Merc 305 Vs. 350 - Input Please!

[jmw129]

Guys,

I have been swamped with options between different boats expecially this time of year. I don't like boat payment so yes I'm looking at older boats typically in the $700 to $2,000 range depending on the boat. Yes these boats need some interior work but the engines are solid and the hull varies (from fade to very good depending on the boat).

Here is my dilema:

17ft 1984 Celebrity - 305 with Edlebrock carb & intake = 230hp - 245hp?? weighs in around 2,200 / beam - 89inches
Price: $850 (winterized)

18ft 1980 Formula - 350 stock = 260hp weighs in around 2,700 (Needs alot of interior work & looks like 1980) beam - 92inches
Price: $700 (Not winterized)

19ft 1978 Chaparral - 305 stock = 228hp weighs in around 2,100 (interior is original but decent) Beam - 86inches
Price: $700 (Not winterized)

The application I would be using is the sun deck with bucket seats so all 3 boats would work. Now is the 305 with edlebrock carb & intake pushing 2,200lbs going to have

the same top end of the 350 pushing 2,700lbs?

My mechanic has a model newer is better, prefer's stock 350 over 305 but didn't say anything bad about the 305 with the edlebrock intake & carb.

I want your opion. Will the 350 with 500lbs more weight to push have a higher top end?

The 305 get's 45mph according the seller with a 19p and the 350 the seller thinks it's around 48mph.

Your thought?

Boat you like most out of the 3?

All 3 companies seem to be good quality (I think).

 

[thumpar]

Re: Merc 305 Vs. 350 - Input Please!

Personally I would go with a 4.3l before I would go with a 305. So between a 305 and a 350 I have to go with a 350. The celebrity is probably the best looking out of the choices though. The only thing I would be concerned with is if the carb is marine. Also don't be in a rush to buy. Prices are going down with the colder weather so you have a couple months to look if none of those are ideal for you.

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

Personally I would go with a 4.3l before I would go with a 305. So between a 305 and a 350 I have to go with a 350. The celebrity is probably the best looking out of the choices though. The only thing I would be concerned with is if the carb is marine. Also don't be in a rush to buy. Prices are going down with the colder weather so you have a couple months to look if none of those are ideal for you.

I haven't bought a boat during the cold months so do you remember some deals you seen during the colder months?

Why the 4.3V6?

The 4.3 has less hp and less torque so would like to know why?

 

[GA_Boater]

Re: Merc 305 Vs. 350 - Input Please!

What do you want to use the boat for? Cruise, fish, ski, putt around, sit at the marina, whatever?

 

[thumpar]

Re: Merc 305 Vs. 350 - Input Please!

The economy of the 4.3l makes up for the lower horsepower IMO. The 4.3l has a good amount of power. My buddy had a 18' maxim with a 4.3l. If I was going to go bigger I would get the 350 and skip the 305. I would bet the 305 uses pretty close to the same amount of fuel as the 350.

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

From GA Boater:

What do you want to use the boat for? Cruise, fish, ski, putt around, sit at the marina, whatever?

My reply: Cruise, go fast, relax, dink around, depends on the mood but every guy has to get his chops on right?

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

The economy of the 4.3l makes up for the lower horsepower IMO. The 4.3l has a good amount of power. My buddy had a 18' maxim with a 4.3l. If I was going to go bigger I would get the 350 and skip the 305. I would bet the 305 uses pretty close to the same amount of fuel as the 350.

Do you remember the top end speed your buddy had with the maxum?

 

[thumpar]

Re: Merc 305 Vs. 350 - Input Please!

I believe it was in the low 40's. I think it was 43 from memory. It was a lot faster than my boat with only a 120.

 

[John_S]

Re: Merc 305 Vs. 350 - Input Please!

Those are all crankshaft hp ratings, and if you want to compare to todays boats which are all rated at the prop, deduct 25-30HP. I wouldn't rate the hp of the 305 w/edelbrock, any more than the stock mercruiser 305/4brl of the day. Considering the engine alone, I'd choose the 350. It would have better pulling power and would still be slightly faster.

But, a greater concern would be floors, stringers, and transom condition. Water logged foam is a high possibility. Boats of that era, could easily need a considerable amount of that type of work. Review some of the restoration threads to make sure you are up to that. Drives, engine condition, so much else plays into it vs possible top speed. Top speed of the boat in the driveway being worked on, zero.

