Block Heaters for Large Detroit Diesels
 

I went to look over a boat the other day that had a pair of large
Detroit Diesels (12V-71TIs). The engines are 22 years old, have
about 2,500 hours on them, but appear to have been well maintained.

One thing that concerned me however was that each engine had a block
heater running continuously at 120 degrees (in southern Florida,
albeit winter time). The owner said that he keeps the heaters running
to ensure quick starts.

Can anyone tell me if this is normal practice for these engines, or is
it more likely that the heaters are being used to compensate for
mechanical issues?

Block Heaters for Large Detroit Diesels
 

On Sat, 07 Feb 2004 00:49:13 -0500, Wayne.B
wrote:

I went to look over a boat the other day that had a pair of large
Detroit Diesels (12V-71TIs). The engines are 22 years old, have
about 2,500 hours on them, but appear to have been well maintained.

One thing that concerned me however was that each engine had a block
heater running continuously at 120 degrees (in southern Florida,
albeit winter time). The owner said that he keeps the heaters running
to ensure quick starts.

Can anyone tell me if this is normal practice for these engines, or is
it more likely that the heaters are being used to compensate for
mechanical issues?

It's possible - cylinder compression problems, starting oil pressures,
that kind of thing.

However, if they have been well maintained, then maybe he just wants
to get a quick start.

Have a good diesel mechanic take a look at them.

Later,

Tom
S. Woodstock, CT
----------

"To the fisherman born there is nothing
so provoking of curiosity as a fishing rod
in a case."

Roland Pertwee, "The River God" (1928)

Block Heaters for Large Detroit Diesels
 

On Sat, 07 Feb 2004 11:06:49 GMT, Short Wave Sportfishing
wrote:

Have a good diesel mechanic take a look at them.
===============================================

Yes, that's a given if I get serious about the boat.

Block Heaters for Large Detroit Diesels
 

Wayne,

It's unlikely, IMO, that block heaters would hide any serious engine defect.
It can be advantageous to have the engine at 120 degrees before starting. A
quicker warm up means less time at high idle at the dock and is considerate of
your marina neighbors. For a Type A kind of person it can get you moving much
more quickly. Any diesel with a lot of hours will get a little fuel in the
crankcase while operating. Keeping the engines warm will help limit dilution
at start up.

I'd guess it is indicative of a maintenance concious owner to keep the block
heaters on while the engines are shut down. Especially if the engines appear
well maintained and the engine spaces are wiped down and clean.

Twin DD 12 bangers.... must be a sizeable boat or damm fast. :=)

Butch

Block Heaters for Large Detroit Diesels
 

On 07 Feb 2004 15:28:32 GMT, (JDavis1277) wrote:

Twin DD 12 bangers.... must be a sizeable boat or damm fast. :=)

================================================== ======

55 ft Hatt Sportfish, 70,000 lbs, alleged to cruise at 22 kts. The
engines do seem well maintained but are high hours and never been
majored. All new hoses, paint, Walkers and exhaust system however.
Interior is freshly redone and very nice, exterior is fairly good but
not perfect. It's a lot of boat but high maintenance and operating
costs.

Block Heaters for Large Detroit Diesels
 

Wayne,

Very nice boat.

As to the high hours engines... IMO one of the best things about the 71 Series
engines is the ease with which they can be completely rebuilt in place with
minimum overhead space. Both engines should be overhaulable(???) in a couple
of days given competent mechanics.

It's pretty much a given that the cranks will be in spec. Rods too, probably,
and a good chance all the pistons as well. However, if you're going to
consider an overhaul it's way too easy to simply change out the liners and
pistons. I've no idea of the cost thses days but the OE parts are very high
quality. While at it I'd pull the unit injectors and have them tested and
rebuilt, if indicated, too. They may just need tip kits. The heads shouldn't
need any work other than decarboning and inspection. Worst case perhaps a
valve job.

If the engines have been well looked after they'd probably go for several
hundred more hours without any excitement. If it was me and a test run
indicated nothing I'd just do tip kits and keep on huffing. Remember, any
mechanic is going to be inclined to suggest work even if it is only slighty
indicated. Gotta make a living don'tcha know?

Butch

Block Heaters for Large Detroit Diesels
 

On 08 Feb 2004 15:51:27 GMT, (JDavis1277) wrote:
If the engines have been well looked after they'd probably go for several
hundred more hours without any excitement. If it was me and a test run
indicated nothing I'd just do tip kits and keep on huffing. Remember, any
mechanic is going to be inclined to suggest work even if it is only slighty
indicated. Gotta make a living don'tcha know?

===========================================

Thanks

Block Heaters for Large Detroit Diesels
 

Wayne.B wrote in message . ..
I went to look over a boat the other day that had a pair of large
Detroit Diesels (12V-71TIs). The engines are 22 years old, have
about 2,500 hours on them, but appear to have been well maintained.

One thing that concerned me however was that each engine had a block
heater running continuously at 120 degrees (in southern Florida,
albeit winter time). The owner said that he keeps the heaters running
to ensure quick starts.

Can anyone tell me if this is normal practice for these engines, or is
it more likely that the heaters are being used to compensate for
mechanical issues?

In Florida, their is no real need for the heaters. They will help
starting the engines, and older Detroits tend to smoke while they warm
up, the owner may figure it's better to run the heaters rather than
have the smoke at start up. I'd want to see how the enginse start when
their cold if I were you. Detroits are one of the less expensive
engines to rebuild in the boat, but it's still a fare amount of money.

Block Heaters for Large Detroit Diesels
 

On Mon, 09 Feb 2004 22:11:12 GMT, (Karl
Denninger) wrote:
BTW the 1271s are "interesting" motors - look at them closely, you'll see
what I mean :)

========================================

I'm probably not experienced enough to pick up on the detail that you
are alluding to. They certainly are bloody big however.

We saw a Hatt 53 Yacht Fish over the weekend that I think I like a
little better all things considered. It's got 8v71TIs in it, not as
fast, but looks to be a better over all boat for living aboard 4 or 5
months of the year.

That 55 is certainly some nice boat though and got my adrenaline
going.