Bmc 1.5 Cylinder Head Rebuild

[Troyboy]

Nice work and good pics but do I take it I should reconsider buying a boat with a BMC engine? Do they all overheat and what are the good points?

I notice you are Peterborough based so assume you will be boating on the Nene . Many narrowboats have cooling systems intended for canals and won't have a large enough skin tank for river use . In fact I'm not convinced some are large enough for canal use . I had overheating problems on the Nene and I know other boaters who have had similar problems but after the external cooling pipes were fitted at Charlie Foxes in March no more overheating .

Good points for the BMC 1.5 engine . Simple to work on and DIY friendly . As already mentioned parts readily available as many interchangeable with the MGB . Oil filters are £3 at Millfield Auto parts in Peterborough . Head gasket sets £22, bottom sets £25,

4 heater glow plugs £34, fuel lift pump £25 all on ebay . You shouldn't be put off a boat because it has a BMC engine .

[paul68]

I notice you are Peterborough based so assume you will be boating on the Nene . Many narrowboats have cooling systems intended for canals and won't have a large enough skin tank for river use . In fact I'm not convinced some are large enough for canal use . I had overheating problems on the Nene and I know other boaters who have had similar problems but after the external cooling pipes were fitted at Charlie Foxes in March no more overheating .

Good points for the BMC 1.5 engine . Simple to work on and DIY friendly . As already mentioned parts readily available as many interchangeable with the MGB . Oil filters are £3 at Millfield Auto parts in Peterborough . Head gasket sets £22, bottom sets £25,

4 heater glow plugs £34, fuel lift pump £25 all on ebay . You shouldn't be put off a boat because it has a BMC engine .

 

Hi, next year the missus and I will be setting off from the Nene and going on a 6 month plus canal cruise. A lot of the narrowboats in our price range have BMC engines fitted hence my questions. I am pretty competent with car engines(older type)so I'm sure i'll be able to do my own servicing. Another good thing(apart from spares being relatively cheap as you point out) is these engines being able to heat water which is an added bonus. If we do buy a boat with one of these engines I will definately contact Foxes as I have heard of other boaters having that mod done. Is there a diagram anywhere showing that modification?

Thanks for the info.

Edited July 23, 2013 by paul68

[andy winter]

I'm also part of the overheating BMC's club!!

 

I can see my skin tank is leaking, anyone know how I can patch it up or how I could bypass it at all??

[Grace and Favour]

I'm also part of the overheating BMC's club!!

 

I can see my skin tank is leaking, anyone know how I can patch it up or how I could bypass it at all??

The best repair you could make to your skin tank is to have it re-welded/brazed (depending upon where the leak is) - though I would always prefer the former

Edited August 3, 2013 by Grace & Favour

[Bill MBS]

Whats a heave and belch?

is it now fitted with a thermostat?

has the water pump been changed?

[regginald]

Excellent thread!! I am wondering if the exhaust or inlet valves are the same as the MGB valves also, they are 1/3rd the price of the chandlers on mgbhive website and have better availability also. Does anyone know if the valves are the same?

 

Thanks in advance for any information.

[Troyboy]

I think the answer is they are not the same . The reason I say that is I have parts books for the BMC 1.5 diesel and the MGB and the part numbers are different . The 1.5 inlet valve is part number 12H 212, and exhaust 12H 213 . The MGB inlet valve is 12H 4211 and exhaust CAM 1717.  

[regginald]

Thanks for taking the time to reply, I have ordered 8 exhaust valve guides for the MGB which have arrived and have been fitted to the BMC head, they are identical, would you mind checking if they have the same part numbers in your books? the MGB had 2 different exhaust valves, early and late, the BMC exhaust velves look very similar to the MGB later valves. Thanks again Troyboy

[Tracy D'arth]

27 minutes ago, regginald said:

Thanks for taking the time to reply, I have ordered 8 exhaust valve guides for the MGB which have arrived and have been fitted to the BMC head, they are identical, would you mind checking if they have the same part numbers in your books? the MGB had 2 different exhaust valves, early and late, the BMC exhaust velves look very similar to the MGB later valves. Thanks again Troyboy

I have found many parts that appear to be common to the MGB engines but have different part numbers for some reason better known to BMC. If the dimensions are the same I see no reason for not using them in a diesel engine.

[Tony Brooks]

It would not surprise me if the B exhaust valves were a different alloy, but if so I suspect the duty in the diesel will be less onerous.

