt or pulleys reducing friction further (little bit of oil or?).  Once it burned off, no more slip, no more smell.

[Rob Schepis]

5/16″Silicon Heater Hose

[Tony Athens]

Early vs Late Belt wrap design–Cummins B

So you can “see” the difference

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[browntw.79]

Rob – 

The coolant recovery tank is lower than the coolant tank and well above the crankshaft.  I will check the tubing.  What type of tubing do you recommend for coolant recovery?  Thanks.

 

Tom

[Tony Athens]

Looks like a very early B that has been well kept up expernally.. Early belt  wrap design , very early front engine brackets and isolators and an early expansion tank.

 

You probably had an extra amout of initial belt slippage on start up with the larger output alternator coupled to a low battery? –Usually you hear a “squeel”..

Get things all spic & span  and check each trip.. To me , pretty normal.

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[Rob Schepis]

Burning rubber smell?…

Where is your coolant recovery bottle located?  It is best at a height just under the height of the expansion tank and should be no lower than crankshaft. And that tubing looks inferior and flattened out against the tank. 

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[John]

I’m in the “not a problem at all” camp.

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