980 hours on engines - compression test

[tpenfield]

Now if Scott can contain himself , here is one of the Comp Cam's(P/N 01-445-8) profile . . .

Looks OK, minimal overlap.

 

[tpenfield]

Here is a high performance street cam . . . it has about 75 Degrees of overlap.
.

.
I'm not sure if there is a 'magic number' for valve overlap on a marine engine. :noidea: The High Performance Marine cam (above) has 49 degrees of overlap, whereas it looks like the stock Mercruiser cam has almost 0 Degrees of overlap.

 

[achris]

Now if Scott can contain himself , ...

Big ask.... :laugh::laugh::laugh::laugh:

 

[Bondo]

Maybe 1,000 hours on a marine engine would equate to about 80,000 - 100,000 miles on a car engine. :noidea:

Ayuh,......... Nice graphs,.........

I think yer guestimate might be 'bout Right,......

But, that little 4.3l that wouldn't start the night ya stopped by is clockin' in the 1200 hours range, 'n still pullin' compression numbers above 150 psi, 'n solid oil pressure when runnin',......

I'm seriously considerin' scrappin' the tinbarge by Spring,..... worth more in parts, 'n scrap, than as a boat,.....

I'll either sell the driveline, or find another hull to slap it into,.....
Maybe that 14', '61 Glastron Jet-Flite in the backyard,.....

 

[alldodge]

Sounds like your wanting to build more power which is good, but then your also getting into the timing tables, AFR and such. Increasing lift and reducing LSA her comes at least a riser extension.

Suggest not getting a cam with less then 114, otherwise your going to start think about reversion

Can cut down the intakes runners to match the plenum height, and a little mild porting

 

[tpenfield]

Thanks, Bondo and AD for your comments.

I have read various comments and info on the web that try to relate an hour of engine operation on a boat vs. a certain number of miles on a car. It seems to be a consensus that 1 hour (boat) is about 100 miles (car). So, I could consider my engines to be about like a car engine at 100,000 miles in terms of wear, etc. You generally do not see automotive engines with 100,000 miles needing a rebuild . . . more like 200,000 miles. So, a rebuild is more preemptive than imperative, but probably a good thing to have done when I go to sell the boat. . . some day

I did not consider the impact of a new cam on what the fuel and timing mapping of the MEFI would be, so maybe it would be best to stay with the stock cam. :thumb:

As I have been reading . . . the cams for flat tappet lifters have a 'taper' to the lobe and the lifter bottom is slightly 'dome' shaped to make the lifter rotate as the engine runs. I always wondered how that happens. . . I assume that roller lifters do not spin (how could they :noidea: ) so the cam lobe must not have any taper ( correct ? ).

 

[alldodge]

Flat starts that way and wears more over time, but this is also why breaking in a flat tappet cam is so critical. Roller cam lobes don't wear very much over time so long as the roller bearings on the lifters do not stop rolling. The rollers also allow for cam lobes to be at a sharper angle (so to speak) so opening and closing can happen in less time due to less load.

A note about Comp Cam's, many on OSO will not use Comp because they break. That said most of these are building motors well above 600HP.

You know if you build some 500HP motors for your boat, you may not want to sell it
If later you want to go that route we can get it done (email)

Along that same note, if you swapped the 454 with 502 you would get a hole new outlook on your boat. Can get a reman for about 5800 and can use your intake stuff, just need remapping

 

[tpenfield]

Yes, I think either way, if I decide to keep or sell, rebuilding at this stage can work out. If I do sell, then I'd be looking to go up to a 35 footer ( F-350SS), as it has a bit deeper V-hull than my 330SS and quite a bit more 'bling' throughout. Selling my 330SS should be easier if it has a rebuilt engine, as folks tend to shy away from boats with a lot of engine hours . . . you always see those type of questions coming up on boating forums, etc. "Too many hours?"

My course of action will just be a matter of how much $$$ I have and what the prices of 10-12 year old boats look like 3-4 years out. If I keep my current boat for longer, then at least I will have rebuilt engines for longevity.

 

[Scott Danforth]

Ted,

you could pull the plugs and look at the bores. that will tell you the condition of your block vs attempting to correlate.

most HX cooled motors run more stable temps, so the wear is less than a raw-water cooled motor running a 140 t-stat

anything other than a stock re-build and your looking at remaping.

