4.3LX acceleration opinions

[Swedefj40]

So I'm curious about what I should expect in regards to how my boat accelerates out of the hole.

I have a 1996 Campion Victoria 215 (3200lbs dry) with a 4.3 LX with 4bbl Carb, 190 prop shaft HP. 600 hrs on the engine. 14.5" x 19"p 3 blade alum prop. Not sure about gear ratio but I think it's 1.81. She's a salt water boat that gets trailered home after every trip and flushed and cleaned. I take good meticulous care of it and she's in great shape. My usual trips fishing usually involve 2 other guys on board. I don't punch it out of the hole but gradually bring it up to speed. Never had any issues accelerating and I usually cruise at 3800 rpm at 28 mph. I'm pretty gentle on it. My last trip out was for a picnic to a local beach so I had 2 young kids and us 4 adults plus fire wood, coolers of food and drinks, and a 9' inflatable dinghy. Sorry for the ramble but I'm trying to paint a picture here . So in order to get up on step, I had to hammer down WOL and had to get one of the guys to head forward to transfer some weight and she would go but I found it odd that being wide open, she would only climb to about 4000 rpm until we started planing then it would creep up to redline (4800). Should I expect the engine to redline (cavitate?) right away or does this seem right given the amount of prop/mass & engine torque? This is my first pleasure boat byw so not a lot of experience. Opinions please thanks.

 

[Swedefj40]

Boat pic in attachment if your curious..

 

[alldodge]

Boat pic in attachment if your curious..View attachment 344285

A pic of an Eagle and something in the background. Nice pic of the Eagle but this is a boat repair help site. If you have a problem with a boat let us know and we can help

 

[alldodge]

OK sorry had to do it
I don't see an issue right now because your overloaded. The boat weight distribution would have issue with what your seeing. Try to run it with normal load and see what it does

 

[Swedefj40]

Normal load she doesn't hit the redline right off the hop but is there in about 5 - 10 seconds or so. I guess what I'm asking is should there be enough torque in the motor to hit redline regardless of the load on the boat. Sorry for the noob question but I don't have enough experience on other boats to know what to expect.

 

[alldodge]

Its weight distribution. With folks moving forward it can tip the bow down and cause the prop to come closer to the surface. Grab some air and ventilate a tad. It would take some testing to figure out exactly what is happening, but this is my thought

 

[achris]

... 215 (3200lbs dry) with a 4.3 LX with 4bbl Carb, 190 prop shaft HP. 600 hrs on the engine. 14.5" x 19"p 3 blade alum prop. Not sure about gear ratio but I think it's 1.81.

That's a lot of boat to be pushing with that prop.

So in order to get up on step, I had to hammer down WOL and had to get one of the guys to head forward to transfer some weight

Like most passengers, they don't understand boat dynamics, and all head down the back for a more comfortable ride. You try to accelerate and the boat starts 'ploughing'. What you're seeing is completely normal.

and she would go but I found it odd that being wide open, she would only climb to about 4000 rpm until we started planing

Again, completely normal.

then it would creep up to redline (4800).

That's not 'redline', that's the manufacturers recommended maximum rev range based on the power curve profile (max power at 4600rpm, 200 rpm each side). Redline for those engines is in excess of 6,000rpm, but you're on the back side of the power curve, and sliding down rapidly, so it's a bit pointless propping for 6,000rpm.

Should I expect the engine to redline (cavitate?) right away or does this seem right given the amount of prop/mass & engine torque? This is my first pleasure boat byw so not a lot of experience. Opinions please thanks.

When you drop your foot in a car, do you expect the engine to IMMEDIATELY hit maximum revs? No, it needs to 'build up'. Same in a boat. As long as you are making the maximum recommended revs, you're golden.

Here's a piece of advice if you have big mates who like to consume copious quantities of the golden liquid, and generally party on the engine cover while you're trying to get the boat on a nice even keel for the cruise.
1. Slap a couple of those beefy guys around the ears and tell them to distribute evenly in the boat (ie, move up the front!)
2. Get yourself a 4 blade prop. They are fantastic for 'stern lift', which will reduce that ploughing, and get the boat on the plane quicker...

Chris.......

