Improving hole shot in 270FV

MDboater

I made two changes this year that have produced a noticeable improvement in getting up on plane.  First I flipped the trim tabs so that the "wings" are facing down.  The following link shows how to do it.  Next, I flipped the Trim-In Limit Pin on the Bravo 3.  One thing to be weary of when making this mod is to be certain that your trim piston rods are clean at the tops.  The piston rods will now travel about an inch further into the cylinders.  I was concerned that the paint, white deposits, and assorted gunk that I had on mine would damage the seals.  I cleaned the piston rods really well with acetone and a little scotch brite where the deposits were heavy.  

https://www.youtube.com/watch?v=vD7zNprwuD4

I have noticed some increased vibration with the trim all the way in now when on plane.  The vibration smooths out after trimming out a little bit.  Any ideas of what this could be?  Could it be an engine alignment issue?  

I have a 2003 350 MPI engine and 24P three blade props.  Yesterday I got up on plane with less struggle than before and topped out at 4600 rpms (with a more than average load of 1/2 tank fuel, full tank of water, 1/4 full holding tank and about 1500 lbs in passengers and gear).  I may drop the pitch of my props in the future and/or go to a 4x3 blade combo.  

randy56

Seems to be a continued discussion, we allmost need a 270 categorie. Just installed a 4/3 21 pitch it helps. used to have 3/3 22 pitch. I can see how you had a struggle, the 22's were a struggle. Have not turned my tab blades over yet. cleaning bottom and waxing this week.

MDboater

randy56 said:

Seems to be a continued discussion, we allmost need a 270 categorie. Just installed a 4/3 21 pitch it helps. used to have 3/3 22 pitch. I can see how you had a struggle, the 22's were a struggle. Have not turned my tab blades over yet. cleaning bottom and waxing this week.

So how did your top speed and max rpms change in going from 3/3 22P to 4/3 21P?

Turning the tab blades was surprisingly easy.  The only hard part is finding a small punch to drive out the hinge pin.  The person in the video made their own.  I happened to have a small enough punch in my boat tool kit.  After flipping, I attached the blade to the actuator to determine the best location within the hinge.  You will now be offset one hinge tooth from your previous position so you want to pick the location that is least likely to bind.  There was some corrosion on my 12 year old hinge pin so I was very careful when reinstalling.  I grabbed it with small vice grips about 1 inch from the hinge and tapped the vice grips with a hammer to drive in the pin.   

randy56

thanks for tip on tabs, every little bit will help. I see you are following the other discussion on same topic. My top speed before was 44, now 38, but I forgot to look at rpms. those 4x4"s sound like the ticket? the 4x3's are better that stock.

jmichels

randy56  "top speed was 44" what the heck u got in that thing! I see 38 on a good day all done

randy56

300 mpi, clean bottom, half tank fuel, no water, no water in poop tank, my bottom was not clean last time out, we will see. that was by myself. just me and a 6 pack. I do use gps not speedo in boat however it is pretty close. It needs to be 502.

reneechris14

8.2 and a Whipple

06Rinker270

@randy56 you get 44mph on a 350 mag?

randy56

@06, yes, what are you doin? next time your out, tab down a bit, trim up a little less than 1/4 on the gage.  Not to high trim, so much you do the Baja bounce.  Is your bottom clean?
 
@reeechris, yes that will do.  

@MD, fliped tabs, easy job.

06Rinker270

@randy56 no where near that.  Having some trouble right now as you will see in my other post.  Trim gauge isnt working so I am going by feel and keeping the bow rail at the horizon.   Bottom needs a good cleaning, been in water since March.  How many bars do you trim down and do you do this before advancing throttle?  I trim drive up as I am accelerating.  

jmichels

best ive ever seen is 38 trimmed up, tabs just one bar to keep porpoise in check and WOT hitting about 4600-4800 rpms. bottom was freshly bottom painted and hull waxed like babys ****. 

randy56

@06Rinker I do not have a gauge on my trim tabs, go by feel, I wait till I'm on plane before adjusting anything. On take off, drive all the way in tabs down, after on plane trim up drive then tabs, probley does not mater which one first. A dirty bottom will slow ya down.

@jmichels, just  to compare, what props are you running? sounds like you are right on if you get up on plane fairly quick. I'm now at 38 with the 4/3 21 pitch. the 3/3 22 pitch were faster but I would rather have hole shot, I'm going to try and pull skier this weekend. But would not even try that  before.

diggin2day1

I was out on the water today... Slight chop with hardly any wind. Just me on board, less than 1/2 tank of fuel, empty waste tank and about 1/2 full fresh water tank. Boat is bottom painted and has been in the water since May 1st. Mercruiser 350 MPI Horizon, Bravo 3 with 22p stainless 3-blade props. I have 12"x18" trim tabs and get up on plane in a "reasonable" amount of time with an average load(me, wife, 2 kids and gear). I was able to reach 39mph @ 4668 rpm... Here is a picture of my VesselView confirming it:

randy56

What! how did you get to go out today. It rained here almost all day. Your vesselview is nice. I bet very true readings. 

jmichels

randy56 said:

@06Rinker I do not have a gauge on my trim tabs, go by feel, I wait till I'm on plane before adjusting anything. On take off, drive all the way in tabs down, after on plane trim up drive then tabs, probley does not mater which one first. A dirty bottom will slow ya down.

