SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: bvparr on April 13, 2019, 11:43:39 AM

Title: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: bvparr on April 13, 2019, 11:43:39 AM
Hello - Just looking for a little help.  Just had a mild 454 built for my Hawaiian.  It's .40 over and a full roller.  Mild cam by SLR.  So here is where I am at - I have the original Hardin Marine logs and snails that came with the 1978 boat.  They are in great shape.  I also have the Mercruiser 89011 exhaust manifolds with the 816900-C 4" risers.  They are also in great shape.  The question is if they are your ONLY choices - what ones would you use? 
Title: Re: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: mash on it on April 13, 2019, 12:38:02 PM
If interior room or doghouse is not a problem, merc manifolds.

Merc manifolds are heavy, compared to logs and snails.

Logs and snails are not as bad as people think.

Dan'l
Title: Re: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: bvparr on April 13, 2019, 06:06:37 PM
Oh that's right - I need to make sure there is room under the hatch.  Thank you for your input.
Title: Re: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: Tahoe540 on April 17, 2019, 07:29:35 AM
I am repowering my jet boat and have no room but for anything but log exhaust because of the doghouse/engine cover.  This is very limiting on a 555 BBC.  You can cut off the ends I guess to get a full 3"?
Title: Re: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: bvparr on April 17, 2019, 09:02:54 AM
Yes.  I did that to them already.  So if the risers do not fit that is what I am going to put on. 
Title: Re: Original Hardin Marine Logs/Snails OR Mercruiser 4" Center Riser Exhaust
Post by: el mojado on April 24, 2019, 10:55:17 AM
My $.02
When I cut off mine I noticed there was a small lip just on the inside. I took my air grinder with a carbide bit and ground it off to get as much of an exit as possible. Every bit counts.

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