Different Serpentine Belt Setup ?!?

[Mr.LG]

Hi All, greetings from a new member.

I have a 1999 Mercruiser 5.7L EFI Alpha.

I bought the boat 3 years ago, and had not realized just until now, while looking at my service manual, that my serpentine belt routing is not layed correct for my engine's serial. Maybe the previous owner changed it...

Looking at the service manual (picture attached), my serpentine belt should have been routed according to the right drawing, but instead it is using the left configuration.

Is there any reason why I should change the configuration to match the correct drawing?
I can't see much difference aside from the water circulating pump rotating the other way.

I tend to think that in my current setup (left drawing) the crankshaft whell would get more belt coverage, and hence this would be a better setup...

Any comments or opinions?

Regards,
LG.

 

[Fun Times]

Re: Different Serpentine Belt Setup ?!?

Normally if the engine is still stock and everything is still in place from new, Then there should be a sticker on the front of the engine area showing the correct way to install the belt to your engine.

What is your engine serial number?

 

[Don S]

Re: Different Serpentine Belt Setup ?!?

You can't just change belt configureation because you want to. The belts in the 2 drawings are probably different length, and the items you are turning (PS pump, alternator, and idler) are located in different places.
Why are you trying to reinvent the wheel here?

 

[Mr.LG]

Re: Different Serpentine Belt Setup ?!?

Not trying to reinvent. As a matter of fact I just noticed that the serpentine belt was routed different, while looking at my service manual for something else.

My engine serial starts with OL624... so according to the service manual it should be routed as in the right drawing above, but instead it is using the left configuration.

Serpentine belt part number is the same, so no changes in lenght. Proof of that is that my engine is using the "old" layout without any issues.
By the drawings the only thing they did, starting on the OL619 and above was to change the circulating pump and crankshaft layout from a "S" to a "Z" shape.

The only thing I can see that this does is to invert the rotation of the circulating pump, and reduce the belt coverage on the cranksharft wheel. Not sure why they did that though.

But should I just change the layout to match the drawing (Z shape)? Not sure if I want to inver the rotation on the circulatin pump and reduce belt coverage of the CS wheel. Unless there are good reasons for that. Any thoughts?

 

[sqbtr]

Re: Different Serpentine Belt Setup ?!?

Acording to the diagram, both pumps are turning in the same direction

 

[Mr.LG]

Re: Different Serpentine Belt Setup ?!?

Indeed... it is rotating counter clockwise in both drawings
My mistake... sorry.

So they only difference I can see is that in the right drawing the CS wheel has the seepentine belt touching 1/2 of of the wheel, while on the left drawing it is touching almost 3/4.

Not sure if I want to change the layout....

 

[sethjon]

Re: Different Serpentine Belt Setup ?!?

Not trying to reinvent. As a matter of fact I just noticed that the serpentine belt was routed different, while looking at my service manual for something else.

My engine serial starts with OL624... so according to the service manual it should be routed as in the right drawing above, but instead it is using the left configuration.

Serpentine belt part number is the same, so no changes in lenght. Proof of that is that my engine is using the "old" layout without any issues.
By the drawings the only thing they did, starting on the OL619 and above was to change the circulating pump and crankshaft layout from a "S" to a "Z" shape.

The only thing I can see that this does is to invert the rotation of the circulating pump, and reduce the belt coverage on the cranksharft wheel. Not sure why they did that though.

But should I just change the layout to match the drawing (Z shape)? Not sure if I want to inver the rotation on the circulatin pump and reduce belt coverage of the CS wheel. Unless there are good reasons for that. Any thoughts?

I would suggest if you aren't having problems leave well enough alone.

 

[sethjon]

Re: Different Serpentine Belt Setup ?!?

Indeed... it is rotating counter clockwise in both drawings
My mistake... sorry.

So they only difference I can see is that in the right drawing the CS wheel has the seepentine belt touching 1/2 of of the wheel, while on the left drawing it is touching almost 3/4.

Not sure if I want to change the layout....

Leave it alone.