@jmichels, just  to compare, what props are you running? sounds like you are right on if you get up on plane fairly quick. I'm now at 38 with the 4/3 21 pitch. the 3/3 22 pitch were faster but I would rather have hole shot, I'm going to try and pull skier this weekend. But would not even try that  before.

Ill have to check. boats in the water at the slip. Will be pulling it in a few weeks to put new gimbal bearing in and ill check it out. Thanks man

jmichels

how much improvement do you think a 383 mag mpi would make ? love to see 45 out of this thing on a regular basis

randy56

www.mercurymarine.com/en/us/engines/inboard-and-sterndrive/remanufacturing/plus-series-bravo-sterndrives/

They say the 383 produces 370 HP so 70 more that what we have.

BellevilleMXZ

Drool!!!

http://www.volvopenta.com/volvopenta/global/en-gb/marine_leisure_engines/AQUAMATIC/c_gasoline_sterndrive/Pages/V8-430.aspx

jmichels

randy56- thought the 383 mag mpi were 350 hp?

belleville- looks very intriguing. any more details and price?

BellevilleMXZ

jmichels said:

randy56- thought the 383 mag mpi were 350 hp?

belleville- looks very intriguing. any more details and price?

probably way too much......lol.......would be sweet though....lighter and 430 hp

jmichels

its never enough lol. more is always better. 

06Rinker270

@randy56 so you bar all the way down with tabs, meaning they are all the way extended when taking off?

What are the standard props for the 270, 22 pitch?

Besides props what are some other ways to improve performance?

Sorry, question master over here.

MDboater

06Rinker270 said:

@randy56 so you bar all the way down with tabs, meaning they are all the way extended when taking off?

What are the standard props for the 270, 22 pitch?

Besides props what are some other ways to improve performance?

My 2003 270FV with 350MPI props are 3/3 24P.  Although I am consider a change to a 4/3 22P configuration.  I always have tabs all the way down when I bring the boat up on plane.  

diggin2day1

Tabs all the way down and trim all the way down.... When I hit approx 20mph I start to raise the tabs and adjust my trim until I hear the engine "free up". I usually run with a "small amount" of trim tabs to keep us level and prevent porpoising... It's always different depending on passengers, chop, wind and weight(fuel, water, waste) in boat. 

randy56

@06Rinker270 , diggin is spot on, on Friday 7/8/16 I'm putting boat back in, I will give a full report, on the 4x3 21 pitch. Rpm's mph ect. also I thought 22's were standard, but MD has 24's I don't know. Just fliped the tabs over so wings point down, easy change, may help. 

reneechris14

I will try to post on sat.
2002 270fv low swim platform
350mag 840hours
Bravo111 2.2
20 pitch 4x4 Hill Marine 

rinker270nb

I have the 383 Stroker EFI on my 99 270.  Put it in 12 mos ago, hardly any time on her. I will put up numbers next time I am out.  No problem getting on plane no matter the load. This week I had 6 adults 2 kids, full tank of fuel, full water, 1/4 waste, 2 coolers, and a damned relaxation station, I am up and out no problem.  I plane in a few seconds when it's just me.  The HP and torque are mind bending compared to the original 5.7.  its a whole new boat!

rasbury

wow, my 270, which has the 350, 2005 with about 200 hours, trailer kept so the bottom is clean- if I have two shall we say portley adults sitting on the back seat with a couple of coolers....I am usually asking them to move forward to get it planed out. That being said, something just broke loose in my drive line somewhere, perhaps I have another issue that was dragging the boat down, we'll see about that. I would gladly swap my props for a better hole shot....most of the river I run you can only go 25 anyway and usually, I'm just not in a hurry for time or to burn a lot of fuel running 35 which I think is about where I top out or used to anyway. Engine runs fine, I always start with everything trimmed down and as I start to plane I start to trim to get up on plane as soon as I can. I am satisfied with the performance overall but do wish I could plane out a little better. Perhaps when I fix what ever the drive line problem is I will have that little "edge" I don't have now for that hole shot...

jmichels

rinker270nb said:

I have the 383 Stroker EFI on my 99 270.  Put it in 12 mos ago, hardly any time on her. I will put up numbers next time I am out.  No problem getting on plane no matter the load. This week I had 6 adults 2 kids, full tank of fuel, full water, 1/4 waste, 2 coolers, and a damned relaxation station, I am up and out no problem.  I plane in a few seconds when it's just me.  The HP and torque are mind bending compared to the original 5.7.  its a whole new boat!

 Nice. This I like to hear.  Now previously you had the old version of the 350 though right, The 350 Mag not mpi and was 260hp? So you went from 260 hp to 350 which is a big jump

MDboater

rinker270nb said:

.... and a damned relaxation station, ....

LOL!! Relaxation Station..... such an oxymoron.  I assume that you mean the behemoth blow up from Costco.  You must have an electric air pump and then devote 20 minutes to blowing it up and another 20 minutes to deflating it.  It includes a rope ladder that is usable by only a gymnast.  It weighs 40 pounds dry and requires a 20 gallon sized bin for storage.  Yeah, it's just what every pocket cruiser fighting to get on plane needs.  I cringe whenever the admiral asks me to bring and deploy it.  We got about three seasons of use out of ours before the mesh middle ripped from the kids constantly playing in there.

06Rinker270

Can you stroke the 350 to get more?