syd
New member
Took some pics so we can compare installations. Anyone know what might cause the grey smoke from the starboard engine ? Just noticed it in the picture.
Syd
Syd
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Detroit Engine pics
- Thread starter syd
- Start date
tinkicker0
New member
Is it smoke or steam? looks like steam to me.
Divemaster1
Well-known member
Very nice Syd ... inclined engines, which means that you will have a "LP" (Low Profile) designation...
These were made both in standard upright block, inclined and in some cases with alloy blocks which were used in mine sweepers.
Ours are inclined too, and whilst it takes some time to get your head around the configuration, it makes for good access both to the main items and also when you do your tune-ups and need access under the rockrer cover...
For true comparison, what you need is your engine serial numbers and call your local Detroit dealer (I can give you phone no to mine if you struggle to find knowlegable people you way...).
Anyway, if you ask them for the Detroit spec sheet of the engines, quoting the serial nos... you should within days receive (FOC) the full engine delivery spec, including series of injectors, turbos, intercoolers, alternators, gearboxes, waterpumps etc...
The in line six cylinder 71's were delivered in anything from 180 (ish) HP to 485, pending on configuration of turbo, injectors, cooling system etc....
SB smoke can be steam ... perhaps slightly restricted air circulation , giving less water in the exhaust = higher exhaust temperature = more water evaporating = more steam...
How is your temperature gauges ?
These were made both in standard upright block, inclined and in some cases with alloy blocks which were used in mine sweepers.
Ours are inclined too, and whilst it takes some time to get your head around the configuration, it makes for good access both to the main items and also when you do your tune-ups and need access under the rockrer cover...
For true comparison, what you need is your engine serial numbers and call your local Detroit dealer (I can give you phone no to mine if you struggle to find knowlegable people you way...).
Anyway, if you ask them for the Detroit spec sheet of the engines, quoting the serial nos... you should within days receive (FOC) the full engine delivery spec, including series of injectors, turbos, intercoolers, alternators, gearboxes, waterpumps etc...
The in line six cylinder 71's were delivered in anything from 180 (ish) HP to 485, pending on configuration of turbo, injectors, cooling system etc....
SB smoke can be steam ... perhaps slightly restricted air circulation , giving less water in the exhaust = higher exhaust temperature = more water evaporating = more steam...
How is your temperature gauges ?
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jfm
Well-known member
Very nice boat, the Bertie 42AC
syd
New member
Temperatures
"SB smoke can be steam ... perhaps slightly restricted air circulation , giving less water in the exhaust = higher exhaust temperature = more water evaporating = more steam...
How is your temperature gauges ? "
Just finished investigating. As I remember, the starb engine was running a little hotter. Just checked the Jabsco and found a bad break in the gasket, looks like quite a bit of water was getting past it.
Might as well change the impellor while I'm here. These engines are awesome, bit scary. How does a two stroke Diesel work ?
Syd
"SB smoke can be steam ... perhaps slightly restricted air circulation , giving less water in the exhaust = higher exhaust temperature = more water evaporating = more steam...
How is your temperature gauges ? "
Just finished investigating. As I remember, the starb engine was running a little hotter. Just checked the Jabsco and found a bad break in the gasket, looks like quite a bit of water was getting past it.
Might as well change the impellor while I'm here. These engines are awesome, bit scary. How does a two stroke Diesel work ?
Syd
Divemaster1
Well-known member
sorry... meant water circulation...
anyway....
basics here... http://auto.howstuffworks.com/diesel-two-stroke1.htm
anyway....
basics here... http://auto.howstuffworks.com/diesel-two-stroke1.htm
Divemaster1
Well-known member
Basically,they fire twice as often as "normal" diesel engines...and instead of valves opening up and forcing exhaust gases up with a piston strok, the over pressure in the air chamber (created by blower and released by scavenging port in cylinder as piston is on downward stroke) forces the exhaust gases up whilst giving "fresh" air in the combustion chamber ready for a compression stroke again ... and on you go for another fuel injection and cylinder fiering... very basic, simple and mecanical action ... (I really have to get that manual to you...)
AndieMac
Well-known member
Very nice boat, the Bertie 42AC
I've not seen this version of a 42 before, looks like there's plenty of accomodation aboard.
Enjoy your boat Syd.
Thanks for the pic. jfm.
