Mercruiser 5.7 Water pump pulley not aligning with crank pulley, any ideas?

Buickgsman

Seaman
Joined
Oct 2, 2015
Messages
56
Hi all, I am trying to get this engine back together with the hope of at least one outing this year just to try out the boat. I'm working on a 1998 Four Winns RS with a 1988 vintage 5.7 Mercruiser / Chevy 5.7. The block that came in the boat had a spun bearing and was very hard to turn over. Upon disassembly I found water residue in the cylinders and the spun bearing. The engine had already been bored +.030 and looked like it had been rebuilt recently ( very clean inside) so I found a similar year block that was in nice shape and just had it honed and cleaned and the crank polished. So I put it all together using the heads off of the first engine and the water pump is sticking out about 1/8" farther than the crank pulley. I used the stock GM timing chain setup that was in the block that I had honed, it was in nice shape. There was no other spacer or oil sling present with either engine. Any ideas on what would cause this misalignment?
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,056
Is there room behind the pump flange to press it further on ? If so just take the rear cover off and press it to line up.
 

Buickgsman

Seaman
Joined
Oct 2, 2015
Messages
56
No Title

Here is a pic. Very close like I said, but the water pump is out around 1/8 or so. Is it possible to leave it alone and buy a spacer for the crank pulley? Summit sells them.
 

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Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
47,305
I would PM a mod to move this from the VP section to the mercruiser section.

my guess the motor needs the 1/4" spacer between the harmonic balancer and the lower timing gear.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
I'm seeing two different balancers, and the 1998 style was only used until 2001 on 5.7, the 350 show another
1988 - 33863T
1998 - 852946 and 852966001 NLA
Newer models - 863397
 

Buickgsman

Seaman
Joined
Oct 2, 2015
Messages
56
Thanks for all the replies, I ended up removing the rear cover on the pump and pushing the flange on another 3/16". Lines up perfectly now with no apparant downside. I did clearance the material on the water pump directly behind the pulley just a tiny bit to ensure no rubbing would occur.
 
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