1.7 dti diesel

Arlon · 27 June 2005, 16:43

I recently got a boat with the 1.7 diesel. So far the little diesel has performed way outside what it specs would have you believe. My boat is a 27' "panga", not exaclty a RIB (my apology) but it is powered by an engine that seems somewhat popular in the RIB circles at least outside the US.. I was curious of any failures with this engine in a rib? I know there have been failures in heavy boats when the engines over boost.. Anyone run a boost guage on the little diesel? Anyone run a pyro to monitor EGT's? These are pretty important when running a diesel at high stress levels. I'm mostly curios about reliability of the 1.7 as my runs to offshore fishing areas are 50-100 miles each way.

First time post, nonRIB and from Texas.. I guess I'm starting with several strikes against me... Hmmm, that's 3 already... Arlon

Nick Hearne · 27 June 2005, 17:22

Hi & welcome!
What make engine is it you have fitted?
Nick

simmons0 · 27 June 2005, 17:27

We have the same Mercruiser 1.7 in our boat, no problems with the engine yet, but it does seem to be running a bit smokey.

If you do a search on Mercruiser diesels there is a thread where a couple of people say their's has suffered holed pistons.

Edit: Found it: http://www.rib.net/forum/showthread....ght=mercruiser

Andre · 27 June 2005, 17:30

Quote:

Originally Posted by Nick Hearne

Hi & welcome!
What make engine is it you have fitted?
Nick

It can only be the Cummins Mercruiser 1.7 TDI (120HP)
a very good engine indeed

Nick Hearne · 27 June 2005, 17:32

Sorry, thought Volvo did a 1.7

I will just take me coat!

Arlon · 27 June 2005, 17:40

Quote:

Originally Posted by simmons0

We have the same Mercruiser 1.7 in our boat, no problems with the engine yet, but it does seem to be running a bit smokey.

If you do a search on Mercruiser diesels there is a thread where a couple of people say their's has suffered holed pistons.

Edit: Found it: http://www.rib.net/forum/showthread....ght=mercruiser

As to running smokey, are you running any diesel fuel additives? Also are you allowing a cool down after running it hard? How many hours do you have on it?

I'm running a diesel additive that has definately reduced the knock/rattle of the diesel and I also let it idle for several minutes to cool the turbo oil before shutting it down. I only have 30hrs on the boat and no smoke at all. I've run about 500 miles (gps) so far. I do a lot of trolling which seems to use almost no fuel. Cruise speed is 28mph at 3800rpm, 5-6mpg depending on sea conditions, turning a mercury mirage 15.5x17pitch prop. Top speed is about 32 mph. No race boat but it sure does pass the fuel dock a lot!

I read the links and would love to figure out what the holed piston boat is turning for a prop/weight/length/ etc. He states several divers, gear, turning 3100rpm and NOT on plane? May just be a case of overloading the engine. I also hear a there was a problem with the waste gate shaft sticking that allows the engine to over boost when heavily loaded. Wonder if this boat is trailered or stayin the water? I would hate to loose a piston 100 miles out in the gulf of mexico! Arlon

Arlon · 27 June 2005, 17:45

Quote:

Originally Posted by Andre

It can only be the Cummins Mercruiser 1.7 TDI (120HP)
a very good engine indeed

well, really it's an isuzu NPR clone made in poland, purchased by mercury marine and supported/licensed/warrantied by cummins. I guess you could say it is truly a mutt.. I'm hoping service won't be a problem. Cummins though they are supposed to be able to suppot them seem to know very little about the actual engine (at least at the local cummins dealer here in Houston).

Ezgoing · 28 June 2005, 21:13

Arlon

Have you considered an auxillary engine?

rgds

Arlon · 29 June 2005, 13:20

Quote:

Originally Posted by Ezgoing

Arlon

Have you considered an auxillary engine?

rgds

Absolutely. Have the bracket and have the cash for an engine, just not sure about details yet. The 9.9 yamaha high thrust would be nice but is over 100lbs. The 6hp tohatsu would be marginal but at 50lbs it would be no problem to handle. I have been looking locally for someone with a 6hp tohatsu to try before I buy. I have a 2.5 tohatsu that actually pushes the boat fine in calm conditions but when running offshore conditions are seldom calm.. Nothing like the North Sea (worked in Aberdeen for some time years ago) but not a pond either. Other issue is carrying two kinds of fuel. Would need enough for 100 miles range on the kicker for the worst of days. Wish someone made a little diesel kicker that was less than 75pounds...

jwalker · 29 June 2005, 14:35

Quote:

Originally Posted by Arlon

...Anyone run a boost guage on the little diesel? Anyone run a pyro to monitor EGT's?

I run a combined boost/exhaust temp guage but it's on a Volvo not on a wee Merc. The boost gives a good indication of the load at a particular speed but, interestingly, exhaust temp doesn't always follow what you might expect. I better add that I'm measuring exhaust temp after the water injection. The exhaust temp is partly to warn of a water failure. The guage has settable alarms and is also linked to an external sounder.

