Merc 3" riser spacer instalation.

[nofuss]

Hi again folks,

After a couple hours of searching, and finding great education along the way i have given up searching and here i am asking the blessings of the Gurus again

I recently converted my 4.3V6 engines in my Regal 2760 from 1 piece bat wing to 2 piece center rise manifolds.
I am now considering adding in the 3inch spacer between the riser and manifold.

I did my research and still cannot confirm if i can actually do this with factory parts.

I recognised that the elbow that is used in the 2 piece conversion, is shaped quite a bit different from the original elbow used in the original 2 piece engines. this one seems to divert the exhaust slightly further back toward the engine. see pics added.
Then I noticed that the original 2 piece carries a different part number for the Y-pipe and this may be where the difference is.
This in mind and the exhaust elbow kit for the 3" conversion costing roughly 250 per engine and weighing about 60lbs in total so costing a lot to ship overseas. I would like to know if anyone has made this change and can tell me for sure if this part will work, before i consider buying.

I also have the idea of making a three inch spacer, either from a piece of stainless steel pipe squeezed into the oval shape and if required the outside built up with fibreglass to be the same as the elbow. or just make an all fibreglass spacer. and in either case use an extra rubber tube to connect them. :redface:

Any thoughts or advice would be greatly appriciated.

No Fuss

 

[mkast]

Re: Merc 3" riser spacer instalation.

http://www.iboats.com/Exhaust-Manif...0335381--**********.702241265--view_id.222007

 

[nofuss]

Re: Merc 3" riser spacer instalation.

Thanks for the link. However thats the straight forward side its the same for all direct bolt straight in. its the other side from the riser elbow to the y pipe that I am having problems with.

No Fuss

 

[Bondo]

Re: Merc 3" riser spacer instalation.

This in mind and the exhaust elbow kit for the 3" conversion costing roughly 250 per engine and weighing about 60lbs in total so costing a lot to ship overseas.

Ayuh,... I haven't done this swap, but I'm thinkin' at 60lbs, you get not only the 3" riser block, but new elbows to make up for the 3" difference....

1 Question though,.... Do you actually Need the extra 3",..??
What is the actual measurement from the turn of the exhaust, to the waterline outside the hull,..??

 

[nofuss]

Re: Merc 3" riser spacer instalation.

Although I dont have the actual measurement with me, since i am now overseas working.
I am seeing 2 situations where I could run into problems with height of the riser. The slip that i use to launch i quite steep and this i believe could be one point where i get some possible water ingress. I often get problems starting when i launch. also since when i anchor near the beach i usually have most of my crew in the aft area of the boat or on the swim platform, and people climbing in and out or the boat. I believe this may also be adding to the engine on the boarding ladder side, suffering from the water ingress problem even more than the other. Im just hoping that this helps.

this is after new manifolds, heard and intake pressure checked. Only time water was seen in oil was when engine was not started and the water was left in the block for 2 weeks since it was not known that there was water in the engine. and it was only enough to slightly discolour the oil.

No Fuss