SR2 smoking

[bizzard]

The HR is a bigger engine of 30 odd Hp.

 

The SR is 13-14 hp,the LR is 10 hp and the SL is close at 9.5 hp so i'd say a prop pitched for the SL would be ok.

[Albion]

The HR is a bigger engine of 30 odd Hp.

 

The SR is 13-14 hp,the LR is 10 hp and the SL is close at 9.5 hp so i'd say a prop pitched for the SL would be ok.

 

It will get you around but, if the engine is really an SR for example then you're about 40% adrift and you're not getting the best out of a relatively small engine. I prefer to leave prop sizing decisions to the experts, after all they've been in the game a long time and know what they are talking about.

Roger

[claudia]

That all means I am back to square one with no idea what my engine is. If its a HR 30HP then its a bloody lazy one as it can't push the prop I have put on. I was joking about filing it down. the numbers on the injector are BK680S05209B and DN 544800 TG. Does anyone have a very cheap SR2 that will bolt straight on to a Ducati box?

[bizzard]

It will get you around but, if the engine is really an SR for example then you're about 40% adrift and you're not getting the best out of a relatively small engine. I prefer to leave prop sizing decisions to the experts, after all they've been in the game a long time and know what they are talking about.

Roger

Hang on Roger if you read all of Claudia's thread you will see that we determined his gearbox reduction as 2.1 and the direction of rotation and as Claudia thought he had an SR2 had the correct prop supplied by i think Crowther for that engine,it was then that he found that the engine was struggling badly with it although his engine sounds in fair nick.We have since discovered that it is not an SR2 but one of the less powerful LR2 or SL2. So he now needs to get its pitch reduced.

[Tony Brooks]

Ahoy Ian,that is definitely not an SR injector i've just compared it with my ones which are definitely SR as they came out of my old SR2 and i had them serviced. They have pintle nozzles and very prominent cooling fins which match the cooling fins on the cylinder head.The SR manual also shows this type only also for the SR. Yours is entirely different.It looks like your engine is an SL or LR for which i'm afraid i have no manual or data. I'll have a search on the internet and see what i can find.

 

 

Are the cooling fins not on a sleeve into which the injector fits? I am sure they are on SLs

[bizzard]

Are the cooling fins not on a sleeve into which the injector fits? I am sure they are on SLs

The SR's fins are built in also the nozzle is conical where as Claudia's one is parallel.A totally different shape.He needs to contact Chris B with those injector numbers.

[Albion]

Do you mean that the problem has been there all the time that you've owned the boat (and/or the engine in the boat)?

If that is the case it could be over-propped perhaps.

Roger

 

 

Hang on Roger if you read all of Claudia's thread you will see that we determined his gearbox reduction as 2.1 and the direction of rotation and as Claudia thought he had an SR2 had the correct prop supplied by i think Crowther for that engine,it was then that he found that the engine was struggling badly with it although his engine sounds in fair nick.We have since discovered that it is not an SR2 but one of the less powerful LR2 or SL2. So he now needs to get its pitch reduced.

 

I'm not disputing that the prop needs reducing in size (whether that be diameter, pitch or a combination of both) and I refer you right back to my post #5 (copied above) where I suggested that it was likely to be over-propped. What worries me is the potential creep of assumptions in this thread. We are told that the original prop was specced correctly by Crowthers for an SR2 and for this boat. That may or may not be 100% true, but even if it is true, using known data from a known engine will by-pass all earlier assumptions/knowledge and enable Ian to make the correct final choice, once and once only. As it is, assuming that the existing prop is correct and then making an estimate as to what should be removed from the pitch only is potentially risky and based on not entirely certain info. Why do that when, once the correct engine has been established, you can get a new, correct full recommendation from Crowther? Can you be sure that 2 inches off the pitch only is equivalent to a reduction of about 40% in engine power (using your figures)? Would it be better to reduce the diameter somewhat as well as the pitch? There are potentially so many open questions that it would be better to start again for complete confidence IMO.

Roger

Edited January 17, 2012 by Albion

[Timleech]

That all means I am back to square one with no idea what my engine is. If its a HR 30HP then its a bloody lazy one as it can't push the prop I have put on. I was joking about filing it down. the numbers on the injector are BK680S05209B and DN 544800 TG. Does anyone have a very cheap SR2 that will bolt straight on to a Ducati box?

 

It's certainly not an HR!

 

I think Biz may have it slightly back to front, that pic looks to me as though it shows a pintle (or Pinteaux) nozzle. These have a flat end with a single hole in the middle and the moving part actually projects through the end of the nozzle, visible as a little 'pip'. The older LD, SL etc definitely had these.

