Proper Gas Engine Installation / Safety tips / lessons learned

Bill

Founder
Joined
Aug 30, 2011
Posts
5,655
Likes
5,931
Location
Hull, Ma
Boat Make
27 Terry Jason
Figured instead of having our usual pissing match of "diesel good ,gas bad" and there is a lot of gassers still out there and being built that we should hash out proper installation of has engines and what is the safest set up to go with.. If anyone has experience with this your input is appreciated ..

Carb vs injected

Fuel lines

Dry/wet exhaust

Tank installations / materials

Blowers.

Anything else
 

F/V First Team

Admiral
Joined
Jan 10, 2012
Posts
6,146
Likes
2,482
Location
Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
We had a BHM 20 with a 302 Ford in her. Fuel tank was above deck under the sterndeck, fiberglass with a sight gauge. Fuel lines were all A1 3/8". Carburetor with wet exhaust, 3" blowers. I believe there were 4 fire extinguishers on board. Only time there was ever a problem was with an Edelbrock carb off the shelf replacing the Rodchester that had some gunk in it from sitting. Wasn't too impressed with the flame shooting out of the top of the carb, but a quick removal of the shirt tossed into salt water and draped across the engine took care of that.



If/when the Packard ever gets slid into a hull she will have a fiberglass fuel tank, quad 4" blowers below the deck, 1" A1 fuel lines and wet exhaust. Already have a 4' extinguisher that can flood the entire under deck area and snuff out any hazards.
 

Keelboater

Admiral
Joined
Oct 3, 2013
Posts
6,287
Likes
4,683
Location
Clinton Harbor
Boat Make
35' Bruno & Stillman
To sum it up: If using a gas motor, just remember that nothing bolted to the outside of it is from an automotive application. This includes carburetor, fuel pump, distributor, alternator, starter, and even the water pump. Pressurized fuel line from pump to carb must be pre-formed rigid tubing with correct fittings - no hose and clamps here. Racor filter must have solid bowl, not plastic bowl for outboard use. Anything electrical that is installed in the bilge must be ignition protected. Fuel tank must be grounded and grounded to the filler neck as well. Suction ports must have anti siphon valves. Fuel line shut off valves must also be used. Good natural ventilation in the bilge as well as a blower are both mandatory. A good alarm system can keep you in the know prior to reaching the point of no return: Water temp, exhaust temp, fire, smoke, oil press, and a good fume detection system. Most important thing is common sense. Without it you will become another statistic like so many who decided to fill their rod holders with gas.
 

steveinak

Admiral
Joined
Sep 1, 2011
Posts
5,656
Likes
3,399
Location
Piker Central
Boat Make
31 BHM
The Great Schnozzola

220px-Jimmy_durante_1964.JPG
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,421
Likes
2,328
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
I have never owned anything but gas engines and I bet there are more gassers out there than diesels (? anyone). Also never had an issue but its common sense that keeps you alive. Open the hatch and smell the bilge. Its that simple.

I am going to get a fume detector for the first time on this boat and decent extinguisher set up plus blowers of course.

I think fuel tanks and hoses a have to be the most overlooked items. I have been on many an old boat with REALLY sketchy looking aluminum tanks resting on wood skids or sitting in foam (trapping moisture against the tanks).

Also think vent hoses are overlooked. They need to go out side of the boat and be sufficiently sized. I also happen to believe they should have steady slope to prevent low spots from trapping water/gas and blocking the line. Gas evaporates but the water/condensate may not.

Here are a couple questions: Are there ever electric fuel pumps at the tank on any boat? I have never seen one but sounds like the fuse to light the bomb to me.

How about static electricity- not sure from what but its a thought.

How about bonding your tanks? They are grounded to the batts via the sender wiring but should they be bonded?
 

Kodiakan

Commander
Joined
Aug 26, 2013
Posts
491
Likes
115
I have never owned anything but gas engines and I bet there are more gassers out there than diesels (? anyone). Also never had an issue but its common sense that keeps you alive. Open the hatch and smell the bilge. Its that simple.

I am going to get a fume detector for the first time on this boat and decent extinguisher set up plus blowers of course.

I think fuel tanks and hoses a have to be the most overlooked items. I have been on many an old boat with REALLY sketchy looking aluminum tanks resting on wood skids or sitting in foam (trapping moisture against the tanks).

Also think vent hoses are overlooked. They need to go out side of the boat and be sufficiently sized. I also happen to believe they should have steady slope to prevent low spots from trapping water/gas and blocking the line. Gas evaporates but the water/condensate may not.

Here are a couple questions: Are there ever electric fuel pumps at the tank on any boat? I have never seen one but sounds like the fuse to light the bomb to me.

How about static electricity- not sure from what but its a thought.

How about bonding your tanks? They are grounded to the batts via the sender wiring but should they be bonded?

I had redundant fume detectors on my 28, one in the bilge and one mid ships by the tanks. Them along with the Nose made me feel pretty safe.

Static electricity is why the filler necks must be grounded, otherwise touch fuel hose to metal filler cap, boom.

I wouldn't bond my (aluminum) tanks as I think you would be creating big zincs out of them.
 

Keelboater

Admiral
Joined
Oct 3, 2013
Posts
6,287
Likes
4,683
Location
Clinton Harbor
Boat Make
35' Bruno & Stillman
.........."Are there ever electric fuel pumps at the tank on any boat? I have never seen one but sounds like the fuse to light the bomb to me".

