BMC 1.5 glow plugs

[Tony Brooks]

EERRRMMMM keep your hair on. I thought I was being polite and I do not need nor do I appreciate you talking to me like that even if this is on a forum. Don't worry I will sort it out myself thank you very much. Thank you for your replies prior to that little outburst

 

Pete

 

Sorry I tried to help and apparently had my comments ignored, skip read, or misrepresented.

[Albion]

Pete,

I have to agree with Tony. It seems likely that you have had an injector replaced at some time in the past and that that injector doesn't have the male to male adaptor that the others have. I cannot see how you could have disturbed what you call a locknut just by undoing the injector pipe nut. To prove the point though, if you remove the injector pipe nut and then try to undo the adaptor you should find either of the following:-

1. If your locknut theory is correct the adaptor should undo and you would be left with a tubular threaded stub pipe in your hand.

2. If the injector is a type without the male to male adaptor you won't be able to shift it.

If by any chance you do try this test then please don't try it with a pair of unguarded pliers on the threads.

I'm pretty sure that you will find that it is case 2 and that the injector is a different type.

 

I also cannot see how a leak at the aforesaid injector pipe union can introduce air, and especially to the rest of the system. In effect your small leak on the pipe nut is only like cracking a union nut open a bit which is exactly what you would do to bleed a system as the last stage of bleeding after you had bled other things like the injection pump etc. In other words a leak there will likely cause a misfire but it won't affect any other cylinders and cause a 'no start'. Do please, as Tony has said, inspect the ends of the injector pipe for distortion or marking as that isn't good and just tightening with more grunt isn't an ideal solution.

I honestly believe that you have to look elsewhere for your air leak that causes a no start. Have you disturbed anything else recently? Have you changed a fuel filter? Have you accidentally disturbed a fuel line by catching it somehow? There are many possibilities that may not immediately come to mind.

Roger

[LEO]

Hi Pete,

 

I think there was one non matching injector on that engine, when I had the injectors serviced in 199? one injector was beyond repair. The specialist firm (Injector Services, Tolpit Lane Watford) fitted a non matching one (which they assured me would run OK (and it did).

 

I carried out a lot of work on the engine in 199?, including, overcoming a chronic overheating problem whilst ticking over (blocked cooling circuits the engine), new valves and seats, converting it from raw water to heat converter, fitting a water pump to the engine and fitting a proper calorifier circuit, Head skimmed and rebuild.

 

Hope that helps, towards solving the mystery and sorry that my memory took so long to 'click in'.

 

Hope you post some pics of the engine, it will be like looking at some pictures of a 'long lost' friend.

 

I will look up the date the work was carried out, the advice about not over tightening the unions and overall cleanliness should not be ignored.

 

ATB

 

Mike.

 

Hi,

 

Looks as if injectors were serviced in Jan 1993 (engine hours 583)

Edited December 3, 2013 by LEO

[mango]

Can anyone advise on what current 12V heater plugs should take on a BMC 1.5? It's a long time since I worked on these engines.

 

Edit To clarify, I mean each plug rather than total current.

Edited August 11, 2014 by mango

[Tony Brooks]

It seems to vary a bit from plug manufacturer to plug manufacturer but I think its about 12 amps and steady but some are higher dropping to about 12 amps each as they warm up. Unfortunately I am not at home with all my data but I know I have answered this question before on this forum. I have this niggling feeling it may only be 6 amps steady but I can not be sure

Edited August 11, 2014 by Tony Brooks

[mango]

It seems to vary a bit from plug manufacturer to plug manufacturer but I think its about 12 amps and steady but some are higher dropping to about 12 amps each as they warm up. Unfortunately I am not at home with all my data but I know I have answered this question before on this forum. I have this niggling feeling it may only be 6 amps steady but I can not be sure

Thanks Tony. It has been many years since I had much to do with these engines, and in these days I did not have a clamp ammeter to check what current they were drawing. I've heard figures of 30 - 50 amps for a set of four but never seen that in writing.

 

A friend has reconditioned an old BMC 1.5 and put in a couple of new heater plugs that draw just over 3 amps each. The originals take about 6 amps. Not surprisingly it takes a bit of cranking to get it started. I think we need some decent heater plugs.

[Tony Brooks]

That 6 amps is, after a night thinking about it, about right. Modern fat plugs for a set of four - a very high current, maybe 100 amps and dropping to about 50 amps as they heat up.

 

Most BMC pin plugs for 4 a steady 25 amps BUT I have had the odd newer plug that behaved closer to the modern fat plugs.