The last SR injectors I dealt with had a 3- or 4- hole nozzle with a rounded tip, definitely not pintle type, though I can't say with certainty that older SR engines weren't fitted with pintle nozzles. They also had the integral cooling fins as described by Biz.

 

Tim

[claudia]

Sorry Roger but why do you think I would lie about getting the prop sized, I went to Crowthers and gave them the information they asked from what I believed to be correct Yes I was wrong but I did not know this at the time, this has emerged from a lot of people on here giving me good advice and the likes of Bizzard putting in alot of effort trying to get to the bottom of this.

[Albion]

Sorry Roger but why do you think I would lie about getting the prop sized, I went to Crowthers and gave them the information they asked from what I believed to be correct Yes I was wrong but I did not know this at the time, this has emerged from a lot of people on here giving me good advice and the likes of Bizzard putting in alot of effort trying to get to the bottom of this.

 

No insult intended I can assure you. I got it into my head that you had got the info from a previous owner and had been told that it was sourced from Crowther, I didn't appreciate that it was yourself that obtained it. It doesn't negate my point though that guessing changes to a prop specced for an incorrect engine is not a scientific way of choosing a new, correct prop. Once you've got the identity of the engine sorted then you can go back with the correct info and get the correct spec. You've got to change the prop sometime so you may as well change it once with correct knowledge, rather than guess a new size.

I would also point out that all of us, not just Bizzard and the others you have listened to, are trying to help you even though it may not feel like it to you. We just have different slants on the advice we give, that's all.

Roger

Edited January 17, 2012 by Albion

[bizzard]

I don't know whats happening but i've recently replied to both Albion and Tim but neither uploaded,lets see if this does.

[bizzard]

It's certainly not an HR!

 

I think Biz may have it slightly back to front, that pic looks to me as though it shows a pintle (or Pinteaux) nozzle. These have a flat end with a single hole in the middle and the moving part actually projects through the end of the nozzle, visible as a little 'pip'. The older LD, SL etc definitely had these.

The last SR injectors I dealt with had a 3- or 4- hole nozzle with a rounded tip, definitely not pintle type, though I can't say with certainty that older SR engines weren't fitted with pintle nozzles. They also had the integral cooling fins as described by Biz.

 

Tim

Confusing init.My injectors were from a very early SR with the Pinteaux nozzle but with conical nozzles.My old ancient manual states as you say Pinteaux type fitted to the LR although no illustrations. As for the SL i have no data,and can't remember either.I think Ian needs to get in touch with Chris B with his injector numbers.

[Albion]

Confusing init.My injectors were from a very early SR with the Pinteaux nozzle but with conical nozzles.My old ancient manual states as you say Pinteaux type fitted to the LR although no illustrations. As for the SL i have no data,and can't remember either.I think Ian needs to get in touch with Chris B with his injector numbers.

 

Agree entirely. While injector numbers may not necessarily give us an absolute definitive answer it would be nice to have to more, objective, information.

Roger

[LesR]

Just to add my observations to the mix, after visiting the boat yesterday. The outward features are similar to a SR2 but the injector has a cylindrical base with a flat bottom with one central hole that has a small pip. My SR2 injectors have the cooling fins as already described, my engine was built in 1969. The leak off pipe is not the self venting type, and originally returned excess fuel to the feed line between the small filter and the injection pumps. This has now been fed back to the tank directly, I do not know what if any effect this would have. The gearbox is a 2:1 ratio, and looks to have been married to the engine for many years. The engine mount seems original with a plate welded to the hull for direct bolting of the engine, no rubber mounts are used, i.e. as fitted to a lister gearbox. The engine does not appear to have been highered to allow a reduction gearbox to replace a 1:1 lister box. As to the original prop running in reverse, I think it may be that in the period before Ian got the boat, the prop was damaged and some kind boater has offered to give the previous owner an old lister prop, not realising it was from a direct 1:1 gearbox that of course runs the opposite way to a reduction gearbox.

 

The engine started first time and ran very smoothly. Full rpm was achieved without the load of the gearbox and prop. Once the gearbox was engaged (forwards or reverse) the engine would hardly pull much above tick over. As usual the revs did drop slightly, but it would happily pull the load of gearbox and prop without stalling at this reduced rpm. It did not show any signs of stress or labouring, but seemed that there was no fuel to allow the revs to increase. Slowly opening the throttle had not effect on building up the rpm, all these tests were at standstill so there was no extra load of forcing the boat through the water. I have suggested to Ian that he carries out these tests again after unbolting the propshaft from the gearbox and seeing what effect it has on the rpm. Also to rig up a small day tank and bypass as much of the fuel system as possible, just to test this side of things.