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

I believe it was in the low 40's. I think it was 43 from memory. It was a lot faster than my boat with only a 120.[/QUOTE

One of the things I take into consideration is the weight of the boat in addition to hp. A bigger boat is going to need more hp to get it's scoot on.

Just not sure if 500lbs with only 20hp-30hp more in the 350V8 is going to give me any more top end.

 

[duped]

Re: Merc 305 Vs. 350 - Input Please!

I would certainly be more concerned about the mechanical and structural conditions of the boats more than anything else. Performance wise, it honestly sounds like a wash to me...

 

[tpenfield]

Re: Merc 305 Vs. 350 - Input Please!

You are asking a really tough question, since the boats are so old. There are a lot of age related variable at play that would effect the boat and the engine. The only way to determine which boat is faster is to grab the GPS and go for a ride on each of them.

Your better question should be which boat will give the best overall performance/ride?

I have a 1991 Formula 24 foot that weighs 4750, has a 454 engine 330HP and it goes 48 mph.

I would go with the bigger/heavier boat to get the best ride.

Based on the age of these boats, do we have stringer, transom or floor rot.?

 

[GA_Boater]

Re: Merc 305 Vs. 350 - Input Please!

From GA Boater:

What do you want to use the boat for? Cruise, fish, ski, putt around, sit at the marina, whatever?

My reply: Cruise, go fast, relax, dink around, depends on the mood but every guy has to get his chops on right?

I agree! Everyone has different goals. That's why I asked. You should grab the one that is in the best overall condition regardless of the power plant. You won't run WOT all day long, but you don't want other probs keeping you at the dock. At the end of the day 35 or 40 mph isn't a whole lot of difference.

 

[TomB985]

Re: Merc 305 Vs. 350 - Input Please!

For the record, my 18.5' Larson with the 4.3L engine will hit 48 MPH with a couple people in it. But seriously, the boat spends less than 10% of it's time going that fast...while it may not seem fast, 48 MPH on water is downright uncomfortable unless you're on the calmest of waters.

I like being able to boat all day on 10-12 gallons of gas!

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

You are asking a really tough question, since the boats are so old. There are a lot of age related variable at play that would effect the boat and the engine. The only way to determine which boat is faster is to grab the GPS and go for a ride on each of them.

Your better question should be which boat will give the best overall performance/ride?

I have a 1991 Formula 24 foot that weighs 4750, has a 454 engine 330HP and it goes 48 mph.

I would go with the bigger/heavier boat to get the best ride.

Based on the age of these boats, do we have stringer, transom or floor rot.?

All 3 seller's have said the transom, floor, and stringer are in good shape. How would I know the transom is bad while on land??

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

For the record, my 18.5' Larson with the 4.3L engine will hit 48 MPH with a couple people in it. But seriously, the boat spends less than 10% of it's time going that fast...while it may not seem fast, 48 MPH on water is downright uncomfortable unless you're on the calmest of waters.

I like being able to boat all day on 10-12 gallons of gas!

My last boat was alot smaller 16ft'er, 120hp and very light. Top speed in the 35 -37mph range so 45mph would be a nice step-up. Even 48 would feel even better.

One of my reasons for wanting a bigger, stonger, and faster boat is I don't like getting pushed around by bigger boats with wakes and was hoping an upgrade in size, power, and weight would take care of that unless I was gettin my scoot on during WOT and hitting wakes or big waves in general then I can see how the ride could be very bumpy or require drawing back on the throttle to not ruin the ride quality.

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

All 3 seller's have said the transom, floor, and stringer are in good shape. How would I know the transom is bad while on land??

So your experience has been with the heavier boat your ride quality improved greatly?

You don't get pushed around or banged around when cutting through strong wakes, waves, chop, etc?? If no, then what speed do you start to slow down to?

Did you own a smaller boat before your formula?

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

Posted to the wrong person.. My bad!

 

[GA_Boater]

Re: Merc 305 Vs. 350 - Input Please!

All 3 seller's have said the transom, floor, and stringer are in good shape. How would I know the transom is bad while on land??

Of course they did. Plenty of ways to check for rot without putting the boat on the water. Search the forums for hints. Are you planning on a water test this time?

 

[jmw129]

Re: Merc 305 Vs. 350 - Input Please!

No water test because it's too late in the season. The 18ft formula and 17ft celebrity owner's both agreed to run the engine on land so I could do an inspection.