fuel usage mercruiser 4.3

[hadaveha]

Hello everyone
Im looking at swaping my old 1984 mercruiser 470, for a 1995 mercruiser 4.3 My question is about fuel, just how thirsty is the 4.3 compaired to the 470. and Im not a big speed guy this boat is used for fishing.
Thanks everyone for your help

 

[Volphin]

Re: fuel usage mercruiser 4.3

The 4.3L is the best balance of power and fuel use IMHO. The problem is, I'm not sure if your motor mounts will fit the 4.3L... I've never tried it. Also, you will need a new bell housing, starter and other misc parts. Are you getting the entire motor and everything with it?

 

[QC]

Re: fuel usage mercruiser 4.3

At the same speeds, fuel use will be . . . . about the same

FWIW, there is very little difference in fuel efficiency between similar technology engines. 4 stroke carbed vs, 4 stroke carbed. 4 stroke MPI vs. 4 stroke MPI. Very similar. 2 stroke carbed, vs. 4 stroke MPI, now that might be worth counting.

 

[hadaveha]

Re: fuel usage mercruiser 4.3

yes im getting everything from the balancer to the coupling, I know Ill have to fab up some mounts but its a aluminum boat it shouldnt be as hard as having to glass something in. from everything I have read. the 4.3 should be a plug and play with my alpha 1 outdrive. I just had heard from a few people that the 4.3 was a very thirsty setup. it seems on these forums u mention anything someone has had experiance with it.

 

[Volphin]

Re: fuel usage mercruiser 4.3

Correct. It mates up to the A1 with no issues. I get a 3 day weekend out of 1 tank of fuel.

 

[HT32BSX115]

Re: fuel usage mercruiser 4.3

At the same speeds, fuel use will be . . . . about the same

FWIW, there is very little difference in fuel efficiency between similar technology engines. 4 stroke carbed vs, 4 stroke carbed. 4 stroke MPI vs. 4 stroke MPI. Very similar. 2 stroke carbed, vs. 4 stroke MPI, now that might be worth counting.

That is absolutely right.

Because all the above engine technologies from the 3.0L engine to the 7.4L etc, exhibit essentially the SAME BSFC,

In the same boat loaded the same, GOING the SAME SPEED, they will use approx the same fuel (in lbs per nautical mile or mpg etc)

NOW, if you do a LOT of WOT driving or WOT starts, the bigger engines will OF COURSE use more.

But for the average running around, the fuel burn between a 470 (3.7L) and a 4.3L in the same boat loaded the same will be very close.....

There's other advantages in getting rid of the 470 that you probably already know............

You MAY have to change the drive though because the ratio may not be compatible, There is a very narrow range of prop RPM that is efficient.......EDIT: Yeah. Both the 4.3L and 3.7L engines use a 1.84:1 drive for many years.

You'll be able to easily part out your 470. Parts for them are in demand as are drives geared for them.

You may be able to get enough money for all your 470 engine/parts/drive etc to buy a new SEI drive of the correct ratio.


Regards,


Rick

 

[hadaveha]

Re: fuel usage mercruiser 4.3

I dont mean to head off down another road, but how big a task is it to winterize the 4.3 Im in alabama our winters are pretty mild. and we have days you would want to use it and re winterize it

 

[HT32BSX115]

Re: fuel usage mercruiser 4.3

I dont mean to head off down another road, but how big a task is it to winterize the 4.3 Im in alabama our winters are pretty mild. and we have days you would want to use it and re winterize it

Change the engine and drive oil, run the engine (on "muffs) and fog, remove the block and manifold drains, poke the holes with a piece of wire (to help clear them of rust flakes/debris) remove the big hose from the circulating pump and allow everything to drain.

Lower the drive and allow it to drain,

and park it.

There's instructions in the sticky-messages for whatever I missed......

 

[achris]

Re: fuel usage mercruiser 4.3

I just had heard from a few people that the 4.3 was a very thirsty setup.