 

As to the engine identification. If anyone knows how to identify what engine this is without measuring the bore/stroke I am quite happy to check it out.

 

Les

[bizzard]

Just to add my observations to the mix, after visiting the boat yesterday. The outward features are similar to a SR2 but the injector has a cylindrical base with a flat bottom with one central hole that has a small pip. My SR2 injectors have the cooling fins as already described, my engine was built in 1969. The leak off pipe is not the self venting type, and originally returned excess fuel to the feed line between the small filter and the injection pumps. This has now been fed back to the tank directly, I do not know what if any effect this would have. The gearbox is a 2:1 ratio, and looks to have been married to the engine for many years. The engine mount seems original with a plate welded to the hull for direct bolting of the engine, no rubber mounts are used, i.e. as fitted to a lister gearbox. The engine does not appear to have been highered to allow a reduction gearbox to replace a 1:1 lister box. As to the original prop running in reverse, I think it may be that in the period before Ian got the boat, the prop was damaged and some kind boater has offered to give the previous owner an old lister prop, not realising it was from a direct 1:1 gearbox that of course runs the opposite way to a reduction gearbox.

 

The engine started first time and ran very smoothly. Full rpm was achieved without the load of the gearbox and prop. Once the gearbox was engaged (forwards or reverse) the engine would hardly pull much above tick over. As usual the revs did drop slightly, but it would happily pull the load of gearbox and prop without stalling at this reduced rpm. It did not show any signs of stress or labouring, but seemed that there was no fuel to allow the revs to increase. Slowly opening the throttle had not effect on building up the rpm, all these tests were at standstill so there was no extra load of forcing the boat through the water. I have suggested to Ian that he carries out these tests again after unbolting the propshaft from the gearbox and seeing what effect it has on the rpm. Also to rig up a small day tank and bypass as much of the fuel system as possible, just to test this side of things.

 

As to the engine identification. If anyone knows how to identify what engine this is without measuring the bore/stroke I am quite happy to check it out.

 

Les

Interesting.It might be worth trying as i've mentioned to Ian a couple of times to over-ride the governor ''just below the lift pump by slackening the little stop plate screw and turning the plate anti-clockwise and so give the engine more fuel and see if that makes any difference.

[Springer Skipper]

I have an lr.1 lying around,900 rpm /2hp so ill have a gander at the injector and see if it resembles any thing that has been so far mentioned.Intruging innit,tough for Claudia though.

Ive a few petters aroun,but the effort of a transplant is hardly worthwhile

[LesR]

Interesting.It might be worth trying as i've mentioned to Ian a couple of times to over-ride the governor ''just below the lift pump by slackening the little stop plate screw and turning the plate anti-clockwise and so give the engine more fuel and see if that makes any difference.

 

Hi bizzard,

I will give that a try, if Ian askes me back. But I can not see how adjusting the stop plate will affect the fuel supply as it is not directly connected to the linkage rod.Its only purpose is to apply pressure towards the right, thus stopping the fuel flow when the engine stop is applied. likewise, the engine governors only role is to stop the engine exceeding safe speeds, (in this case max. of 2500rpm) by centrifugal force acting on weights and springs so unless these speeds are exceeded the governer is not used. We also know that the engine will reach its designed maximum rpm without load, showing the linkage and governor is basicaly set correctly and working. My concern is that if it was just being caused by lack of power to drive the prop. through the water, then it would still gain some extra rpm say maybe 50% of maximum, but would not have the power/torque to exceed this. But infact it is not moving much above tickover rpm with the load applied and throttle fully open.

 

Les

[Timleech]

Hi bizzard,

I will give that a try, if Ian askes me back. But I can not see how adjusting the stop plate will affect the fuel supply as it is not directly connected to the linkage rod.Its only purpose is to apply pressure towards the right, thus stopping the fuel flow when the engine stop is applied. likewise, the engine governors only role is to stop the engine exceeding safe speeds, (in this case max. of 2500rpm) by centrifugal force acting on weights and springs so unless these speeds are exceeded the governer is not used. We also know that the engine will reach its designed maximum rpm without load, showing the linkage and governor is basicaly set correctly and working. My concern is that if it was just being caused by lack of power to drive the prop. through the water, then it would still gain some extra rpm say maybe 50% of maximum, but would not have the power/torque to exceed this. But infact it is not moving much above tickover rpm with the load applied and throttle fully open.

 

Les

 

If as originally described the engine is (black) smoking heavily when in gear, fiddling with the governor won't do anything useful.

