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Crank driven pump change over on 5.7 L

F

franks

New member
I'm in the process of converting twin 5.7's from the Sherwood belt driven pump to the Johnson crank driven pumps.

I have a question regarding the belt drive pulley that drives the Sherwood. Do you remove this pully and bolt the Johnson pump directly to the balancer? I have not removed this pulley yet but it appears that a shorter bolt for the harmonic balancer would be required as currently this bolt with a washer underneath is one of 4 bolts holding the Sherwood pulley on and will extend further into the crank end once the pulley is removed.

Thanks in advance for the combined wisdom of this forum.
 
Usually, the crank pulley needs to remain in order to drive the circulating pump and the alternator...some have a spaced out pulley that separates from the larger pulley. In those cases, going on memory, you remove the spaced out pulley and the sleeve under it. The balancer bolt should not have to be changed it should be below the pulley mounting face on the balancer.
 
franks said:
..........
Do you remove this pully and bolt the Johnson pump directly to the balancer? I have not removed this pulley yet but it appears that a shorter bolt for the harmonic balancer would be required as currently this bolt with a washer underneath is one of 4 bolts holding the Sherwood pulley on and will extend further into the crank end once the pulley is removed.
Click to expand...
The engine alternator and engine circulating pump are typically driven from the standard GM crankshaft double shiv pulley.

The Sherwood pump is often driven from an additional and further forward single shiv pulley mounted via the three harmonic balancer bolts.

When you remove the Sherwood belt driven pump, you will also be removing the forward single shiv pulley.

The Johnson crankshaft pump flange will index to the GM double shiv pulley.
The correct indexing is accomplished via two raised dowel areas.

Since there are only three mounting holes, there will be three possible indexing positions..... But keep in mind that there are two alignment dowels ONLY!
The two-on-three will only work during one indexing.

IOW....... only one of the three indexing a will work correctly!

.
 
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In post #14 of this thread, I posted an image of a Volvo Penta AQ200 "B" engine w/ a Sherwood belt driven seawater pump.
http://www.marineengine.com/boat-forum/showthread.php?389830-305-to-350-flywheel-inquiry

This bracket is rather unique to Volvo Penta. It provides mounting for the Sherwood pump, and also melting for the engine alternator.
However, the pulley and belt arrangement (not necessarily the pump location ), may be very similar to the Crusader!
The third and most forward shiv can be unbolted and removed.

In this thread I help Doug C. make a similar conversion from a MerCruiser belt driven seawater pump.
http://www.baylinerownersclub.org/~...38560-johnson-raw-water-pump-installed-on-6-2

Note in post #9 where I elude to the raised dowels for pump base and crankshaft pulley indexing.



.
 
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Rick,
You're dead on, went to the boat and removed the front cast pulley just as you said. One thing I'll add for the record is the hub bolt a 7/16 UNF grade 8 bolt will now be 2 3/8 inches long down from 4 inches, and the 3 bolts for the Johnson pump flange will now be 3/8 UNF grade 8 by 7/8 inch long.

The key to this change is to leave the stamped second pully in place on the front of the damper as it locates the Johson pump and keeps it concentric to the rotation of the crank.

Thanks all for your help!!
 
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