EFI Repower

Engines, Shafts, Steering, Struts, Rudders, etc.
Joefuskie
Member
Posts: 12
Joined: Fri Oct 07, 2016 11:21 am

EFI Repower

Post by Joefuskie »

I'm looking into repowering a 26' Sportsman. It has an old For-Dagenham Diesel engine; and transmission that looks like a velvet drive. Both are frozen after years of sitting (25+).

I'd like to use a GM 350 block as I've had good luck with them and parts seem to be readily available. Fuel injected is the fueling method I would prefer, in particular a throttle-body injection system. I've got nothing against multi-port injection it just seems like a more complicated setup.

The real question is, can an automotive engine be used instead of a marine engine? I plan on fresh water cooling as this boat will see time in salt and brackish water. What kind of transmission options are available for GM blocks? Is the velvet drive still an option?

Thanks for the input,

Joe
197X Sportsman "Janet C."
6cyl Ford-Dagenham diesel (frozen)
Velvet-drive (frozen)
Restoration project
Bangor, Maine
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: EFI Repower

Post by Fastjeff »

You can easily adapt a Velvet Drive to a SB Chevy, but the EFI set up presents a problem: Were do you put the O2 sensor? Modern EFI marine engines are designed with the sensor located where it will work properly. Not sure how to do that in this case.

Why not a carb? hey work well on a marine engines and nearly get the same gas mileage.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Joefuskie
Member
Posts: 12
Joined: Fri Oct 07, 2016 11:21 am

Re: EFI Repower

Post by Joefuskie »

Excellent point Jeff. The three ways I can think of to get around O2 sensor are: 1) bypass it all together with a closed-loop computer reprogram, which would essentially turn it into a carburetor; 2) use a dry manifold that would allow stock placement of the sensor, which would result in a lot of heat in the engine bay; 3) find some wet exhaust manifolds for the stock block, which might be more trouble than it's worth.

I like carbs for their simplicity, and more importantly their lack of electronics to get fouled up in a high moisture marine environment.

Aside from the O2 sensor placement, are there other differences between marine and automotive engines? For instance, camshafts, crankshaft bracing, heads, etc.?
197X Sportsman "Janet C."
6cyl Ford-Dagenham diesel (frozen)
Velvet-drive (frozen)
Restoration project
Bangor, Maine
EWRice
Royal Aluminum Star
Posts: 319
Joined: Thu Feb 04, 2016 12:37 pm

Re: EFI Repower

Post by EWRice »

Somebody out there makes a spacer plate for the Mercruiser risers so an o2 sensor can be used. I can't remember who makes it though.

If you want TBI, you could try Affordable Fuel Injection outside of Lansing, MI. They build custom systems for different applications.

I would recommend staying away from TBI systems. They are simple, yes, but that is part of what makes them frustrating to diagnose issues. I have worked with some decent aftermarket MPI systems that "self learn" and work pretty good.

Mercruiser, PCM, Crusader and others offer turn key injected engine packages, if you are willing to spend the money.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson
spdracer
Tin star
Posts: 21
Joined: Fri Aug 05, 2016 6:59 pm
Location: Port Clinton, Ohio
Contact:

Re: EFI Repower

Post by spdracer »

Marine engines are open loop (don't use O2 sensors) that are not catalyst equipped. New inboard and I/O boats from 2011 on have Catalysts. The main purpose of traditional Zirconia O2 sensors are for effective use of the Catalyst. My suggestion is if you are leaning to go EFI buy a complete engine with it such as a Crusader. They aren't cheap.
Chris Hamann
Lakeland Auto & Marine
Port Clinton, Ohio
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: EFI Repower

Post by Fastjeff »

..."Marine engines are open loop (don't use O2 sensors"

Then how do they work properly? I seem to recall seeing an O2 sensor on a Mercruiser EFI engine.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
EWRice
Royal Aluminum Star
Posts: 319
Joined: Thu Feb 04, 2016 12:37 pm

Re: EFI Repower

Post by EWRice »

Fastjeff wrote:..."Marine engines are open loop (don't use O2 sensors"

Then how do they work properly? I seem to recall seeing an O2 sensor on a Mercruiser EFI engine.

Jeff
They don't run properly. They all run rich to be on the safe side. The first 3 or 4 generations of efi don't use O2 sensors.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: EFI Repower

Post by Fastjeff »

So the NEW generation does? Where is the sensor?

Jeff

PS: Running in open loop, the old EFI set up shouldn't do any better on gas mileage than a well-tuned carb. Motor would start and initially idle better, I suppose.
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
EWRice
Royal Aluminum Star
Posts: 319
Joined: Thu Feb 04, 2016 12:37 pm

Re: EFI Repower

Post by EWRice »

Most of the o2 sensors are in the risers. Most of the efi boats I have run do worse on fuel consumption than a good Q jet or afb, until they hit about 2/3 throttle.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson
honestcharlie56
Royal Aluminum Star
Posts: 258
Joined: Tue Jul 19, 2016 8:27 pm
Location: Lake Charles, LA

Re: EFI Repower

Post by honestcharlie56 »

Just a thought from someone who has spent a lot of time attempting to get consumption down on sportfishers. I've noticed efi really only saved fuel at varying load conditions. When identical hulls and power are run side by side at a continuous load, efi and carb setups are fairly indifferent. The art here is truly understanding and setting up a carb. I wonder how long the fuel savings from efi would take to pay for itself. Google water/methanol injection.
1990 Marinette 32 Sedan Flybridge "Hubba" Lake Charles, LA
Twin Chrysler 318's
Post Reply