 

Tim

[claudia]

Ok all, so would I be right in assuming its either a SL or LR and working on a 10 horse engine and getting a prop that best suits that format. Don't fancy the thought of going back down the weed hatch and doing all that again, it was cold then now its iced over! Such a waste of money and effort, still hope someone learns from this and does not take it as read that they have a certain engine without a thumbs up from the experts. Which is what I think Roger is saying but it still smarts when told.

[LesR]

You might find this of use. It's the LR & SR manual:

 

http://www.bluemoment.com/manuals/lister_man.pdf

[Albion]

If as originally described the engine is (black) smoking heavily when in gear, fiddling with the governor won't do anything useful.

 

Tim

I agree completely. The engine is already being supplied additional fuel to try, in vain, to accelerate it but it is unable to reach the set speed due to overload (hence the black smoke). Fiddling with the settings of the governor won't achieve anything because the engine is unable to achieve governed speed as it is now. So, providing a partially seized gearbox or prop shaft has been eliminated, which I think it has from memory, then it has to be an under-powered engine for the size of prop.

 

Ok all, so would I be right in assuming its either a SL or LR and working on a 10 horse engine and getting a prop that best suits that format. Don't fancy the thought of going back down the weed hatch and doing all that again, it was cold then now its iced over! Such a waste of money and effort, still hope someone learns from this and does not take it as read that they have a certain engine without a thumbs up from the experts. Which is what I think Roger is saying but it still smarts when told.

It's a pity that it has happened but that's life. Anyone that has never made a mistake has never made anything. I'm still a bit worried about assuming anything, I'd rather be certain what engine it is and certain as to the rated power, but that may just be the engineer in me. If there is only about half an hp between the two types, as Bizzard has quoted, then you are only talking about 5% difference which isn't a lot. I'd sleep easier in my bed if you could ask an expert about the part numbers from your injector and what engine they match although even this may not give a definitive answer as Lister might, for all I know, have used the same injectors for both similar power rated engines and modified the delivery slightly in the pumps. I tried to look in the attic last night to find some info that I obtained when I worked for Listers, briefly, shortly before they closed down full production but, sod's law, couldn't find the books that I was searching for.

Roger

Edited January 18, 2012 by Albion

[Timleech]

 

It's a pity that it has happened but that's life. Anyone that has never made a mistake has never made anything. I'm still a bit worried about assuming anything, I'd rather be certain what engine it is and certain as to the rated power, but that may just be the engineer in me. If there is only about half an hp between the two types, as Bizzard has quoted, then you are only talking about 5% difference which isn't a lot. I'd sleep easier in my bed if you could ask an expert about the part numbers from your injector and what engine they match although even this may not give a definitive answer as Lister might, for all I know, have used the same injectors for both similar power rated engines and modified the delivery slightly in the pumps. I tried to look in the attic last night to find some info that I obtained when I worked for Listers, briefly, shortly before they closed down full production but, sod's law, couldn't find the books that I was searching for.

Roger

 

I have it in my head that the SL & LR produce their very similar horsepowers at different rpm, if so it would indeed be a good idea to establish which of those it is.

If not, I reckon 5% is well within the margins for error of prop calculations for this sort of situation!

 

Having looked at the linked manual, the injector shown is definitely not for an SR. Incidentally the book says quite specifically that the LR has a Pintle nozzle, as per the OP's pic, while the SR has a 3-hole nozzle.

 

Tim

[Albion]

I have it in my head that the SL & LR produce their very similar horsepowers at different rpm, if so it would indeed be a good idea to establish which of those it is.

If not, I reckon 5% is well within the margins for error of prop calculations for this sort of situation!

 

Having looked at the linked manual, the injector shown is definitely not for an SR. Incidentally the book says quite specifically that the LR has a Pintle nozzle, as per the OP's pic, while the SR has a 3-hole nozzle.

 

Tim

Now that is a very good point because when asking for prop calc recommendations they want to know (among other details) what rated max power at what rated speed.

Roger

 

 

Edited to add that I've just dug out this link to data on Lister engines Lister data and it shows that the SL2 gives 9.5hp at 2000 rpm and the LR2 gives 10.5 at 2500 rpm (no rating differences in marine or industrial types). That is a 10% power and 500 rpm difference so I would still press for a definitive identification of the engine personally.

Edited January 18, 2012 by Albion

[LesR]

I think Ian needs to clarify the amount of black smoke it was producing. I did not see any, but I was in the engine bay.If my friends BMC is anything to go by, that does produce black smoke, all down the moorings.

 

Les

[Springer Skipper]

I have just popped the rocker box off of a LR and that injector looks the same.If claudia still needs numbers ill pull the injecter out to get numbers tommorow.

hope this helps.

Robin