Divemaster1
Well-known member
Love the boat by the way...
Interesting pictures of the engines .... you may have a Bypass (con)version "B" here...., but not certain as it is difficult to determine the function of the spring (going between exhaust manifold and rocker cover on the first picture), which I presume goes to the throttle control on the governor. This may in turn be linked to a bypass valve etc., which when married up with the right injectors and turbo, allows a relatively easy tune-up from 435 to 485 HP...but once again need to see spec sheet and also to understand what injectors are installed (Remove rocker cover and each injector should have a stamp stating a coded.... such as "M95".....on circular inset just above my thumb on picture below...
Interesting pictures of the engines .... you may have a Bypass (con)version "B" here...., but not certain as it is difficult to determine the function of the spring (going between exhaust manifold and rocker cover on the first picture), which I presume goes to the throttle control on the governor. This may in turn be linked to a bypass valve etc., which when married up with the right injectors and turbo, allows a relatively easy tune-up from 435 to 485 HP...but once again need to see spec sheet and also to understand what injectors are installed (Remove rocker cover and each injector should have a stamp stating a coded.... such as "M95".....on circular inset just above my thumb on picture below...
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AndieMac
Well-known member
Can anyone else tell that Alf is loving this thread? 
Divemaster1
Well-known member
Nah.... just want to encourage the pics of the Bertie.... engines can be done via PM as it gets a bit nerdy.. ....
....
Bajansailor
Well-known member
I have scanned a couple of pages from the Bertram 1977 brochure re the 42 Convertible (ie the sports fisherman) and the 42 Yacht (like Syd's) and tried to download them to Photobucket, but the Bucket is not being very co-operative - I am hoping it might be just a temporary glitch tonight, and it might be in a better mood in the morning.
A new Convertible back then had a basic cost of US $99,890 with twin 330 hp petrol Mercruisers or $136,990 with 335 hp GM 6V71-TI lumps, while the Yacht cost $101,590 with the petrol engines and $138,450 with the GMs.
A new Convertible back then had a basic cost of US $99,890 with twin 330 hp petrol Mercruisers or $136,990 with 335 hp GM 6V71-TI lumps, while the Yacht cost $101,590 with the petrol engines and $138,450 with the GMs.
AndieMac
Well-known member
A mid-80's Oz built sport fisherman with Detroits (6V92's at 475hp and the most desirable) or Cats (450) in reasonable nick can still have an asking price of up to $AU375,000.00. The ones with the 903 Cummins are not so desireable, and struggled on speed.
With a dry weight of 18 tonnes and a 14' beam, every bit of those horses are required, so cruise at 18 and sprint to 24 knots.
syd
New member
Enjoying
Yeah, its great ain't it. Nice to have someone who knows his stuff, I've not come across engines like this before, used to Mercruisers and Penta's.
The accommodation is awesome. The main bedroom has its own en suite with huge shower, the saloon is like a dance hall with a full size kitchen/Galley just off it and a guest bedroom with its own toilet and shower. I've only had sports cruisers in the past with heads you have to squeeze yourself into just to take a pee. I'm lovin it.
Syd
Yeah, its great ain't it. Nice to have someone who knows his stuff, I've not come across engines like this before, used to Mercruisers and Penta's.
The accommodation is awesome. The main bedroom has its own en suite with huge shower, the saloon is like a dance hall with a full size kitchen/Galley just off it and a guest bedroom with its own toilet and shower. I've only had sports cruisers in the past with heads you have to squeeze yourself into just to take a pee. I'm lovin it.
Syd
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epervier
Active member
Nah.... just want to encourage the pics of the Bertie.... engines can be done via PM as it gets a bit nerdy..
there may be truth in what you say Alf, but it still makes for an interesting read.
Divemaster1
Well-known member
OK ..if no one objects, here is some more information for the new Detroit owner...
There are two zink plugs (one on each side of the heat exchanger)... if they loosen/break off, you will have a waterflow restriction... and it looks like you have some seapage here... anyway, zinks are located at the red arrow... (each side). Unscrew this and see if there is anything left.... if not, you;
a) need to replace
b) identify if you have a restriction, so remove the pipes and inspect for debiris...
What you see here is the inlet part ... on the other side, you may have the zink blocking the fuel cooler etc., so a bit more complex if it is broken off on the other side.. (engines also use fuel as cooling medium for injectors etc., so return fuel to the tanks is warm... these engines easily pump 50% more fuel than consumption for cooling of injectors etc.)
