I have twin Gen V 454 mags. Currently all stock.

I have purchsed 2 sets of EMI thunder with stainless long risers. I am looking for the best intake/carb combo to go with the exhaust upgrade and make some noticable hp gains if at all possible. What do you think?

I would contact RMBuilder (Bob Madara) and have a good cam done. Then ask him what would work well with that particular cam. If you want a noticable hp increase, intake, carb and exhaust alone ain't gonna do it.


Marine Kinetics
Bob Madara
585-654-8583

Like was said, you will also need a cam change for any significant gains. An Edelbrock Air Gap intake and 800fm Holley carb would probably be my choices for what you are doing.
How many hours on the engines???? The top ends might need gone through anyway.

I was trying to get away without pulling the motors. So I am not sure about doing the cam. They have about 250 hrs on them.

I guess I am not gonna see alot of hp gain with just exhaust carb and intake.....

With the mods you are speaking of, you will need to pull the motors anyway. When doing exhaust, intake and carb, a cam install is not a big extra step. Not trying to be a stick in the mud, but to answer your question as simple as possible, no.

Why would I have to pull the motors to install carb/intake/exhaust?

I can't imagine there being room for exhaust install on the twins between the motors.

My formula 292 is going to be the same as your 272 in the engine compartment. There is no way you can change the exhaust in the boat. Even if you could it would be very frustrating and time consuming do to how tight everything is back there. In the long run pulling the engines will be easier and quicker.

Not only that, but it gives you the chance to inspect items that you normally wouldn't be able to get to. You can clean any rust and touch up paint, clean and/or paint the bilge, clean the engines really well. On top of that, I think you will have a better chance at a successful job with the engines on a stand. It is very easy to drop something in the engine, especially when you are in an awkward position in the bilge.
You will be able to complete the job much faster with the engines out. It will probably all equal out in time in the end. The time it takes to remove them will be made up by the time you save working on them on the stand.
Good luck. Let me know if I can help.
Eddie

Well.......you guys are right. they have to come out!

I actually have room and can get a 1/2" drive ratchet and socket in there......the problem is that there are just about no heads left on the damn bolts!!!

These things are so freaking rusted I don't know what I am gonna do to get them off wven with the motors out!!!

I got the risers off, one had a hole rusted straight through, one was gone...I don't know how the exhaust hose stayed connected as there was no metal left. The other two were about the same.

These motors were installed in 1999 and have about 250 hours on them. I am assuming the original exhaust was used. I have never seen rust like this!!!