 

[nola mike]

Here's a piece of advice if you have big mates who like to consume copious quantities of the golden liquid, and generally party on the engine cover while you're trying to get the boat on a nice even keel for the cruise.
1. Slap a couple of those beefy guys around the ears and tell them to distribute evenly in the boat (ie, move up the front!)

Or put the cooler on the bow...

 

[alldodge]

Or put the cooler on the bow...

 

[Swedefj40]

That's a lot of boat to be pushing with that prop.

Like most passengers, they don't understand boat dynamics, and all head down the back for a more comfortable ride. You try to accelerate and the boat starts 'ploughing'. What you're seeing is completely normal.

Again, completely normal.

That's not 'redline', that's the manufacturers recommended maximum rev range based on the power curve profile (max power at 4600rpm, 200 rpm each side). Redline for those engines is in excess of 6,000rpm, but you're on the back side of the power curve, and sliding down rapidly, so it's a bit pointless propping for 6,000rpm.

When you drop your foot in a car, do you expect the engine to IMMEDIATELY hit maximum revs? No, it needs to 'build up'. Same in a boat. As long as you are making the maximum recommended revs, you're golden.

Here's a piece of advice if you have big mates who like to consume copious quantities of the golden liquid, and generally party on the engine cover while you're trying to get the boat on a nice even keel for the cruise.
1. Slap a couple of those beefy guys around the ears and tell them to distribute evenly in the boat (ie, move up the front!)
2. Get yourself a 4 blade prop. They are fantastic for 'stern lift', which will reduce that ploughing, and get the boat on the plane quicker...

Chris.......

Well that was exactly the kind of answers I was hoping to get Chris, they explain a lot! Interesting point about the peak RPM explanation too, I've been reluctant to get even close to the 4800 RPM range thinking I'd be stressing an older motor at that speed. Not that I'm going to start running it up there but it's nice to know that there's some headroom there. I've been tossing around the idea of going to a stainless 4 blade prop and I might look into it more seriously now. Fantastic answers thanks!

 

[Scott06]

As mentioned thats a lot of boat and people for that engine and a 19” prop try a 17” or better yet the 4 blade. If you want a inexpensive one to try out try a michigan votex 4 blade 16”. I used to run one of these when skiing on a 3.0( aka underpowered) boat. At the time i was about 250-260 lbs and it would pull me right up on skiis. Better to be slightly under proped than overproped like you are now

 

[Swedefj40]

It's a rare occasion that I had so many people and stuff with me. Generally it's 2 - 4 people not 6 and most often just 3 of us so there's not usually an issue. If I opt for a new prop I'll get the best one I can that works for me. I won't scrimp there.

 

[Scott Danforth]

Here is my take

So I'm curious about what I should expect in regards to how my boat accelerates out of the hole.

I have a 1996 Campion Victoria 215 (3200lbs dry) with a 4.3 LX with 4bbl Carb, 190 prop shaft HP.

that is a lot of boat for that wee little V6. just looking at dry weight you are at 16.8#/hp , you are at you are trying to push a lot of weight ..... compared to the 130-140hp with the 1600# 16.5' Avanti i had (12.69#/hp) , or the 220hp for the 19' 3000# SeaRay 190 I had (13.63#/hp) or the current 430+hp with the current 26', 3500# Cruisers (8.14#/hp).

My last trip out was for a picnic to a local beach so I had 2 young kids and us 4 adults plus fire wood, coolers of food and drinks, and a 9' inflatable dinghy.

so on top of your boat being a bit heavy, you have 800# of adults, 200# of kids, about 200# of firewood, about 400# of coolers and 70# of dingy along with other gear. that is 1670# of people and stuff (probably closer to 2000# if you include purses, PFD, phones, toys, etc) add 250# for fuel, and 200# for anchors/lines/fenders/etc

your wee little V6 is now trying to push 5320#. so your power to weigh ratio drops to 28#/hp.

i am surprised you made it up on plane.

additionally, Campion boats tend to be heavier than they published, even the new boats for M/Y 22 are heavy.

as stated above, being heavily loaded, your performance loss is normal.

 

[Swedefj40]

Lot's of great info, thanks guys!

 

[AKJohne]

Do you have trim tabs? they can help getting on step by pushing the bow down.

 

[Swedefj40]

Yeah I do, I'll try them next time.