 

I agree 3 amps per plug is not going to help cold starting but I should warn you that voltdrop on any cables or connections could cause this. I suppose that is why you want to know the individual current.

[mango]

That 6 amps is, after a night thinking about it, about right. Modern fat plugs for a set of four - a very high current, maybe 100 amps and dropping to about 50 amps as they heat up.

 

Most BMC pin plugs for 4 a steady 25 amps BUT I have had the odd newer plug that behaved closer to the modern fat plugs.

 

I agree 3 amps per plug is not going to help cold starting but I should warn you that voltdrop on any cables or connections could cause this. I suppose that is why you want to know the individual current.

You are right about voltage drop. I've seen many boats where the heaters were powered via the keyswitch and lightweight cable. I did the wiring on this boat with heavy cable and a starter solenoid from a lawn tractor acting as a relay, so no problem with voltage drop. We will change the heater plugs and a bigger fuse to suit the load.

[rustyhook]

I bought my set of glow plugs for my bmc 1.5 for less than £16 on ebay

 

http://www.ebay.co.uk/itm/4-X-ROVER-MARINA-1-5-D-Leyland-154-Tractor-Glow-Plug/131633076250?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Edited November 21, 2017 by rustyhook

[peterboat]

On 11/21/2017 at 19:13, rustyhook said:

I bought my set of glow plugs for my bmc 1.5 for less than £16 on ebay

 

http://www.ebay.co.uk/itm/4-X-ROVER-MARINA-1-5-D-Leyland-154-Tractor-Glow-Plug/131633076250?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I think I bought mine from the same place worked great

[rustyhook]

mine got delivered today. will be putting them in my engine on saturday. hopefully i can finally get it going,

  

[Chas78]

I thought dual core plugs were better that's what i am getting for my BMC 1500  http://www.ebay.co.uk/itm/DUAL-CORE-DIESEL-HEATER-GLOW-PLUGS-x4-BMC-950cc-1-5-1-8-TEMPEST-THORNYCROFT-BOAT/161236059205?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

[rustyhook]

well I put mine in today. And it started first time. and ran like a dream, it's the first time i've seen the boat run and i'm well pleased.

 

[Tony Brooks]

22 hours ago, Chas78 said:

I thought dual core plugs were better that's what i am getting for my BMC 1500  http://www.ebay.co.uk/itm/DUAL-CORE-DIESEL-HEATER-GLOW-PLUGS-x4-BMC-950cc-1-5-1-8-TEMPEST-THORNYCROFT-BOAT/161236059205?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

I think the word "better" needs defining. That page has the whiff of marketing bullshine about it.  I think all glowplug elements are an alloy of metals.

If they claim there are two elements, one of which heats faster than the other I suspect the fast one would need to turn itself off when up to temperature to save melting, In my book that would make it less reliable than one slow element that stay connected. However I need to know more about these duel core plugs than is on that page.

[Chas78]

I was advised by a friend who happens to be a Marine Engineer and has been for over 20 years so i think he knows a little bit 

[Tony Brooks]

39 minutes ago, Chas78 said:

I was advised by a friend who happens to be a Marine Engineer and has been for over 20 years so i think he knows a little bit 

If you really do mean a Marine Engineer then so well and good because he will have a degree level qualification and practical experience., if you mean what I will describe as a boatyard fitter" who may or may not have an formal qualifications then I still question what  he said.  I think known formal qualifications and about 48 year's experience might indicate a bit of knowledge and scepticism born from that experience.

[peterboat]

After fitting the plugs the engine would start after 3 seconds heat in the summer I have now removed it from the bathtub and fitted an electric motor so the engine and box are now surplus and for sale

[Chas78]

7 hours ago, Tony Brooks said:

If you really do mean a Marine Engineer then so well and good because he will have a degree level qualification and practical experience., if you mean what I will describe as a boatyard fitter" who may or may not have an formal qualifications then I still question what  he said.  I think known formal qualifications and about 48 year's experience might indicate a bit of knowledge and scepticism born from that experience.

I really do mean a Marine Engineer who started his apprentice working on train diesel/industrial engines and worked his way up a very knowledgeable chap.   

[cereal tiller]

4 minutes ago, Chas78 said:

I really do mean a Marine Engineer who started his apprentice working on train diesel/industrial engines and worked his way up a very knowledgeable chap.   

I wonder if Fred Dibnah had an Engineering Degree?

[Tony Brooks]

I think that unless I can see more than assertions we must agree to differ on this. Of course all train diesels use glow plugs don't they? Especially the large ones.

Edited November 26, 2017 by Tony Brooks

[Tony Brooks]

1 minute ago, cereal tiller said:

I wonder if Fred Dibnah had an Engineering Degree?

