4.3 merc speed

sdw41lite

Petty Officer 3rd Class
Joined
Sep 5, 2011
Messages
75
Re: 4.3 merc speed

I have a 2011 Tahoe Q7i with the 4.3 MPI (220hp) Alpha 1, it has a 19P Mercury Enertia 3 blade stainless. The boat really has not been broken in fully yet however I did do a WOT run briefly and it registered 58 mph on the speedo trimmed up (can't remember the RPM I think it was at about 5000) This was with myself and two others in the boat.

I agree with Smoke however...all of us telling you what our boats do doesn't really mean much for yours. You should be telling us what YOURS does and what you have...and also go by the guidlines of WOT and what rpm you are at with your prop size.
I started this tread for people that have 4.3s could see how other boats are running and what they are running. I wasnt looking for advice. I know all boats will be differant and will not have the same results but it could help someone if they have the same boat or something close. I did add the part about a 4 blade prop becuz I noticed everyone was using a 3blade, and was wondering if anyone was using a 4 blade and how they liked it. I had been thinking about one. Any way I ll put it on here again I have a 1996 Monterey Montura 210 with a 4.3 lx vortec heads with a 4 barrel webber carb. does mid 40s at 4800 rpm thats rite were it should be motor range is 4400 to 4800rpms. I have a merc 19 pitch 3 blade alum prop
 

PrinceValium

Chief Petty Officer
Joined
Jun 2, 2010
Messages
421
Re: 4.3 merc speed

Dang PrinceValium, you must have that thing waxed up! 58 is awesome! I hope my new one runs like that...

LOL...just keep in mind that was just indicated. I need to take it out by myself with a GPS and get the real numbers. The Enertia 3 blade works really well though!
 

PrinceValium

Chief Petty Officer
Joined
Jun 2, 2010
Messages
421
Re: 4.3 merc speed

I started this tread for people that have 4.3s could see how other boats are running and what they are running. I wasnt looking for advice. I know all boats will be differant and will not have the same results but it could help someone if they have the same boat or something close. I did add the part about a 4 blade prop becuz I noticed everyone was using a 3blade, and was wondering if anyone was using a 4 blade and how they liked it. I had been thinking about one. Any way I ll put it on here again I have a 1996 Monterey Montura 210 with a 4.3 lx vortec heads with a 4 barrel webber carb. does mid 40s at 4800 rpm thats rite were it should be motor range is 4400 to 4800rpms. I have a merc 19 pitch 3 blade alum prop

Well the way you started the post it was unclear what replies you were wanting. I guess it all depends on what you are looking for...a 4 blade will have better low end torque while losing some top end while a three blade will give you the best of both worlds. For us we pull tubes and wakeboarders and skiers and this 3 blade does quite well. We also love to have some top end to have some fun with the other boats on the way to the coves. :) Good thing about the stainless is that there is less flex...the bad things are they are really expensive and if you hit something they are not as forgiving as an aluminum prop. I will stick with my 3 blade.

Are you needing the extra pull out of the hole wanting a 4 blade?
 

joewithaboat

Lieutenant Junior Grade
Joined
Jul 3, 2011
Messages
1,172
Re: 4.3 merc speed

Hey sdw41lite,
I knew exactly what you meant when posting. Just getting a feel for other boaters experience's with 4.3's in general.
Folks can get pretty bossy around here, even though ultimately they mean well.
 

sickwilly

Lieutenant Junior Grade
Joined
Jul 9, 2007
Messages
1,089
Re: 4.3 merc speed

Wow ... who was bossy? I assumed the same thing as many of the others. He wants some context to evaluate the performance of his motor, out drive, prop combo. Then when he asked what people think about his going to a 4 blade, bingo, he wants advice.

I know some of us have winter fever, but come on. What is wrong with trying to offer a guy some help?

Context is everything. There are 4.3 pre and post vortecs. 4.3's with 2 barrels, 4 barrels, and fuel injected. 4.3 merc and volvos. there are also lots of different gear ratios within both.

There are those of us that want top end and those of use that want low end.

Without some context, its apples to oranges, even if they are all 4.3s.
 

sdw41lite

Petty Officer 3rd Class
Joined
Sep 5, 2011
Messages
75
Re: 4.3 merc speed

Thanks gunsup, hope the new motor runs god for you
 

Chaz7R

Seaman Apprentice
Joined
Jun 7, 2009
Messages
47
Re: 4.3 merc speed

Simple questions should get simple answers lol. I dont have a 4.3 in my boat but my old man has a older 1992 regal bowrider that can just touch 50 mph in perfect conditions 190hp version. But usually with extra people and gear and chop will run about 46 mph wot
 

PrinceValium

Chief Petty Officer
Joined
Jun 2, 2010
Messages
421
Re: 4.3 merc speed

Hey sdw41lite,
I knew exactly what you meant when posting. Just getting a feel for other boaters experience's with 4.3's in general.
Folks can get pretty bossy around here, even though ultimately they mean well.