 

[Lou C]

I think as far as resale, the 900+ hrs with closed cooling before it was put in salt, should not be a hard sell. It is not that easy to find I/O boats in our area that age that have had closed cooling installed and that alone will make it easier to sell. If for sure I knew I wanted to sell in few years, I'd let that good runnin' boat be. You never know what can happen when we start taking things apart lol. I think we've all been there and done that. That factor (unknown) and also changing stuff from the stock configuration I feel is just risky. I think Merc for the most part knew what they were doing when they set up these engines and with EFI anyway, modifications get more tricky, and/or troublesome.

Now on the other hand if the engines were raw water cooled here and were pushing 2,000 hrs, then yes, I'd say doing a top end rebuild (even if only a set of re-man heads like I did last year, to avoid hydrolocking issues from cyl head rust through) would make sense.

Even so, I'm not sure you'd get that money back in a better price, it would make a sale easier depending on how knowledgeable the buyer is...

 

[tpenfield]

Good points, Lou. I was thinking of seeing if I could sell the boat in a few years without the engine rebuilds, but then if I cannot sell it, I'm in a bit of a pickle.

The Admiral and I have had a deal in place over the years . . . and that is I have to sell my current boat before I can buy a new(er) boat. So, I'm just trying to anticipate obstacles that may make it more difficult to sell.

If I continue to do my 40-50 hours per year, I'd have about 1,150 hours on the engines by the end of 2022. (seems crazy that we are getting that far into the 21st century, right )

So, I'm just trying to visualize selling the boat with 1,150 hours on original engines or 120-ish hours on rebuilt engines. :noidea:

 

[achris]

454s with 1150 hours is still 'light use'... Especially if they're well maintained and not over propped...

JMHO

Chris...

 

[Lou C]

Exactly...and I think the cost of the rebuilds being that its 2 engines, will not necessarily be reflected in the boat selling more than it would if you sold it as is. I actually thought it would have made sense to put a re-man engine in your old boat since that while a big investment, would have given you relatively low cost boating for some years as you already had paid for it and had made many upgades. Once the buyer learns what you did in terms of maintenance and upgrades, if they are smart they will realize that there are not too many boats that are maintained to the level that you do....hence I think it will sell pretty fast.

What is an average # of hours for a boat that age in your area?

 

[tpenfield]

Good points, which I'll have to consider. I can check on 1996 - 1998 F-330's and similar brands for that matter to see what is typical hours for those selling their boats. That will give me an idea of how my hours compare.

 

[alldodge]

If I was buying a boat with 1000 hours I would figure on rebuild unless I knew who owned it (like Ted). If there was paper showing it was rebuilt, this would give me a better feeling, but that stuff can be forged also

 

[Lou C]

1,000 hrs over approx. 20 years...that's like 50 hrs a season. Just enough that its bein used but not so much that its used up!
I recall reading that a closed cooled inboard properly propped has a life span of at least 2000-3000 hrs but twin 454s as long as maintained I think could go even more perhaps 4,000. Properly maintained 4 stroke outboards do it all the time and they are all lightweight aluminum not built like a truck engine....

 

[Lou C]

If I was buying a boat with 1000 hours I would figure on rebuild unless I knew who owned it (like Ted). If there was paper showing it was rebuilt, this would give me a better feeling, but that stuff can be forged also

Unless I knew for sure who rebuilt it and with what parts, I think I'd trust an original un-molested engine more than a rebuild.

 

[Scott Danforth]

raw water cooled motors will hit 3000 hours

HX cooled should hit closer to 4000

Ted, if needed, simply buy two of these

 

[tpenfield]

I was thinking if I hit one of those mega lottery jackpots last week, none of this would matter. . .

But I didn’t

 

[tpenfield]

FWIW -

I did some checking of Formula and Sea Ray boats for sale in the 1995 - 1998 model year range as to what the engine hours were. A few boats did not list the engine hours, so I assume they were on the high side. Most listings did indicate the hours and some had photos of the hour indicator. Overall, I think I have enough info to paint the picture . . .

So here is how things look on the market for older boats. Age vs. Engine Hours


So, 1,000 hours is on the high side vs. the market. There were a couple of boats with very low hours because the engines were rebuilt. By comparison, my boat would be on the high side vs. many other boats, which is what my thoughts were originally.

This data sort of spells it out.