1974 Starcraft Islander project

I just bought a 1974 islander 21 ft. It is now powered with a 4 cyl mercruiser.
The original should had been a 6 cyl because of the empty space in front of the engine.

I found a complete 5.7 with close cooling, foot gimbal etc for under $2000 this engine setup is said to only have 100 hrs.

My question is if the islander is build strong enough to handle over 250hp.

if not, how to modified improved the engine mounting to make it possible and safe.

Thanks

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

Hey! Nice rig Roy! Yours is in WAYYY better shape than mine! I wouldn't be the pro in this area but man, I'd say that would be huge power to be putting in that tin boat! Over powered? I am sure others will give you a heads up on that.

Cheers!

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

Hey man, I have the 5.8 250 HP in my boat. Make sure the transom is in great shape and you should be fine. I did notice that your existing engine mounts on the front and back horizontally. On a V8 installation you'll be mounting longitudinally. You'll have to put in a larger fuel tank or bring more fuel along for that beast!

5 speed

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

The original should had been a 6 cyl because of the empty space in front of the engine.

Click to expand...

Ayuh,... You have the original motor, the I6 was an Option...

I shoe horned a 4.3LX into My 74 Islander... It's borderline Over-powered with It...
A 350 will make that hull FLY...

That's a nice clean Original lookin' hull... Welcome Aboard...

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

I decided to keep an inline engine there.
so I will stick with the 4 cyl for now. I don't like the way the transom flex so i will pull of the engine and install a new transom in, since there is something wrong with the stering i will fix that at the same time.

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

Well i found a donors boat , its a Glastron sv 189 with a mercruiser 165 hp inline 6. will send pics next week .

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

nice looking boat, don't be surprised if you start the transom and find some more work to do. Good Luck and welcome to the club

Re: 5.7 in 1974 21 ft islander

Re: 5.7 in 1974 21 ft islander

For what it's worth I had a very good friend that had a late 90's 21 ft Islander WITH a factory hard top which was powered with a 4 cyl 130 hp Mercruiser.

He and I fished it a lot, with lots of off shore here in New England and I have to tell you that we were never at a loss for power! Usually 3 to 4 people, full tank, dual batts. and gear. Sometimes 4 or five people on board. Suprised the heck out of me.

Can't imagine what a 5.7 in one of those would be like as while the hull is awesome it is not designed with "performance" in mind.

Also, that 3.0 is probably one of the most reliable power choices available, parts are cheap, it is easy to work on, only has 1 cylinder head and one set of manifolds. Hell, with all the space in the motorwell it's almost a joy to service them!

Can't say that about ANY of the V blocks out there.

Re: 1974 starcraftb islander project.

Re: 1974 starcraftb islander project.

I had my islander running with a 1977 165 hp inline 6 complet with transom and drive. boat work fairly good , next stage in the project will be to removed all the drive and engine from the boat and redo the transom, removed floor , removed fuel tank and replaced with 95 ltr under floor plastic tank. replaced missing stringer rivet put in new floor with no carpet , two part garage floor paint or vinil . there is some work to be done in the cudy, wiring and dash so it came out to be a big project.

It will take me over a year to finish.

I have a 74 21' islander and it is equipped with a factory olds 455 and jet

Cherokee - It's been over 4 years since this topic had any activity. Please do no post in topics with no activity for 90 or more days. Thanks