:shock: N E V E R . E V E R . That would mean the entire fuel line is pressurized. One loose clamp and the Flying Sisu would be exactly that......no crane need apply. :grin:
 

james

Lieutenant
Joined
Aug 5, 2013
Posts
20
Likes
1
Location
brunswick ga
Boat Make
crusader 34
i had a 36 foot trojan when i was 19 my first big boat with twin 350 mercruisers inboard she blew up with me standing between the engines it burnt my shirt off before i could get out of what was left of the engine room my brother managed to flip me into the river and put me out after i had passed out on the aft deck it burnt my left ear and half of my face to charcoal and spent quiet a good bit of time in shands of jacksonville fl burn treatment center my face healed amazingly due to a tip from an old man in the marines who told me if i was ever burnt severly to find a quart of clean motor oil and poor over the burn it would be nasty but stop the damage process so that is exactly what i did i have minimal scars compared to the extent of my burns the doctors were astonished at the way i healed i didnt have to have the plastic surgery they originally scheduled me for so my advice if you have a gas inboard is to keep some clean oil onboard because they are dangerouse gas is very unstable when a small pin hole in a fuel tank puts gas in the bilge i thank the lord for the healing he gave me through the knowledge of an old marine and that i was at the dock with my brother who was there and saved my life
 

Pedlyr

Captain
Joined
Aug 31, 2011
Posts
535
Likes
179
Location
Southern RI
I would be more worried about the fuel tank(s) and material used. E10 and other additives can turn gas into a gooey paste in some plastic tanks.

My twin Shamrock tanks have deck plates. The tanks were leaking about 8 years ago. I could smell it easily coming thru the limber holes. So I pulled them and repaired them. Problem was water getting on them and pitting the aluminum. So you just want to make sure you paint or waterproof the outside of the metal tank. And make them accessible if possible. I installed plastic strips under the tank and used as little foam as possible to hold them in place. So any water that may be there can get out.

I also like my closed cooling system. Just the riser see raw water.
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,421
Likes
2,328
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
i had a 36 foot trojan when i was 19 my first big boat with twin 350 mercruisers inboard she blew up with me standing between the engines it burnt my shirt off before i could get out of what was left of the engine room my brother managed to flip me into the river and put me out after i had passed out on the aft deck it burnt my left ear and half of my face to charcoal and spent quiet a good bit of time in shands of jacksonville fl burn treatment center my face healed amazingly due to a tip from an old man in the marines who told me if i was ever burnt severly to find a quart of clean motor oil and poor over the burn it would be nasty but stop the damage process so that is exactly what i did i have minimal scars compared to the extent of my burns the doctors were astonished at the way i healed i didnt have to have the plastic surgery they originally scheduled me for so my advice if you have a gas inboard is to keep some clean oil onboard because they are dangerouse gas is very unstable when a small pin hole in a fuel tank puts gas in the bilge i thank the lord for the healing he gave me through the knowledge of an old marine and that i was at the dock with my brother who was there and saved my life

Holy shit- amazing story and glad to hear you recovered so well.

What caused the explosion?
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,421
Likes
2,328
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
Just ordered new tanks and they are coming epoxy coated which is a change from my last set about 15 years ago. Seems like a great idea too.

Also went fuel injected just for efficiency reasons (you asked in your OP).
 

Keelboater

Admiral
Joined
Oct 3, 2013
Posts
6,287
Likes
4,683
Location
Clinton Harbor
Boat Make
35' Bruno & Stillman
hope your not expecting much, a correctly tuned carb will net same nmpg as fuel injection without all the stuff to crap up

Are you saying that a carbureted motor has the same efficiency as a fuel injected motor under daily operating conditions? Please show me how this is possible.
 

Toolate

Admiral
Joined
Aug 6, 2013
Posts
6,421
Likes
2,328
Location
Southwestern CT
First Name
Ben
Boat Make
1998 36' Sabre Express CAT 3116TA's, 2015 ROS Scotia 16 Etec 50
hope your not expecting much, a correctly tuned carb will net same nmpg as fuel injection without all the stuff to crap up

Missed this- real reason I did it was to avoid finding myself cruising on the verge of the secondaries opening. I am not sure how my boat will run when its all put together (new engine, gear, prop, rudder, thinking lifting rails, etc) so didnt want to be "in between" and fuel injection is a potential future pain in the ass but it does eliminate the carb and gas issues there. Time will tell.
 

jerseysportfisher

Rear Admiral
Joined
Feb 13, 2012
Posts
1,181
Likes
149
Location
Communist part of NJ
Boat Make
Bertram 33SF
Are you saying that a carbureted motor has the same efficiency as a fuel injected motor under daily operating conditions? Please show me how this is possible.


i will repeat, a CORRECTLY tuned carb will net the same NMPG as fuel injection on identical built setups

IE 350 cheby = makes 235hp @ 3000 rpms to make 235hp the engine requires X fuel and y air and is not dependent on how the fuel is delivered.

so what does fuel injection really give you ?

better cold weather start
dont have to adjust carb
allowance for monitoring system hookup
(debatable) some say they run more stoich, we have found that in race applications, A/F is all over the place and requires a chip with custom injector pulse at certain rpms to correct this. Even worse in boosted situations.



problem is average people dont understand this and will compare: well i had a beat 350 chevy 270hp, and i went to a NEW 330mpi, with different gear and different prop and it runs so much better and i burn less fuel!!! You might as well compare a 2bbl 350 nova with a powerglide to a 383 dfi nova with a th400 on a brake.
 
Top Bottom