Detroit Engine pics

[syd]

Nice brochure Andie. Are these boats quite rare ? Mine is the first one I've seen, in this country anyway. Saw one in Cuba of all places, never dreamed I'd be lucky enough to eventually own one. Gonna take some more photos on Saturday, inside and out, different layout to the one in the brochure.

Syd

 

[AndieMac]

Are these boats quite rare ? Mine is the first one I've seen, in this country anyway. Saw one in Cuba of all places

Bajansailor kindly sent us the brochures Syd, as he often posts pics. of 70's and 80's mobos.
I haven't seen the 'Yacht' version of the 42 before in my little corner of the world, but she is built on a very sea-worthy hull indeed, as a direct relative of the sportfisher.
Certainly a boat worth spending a few bob on if the intention is to keep her and do some offshore cruising.
Bajansailor may be able to enlighten us more, as in his location there seems many earlier USA Berties.

 

[Bajansailor]

My Photobucket is still not being co-operative - refuses to upload anything. I shall toddle along to the Lounge I think, and ask a question in there as to what might be happening to it.
A big thank you to AndieMac for posting the catalogue photos above - if I ever get my P-Bucket sorted I will post some photos of the bigger Berties as well.
And TNX too to Alf for the excellent photo descriptions above.

There is a slightly later 42 Sportsfisherman here, and a motley assortment of other Bertrams (all SF, some with tuna towers) including a few 25's, two 31's, a 46, a couple of 50's, and one about 60'.

Oh, and a 38 that had a bit of a fire on board last year - I posted some photos of her here http://www.ybw.com/forums/showthread.php?t=211869
She is now being slowly re-built as a dive boat; the deck saloon has been gutted and opened up, and she should be very effective, especially as the Owner plans on offering dive trips round to the east side of the island, and it is a 15 mile slog to windward to get there from Carlisle Bay.

I crewed on a 98' Philip Rhodes designed motor sailer 20+ years ago that had a pair of GM 6V-71s down below - and a beautiful engine room that you could walk around in..... She was built I think in the 70's, and she probably still has her original engines........

 

[syd]

Such a sporty looking boat, shame about the damage Fancy arriving at the marina and finding your boat in that condition. I've read the hulls are very well put together, even over manufactured for an American boat, so are very strong, probably why the one in the picture didn't melt or distort. Must have withstood some intense heat.
Can't wait to see the rest of the pics.

Syd

 

[Bajansailor]

Aye, these older Bertrams are pretty solid boats!
As very often is the case with fire damaged boats, the visual apparent damages often appear to be much worse than the actual physical damages, as the sight of all that blackness and charred wood and fibreglass is rather disconcerting..... with the Bertram 38 above, even though there was a raging fire in the deck saloon, the engine room insulation protected the engines very nicely from most of the heat, and I was told that they didnt need an awful lot of work to get them up and running again.

 

[Divemaster1]

Still consious that 800 page service manual is still lying in my computer bag and we are approaching the Week-end...so...

Here is an illustration of where you find the Airbox Drain Pipes/tubes which I referred to earlier...

Will try to get to the post office...

 

[DownWest]

Don't often look here, being a raggy, but I used to look after a big raggy with 2X 4cy DDs
The blowers were not turbo, but Roots superchargers. The cylinders were scavanged by blowing air through with the valves open before the compression stroke. The injectors were the same type operated by a separate lobe on the cam. And I remember being pleasantly surprised at the cost of o/hauling them. In some of the local fishing boats they were rated at 120hp, but ours were 140hp, giving a max of 12kts on a 70ft hull. In the USA, their poor emmissions are causing some problems now. Like in refurbing old boats for passenger use.
A

 

[syd]

I have a great idea concerning the cd Alf. I'll pop up and give you a lift to the post office. Put the kettle on.

I'm looking forward to seeing the diagrams so I can get it in my head how these engines actually work, can't seem to grasp the concept of no inlet valves and cam powered injecters etc. they're a work of art.

Syd

 

[DownWest]

Syd, inlets are ports low down in the cylinder. The ex valves open a little before they are exposed by the piston. This reduces the pressure before the clean air is forced in and the residual exaust gasses blown out through the valves. Followed by the closure of the valves and the piston passing the inlet ports for the compression stroke. Big ship engines work a bit similar but use turbos. Turbo might be 3ton!
A

 

[Divemaster1]

Nice one Syd ... and point taken ... heading for the post office after lunch... ... take the tea though...

Single cylinder animation linked below...

http://www.youtube.com/watch?v=25xolzhg3lo

You have a root blower (like animation) and you also have a turbocharger and Intercooler to increase the airflow & pressure. Turbo kicks in at about 1200 RPM and you will experience a quite radical change in engine performance... and my guess is that you should experience that the boat goes from displacement mode to planing mode in a space of 4 - 600 RPM from there on..

 

[Bajansailor]

Well, I threw out my cookies, updated the Flash and the Java - and Photobucket still does not work in Firefox, but it is working in Internet Explorer.
Ace!
So here are the last 2 pages from my 1977 Bertram catalogue.

Basic prices in 1977 were :

Bertram 46 with 2 x GM 8V71-TI (435 hp each) :
Convertible $ 177,990, Yacht $ 187,890

Bertram 58 Yacht with 2 GM 12V71-TI (650 hp each) : $ 343,000

 

[AndieMac]

Thanks Martin, good to see picture posting is back under control once more.

Looking at the power options on the 58 reminded me there are still 12V92's operating in commercial passenger ferries locally.

 

[Deleted member 36384]

Halliburton Cement Units use the Detroit 2 stroke diesels (inclined to reduce height on the skid) with Alison Gearboxes.

 

[Divemaster1]

Reminder !

Just bumping this up to remind Syd, who may have his head burried in a 890 page manual on his engines...

....to take some pitures of his Bertram for us to see....... if he is visiting the boat this week-end of course

 

[Divemaster1]

Inspired by the runaway engine on the Thames, I thought it prudent to inform you, Syd, that your engines are fitted with a ait shut-off system. (page 423 in the manual I sent you).

Basically this shuts off air supply going from the blower into the air chamber and susequently the cylinders removing air from the combustion cycle. So if you have a "runaway" situation for whatever reason, you can cut the air supply to the engine(s).

The top arrow on the picture below is the stop solenoid, which stops fuel supply, whilst the bottom arrow show the air shutoff release wire. You should have two pull leavers near your helm which actuates these. By pulling the leavers you release a spring loaded clamp which holds the air shield open... gravity and air pressure/vacuum does the rest of the job.

Make sure you find these leavers, check that they operate and also ensure you know how to re-set the shields (very simple) as the cables may inadvertently be pulled by inquisitive visitors. Also handy to know how to if your stop solenoids should stop working due to electrical failures etc. Once operated your engine(s) will not start until shields are re-set.

 

[syd]

Fantastic !!
Great advice. The two shut offs are on my helm marked "Emergency Stop" and have tape over them to stop any inquisitor pulling them . I'm working on the photos, frustraitingly I've not had a lot of time to get down to my new adventure due to selfish gits going on holiday and expecting ME to cover them. My turn soon from the 4th of Sept. I'm enjoying the challenge of finding the many systems on board and how they work, wish I had a users manual though. I've found , what I think anyway, an interesting bit of kit in one of the many hidden lockers, it has a trigger, a compass, a keypad, a dial and a morse code chart, but I'm buggered if I know what it is ! I've uploaded pics of it but am waiting for moderator approval so I can show you all .
Watch this space.
Thanks for all the great info. Keep it coming please.

Syd