Converting from log style to center rise exhaust.

[holorinhal]

I have a 81 Spectra 20 With a 260 Mercruiser. I am going to convert the exhaust, from the log style to center rise and thru hull exhaust. I will be getting rid of the Y pipe and installing a block off plate. The exhaust manifolds will be an Oem style manifold.
Do I have to buy a different Tstat housing, or can I use my existing housing?
Is there any thing else that won't work with the conversion, like accessory brackets and such? thanks........Hal

 

[TEAGUE CUSTOM MARINE]

I have a 81 Spectra 20 With a 260 Mercruiser. I am going to convert the exhaust, from the log style to center rise and thru hull exhaust. I will be getting rid of the Y pipe and installing a block off plate. The exhaust manifolds will be an Oem style manifold.
Do I have to buy a different Tstat housing, or can I use my existing housing?
Is there any thing else that won't work with the conversion, like accessory brackets and such? thanks........Hal

Hey Hal,

Who's exhaust are you going to install and what riser is on it?

the y-pipe block off plate will solve the entire problem on the transom. You might have to cut the y in half to get it out without pulling the engine?

Depending on the system you have or are going to get, the risers should aim you in the general direction and/or you can instal s-pipes to connect to your existing tips.

Most manifold systems have the option to plumb with from the bottom or dual inlets if you are running a 4 port therm housing. Depends on how you want to plumb it.. Therm housings are pretty cheap if you want to change to a single hose to each side and clean it up.

Most manifold systems should have the necessary brackets to replace or you can just move things around? Shift bracket can move to the transom or a stringer, etc and the oil filter can be relocated/mounted. See if there are brackets...

-Eric

 

[holorinhal]

Hey Hal,

Who's exhaust are you going to install and what riser is on it?

the y-pipe block off plate will solve the entire problem on the transom. You might have to cut the y in half to get it out without pulling the engine?

Depending on the system you have or are going to get, the risers should aim you in the general direction and/or you can instal s-pipes to connect to your existing tips.

Most manifold systems have the option to plumb with from the bottom or dual inlets if you are running a 4 port therm housing. Depends on how you want to plumb it.. Therm housings are pretty cheap if you want to change to a single hose to each side and clean it up.

Most manifold systems should have the necessary brackets to replace or you can just move things around? Shift bracket can move to the transom or a stringer, etc and the oil filter can be relocated/mounted. See if there are brackets...

-Eric

I am useing a set of EMI Thunder exhaust and I have isues and questions. I had the engine out and i did remove the Y pipe and I made a block off plate.
I got the engine back in the boat, and where it sits the risers come in, in a position that will not work. The riser and powersteering unit are interfearing with each other.
What I need to do is have the tips come thru below the power steering unit and in order to do that i will have to use an S pipe and hose, and inorder to do that the risers need to be shorter. My question, is there any reason that I could not cut the risers shorter? I really hate to cut them, but its what I have and I dont want to spend the money to just buy shorter ones.
Also I had to switch T-stat housings and the original water inlet hose came in on the starboard side, but the new housing has the inlet on the port side. I need to rout the hose from the tramsomplate on the starboard to the port side. Can I route the hose and cross under the oilpan to the port and use the molded hose for the port side conection?
Here are a couple pics of the issues.

I took care of the alternator mounting with this bracket.

I also need to find a new location for the starter slave solinoid, which was mounted on the rear undeside of the logs. It will require some rewire to move it.

 

[holorinhal]

My risers are essentially the same as this short riser, only with a longer tail pipe.

See the inner pipe with the flare. It is the same on mine, only longer. it is loose, not welded, from the outer weld to the exit and only forms a sleeve. the only place it is sealed is back close to the bend.
If I were to cut mine, I would have the exit same thing as the pic above, only longer and without the flare on the end.
Cut shorter, I could add hose and 90s to go down and out.
Would it work?