Best replacement engine for a BMC 1.8

[Grassman]

My 30 year old BMC 1.8 with 13,300 hours on the clock has blown the head gasket. Obviously the extent of the damage and subsequent repairs needed, wouldn't be known until further investigations are carried out, and on the basis that I'd have to pay somebody to do this which would obviously cost a lot, and might end up needing a major overhaul or even a replacement engine, I'm considering biting the bullet and buying a brand new replacement engine. I don't want a reconditioned one because I've read on here and heard elsewhere too, that they don't always turn out well.

 

So I'm looking for advice on which engines would compatible on a 'like for like' basis. At a Crick show a couple of years ago the chap at the Canaline stand told me theirs would be an ideal replacement, with none of very little work needed to adapt it. Do any of you know if this is true, and if Canaline engines are any good? Also what other makes of engine might be suitable please?

 

In case it's relevant, my current set up is a PRM 150 gearbox and a Colecraft cruiser stern. Also, because the boat is immobile would a supplier install it in the marina I'm currently in? The marina (Kings Bromley Marina near Lichfield, Staffs) have a work bay with a pontoon each side and reversed in, the stern is right by hardstanding so accessibility is good.

 

I'd be grateful for any advice please.

[beerbeerbeerbeerbeer]

I worried the other month that I might have  blown the head gasket on my BMC 1800.

I got a quote of £300 to refit the head gasket, but I don’t think that included having the head skimmed (which I always thought was done as a matter of course before refitting).

My point being it may not be that expensive to fix. 
 

I personally would pay someone to take the top off to find out. 
It might cost a few hundred quid to find you’ve got further high end expenses and you’d then prefer to start again with a new engine. 
Or you might find it just needs a new gasket 😃

 

what issues you had with the engine?

any reason you think the gasket blew?

 

 

 

[magnetman]

Beta marine probably worth talking to. They are happy to make up custom engine "feet" to fit onto existing mountings. You will need accurate measurements and they charge a little bit extra but it is quite a handy option.

 

Edited February 9, 2023 by magnetman
Typo

[Tracy D'arth]

The Canaline engine is the closest thing to a drop in replacement for a BMC 1.8 that you can find. All the "bits" are on the same side, it will drop onto the mountings with maybe a packing piece depending on your gearbox.

It was modeled on the BMC 1.5 layout so dimensionally it is almost a clone. The 1.5 and 1.8 BMCs share the same layout and major dimensions.

Oh, and it can be ordered to take your existing gearbox too!

Much loved by the hire fleets, its a robust trouble free engine.

[beerbeerbeerbeerbeer]

another BMC is of course a drop in replacement. 

Grass man, I don’t know why you’ll right off an engine over a head gasket?

Has a shiny new engine been on the cards for awhile and this issue is the decider?

 

 

 

[Grassman]

1 hour ago, Goliath said:

another BMC is of course a drop in replacement. 

Grass man, I don’t know why you’ll right off an engine over a head gasket?

Has a shiny new engine been on the cards for awhile and this issue is the decider?

 

 

 

 

Thanks to all of you for the very helpful replies. Goliath your last sentence sums up my thoughts perfectly! 🙂. At least it did until I’ve now had an eye-watering quote from Canaline Engines 😮.  I might well re-consider buying a new one now!

I'm guessing it is serious, and a prime example of ignoring a problem until it gets really bad. But I admit it does make sense to get it checked out before I consider whether or not to shell out for a new engine as it might not be as serious as I fear.

 

So if I can bore you with some details of how it has developed and has come to where we are now, perhaps some of you knowledgeable folk might be able to give me some pointers please?

I'll try to be as brief as possible. Nearly 4 years and 2,000 hours ago when chugging along the canal at about 3 mph some coolant in the header tank suddenly shot out of the overflow spout together with a little steam. The temperature which is normally 70c rose to about 90c but then soon settled back down to 70. 

 

Since then the coolant in the header tank has constantly bubbled away from when the engine is first started and needs topping up, approximately 1/4 litre every 8 hours cruising and has required this for the last 4 years. The content of the header tank has never been particularly hot though. There has never been any sign of water in the oil and it rarely needs topping up with oil as it hardly uses any. I've had the skin tank bled, the coolant drained and replaced, checks for leaks, water pump tested, etc and nobody has got to the bottom of it so I just accepted that it needed the coolant topping up regularly.

