MSefi.com read only forum (Jan.15,2018)

Hello!

I am a new member who finally joined the group after all of the years of just looking! I have followed the whole "Fuel Injection" revolution on and off since it started. The progress that everyone has made is nothing short of amazing so that's my Kudos to everyone who played a part!! With that being said, I am just an average guy with ten thousand questions. Most of them have been answered either by me reading countless posts or buying books. However, I never really had a reason to apply any of this knowledge until now. My issue is that my interests are in Marine use and so there's not a whole lot of revolution going on with respect to that, yet. I recently installed two 383 stroker engines in my 310 Silverton. These engines were built by a respectable Hi-Po shop and were both dynoed. I have made it through the whole season (Knock on Wood) without any catastrophies but I think the engines need further tuning. Currently I have two Edelbrock marine carbs that are 600 cfm. This is not a great setup and the engines are running extremely rich as evidence by the exhaust smell and spark plugs. Before I go crazy wasting money, I thought it would be a great idea to explore switching over to EFI. I am not intimidated at all by it, and I think it would give me a better range of tuning. There are two caveats that I can't find answers for:

One: Has anyone successfully tuned two engines at the same time? This boat is way to big and heavy to try and use one engine! I thought about leaving the carb on one and just doing one at a time but my guess is that initial tuning could change again for the primary engine after I install EFI on the secondary. Seems counterproductive to not have both running... Any suggestions???

Two: The infamous O2 Sensor works/doesn't work for marine use. Has anyone had any real success with an O2 sensor in a Mercruiser style exhaust system? Open loop possibilities??

I know there are some aftermarket speedshops who offer other alternatives but I like Megasquirt better. Most marine setups are open loop without feedback from the O2 sensor. However I visited a recent Boat show where Mercruiser was showing off their new 6.2 liter V8 with four O2 sensors and twin cats for emission control. I can go with a bigger carb but that to me is repeating the same thing over again. I do have dyno sheets and a breakdown of all of the upgrades I made if someone is interested in looking.

The easiest idea I had was to go the Holley 900 CFM TBI setup with Megasquirt. Just don't know which one and if it's at all possible.

Anyway I am just curious to see what the opinion is of others.

Thanks and Happy New Year!!!

The easiest idea I had was to go the Holley 900 CFM TBI setup with Megasquirt. Just don't know which one and if it's at all possible.

That's what I use on my 383 SBC. It's bad a** and easy to tune.

http://kandlservices.com/image/obj182geo119pg3p1.jpg

I can't answer your questions about marine use of O2 sensors though. But, I will say that tuning is a lot easier with a good wideband unit.

Just my thoughts......

Ken

Thanks for the reply.

I was starting to think I posted in the wrong area. I am still combing through countless posts and setups with the same minimal results. I did see a post on the MS success stories forum about someone with a 454 style 2 barrel TBI using an MSII on his boat. He had a video of the setup running on YouTube and it was pretty cool. However he was not tuning with an O2 sensor which imho kills the idea of EFI. Anyway, I read some information about CAN Networks and the ability to communicate between hardware. It does seem possible as I tried to experiment with some of the settings in TunerStudio. I still have the same questions though regarding simultaneous tuning which in my case would be either two operating MSII's or MSIII's.

In the end, I feel like I am at a disadvantage because of my marine setup. It's my fault because I am too stupid to realize that I would probably have more fun with one engine in a cool car! Boats are really addicting though as I have pushed my 310 to speeds of 42mph on a nice day in the Great Bay! I just want more tuning capabilities and the ability to plug n play. Has anyone tried to jet a carburetor lying across the engine upside down? It's a PITA... and I have to do two.

My next stop is a re-visit to the High-Po shop. I probably should have went there in the first place.

Hey your engine looks great - Good luck with it!!!

Hi
I know this is an old thread, but I'm in a similar situation, and wanted to ask if things have been worked out for you?

I know there's an outfit that sells bungs for O2 sensors that are somewhat hooded, and might protect the sensor. What about using the sensor to time the system before introducing water into the exhaust? What's the purpose of a wet exhaust? Is it just to keep the engine bay and bilge at a reasonable temp?

Don

Donski wrote:What's the purpose of a wet exhaust? Is it just to keep the engine bay and bilge at a reasonable temp?

Don

Being a non-boat guy, I've always wondered about that too!

Ken

Donski wrote:Hi
What's the purpose of a wet exhaust? Is it just to keep the engine bay and bilge at a reasonable temp?

Being an old boat guy, sending engine exhaust and used cooling water out the same pipe is just one less hole in the hull. Same is true whether you have a closed cooling system cooled by sea/lake/river water or an open system where you pump outside water directly through the engine's cooling jacket. Unlike auto design where you cool coolant with air.
Holes in hull are not generally considered desirable.

kholman wrote:Holes in hull are not generally considered desirable.

That explains we don't see screen doors in submarines, huh?