Also, you do have the standard 6/71 oil seapage around governor control arm, governor balance weight and also around the blower (indicated by arrows)..
Do go down and check the bolts/nuts etc. every now and then (1/2" and 3/8")... yes you do need imperial size spanners/sockets.
Yours look very nice and dry for 71's, so just keep an eye out and put the spanner/socket against it and check ...but don't pull too hard, as she obviously is not leaking much...
Looking at the pictures, you have a quite early configuration with vent from crankcase to air intake (simple and reliable)..., but if you want to keep your bilges clean, you will find a small oil drip from the aibox breather drain --- on the outside of the engines, in front of gearbox ... low down.. A small outlet pipe.... which you can connect a hose to and lead it into a collecting bottle (std gas hose fits perfectly)....and if situated low enough down, you may end up emptying this every 200 hrs ...or once a season...(previous owner may have done this already)..
There are two zink plugs (one on each side of the heat exchanger)... if they loosen/break off, you will have a waterflow restriction... and it looks like you have some seapage here... anyway, zinks are located at the red arrow... (each side). Unscrew this and see if there is anything left.... if not, you;
a) need to replace
b) identify if you have a restriction, so remove the pipes and inspect for debiris...
What you see here is the inlet part ... on the other side, you may have the zink blocking the fuel cooler etc., so a bit more complex if it is broken off on the other side.. (engines also use fuel as cooling medium for injectors etc., so return fuel to the tanks is warm... these engines easily pump 50% more fuel than consumption for cooling of injectors etc.)
Also, you do have the standard 6/71 oil seapage around governor control arm, governor balance weight and also around the blower (indicated by arrows)..
Do go down and check the bolts/nuts etc. every now and then (1/2" and 3/8")... yes you do need imperial size spanners/sockets.
Yours look very nice and dry for 71's, so just keep an eye out and put the spanner/socket against it and check ...but don't pull too hard, as she obviously is not leaking much...
Looking at the pictures, you have a quite early configuration with vent from crankcase to air intake (simple and reliable)..., but if you want to keep your bilges clean, you will find a small oil drip from the aibox breather drain --- on the outside of the engines, in front of gearbox ... low down.. A small outlet pipe.... which you can connect a hose to and lead it into a collecting bottle (std gas hose fits perfectly)....and if situated low enough down, you may end up emptying this every 200 hrs ...or once a season...(previous owner may have done this already)..
Divemaster1
Well-known member
... and if you are interested in a comparison between two and four strokes, have a read of this stuff....
http://www.yachtsurvey.com/comparing_diesel_types.htm
http://www.yachtsurvey.com/comparing_diesel_types.htm
syd
New member
Hi Alf.
Now that is an eye opener. Its good to know how well they rate the reliability of these engines. Very interesting read. Are the injectors pricey ? The write up said they act as a pump as well as an injector, that would explain the size of the one in your picture. Going to check the anodes in the cooling system, thanks for the heads up, also replace the gasket on the water pipe where it joins the heat exchanger. Does antifreeze/Coolant have to be a specific type Alf ?
Cheers for now
Syd
Now that is an eye opener. Its good to know how well they rate the reliability of these engines. Very interesting read. Are the injectors pricey ? The write up said they act as a pump as well as an injector, that would explain the size of the one in your picture. Going to check the anodes in the cooling system, thanks for the heads up, also replace the gasket on the water pipe where it joins the heat exchanger. Does antifreeze/Coolant have to be a specific type Alf ?
Cheers for now
Syd
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Divemaster1
Well-known member
Article s not new, so four stroke technology have changed a bit since then with introduction of electronic governance etc., but principles of reliability of the Detroit two strokes remain...
Injectors are a mindblowing £39.60 ..
. when you do a core exchange (hand the old one in), if not they will retail at about £97...oh yes, do change that gasket .. paper I seem to recall... No special coolant required, but don't go for the very expensive stuff (red in colour I believe)...
AndieMac
Well-known member
From Bajansailor
Bajansailor emailed me these scanned pics. he promised to post previously, as he is still having issues with photobucket....
Below is the Sportfish version
Bajansailor emailed me these scanned pics. he promised to post previously, as he is still having issues with photobucket....
Below is the Sportfish version