 

Since then I've done the Ribble Link, Thames Tideway twice, River Mersey, and last summer the Severn Estuary from Sharpness to Bristol, all with no problems such as overheating. I did have the skin tank enlarged 6 years ago which probably helped with that though.

 

On Monday when cruising along the T&M it started p*ssing out of the header tank overflow, at least a litre or more. It stopped coming out after 5 minutes presumably because the level of coolant had reduced. The temperature rose by 10c to 80c and stayed at that for the 3 hours it took to get back to my moorings. But there was a constant rush of air coming out of the spout with a force loud enough to make quite a noise.

Since then, within a minute of starting the engine it bubbles and steam comes out of the header tank overflow pipe and this is what makes me think the problem is serious.

 

If I go ahead with having it investigated are there any decent BMC mechanics in the Lichfield, Fradley area who anyone can recommend please?

[beerbeerbeerbeerbeer]

Much better advice will be given from others but..I don’t think that’s a gasket problem perhaps water pump.

 

but hey, I hold my hands up and say I don’t know the answer,

just hope it’s simple,

 

[Annie cariad]

Calcut boats BMC specialist call them they will advise

[beerbeerbeerbeerbeer]

Have you checked some basics, such as the Thermostate?

Try running the engine without the Thermostate and see what happens.

You can boil a Thermostate to see if it still opens when hot.

My Thermostate is 82c, if you turn your Thermostate upside down you’ll see a number which’ll tell you which you have.

 

I’ve had on off issues with over heating and loosing water for a few years.

I think I’ve solved them then it happens again.

Usually on an old pipe goes or a jubilee comes loose.

 

and I have worried about a blown head gasket, just as you have

 

you’ve had the boat long enough to know not to over fill with coolant?

if you over fill with water the excess will force it’s way out somewhere

would you be able to get to Streethay?

Edited February 9, 2023 by Goliath

[Tony Brooks]

47 minutes ago, Grassman said:

But there was a constant rush of air coming out of the spout with a force loud enough to make quite a noise.

 

That "air" has to come from somewhere, and for 3 hours it could not be simple air expanding with heat. I very much fear your diagnosis is probably correct.                                  

[beerbeerbeerbeerbeer]

9 minutes ago, Tony Brooks said:

 

That "air" has to come from somewhere, and for 3 hours it could not be simple air expanding with heat. I very much fear your diagnosis is probably correct.                                  

in that case, I’d definitely get in touch with Calcutt Boats, by email, they’re the ones who quoted me £300)

they also advised there are temporary fixes you can put into the coolant which’ll get you ‘somewhere’.

might be worth trying one of these temporary fixes to see what happens?

 

 

[magnetman]

Is there a calorifier in this circuit somewhere? Not likely to be the problem and probably ruled out already. 

 

I once had an endlessly overflowing header tank which turned out to be a cracked coil on the calorifier and domestic water pump pushing water into the engine cooling circuit. 

 

That was an open header tank with no pressure cap so not the same situation as this to be fair. 

 

 

 

[David Mack]

2 hours ago, Grassman said:

Since then the coolant in the header tank has constantly bubbled away from when the engine is first started and needs topping up, approximately 1/4 litre every 8 hours cruising and has required this for the last 4 years.

 

2 hours ago, Grassman said:

On Monday when cruising along the T&M it started p*ssing out of the header tank overflow, at least a litre or more. It stopped coming out after 5 minutes presumably because the level of coolant had reduced. The temperature rose by 10c to 80c and stayed at that for the 3 hours it took to get back to my moorings. But there was a constant rush of air coming out of the spout with a force loud enough to make quite a noise.

Since then, within a minute of starting the engine it bubbles and steam comes out of the header tank overflow pipe and this is what makes me think the problem is serious.

 

I suspect that for four years you have had a very small leak through the head gasket from a cylinder to a waterway, but which didn't reach an oilway. If you had replaced the head gasket during that four years you might not now be in your current position.

You now have a full blown gasket failure and the cylinder pressure is blowing water out of the system. Just topping up the coolant is a very short term fix, not really suitable even to get you home.

 

But nothing to lose now by whhipping the head off and seeing what the damage is. If you are lucky a new gasket and maybe a head skim could be all that you require. If the damage to the head is more extensive, but the block is OK, then a replacement cylinder head would be cheaper than a new engine.

 

[Adam]

Do the bubbles / overflowing happen immediately on startup?