Complete bollocks! Sorry, I have to be more diplomatic. That's not essential true.... I'm not gentle with my right hand (heck, God gave me 220hp. Who am I not to use them : :facepalm... My average fuel usage is around 1.3 litres per nautical mile .... Way better than my old 165 (in-line 6)...

Chris............

 

[QC]

Re: fuel usage mercruiser 4.3

Complete bollocks!

It's OK, Chris, we don't know what bollocks is (are)

 

[achris]

Re: fuel usage mercruiser 4.3

It's OK, Chris, we don't know what bollocks is (are)

A couple of my favourite expressions for a 'not truthful situation' comes from Harry Morgan as Colonel Sherman Potter... "Poppy-****!" and "Horse-hockey"....

 

[QC]

Re: fuel usage mercruiser 4.3

Yeah, see you would hear American ones from TV. We, on the other hand, are in our isolated little world. Before I started traveling I had never heard bollocks, chocker, chocker block, (flip) all, shed load (we use a variation), flyer, punt (not the football one), good on ya, sheila, and we thought you all drank Fosters . . . Sorry for the hijack.

I had my first Crownie on the Swan

 

[hadaveha]

Re: fuel usage mercruiser 4.3

ok guys sold I think im out of the 470 buisness forever, I know some people love them but IM going to comeover to the 4.3 team as long as the guy im buying it from still has it.

 

[HT32BSX115]

Re: fuel usage mercruiser 4.3

Yeah, see you would hear American ones from TV. We, on the other hand, are in our isolated little world. Before I started traveling I had never heard bollocks, chocker, chocker block, (flip) all, shed load (we use a variation), flyer, punt (not the football one), good on ya, sheila, and we thought you all drank Fosters . . . Sorry for the hijack.

I had my first Crownie on the Swan

You can buy Fosters at Safeway!

I like Tooheys though................

Chris,

You get that good beer out in the Western Frontier? It's a LONG ride from Sydney!

 

[QC]

Re: fuel usage mercruiser 4.3

No. I got it there. The joke is you can't find Fosters in Australia very easily. VB, Toohey's, Carlton, Crown (their Budweiser I guess), but no Foster's. It's Australian for "the Jokes on you Yanks!".

 

[achris]

Re: fuel usage mercruiser 4.3

You Chris,

You get that good beer out in the Western Frontier? It's a LONG ride from Sydney!

The drink of choice over this side is 'Swan', both lager and bitter. Swan Brewery

.... It's Australian for "the Jokes on you Yanks!".

 

[HT32BSX115]

Re: fuel usage mercruiser 4.3

The drink of choice over this side is 'Swan', both lager and bitter. Swan Brewery

When I used to go to RAAF Base Richmond (then Alice Springs & Learmonth) on a regular basis, we always had the cabs stop on the way to Sydney so we could pick up a few cases of Tooheys, Fosters and whatever else was there! I don't remember Swan but I'll bet I can find it here somebody must be importing it!!!

I'm gonna ask my (Kiwi) Future Son-in-law if he can get it in Auckland!

 

[achris]

Re: fuel usage mercruiser 4.3

When I used to go to RAAF Base Richmond (then Alice Springs & Learmonth) on a regular basis, we always had the cabs stop on the way to Sydney so we could pick up a few cases of Tooheys, Fosters and whatever else was there! I don't remember Swan but I'll bet I can find it here somebody must be importing it!!!

I'm gonna ask my (Kiwi) Future Son-in-law if he can get it in Auckland!

I'm currently about 40 miles north of Exmouth....

 

[HT32BSX115]

Re: fuel usage mercruiser 4.3

I'm currently about 40 miles north of Exmouth....

Hmm...I've been out there several times......but if I told you where......Well, I'd have to.............well........(you know!)

When we went there though, now that I think about it, someone used to bring us these HUGE bricks of frozen shrimp! The shrimp were huge too! I don't remember what it cost but it was a bargain!


We'd bring them all the way back to the states in the wheel well. (they stayed frozen in the -55 temps!)