[Troyboy]

2 hours ago, regginald said:

Thanks for taking the time to reply, I have ordered 8 exhaust valve guides for the MGB which have arrived and have been fitted to the BMC head, they are identical, would you mind checking if they have the same part numbers in your books? the MGB had 2 different exhaust valves, early and late, the BMC exhaust velves look very similar to the MGB later valves. Thanks again Troyboy

 

The MGB parts book I have relates to the later 1976 rubber bumper cars and the part numbers for the valve guides are inlet 12H 222, exhaust 12B 1339  . The BMC 1.5 diesel parts book I have relates to the J2 van which was fitted with 1500cc and 1622cc  petrol engines plus the 1.5 diesel . The exhaust valve guides on the petrol and diesel engines are all the same part number namely 11G 193, The inlet valve guides are different namely 11G 313 for the petrol engines and 11G 193 [ same as exhaust] for the diesel.   

I also have a Brown Brothers Motor Factors  catalogue from the early 60's and looking at the part numbers for the 1964 MGB exhaust valve guides and the 1963 J4 1.5 diesel engine exhaust valve guides and they are the same namely James part number G2616S .The actual valves have different part numbers . 

[regginald]

Thanks for your time, so the guides are the same but have different numbers, I am thinking the valves will be the same also but need confirmation, i guess your books do not give dimensions of the exhaust valves in the data section, perhaps just the seat angle and height to head face. I could be wrong but if the cam shaft is the same too the price difference at the chandlers is astronomical and I getting fed up with being ripped off all the time by chandlers, camshaft at chandlers £250 and mgbhive new at £85 and the pictures seem the same but 3 times the price, Quite frustrating

 

The guides I just receives were 12B 1339 and are correct for bmc inlet and exhaust

Edited July 30, 2021 by regginald
More info in case it helps someone else

[Troyboy]

Unfortunately I do not have a MGB workshop manual I got rid of that when I sold my MGB . It is the workshop manuals that gives the dimensions for seat angle and height to head face . If it is any help the 1.5 diesel seat face  angle is 45 degrees the same as the 1500 and 1622 petrol engines . The exhaust valve head diameter for the diesel is shown as 29.2 - 29.4 mm. Have you tried Ebay for cheaper 1.5 diesel spares ? Often bargains to be found compared to chandlers .  

[regginald]

Thanks, thats good info because the mgb is 34mm head diameter so i now know they are not the same. This morning i found out that layland tractors have the bmc 1.8 and the spare parts are a lot cheaper than chandlers, the camshaft is 90 instead of 240 and a new injection pump is 250 instead of exchange at 400, many other parts are cheaper also

 

[TNLI]

On 03/08/2013 at 12:21, andy winter said:

I'm also part of the overheating BMC's club!!

 

I can see my skin tank is leaking, anyone know how I can patch it up or how I could bypass it at all??

I agree with the others that this thread is a very good one!

 

Trying to bypass a keel cooling tank is going to result in the need for an entire new cooling system including an expensive heat exchanger. You would need to describe the type of tank and materials used for anyone to guess at a way of fixing a leak. 

 

If you really can't fix a keel cooling system due to excessive corrosion or damage, one cheap but crazy option I've seen work well, consisted of a car radiator and fan. That rather odd homebuilt fishing boat was based on a steel bilge keel yacht hull and the rest on a wood epoxy design for a cabin cruiser. The original inside tanks failed due to corrosion, so the owner fitted the radiator and fan unit flat on the cabin top. It looked weird, like some kind of satellite antenna mounted on a minature wind  generator. I thought it was a heat exchanger for a freezer until I spoke to the owner! 

[Bee]

I've seen a radiator and fan mounted in the usual place, in front of the engine in an old wooden narrowboat - so no skin tank and no underwater inlet - worked fine.

[StephenA]

29 minutes ago, Bee said:

I've seen a radiator and fan mounted in the usual place, in front of the engine in an old wooden narrowboat - so no skin tank and no underwater inlet - worked fine.

 

In an open engine room with the doors open I imagine?

 

Suspect it would be a complete non starter under a cruiser stern.

[David Mack]

2 minutes ago, StephenA said:

 

Suspect it would be a complete non starter under a cruiser stern.

Should be OK as long as you have large enough ventilation openings and the right ducting, just as with the many boats that had air cooled Listers under cruiser stern decks.

[StephenA]

5 minutes ago, David Mack said:

Should be OK as long as you have large enough ventilation openings and the right ducting, just as with the many boats that had air cooled Listers under cruiser stern decks.

 

Which you wouldn't have if you had a regular BMC install.

[TNLI]

1 minute ago, StephenA said:

 

Which you wouldn't have if you had a regular BMC install.

A small car radiator and integral fan is one nice way of heating a cabin or wheelhouse. You can even fire up the air cooled gen set to pwer up the AC system to cool the area down again during the summer.

  I need to fit a keel cooler which will cost about 100 quid for the extra alloy plate, but another 200 for the welding, plus a final few hundred for the header tank, hoses, thermostats, (Several types), low level alarm plug into the alloy header tank, and unforecast blood sweat and tears if it leaks. A good used radiator and header tank from a scrap yard should cost about 50 quid. I can install it myself and the alarm wiring is no big deal. 100 quid vs 4 or 500 quid. 