[dmr]

At 13,300 hours you really should be thinking about a rebuild rather than just a new head gasket. Despite some negative stuff on this forum the BMC is a nice engine, but sadly a new modern thing might be more cost effective than a rebuild.  Calcutt do (or used to do) "new" BMCs but I don't know how good they are.

It's your decision, do you like the BMC and does it fit in with the ethos of the boat? or will any engine do as long as it pushes you along?

[Grassman]

Thanks for all your helpful advice and I’ll try to answer them as best I can.

 

Goliath & Magnetman - During the last 4 years I’ve had the thermostat, the calorifier, the water pump checked, and I’ve checked the hoses/pipes for leaks. I will give Calcutt a call as you suggest.

 

Adam – Yes the bubbles start immediately after start up but it was only on Monday that the coolant overflowed and the hissing from the overflow pipe started

 

Tony, yes I think my/your fears are correct unfortunately.

 

David – Yes I should have had it properly investigated when the bubbling first started. As I’ve said, I had everything checked out except the removing of the head because I suspected that would be a major job and cost. It’s seems it’s now pay-back time for me having buried my head in the sand for 4 years! As you say, I’ve nothing to lose having the head off now, or not much to lose at least.

 

DMR – The previous owners had a re-build in 2007 but the paperwork was just an invoice from the marina they were in. They’d obviously subbed the job (to Calcutt I suspect) so the details were rather vague and just said ‘Engine refurbish, rework and rebuild engine, renovate cylinder head’.

 

At a cost of £2,100, I reckon it looks as if it was a major overhaul even allowing for the marina adding their mark up to it. Annoyingly there was no record of the boat’s hours but I’m guessing it was about 7,000 hrs. Like I have, they’d also worked it hard doing a lot of rivers including tidals, since they’d had it new in 1995.

 

DMR – I neither like or dislike the BMC so any replacement would do as long as it’s a decent engine. With the BMC I do worry about getting certain parts in future if anything else goes wrong, or are they all still readily available?

 

Tracy – Thanks for the endorsement of the Canaltime and if I decide to replace the engine I think it would be my preferred choice. I’ve only heard good things about them. No doubt some will say there are better options and I’d also take a look at others such as a Beta as suggested by you Magnetman.

 

[Tracy D'arth]

7 minutes ago, Grassman said:

 

 

Tracy – Thanks for the endorsement of the Canaltime and if I decide to replace the engine I think it would be my preferred choice. I’ve only heard good things about them. No doubt some will say there are better options and I’d also take a look at others such as a Beta as suggested by you Magnetman.

 

Fitting a Beta will involve a considerable amount of work to the engine beds, the footprint is mightily different.

 

I can see no shortfalls on spares for BMC 1.8D engines in my foreseeable future,  The plant in Turkey is still going as far as I know, they had all the tooling.

But, that may not be long enough for you!

 

Many parts are the same as the 1.8 MGB engine which is well supported by the classic car collectors.

Edited February 10, 2023 by Tracy D'arth

[Adam]

5 hours ago, Grassman said:

Thanks for all your helpful advice and I’ll try to answer them as best I can.

 

Goliath & Magnetman - During the last 4 years I’ve had the thermostat, the calorifier, the water pump checked, and I’ve checked the hoses/pipes for leaks. I will give Calcutt a call as you suggest.

 

Adam – Yes the bubbles start immediately after start up but it was only on Monday that the coolant overflowed and the hissing from the overflow pipe started

 

Tony, yes I think my/your fears are correct unfortunately.

 

David – Yes I should have had it properly investigated when the bubbling first started. As I’ve said, I had everything checked out except the removing of the head because I suspected that would be a major job and cost. It’s seems it’s now pay-back time for me having buried my head in the sand for 4 years! As you say, I’ve nothing to lose having the head off now, or not much to lose at least.

 

DMR – The previous owners had a re-build in 2007 but the paperwork was just an invoice from the marina they were in. They’d obviously subbed the job (to Calcutt I suspect) so the details were rather vague and just said ‘Engine refurbish, rework and rebuild engine, renovate cylinder head’.

 

At a cost of £2,100, I reckon it looks as if it was a major overhaul even allowing for the marina adding their mark up to it. Annoyingly there was no record of the boat’s hours but I’m guessing it was about 7,000 hrs. Like I have, they’d also worked it hard doing a lot of rivers including tidals, since they’d had it new in 1995.

 

DMR – I neither like or dislike the BMC so any replacement would do as long as it’s a decent engine. With the BMC I do worry about getting certain parts in future if anything else goes wrong, or are they all still readily available?