Yeah smoke...stop being so bossy!:rolleyes:;)
 

cyclops2

Banned
Joined
Apr 19, 2011
Messages
1,237
Re: 4.3 merc speed

Well once you can get the RPM Limiter to start dropping the rpms every 5 or so seconds..............

There is no more, no how , no way. For sure. :D

Rich
 

MCL

Petty Officer 2nd Class
Joined
Feb 13, 2010
Messages
109
Re: 4.3 merc speed

I have a 2011 Tahoe Q7i with the 4.3 MPI (220hp) Alpha 1, it has a 19P Mercury Enertia 3 blade stainless. The boat really has not been broken in fully yet however I did do a WOT run briefly and it registered 58 mph on the speedo trimmed up (can't remember the RPM I think it was at about 5000) This was with myself and two others in the boat.

I agree with Smoke however...all of us telling you what our boats do doesn't really mean much for yours. You should be telling us what YOURS does and what you have...and also go by the guidlines of WOT and what rpm you are at with your prop size.

I quess you are have the 1,62 gear ratio on the alpha.Have you confirmed your speed with a gps?
Im building a older boat for a somewhat similar speed goal.Boat is a older 19,5 ft cuddy,gutted of all wet foam to make it light again.
Engine is a new 4,3 vortec with 4bbl edelbrock and performer intake,aluminum water pump,aluminum hge manifolds with runners and ss risers.Should make the same or more hp as your engine with less weight.The drive is replaced with a 1,62 sei.I have a 19p balanced mirage plus and going to get a 20/21 p enertia to try it out.I quess it all boils down to hull efficiency but hoping for similar numbers as your setup.
 

PrinceValium

Chief Petty Officer
Joined
Jun 2, 2010
Messages
421
Re: 4.3 merc speed

I quess you are have the 1,62 gear ratio on the alpha.Have you confirmed your speed with a gps?
Im building a older boat for a somewhat similar speed goal.Boat is a older 19,5 ft cuddy,gutted of all wet foam to make it light again.
Engine is a new 4,3 vortec with 4bbl edelbrock and performer intake,aluminum water pump,aluminum hge manifolds with runners and ss risers.Should make the same or more hp as your engine with less weight.The drive is replaced with a 1,62 sei.I have a 19p balanced mirage plus and going to get a 20/21 p enertia to try it out.I quess it all boils down to hull efficiency but hoping for similar numbers as your setup.

No it has not been GPS confirmed as of yet...I really want to take it out and see what it will do. I would actually expect it to run better in the cooler weather. I really don't know the gear ratio to tell you the truth...I will have to look into that. I will soon ad some smart tabs to the boat too, to help get it out of the hole better with a skier and to stop the proposing especially when the lake starts to chop. I need to find my paperwork to see if the gear ratio is listed.
 

PrinceValium

Chief Petty Officer
Joined
Jun 2, 2010
Messages
421
Re: 4.3 merc speed

LOL I guess sometimes I don't know the strength of my typing fingers.... Good thing I wasn't trying to be mean... I mighta killed the poor guy:facepalm:

Maybe I could recommend some anger management.:D

This site really needs more smileys!
 

jbetzelb

Petty Officer 1st Class
Joined
Apr 28, 2011
Messages
301
Re: 4.3 merc speed

I had a prop sales guy tell me a 4 blade wouldn't do much for 4.3. He said a good 3 blade would out perform any 4 blade on both sides with the 4.3 engine and OMC out drive. I have a 89 19 foot reinell 2 barrel carb that will run 55 with just me in the boat. Shoots out of the hole quick too. 3 blade 21 pitch stainless prop.
 

jkust

Rear Admiral
Joined
Aug 2, 2008
Messages
4,942
Re: 4.3 merc speed

Looks like most of the 4.3's are in a pretty tight range. To give some context, my 18 footer to my knowledge has the heaviest dry weight of just about any made in the 2000's. Newer boats have started to catch up. Hull and engine only without batteries, gas, accessories is 2900lbs and a 4.3 gets worked hard with 33 gallons, lots of gear and 4 passengers. Completely loaded with 4 passengers, with my 21 pitch, agressive Turning Point, aluminum hustler is 46mph on gps at max rpms. If I am alone with low gas I can gps out at 51.2mph. The Pitot speedo is very close to gps along the range.
 

ksukats57

Petty Officer 3rd Class
Joined
Jun 30, 2011
Messages
78
Re: 4.3 merc speed

19' VIP 19" prop 4.3LX will run about 43-46. Smart tabs really helped the hole shot.
 

Jasoniboat

Seaman Apprentice
Joined
Jun 23, 2011
Messages
38
Re: 4.3 merc speed

I have an 1997 18 ft Sea Ray, 4.3L, 18 inch prop. I can get up to 47mph in perfect conditions...based on the speedometer.

However, not sure of the speedometer is correct, though I have no reason to believe it isn't.

Is a GPS accurate on the water ?

By the way, I am a newbie.
 
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