I think he did get an honorary one in the end. You will note that nothing apart from an assertion has been produced to support the word "better".

Having had more 1.5 type plugs snap on me than I care to remember all the plugs I have seen inside consist of an outer metal "tube" with a single fairly thin heating element up the middle surrounded by a ceramic powder. The only sign of different metals are the different materials used for the element, the tube, and the plug body,  not two different metals in the heating element.

I take great exception to the half truths so beloved of marketeers and those that repeat them and can not substantiate their claims. This does not  mean Chas is wrong, its just that he can not substantiate his statement that is contrary to my experience.

[Chas78]

Blimey i wish i had not commented on this my initial comment was i thought dual core plugs were better didn't think it would turn into an i know better i have more experience than what you or who you know scenario 

[Tony Brooks]

34 minutes ago, Chas78 said:

Blimey i wish i had not commented on this my initial comment was i thought dual core plugs were better didn't think it would turn into an i know better i have more experience than what you or who you know scenario 

It did not until you quoted your friend and the length of his experience. I just questioned your assertion. If you quote a job title" and experience all I can do is to give counter experience.

I fully accept that you may believe those plugs are "better" but I can not, at present, accept that your belief is valid unless you can justify it - and by that I do not mean by quoting a job title that may or may not imply any degree of knowledge. You need to come up with either an independent resource that applies to the 1.5 pin type plugs or describe what this dual core thing really is  and how it works. I note that you have not defined what "better" means in this case.

Maybe you are correct and I am wrong but if so I want to understand what its all about.

If you go through a few year's of topics on here you will see any number of cases where "engineers" have given bad advice and in a fair few cases they have very little training so are unable to justify their apparent experience by working through the underlying theory. In this case I am not going down the "he is not a chartered engineer" thing but do question exactly the basis upon which your friend calls himself a Marine Engineer and his experience relevant to the point in question.

I know it was not you but someone raised Fred Dibnah, presumably an example of a good practical engineer who had no qualifications but if you remember his TV programmes you will know he used the wrong metal for a plain  wheel bearing on his traction engine and also messed up one of his pistons so it needed modification by someone who new more about the subject. In my view this well illustrates the sort of problem when experience has little theoretical backing.

How your friend arrived at his view I have no idea. Likewise I have no idea about his experience with the 1.5 type pin glow plugs. I accept the modern large "pin" glow plugs may be "dual core" and there is space to put some mechanism into them (unlike the 1.5 type). They certainly heat a lot faster but then they should because they draw far more  current. However even then I doubt the total electricity typically consumed is much different or if that makes them any "better". They are far superior in respect of their mechanical strength so are far less prone to the in snapping.

I only warned that general belief and marketing speak (especially in Ebay type adds) may not be correct unless backed up by facts.

[Tony Brooks]

Right, I was right to be sceptical.

I have found references to "Dual Coil" glow plugs, not dual core. I have also found  description BUT the description has what I see as a problem. it says the heating coils use a positive temperature coefficient heating element so they self regulate the current and do not burn out. Sounds good ---------- except most if not all heating elements use wire with a positive temperature coefficient to prevent them burning out.

Now, having established we may be talking about twin COILS I can not see how twin coils will fit into a 1.5 type pin but would do so easily in a modern plug. I almost suspect the claimed advantage of greater reliability might be  related to having two coils giving a degree of redundancy when one fails, even if that is at the expense of a slower warm and a lower heat output.

[Mikexx]

4 hours ago, Tony Brooks said:

Right, I was right to be sceptical.

I have found references to "Dual Coil" glow plugs, not dual core. I have also found  description BUT the description has what I see as a problem. it says the heating coils use a positive temperature coefficient heating element so they self regulate the current and do not burn out. Sounds good ---------- except most if not all heating elements use wire with a positive temperature coefficient to prevent them burning out.

Now, having established we may be talking about twin COILS I can not see how twin coils will fit into a 1.5 type pin but would do so easily in a modern plug. I almost suspect the claimed advantage of greater reliability might be  related to having two coils giving a degree of redundancy when one fails, even if that is at the expense of a slower warm and a lower heat output.

 

https://www.boschautoparts.com/documents/101512/0/0/0b189154-b815-46d7-bf70-e153bb6ecb88

This talks of a "dual-control regulating and heating coil" which isn't the same as "dual coil". I would be surprised if they had 2 coils.

There are other explanations too, but it does appear to offer an advantage in terms of warm up time and allowing a hotter plug temperature as preventing burn out.

The result may be not having to wait so long for the glow plugs to 'glow' which can't be a bad thing.