Not allowed full speed with 8v71’s whilst surveying

[eshvisser]

Hi all,
before putting in an offer on a 53my with 8V71’s on board I had an extensive chat with the owner to find out what was and wasn’t on the Hatt that I do have on my current ship.
One of my questions was if it was possible during the survey to go full speed for 5 minutes.
I got a ‘no, we are not doing that!’
’you can go up to 1600 rpm but I always cruise on 1300 rpm’.
’I think maximum rpm is around 2300 but never in 20 years tried that’.

Any thoughts on what could happen when we díd go full throttle and how many of you with these engines would also be reluctant to try?

thanks
Edward

[racclarkson@gmail.com]

It’s not a survey unless it’s surveyed. If seller won’t allow a complete survey reduce your offer the rebuild price. Or don’t even bother unless, of course, no full power was stipulated in the contract.

[Pascal]

5 minutes may be a bit long. What you want to check is for rated 2300 rpm. That s a minute on the pins or less.

No more than 1600 rpm isn’t a survey... you need to check for temp at cruise speed which is 2000 rpm...

[Jammin']

I had a separate engine surveyor and the owner wouldn't wick it up beyond a certain point so the engine surveyor did it at the engines. The owner was quite nervous. I don't think he had ever heard the engines run up before.

[eshvisser]

Tnx for the replies. I found a Detroit specialist in the area in the meanwhile who I’m going to invite to sail along during the survey. He will be able to tell me and the owner if it’s responsible to go up in revs at a certain point.
don’t want to rock the boat! ;-)

[Boatsb]

3 to 5 minutes is normal. You need to make sure its cooling. If it's running hot abort the WOT test.

If the boat has naturals its probably not going to plane. If turbos and not getting on plane theres something wrong. Make sure the props are the right size too.

Sometimes the get smaller props to hide engine issues.

[jim rosenthal]

They should check the high idle, and WOT under load. Doesn't have to be for very long, but I agree with Pascal and Scott. And, yes, folks have been known to underprop engines which won't come up to WOT under load, although it would be hard to do that when you are having a pre-sale survey- no one's going to invest in a set of wheels just to get a boat through a survey. What might happen, though, is that someone found they wouldn't turn up to full rated load revs in the past and instead of determining whether something was wrong with the engines, they just fitted smaller wheels.... that COULD happen.

Also, if they are turbos, the surveyor should measure boost as part of the survey, if he can. Most of these boats are not equipped by boost and pyrometer gauges, though. Usually there's a port on the intake manifolds you can hook a boost gauge up to.

[miboatnutz]

When we put in an offer to purchase our Chris Craft we hired one of the most reputable and experienced surveyors in the Great Lakes area (he has since passed away). This guy did a phenomenal job and looked at so many little details that I'm convinced many people even with a trained eye would have missed.

Comes time to do the sea trial and we're out on the water for about 45 minutes operating at various speeds while the surveyor recorded bits of information. Finally he says "OK, last test is full speed under load at max RPM for three minutes". Without hesitation previous owner says "Absolutely not!". Surveyor then turns to me with this irked look on his face and says "What do you want to do? It's your survey." I said without hesitation "Absolutely not!".

Surveyor was beside himself! Started grumbling to both of us that it's an incomplete survey without observing max engine speed under load and we'll never know if it's over propped or under propped, etc, etc. All I knew was that for 45 minutes those engines came up to temp and ran flawlessly and that was after a very comprehensive inspection which included compression checks, timing checks, carb adjustments, etc, etc.

Both PO and I knew there was no point in taking a risk running those engines at max RPM for any length of time especially since the Ford FE side oiler engines in the boat are pretty much irreplaceable.

Got a little smarter when we bought our Hatt.

Even before hiring the surveyor, we sat down with the PO and put together a sea trial plan that included total time out on the water, amount of time to bring the engines up to temp, various cruise speed RPM's and duration for each. He permitted a max RPM run, but we agreed it would be from the highest cruise speed (no firewalling from idle) and only until the boat reached a maximum speed. Once we hit a steady state speed at max RPM we shut it down.

[rustybucket]

Not being able to attempt a WOT run would be a deal killer for me. These engines are made to run up, you aren't going to hurt anything, unless it was already giving up the ghost, at that point I want to break it so I know what I've got.

We do a short WOT run at the end of every extended excursion. Just for a minute or two.

If the engines will not spin up to the correct rpm at WOT 'something' is wrong. Without trying to run WOT you will never know.

How could you responsibly own/operate the boat without occasionally checking to make sure everything is ok?

The owner thinks it's irresponsible to run WOT, I say it's irresponsible to never run WOT, even if it is just for a few mins.

[oscarvan]

OP is looking at naturals. I hope he posts pictures here. Someone spent a lot of money on that boat and it's stunning. The interior is top quality Dutch work.