Re-powering a soon to be mine chieftain.

jasoutside

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Re: Re-powering a soon to be mine chieftain.

Well...

I know I went through many days and sleepless nights toiling over how I was going to power my rig. I knew it wasn't going to be of the OMC persuasion!

I ended up going with a donor Baja named Thumper - 4.3 Merc Alpha One. I've chopped up the boat, sold off some of the rigging, will sell some more gear that came off the Islander and the Baja, and when it is all said and done it was a super decision financially (I think, I hope). I know piecing together a drivetrain/controls/parts can get ridiculous expensive pretty quick. With a donor boat it's all there (er, should be all there) for you. And hey, there are plenty of glass boats out there with good drivetrains that have sat out for mother nature to have her way.

Two things in my situation...

First, I have yet to mount up and turn the key. I may have very well bought my self a giant headache. I gambled on it, but, I think it was a pretty safe bet for many reasons. Round about the middle or late summer I'll know for sure how good or bad I did.

Second, I'd have to say that the credit goes to Bondo for my selection in power - he called it from the start! Thanks again buddy.

So, I suppose, in my rookie and hardly educated opinion on such things I'd say:

If the boat comes with a reasonable motor/outdrive rebuild and have fun.

If the boat comes with something that is shot, spent, burned up, cracked, ugly, smells bad, has poor manners, lives in it's mothers basement and smokes weed while watching daytime talk shows -or- there isn't even an engine there, I'd say pick up a donor boat, keep what you need/like, sell off what you don't need/like and have fun.

Whoops, I blended my high school students and marine engines there for a second there, sorry. I suppose the criteria still applies though.

Either way, have fun!
 

achris

More fish than mountain goat
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Re: Re-powering a soon to be mine chieftain.

Ayuh,... Of Course it is,....Who ever heard of Too Much Horsepower......

Me!! (sorry Bond-o). Think about the speed you'll be cruising at most of the time... If you have WAY too much power, then that cruising speed is going to be outside the engine's power band. It will be a dog! Power a boat to have a top speed of about 1.7 times your favoured cruising speed. So if you like to cruise at 20 knots, then power the boat to top out at about 34 knots. That will keep the engine in the power band while cruising and still give you a nice top speed.

It's lovely to travel at 45 knots (I know, I've done it a few times :D:D:D), but most of the time the weather isn't that favourable... and if you have a top end far too high, then at cruising speed your engine is going to be too slow... Remember these engine (petrol) produce maximum torque at around 3500-4000. The power band starts at about 2800. Try and cruise below that and the engine can't hold a steady speed in adverse conditions. And the more the power from the same engine (bigger carb, bigger cam etc) the narrower the power band.... (that's why truck engine cams are better in boats)

0.02

Chris..........
 

Bondo

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Re: Re-powering a soon to be mine chieftain.

Second, I'd have to say that the credit goes to Bondo for my selection in power - he called it from the start! Thanks again buddy.

Ayuh,... You're Welcome....

When you guys are ready,...
I'll tell ya how to bend up a set of motor mounts for them there V-motors....;)
 

jasoutside

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Re: Re-powering a soon to be mine chieftain.

Ayuh,... You're Welcome....

When you guys are ready,...
I'll tell ya how to bend up a set of motor mounts for them there V-motors....;)

OOooo, intriguing! Hey buddy, have you got some photos somewhere here on iboats of your old Islander. Whoops, hijacking, sorry.
 

achris

More fish than mountain goat
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Re: Re-powering a soon to be mine chieftain.

...I'll tell ya how to bend up a set of motor mounts for them there V-motors....;)

:eek::eek::eek::eek:

I'm hiding under my desk. The keyboard is wireless so luckily I can type without giving away my position... :D
 

Bondo

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Re: Re-powering a soon to be mine chieftain.

:eek::eek::eek::eek:

I'm hiding under my desk. The keyboard is wireless so luckily I can type without giving away my position... :D

Ayuh,... Maybe abit of the language barrier thing again,..??
Or,...
I'm just missin' the joke...
Tin-knockers around here refer to forming tin into shape as Bendin' Up...

You can just see the mounts in this picture...
100_4163.jpg


Straight across the top of the stringers(riveted), bent downward, then a lip to rivet to the ribs...
I used .090 aluminum...
 

achris

More fish than mountain goat
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27,468
Re: Re-powering a soon to be mine chieftain.

Gee, for a minute there I thought you were referring to the engine mounting brackets themselves (the bits that bolt onto the engine)....

Nice pic... But YELLOW!!! really... why not a nice blue?

:D:D:D

Chris......
 

Bondo

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Re: Re-powering a soon to be mine chieftain.

But YELLOW!!! really... why not a nice blue?

Ayuh,... Cause I was paintin' Cat dozers at the time that motor was built,...
Next 1 is gonna be Mack Maxidyne Gold....;)
 

reorod

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Re: Re-powering a soon to be mine chieftain.

Ayuh,... Of Course it is,....Who ever heard of Too Much Horsepower...

My ole 74, with the 205hp, 4.3LX will poke along at 43mph, at 4800rpms... In Freshwater..
52mph in the Saltwater off Maine...
With the 140hp I took out it did 28mph...

And, That's a fully outfited Fishin' machine....

I'm guilty of over powering cars and promised myself I would not go over the top with relaxing project. Your tempting me and I always fail at staying on the low side of horse power.
 

Don S

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Re: Re-powering a soon to be mine chieftain.

I always fail at staying on the low side of horse power

Well, with that 120, you can't go any lower. It's the bottom of the HP list. Even if you were to put in a 3.0L engine, it would be an increase. ;)
 

achris

More fish than mountain goat
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Re: Re-powering a soon to be mine chieftain.


I thought something looked hinky... That engine was running when you took that photo, wasn't it?

Cheers,

Chris...
 

reorod

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Re: Re-powering a soon to be mine chieftain.

The power band starts at about 2800. Try and cruise below that and the engine can't hold a steady speed in adverse conditions. And the more the power from the same engine (bigger carb, bigger cam etc) the narrower the power band.... (that's why truck engine cams are better in boats)

0.02

Chris..........

Totaly under stand your view. The same with my old 46 1.5ton need that low rpm torque to tug along. Its not a speed machine but works well.
 

Bondo

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Re: Re-powering a soon to be mine chieftain.

I thought something looked hinky... That engine was running when you took that photo, wasn't it?

Cheers,

Chris...

Yes,... Just after the T-Stat housing swap...
 

HT32BSX115

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Dec 8, 2005
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10,083
Re: Re-powering a soon to be mine chieftain.

Well, with that 120, you can't go any lower. It's the bottom of the HP list. Even if you were to put in a 3.0L engine, it would be an increase. ;)


Yeah!


I'd vote for a 454/Bravo setup!!

B3.gif
 
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