Arlon · 29 June 2005, 14:53

Quote:

Originally Posted by jwalker

I run a combined boost/exhaust temp guage but it's on a Volvo not on a wee Merc. The boost gives a good indication of the load at a particular speed but, interestingly, exhaust temp doesn't always follow what you might expect. I better add that I'm measuring exhaust temp after the water injection. The exhaust temp is partly to warn of a water failure. The guage has settable alarms and is also linked to an external sounder.

I'm really keen on getting a boost guage set up on the wee merc. Seems all the failures I've heard of for this engine have to do with failure of the waste gate to function properly and causing an over boost condition (way overstressing the engine). Is the alarm settable for for the boost part too? That would be helpful for the merc owners I think. I'll do some nosing around for the volvo guages. Automotive guages are available but none are made with stainless hardware... I'd use guages like in my truck (also a cummins diesel) if they where just stainless.. Thanks for that bit of info! Arlon.

jwalker · 29 June 2005, 14:58

Can't remember about the boost alarm. I'll have a look. The gauge is not a Volvo component, it was designed for competition vehicles. The boost sensor is stainless, the temp one is brass, the cabling is all well sealed and twisted screened pairs are used to limit interference.

There are also temperature sensors which are designed for direct exhaust gas temp. measurement. Sensors are chosen to suit the application. I chose the one which reads standard engine water temp because the cooled exhaust temp. is approx. 65°c, so nicely in range.

Edit: Yes, there is a settable turbo boost alarm.

Arlon · 29 June 2005, 15:51

Can you tell me who makes the guage? sounds nice. Are the guages seperate or on one face? dials or digital? sorry for being a pest but that just sounds like a great guage for the application I have. Arlon

jwalker · 29 June 2005, 17:03

Quote:

Originally Posted by Arlon

Can you tell me who makes the guage? sounds nice. Are the guages seperate or on one face? dials or digital? sorry for being a pest ...

Yup, SPA Design. They're a UK company - enquiries@spa-uk.co.uk - for info. The folk who sell them are - www.demon-tweeks.co.uk I didn't find their web side particularly informative about what was included in the various kit options but the boost/temp gauge comes as standard with the boost sensor and the normal engine temp sensor. If you want the direct exhaust temp, you'll need the thermocouple and the adapter which scales the thermocouple output to the gauge input. Tha gauge is digital, has a back-light which is adjustable for brightness and colour and contains two readout fields. The connector on the rear of the gauge is not water resistant although the engine end is fine. You're not a pest - it's no problem.

Arlon · 29 June 2005, 18:19

Thanks JW, found it. That's about a perfect fit for what I want! Didn't realize anyone had a combo unit and the alarm just seals the deal! I think I just found by christmas present and birthday present! One for the boat and one for the truck! Arlon

jwalker · 29 June 2005, 18:26

Cool. It's pity (at your end

) that the $ is still about 1.8ish/£.

If you are serious and have any difficulty sourcing it, give me a shout and something can likely be organised.

alt · 30 September 2006, 18:42

Quote:

Originally Posted by Arlon

Thanks JW, found it. That's about a perfect fit for what I want! Didn't realize anyone had a combo unit and the alarm just seals the deal! I think I just found by christmas present and birthday present! One for the boat and one for the truck! Arlon

I know this is an old thread but, what product are you talking about?!

Niall

jwalker · 30 September 2006, 18:52

http://www.demon-tweeks.co.uk/produc...pcode=P/EDG206

and for other gauges

http://www.demon-tweeks.co.uk/produc...051&tlgrp=M027

alt · 30 September 2006, 19:08

Quote:

Originally Posted by jwalker

http://www.demon-tweeks.co.uk/produc...pcode=P/EDG206

and for other gauges

http://www.demon-tweeks.co.uk/produc...051&tlgrp=M027

Cheers for that! Is that just for the gauge? Where on the Merc 1.7 should I be connecting to for the boost?

jwalker · 01 October 2006, 00:24

Nah, it's the complete kit. The boost sensor needs to screw into the inlet manifold or the air ducting from the intercooler. I have a big screwed plug in mine so I drilled a hole in it and tapped a thread to suit the sensor. If you have something already screwed into the manifold, you can buy a T piece to take both original and boost sensor. I don't know your engine so can't give specific advice. If it has a fitting to take a manifold heater, perhaps you could use that.

The temperature sensor is similar to a standard car fitting. I made a wee adaptor and clamped it to the top of the exhaust riser, below the water section, with a jubilee clip. From memory, the riser on your motor goes upwards from the turbo outlet and it is easily accessible so it shouldn't be too difficult to arrange something.

I've just had a wee look at the manual. It's difficult to tell from the line drawings but there appears to be some sort of plug at the starboard end of the airway which passes over the top of the motor from the heat exchanger.
The exhaust downpipe is shown and that would be a good place for the temp sensor if you can get access to it. Also, it shows the plug at the front of the heat exchanger which was removed to adapt a tell tale as mentioned in the other thread. It is the heat exchanger drain plug.