VOLVO MD1

[rajjes]

I'm currently refitting a recently purchased 1975 GRP folkboat variant and I'm undecided about the engine. Would anyone suggest rebuilding a VOLVO MD1 or should I go for a later engine, preferably fresh water cooled?

I've heard such different opinions from '..the old ones are the best..' to '..heap of scrap iron..' that I'm really unconvinced of the way to go.

If I opt for the rebuild would parts be a problem?

Any info given is appreciated.

 

[bedouin]

If the engine is still running okay then why do anything? Properly maintained they will go on for ever.

The problem with rebuilding the old Volvos is that replacement parts can be prohibitively expensive. Standard maintenance parts (filters, gaskets, injectors) are readily available and cheap, but pistons and so on, while still available, are expensive.

I have a 31 year old MD2B which still runs fine. My attitude is to keep it going as long as possible without doing any major work - but if I am ever faced with spending £1000 on it then it is likely to be more cost effective to replace it with a modern one.

 

[PBrooks]

I've looked at re-building my old MD1 a couple of times but the problem for me was cylinder wear - there were / are no oversize pistons, cylinders or rings (as well as all other parts being very highly priced). I'd be happy to be corrected by others who know the engine better or have found a way around the lack of these parts (I've half looked at a liner, but thought that the wall thickness would not be great enough - anybody tried this?). So in answer to your question, once it stops running due to bore wear, you'll probably have to replace it. The Yanmar is the obvious option, but it is a lot lighter and this may affect your ballast...

 

[Lofty]

I had my MD2B changed for a reconditioned MD11 in Holland this year for less than the cost of the bits to recondition the engine myself here in England. See my post Re: Volvo Penta MD2B 8/11/02. If I can help any further get in touch.

 

[seaesta]

I agree it is best just to keep an existing engine running - if it is a good starter.

I tend to view old things as an asset rather than a liability - if I blow up the old one I can justify replacing it - if I blow up a new one then I am bu**ered.

The MD1 seems very economical and it is perfectly matched to my drive-line and prop. Corespondents with new engines seem to have difficulty in lining up the drive and prop sizing.

A tips from me on the MD1 are

- use Mobil 1 oil - this is expensive but has a low cold viscosity (0W40). It means that the oil is so thin that I can hand start if the battery goes flat. Since the engine only holds 1 litre of oil the expense is bearable and worthwhile

- After a long lay up (or any other time) you can get a first time start by using an oil can with a felxible nozzle and put 1 or 2 squirts of oil into the cylinder before starting. You remove the air filter to gain access. Do not put in more oil than this or you could damage the engine. Do not turn the engine until after removing the oil can. The engine seems to run on the oil or perhaps it just radically increases the compresion - suggest conventional oil for this purpose.

- If the engine has a dynastart unit then this may not produce all the electrical charge that you would like. This could affect your decision although personally I use solar back up anyway.

Martin

 

[bedouin]

I used to have an old Coventry Victor single cylinder diesel that had a 'cold start' mechanism based on injecting engine oil directly into the cylinder. It had a special dispenser attached to the cylinder to make it a simple operation. It worked a treat - I always assumed that it was due to improved compression.

I hadn't thought of Mobil 1 - other people have advised that high-performance diesel oils of this sort are not really suited to older marine engines (being designed to work at higher temperatures), but the ability to hand start would be nice (I've tried this with a warm engine, and failed!). I would be slightly concerned as to whether the low viscosity might make it difficult for the oil pump to prime after it has been standing for a while - I presume you haven't experienced any problems with that?

 

[seaesta]

I have heard some old guff about synthetic oils such as Mobil 1 being "too good" for ancient diesels but do not believe a word of it. Some folks say that you need inferior oil to prevent bore glazing but I do not belive that either. Better oil = better lubrication=less wear.

My own experience over the past 6 years is that Mobil 1 works fine - and I have tempted fate by dropping the mast and going through the canals with lots of engine idling at locks etc.

As to oil circulation on cold start I think the thinner oil will circulate quicker and easier and probably get "thrown" better to those parts lubricated by splash.

Cheers

Martin

 

[Peter_Shipley]

The decission to rebuild may depend on your own mechanical skills. To get someone else to overhaul would probably be cost prohibitive. While it is true that Volvo parts are expensive, there are a number of second hand MD1 engines available to rob parts from. I would suggest you do the following:

Take the exhaust off and check engine cylinder and cylinder head for internal waterway corrosion. Saltwater causes extensive corrosion even on old volvo's. Not easy to repair.

Start the engine. If it starts easily its a good sign. Hard to start indicates problems. Generally check for unusual noises from the engine. Again a possible costly repair.

Check the operation of the gearbox. The box often 'goes' before the engine.

If dynastart is the only battery charger, a new engine with an alternator is more than a luxury.

Remove the rocker box cover. If solid inside with black gunge, it is possible the engine oilways are similarly blocked. This may of starved the engine of oil causing excessive wear. While inside check the rockers to rocker shaft bearings for wear. Another indication of engine condition.

Check engine mounts as to replace all four is costly and is a common problem.

The above should give you some indication however if you decide to re-engine, don't forget the additional costs for modifications to the boat, prop shaft, exhaust system, possible new prop etc.

As far as hand starting is concerned, use the decompression lever correctly and you should have no problem, irrespect of the oil used (recommended grade meets CD specification). To start the engine after a layup simply lift the decompression lever, turn the engine over by hand for a good few turns to add additional diesel to the cylinder, then start as normal.

The engine is easy to rebuild, however it is not as simple as bolting on new parts. You often need to select gasket thicknesses etc. to set the correct running tolerances.

 

[Idlerboat]

I put an alternator on my md gives me heaps of power but..... a 35 amp alternator pulls about 3 to 4 horse power. roughly half the power of a md. The solution was easy I installed an alternator with a seperate built in voltage regulator and by putting a switch between the DF (field) wire I can turn it on or off. So I now have either a 8 horse engine or an 8 horse generator !!! When Im sailing I put the engine out of gear and run the alternator for a little while to top up the bateries.

regards
marty_dean@yahoo
Idler