[Bee]

Back in the good old days of fixed fans on car engines and little radiators a hot summers day would see many cars overheating in traffic jams on the way to the seaside. In a boat you can bung in a bigger rad and an electric fan - much more powerful than the little windmill thing on the water pump of a Morris 1000. A bit of ducting and you can suck air in from under the cabin floor and dry that out too. Not all good ideas come from chandlers and the boat industry.

[TNLI]

1 hour ago, Bee said:

Back in the good old days of fixed fans on car engines and little radiators a hot summers day would see many cars overheating in traffic jams on the way to the seaside. In a boat you can bung in a bigger rad and an electric fan - much more powerful than the little windmill thing on the water pump of a Morris 1000. A bit of ducting and you can suck air in from under the cabin floor and dry that out too. Not all good ideas come from chandlers and the boat industry.

Bee is 99% right, it's such a great idea I'm definitely going to cool my old BMC donkey with a new of pre-loved modern radiator and intergral fan from a German car company, Ford or Volvo, (If I win the Lotto). I plan to install it fairly near the marine head, (WC for canal land lubbers), during the winter, but also like the idea of moving it to the central rescue/fishing deck during the summer. I don't see the need for a bigger than normal radiator & intergral fan unit, so will look for a Ford, VW or Volvo 1.5 diesel engine cooling assembly with hoses etc. I don't think Volvo make a diesel car with a diesel engine of less than 1.9, and that's a tubo, so has a bigger radiator. I think Ford make a 3 cylinder TD of 1.4 ltrs, so will target small car diesel radiator in Google later. That cooling system will save me about 500 plus quid, as my old donkey is missing its Jabsco pump and as I'm thinking of fitting a bigger hydraulic box heat exchanger I might just see what happens if I just place the larger port ZF cooler first inline after the existing circulating pump. 

  Only the good Lord himself will know if it's going to work.

 

PS: I think Bee might have the air flow plan backwards, as nothing is better than reversible under floor heating! If the fan fails, (Electric motors are incredibly reliable these days), just use your 240v fan to help cool the born again BMC radiator system.

Edited October 23, 2021 by TNLI

[Mad Harold]

2 hours ago, TNLI said:

Bee is 99% right, it's such a great idea I'm definitely going to cool my old BMC donkey with a new of pre-loved modern radiator and intergral fan from a German car company, Ford or Volvo, (If I win the Lotto). I plan to install it fairly near the marine head, (WC for canal land lubbers), during the winter, but also like the idea of moving it to the central rescue/fishing deck during the summer. I don't see the need for a bigger than normal radiator & intergral fan unit, so will look for a Ford, VW or Volvo 1.5 diesel engine cooling assembly with hoses etc. I don't think Volvo make a diesel car with a diesel engine of less than 1.9, and that's a tubo, so has a bigger radiator. I think Ford make a 3 cylinder TD of 1.4 ltrs, so will target small car diesel radiator in Google later. That cooling system will save me about 500 plus quid, as my old donkey is missing its Jabsco pump and as I'm thinking of fitting a bigger hydraulic box heat exchanger I might just see what happens if I just place the larger port ZF cooler first inline after the existing circulating pump. 

  Only the good Lord himself will know if it's going to work.

 

PS: I think Bee might have the air flow plan backwards, as nothing is better than reversible under floor heating! If the fan fails, (Electric motors are incredibly reliable these days), just use your 240v fan to help cool the born again BMC radiator system.

Apart from saving money,I can't see that using a vehicle radiator and electric fan will be satisfactory for very long.

I think the electric fan will be running constantly for normal canal cruising and if you are pushing against wind and tide,I think it will be working overtime,and if it hands it's dinner pail in,you could be knackered.

A heat exchanger system I think will be more reliable,although I accept more expensive.

[StephenA]

20 hours ago, TNLI said:

I agree with the others that this thread is a very good one!

 

Trying to bypass a keel cooling tank is going to result in the need for an entire new cooling system including an expensive heat exchanger. You would need to describe the type of tank and materials used for anyone to guess at a way of fixing a leak. 

 

If you really can't fix a keel cooling system due to excessive corrosion or damage, one cheap but crazy option I've seen work well, consisted of a car radiator and fan. That rather odd homebuilt fishing boat was based on a steel bilge keel yacht hull and the rest on a wood epoxy design for a cabin cruiser. The original inside tanks failed due to corrosion, so the owner fitted the radiator and fan unit flat on the cabin top. It looked weird, like some kind of satellite antenna mounted on a minature wind  generator. I thought it was a heat exchanger for a freezer until I spoke to the owner! 

 

I suspect 8 years on the problem has been solved....

[MtB]

13 minutes ago, StephenA said:

 

I suspect 8 years on the problem has been solved....

 

I notice however, that nice Mr TNLI is developing a penchant for answering decade old threads.