 

Tracy – Thanks for the endorsement of the Canaltime and if I decide to replace the engine I think it would be my preferred choice. I’ve only heard good things about them. No doubt some will say there are better options and I’d also take a look at others such as a Beta as suggested by you Magnetman.

 

If the bubbles start immediately its a pretty dead cert combustion gasses are leaking into the water jacket. Whether it is a head gasket or anything more severe wouldn't be apparent until the heads off. I did a raw water Thornycroft one not so long ago, head didn't even need skimmed and it had been ran for 4hrs with the the impeller damaged.

 

 

[Tracy D'arth]

2 minutes ago, Adam said:

If the bubbles start immediately its a pretty dead cert combustion gasses are leaking into the water jacket. Whether it is a head gasket or anything more severe wouldn't be apparent until the heads off. I did a raw water Thornycroft one not so long ago, head didn't even need skimmed and it had been ran for 4hrs with the the impeller damaged.

 

 

Skimming BMC small diesel heads is not a good idea unless absolutely vital. The pre-combustion chambers are pressed in and are too hard for a fly-cutter, they need a surface grinder.

Also as installed they should protrude by I think a few thous from the head face, which they will not of course if ground in situ.

[Richard T]

On 09/02/2023 at 14:04, Grassman said:

My 30 year old BMC 1.8 with 13,300 hours on the clock has blown the head gasket. Obviously the extent of the damage and subsequent repairs needed, wouldn't be known until further investigations are carried out, and on the basis that I'd have to pay somebody to do this which would obviously cost a lot, and might end up needing a major overhaul or even a replacement engine, I'm considering biting the bullet and buying a brand new replacement engine. I don't want a reconditioned one because I've read on here and heard elsewhere too, that they don't always turn out well.

 

So I'm looking for advice on which engines would compatible on a 'like for like' basis. At a Crick show a couple of years ago the chap at the Canaline stand told me theirs would be an ideal replacement, with none of very little work needed to adapt it. Do any of you know if this is true, and if Canaline engines are any good? Also what other makes of engine might be suitable please?

 

In case it's relevant, my current set up is a PRM 150 gearbox and a Colecraft cruiser stern. Also, because the boat is immobile would a supplier install it in the marina I'm currently in? The marina (Kings Bromley Marina near Lichfield, Staffs) have a work bay with a pontoon each side and reversed in, the stern is right by hardstanding so accessibility is good.

 

I'd be grateful for any advice please.

Talk to Richard Powell he is an excellent engineer he posts on here @RLWP and trades as https://www.mes-midlands.co.uk/

He is based in Kenilworth so not that far from you. He specializes in old engines and gear boxes.

[Onewheeler]

We replaced a knackered BMC1.8 with a Beta 38 a few years ago. Almost a drop-in replacement, just some minor mods needed to the mountings. Kept the gearbox, and from memory the bell housing is compatible. Beta took the gbox and housing to fit it, even gave them a nice respray. I did a lot of preparation for the new engine myself, resulting in a bill of less than £500 from the fitter ( a good chunk of which was craning the engines out and in).

[MtB]

9 minutes ago, Onewheeler said:

resulting in a bill of less than £500 from the fitter ( a good chunk of which was craning the engines out and in).

 

 

This makes me think the OP's mention of a bill of £2.1k for a "refurbish" can't really have been for a full rebuild.

 

The cost of a crank grind, new bering shells, rebore and new pistons, rebuild the cylinder head would have been double that at least, especially with Calcutt doing the work, and let alone with lifting out and in fees and a profit margin for the marina. I'd have thought a final bill of £6k more likely, at least once everything is included. 

 

 

 

 

[beerbeerbeerbeerbeer]

https://aussieboater.co.uk/bmc-1-8-engine-rebuild/
 

this boater paid £4000 at Calcutt for his rebuild

[MtB]

6 minutes ago, Goliath said:

https://aussieboater.co.uk/bmc-1-8-engine-rebuild/
 

this boater paid £4000 at Calcutt for his rebuild

 

My point exactly.

 

Add £500 labour charges for the lift out and lift in at a different marina, plus the marina adding their own profit margin and you're up to £5k. 

 

And the chap in your link didn't have a rebore and new pistons. Add another grand,

 

 

[beerbeerbeerbeerbeer]

We can imagine any bill we want for the OP

 

but he may just need a new gasket

and the full cost sees him plenty of change for £500