Volvo AQ120B/270 upgrade/modification questions

C

chpprguy

Cadet
Joined
Aug 10, 2009
Messages
10
I have a 1979 Galaxy 19? 6? open bow boat, with a an AQ120B/270 combo,
A couple questions please.

The stern tilt/lift was rammed up through the stern plate, I would assume the previous owner forgot to put in the trailer bracket.
I have found a new stern plate and am preparing to pull the motor/outdrive this winter to replace it, and do some interior and floor work as well.

The motor runs well, and the speedo says she?ll hit 25mph (it only works some of the time)
Although it takes a few minutes for the boat to ?plane out?
Are there any easy ways to get more power from the motor?
(fuel injection,forced induction, etc?) or should I consider a motor swap since I will have it out?
Is there a retro fit power trim/tilt system for the 270 outdrives?
Or could I fabricate one using Mercruiser or OMC parts?
My friend has a Mercruiser outdrive and the tilt cylinders appear pretty simple, I believe I could fabricate brackets to mount on my outdrive.
I like the size of this boat, (fit?s my family well, and rides well in the water)
I am a welder by trade and have a mill/lathe at my disposal, so I can fabricate and weld aluminum.

Thank you for any tips/advice in advance,
Andy
 
C

chpprguy

Cadet
Joined
Aug 10, 2009
Messages
10
Re: Volvo AQ120B/270 questions

Re: Volvo AQ120B/270 questions

any thoughts/opinions would be appreciated....
 
C

captmello

Captain
Joined
Jun 30, 2008
Messages
3,849
Re: Volvo AQ120B/270 upgrade/modification questions

Well, I guess the logical, practical thing to do would be to either get a different boat, or repower with a drivetrain out of another boat. However, it sounds like you've got some Ideas that most of us wouldn't consider.:)

What RPM are you getting at 25 mph?

How bad is your floor?
 
C

chpprguy

Cadet
Joined
Aug 10, 2009
Messages
10
Re: Volvo AQ120B/270 upgrade/modification questions

I don't know the RPM, the tach doesn't work,
I am planning to work on that soon. The Previous owner fumbled with some of the wiring, so I hope it's an easy fix,
I am not sure on the accuracy of the speedo, as it doesn't seem to work until I go over 15 MPH....
This is my first boat, and as the motor and outdrive seem to work well, I was hesitant to replace them if I can get moderate performance from them.

I want a fishing boat, my wife wants a family boat...:)
It is a good size for the family, a little big for fishing. (fresh water only)

The floor is soft right in front of the drivers seat and the aft starboard in the battery well is really soft, but the rest of the floor seems ok, and I tried to look at the sternplate (board?) closely, it seems very sound.

My rough idea at this point was to use the "pin mount holes" in the stern plate
(the ones for the fixed trim latch point on the 270 outdrive)
to mount rams, and make a custom plate to attach to the outdrive,
then use the stern lift hole in the stern plate to make a custom hydraulic feedthru.
I can machine fairly well and am a professional welder (I can Tig aluminum, stainless,etc)
so the labor isn't an issue, but I would like to go with a reasonably cost effective route.
Would a home brewed stern lift system make it more user friendly, or is it not worth it? (adjustable trim)
The compression numbers vary a little between cylinders in the motor, but it seems to run well.

I did learn that the previous owner ran improper spark plugs (too short), so I would "assume" there was some spark plug shrouding that may have caused it to run rich and perhaps wash out the ring some?
I had planned to run the motor some more and then do another compression check.
The prop is a 14 x 17L and is banged up, I would guess a new prop, and maybe a different pitch might make a substantial difference?

I also took the shift mechanism apart, it is badly worn. I would need to weld the teeth up and reprofile it, is there replacement availability, or an aftermarket/common replacement?

Thanks again for reading my ramblings,
Andy
 
R

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: Volvo AQ120B/270 upgrade/modification questions

You are looking at way too much work to fix that boat, that is not really worth much. If you really like it, you will probably end up re-doing the floor, and stringers, since there is rott. And maybe even the transom. If you really want more power, your best bet is to buy a doner boat and use the parts from it and sell what you have on e-bay or craigslist.

Have a great day

Rob.
 
C

captmello

Captain
Joined
Jun 30, 2008
Messages
3,849
Re: Volvo AQ120B/270 upgrade/modification questions

Sounds like you've got your work cut out for you. With restorations, like your talking about, the first thing to do is get your engine dialed in, running really good. At the same time you should be going throught the routine maintenence items on the outdrive. Make sure the outdrive is good, Then you can get a true idea of how it performs. Then move to the floor, interior, etc.

With an underpowered boat, the prop is the best way to change the performance depending on what your doing at the time.

What were the compression numbers?

Why do you think your need power trim?
 
C

chpprguy

Cadet
Joined
Aug 10, 2009
Messages
10
Re: Volvo AQ120B/270 upgrade/modification questions

I have the compression #'s written down, but off the top of my head it was 140,120,130,140 front to back..... 20 psi seems a bit much to me.

I have a new prop coming, I realize I need to fix the tach.
Where can I find the recommended operating RPM for the engine?

I'll probably keep the boat and do the work, I like it (although it is HEAVY)
and more importantly, my wife likes it.....:p

I don't know that I need power trim, my friends locally (who are by no means boat experts) tell me that the power trim will help get the boat up to speed quicker, will help when pulling my daughter on a tube, and will allow me to pull the prop up when putting the boat in/out of the water or in shallow water. Is power trim is a useful advantage?

I did drain and refill the outdrive before I ever hit the water, the oil I took out looked like it had just been put in. The small volvo/penta owners manual recommended 10W-40 for engine and outdrive, so that's what I put in it.
Other than being hard to shift (which I am sure is at least 90% in my shifter/throttle mechanism) it ran well, idled well, didn't hesitate or bog.....

Again, thank you for your tips/info
Andy
 
C

chpprguy

Cadet
Joined
Aug 10, 2009
Messages
10
Re: Volvo AQ120B/270 upgrade/modification questions

Thank you for the info....
is there anything special about trim cylinders?
Are they standard hydraulic rams, or made of a special material for marine conditions?

Andy
 
You must log in or register to reply here.
Top