Engine life..gas engines (ford 351) in 3288??????-gctid393927

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I wasn't sure if I should post this in technical or motor yacht section....

Anyway, I have twin 351's in my 3288. They have somewhere between 600 and 1000 hours on them. The previous owner hardly used the boat and did not have hour meters so since 2005 I have put just over 600 hours on the engines.

We run mostly between 1800 and 2200 rpm probably 95% of the time.

The engines are in good condition with good compression and do not burn or leak oil and start quickly.

I'm just curious as to how many hours others have put on these engines before requiring major work like heads or rebuilds, especially those that operate like I do, mostly as a trawler?

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IMO there's no absolute expiration date/shelf life for gas engines in boats. It all depends on too many factors.....

I say enjoy them till they die, then worry about them.

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I like the Ford 5.8L's. If anything, they could use having the exhaust ports opened up a tad bit.

Otherwise, they seem to hold up very well.

FYI for any of you 5.8L owners... and a bit of a hi-jack, Larry!

I have a set of 1993 Volvo Penta 5.8L cylinders heads with 6 hours on them. They need a new owner.

Heads were fresh, but it turned out to be a bad lower end. Owner went with complete new engine.

I have all rocker arms etc. and two very nice marine valve covers. Also, a cast iron 5.8L 4 brl intake manifold.

First decent offer takes them.

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Depending on maintenance, salt or fresh water, how often used, quality of the parts used to rebuild, etc you can expect 2000 - 3000 hrs on engines.

YMMV

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If those engines were in pickup trucks, at that RPM, (about highway speed in overdrive) 1000 hours at 60 mph average is only 60000 miles. They got lots of life as long as you take care of them.

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At those cruise RPM's I would expect over 2000 hours. Take care of them and maybe look into a valve job further down the road when it comes time to do manifolds(if raw cooling).

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Thanks for the replies.....

I know the theory is 2000 to 3000 hours and I have run a few of my boats between 1000 and 2000 and never cracked the engine open. When I sold the boats the compression was within spec.

With a closed cooling system and fresh water only boating even manifolds last.

I wondered what practical experience people had with this engine. Every other gas boat I have owned had GM based engines.

Larry

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I've only heard of a theoretical engine hour limit in the pleasure craft side of the boating industry. The commercial operators I know never push their engines too hard and get thOusands of hours out of them...

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Well my experience turning out to be not so rosy. In fact I think your boat is already over double it's expected life. I know, I have a bad attitude right now. See my post earlier this week. 280 hrs on a 5.7.

Yes I use in in salt water. Trailer stored, used all year in so cal, and if two,weeks go by that I can't go out to either the ocean or fresh water use I can run it at home. I don't try and pretend I am some great mechanic. I use a great marine mechanic to do much of my up keep.

Now a spark plug blows out with no apparent mechanical reason and I facing major repairs..

Like you most of my cruising is between 2800 and 3100 hrs I will occasionally open her up and wot is around 4500. I treat my fuel with Stabil and buy most from marine sources. All fuel on board is fresh.

Ok I'll stop bitching but my point is I'm trying to do things riight on a boat I planned to keep a long time. looks like it didn't do a bit of good. My advise is run the hell out of it, change the oil if you have time if not don't worry about it. It's still gonna fail.

Sorry. That's not true. But feels good to rant some....

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We were third owners of a 1987 2750 Ciera Sunbridge with a GM 5.8L. It crapped out at 325 hours. We bought it at 312 hours or so, and thought we'd found the steal of the century lol. So, it will be what it will be I suppose! I wasn't nearly as cavalier when we had to open our cheque book. :sorrow:

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jnicholas wrote:
My advise is run the hell out of it, change the oil if you have time if not don't worry about it. It's still gonna fail.

If I treated my engines like that, I'd not expect much engine life either!

Talon wrote:
If those engines were in pickup trucks, at that RPM, (about highway speed in overdrive) 1000 hours at 60 mph average is only 60000 miles. They got lots of life as long as you take care of them.

It requires somewhere in the neighborhood of 40-50 horse power to keep a full size vehicle moving once up to speed.

Conversely, it requires almost all of a Marine Engine's horse power to remain on plane.

IMO, you'd need to load those pick up trucks with weight, and give them a continuous up-hill grade, in order to make that 60,000 mile comparison.

That 60k now becomes more like a very hard 60k, or perhaps even more.

I suppose that in the Marine scenario at 2k RPM and below, the wear is not quite the same.

It's still an apples/oranges comparison, IMO.

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