Free Credit Report

Manifold/Riser question for inboard mechanics

Greetings,

I have twin 350 Merc's with full fresh water cooling......I'm in the process of replacing the risers, and when I disassembled them, I found the typical stainless block-off plate sandwiched between two gaskets.....

Looking at the new Merc part number and schematic, it seems that only a single gasket is now used, and the stainless block-off plate is a thing of the past...

Can anyone kindly confirm if in fact the current set-up only requires the single block-off gasket (Merc # 27-863725 1), or is the stainless block-off plate still required?

I've seen manifold/riser "kits" available, and they too only have the block-off gasket, but if I'm going to the trouble, I want to be sure....I guess they could have changed the gasket design so the stainless plate is no longer needed, but......

Thanks a bunch!!!

 rc620
Jun 1
2006
I don't have the fresh water cooling, but my manifolds and risers both use only one gasket. Mine is a 350, 1997. JohnH
Jun 1
Sounds like your manifolds are part of the closed side. You can just use two of the regular gaskets with your existing block off plate or there is also a different gasket that has the holes blocked off in the gasket. Either will work, the objective is to block the water passages between the manifold and the riser. The only opening should be the big one in the middle for the exhaust.

I've also seen this used on raw water cooled engines to preheat the water by running the incoming water through the manifold(s) before it goes to the block. The dumping the water via the risers.

 jamesgangnc
Jun 2
   
Disclaimer: This is a computer-generated and formatted feed of current postings to a public
Internet forum. We do not control the information delivered, nor do we endorse or monitor its
content. Internet forums may carry offensive, harmful, inaccurate, and otherwise inappropriate material.
 Click to see the RSS XML version of this page   Click to see the Atom XML version of this page