Bottom end overhaul

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MikesDexta
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Bottom end overhaul

Post by MikesDexta »

Hi all
My 1959 Dexta previously suffered from diesel getting into the air intake and eventually the sump. Initial symptoms were oily gunk spewing out of the exhaust, then oil spewing out of the dipstick then the most horrendous racing on startup after a rest period over winter. I was advised to fit an aftermarket tap but that was faulty allowing fuel through when closed (I tested it)! So I gave up and solved the problem by simply capping off the primer pump and also the glow plug intake in the air manifold with the intention of fitting the glow plug mod from Old 20 later this year. Since the cap off she has started and behaved perfectly, I fitted an oil gauge last year and it has consistently displayed 50 psi whilst she was both working hard and idling......until last week.

After a few weeks renovating a badly neglected field involving ploughing, pulling out strong but dead nettle roots and some largish rocks with my David Brown cultivator (marvellous piece of kit), then levelling, rolling and harrowing, it now displays 50 psi on cold startup then drops to 20 psi when warm. The crankcase breather is smoking a bit and she is getting through about half a litre of oil a week. She is still starting and working very well but there has been a knocking noise for a while which my old ears dismissed as a flakey water pump but I'm now thinking the crank is overdue a regrind and new bearings fitted. When I had the engine overhauled by a diesel engineer a few years ago the head was so far gone (he showed it to me) we decided to fit a new head complete with valves, and also new pistons etc. but he said the crankshaft was good. I've used Morris Golden Film SAE 20w-50 Classic in her for a couple of years now.

Before I present a cost benefit analysis to the Finance Director how much should I expect a bottom end overhaul to cost in the UK and what else do I need to make sure is replaced? This assumes I will deliver the tractor to a local restorer and not just the engine.

thanks in advance

Mike
1959 Dexta
I'm not retired just re-deployed

mathias1
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Re: Bottom end overhaul

Post by mathias1 »

Mike,

things to do when you are there:
renewing all bottom seals
oil pump
all bearings on the crankshaft
eventually new waterpump
see if the clutch is alright
it's also worth checking out of the camshaft is alright.
Fordson Super Major New Performance
County Super 4 built on the Fordson Super Major
Selene built on the Fordson Super Major New Performance with Silvant winch

Billy26F5
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Re: Bottom end overhaul

Post by Billy26F5 »

Hi Mike,
This is sounding all too familiar, eventually the engine will refuse to start. This is what happened to Super Billy; it turned out to be a big end failure, and his crank and con-rod are write-offs. A large amount of swarf came with the oil, but this might not show up in your case. Our knock was very loud (louder than the normal engine noise) and it struggled to run. The play was in the order of 1/8".
I would inspect everything as it's likely that dirt might have caused this, and it is likely to be pretty expensive. I can't tell you what it would cost if somebody does it for you, but adding up the spares and specialist jobs it could well come to over £1000. Admittedly we did the injector pump as well, but it will still be pretty pricey to find and prepare the crank and con-rods.
I would doubt the knock could come from the water pump, more likely to be a metallic hum.
Sorry to see another engine in serious trouble.
Sandy
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mathias1
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Re: Bottom end overhaul

Post by mathias1 »

grinding the crankshaft might cost as much as buying a new one. So be sure to check that option.
Cost wise I think it's 1 day work to take out and install the engine back in the tractor and one other day to do the work on the engine. Add the price of the parts to it and you can make an estimate.
Fordson Super Major New Performance
County Super 4 built on the Fordson Super Major
Selene built on the Fordson Super Major New Performance with Silvant winch

Emiel
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Location: Netherlands

Re: Bottom end overhaul

Post by Emiel »

Hi,

Recently did a bottom overhaul on our dexta. Should update my topic on that.

Except for pressing in the new liners it all is pretty easy and straight forward. Had good experience with overall quality of Anglo parts. Assume they are comparable to other non oem suppliers. Prices are ridiculy low compared to spares for German tractors.

Rgds emiel
Best regards

Emiel

N 1937, E27N 1948, 8N 1949, E27N 1950, E1A Diesel 1953, E1ADKN PP 1956, Dexta 1959, NH Clayson M103 1964

MikesDexta
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Re: Bottom end overhaul

Post by MikesDexta »

Thanks for the advice chaps it's most appreciated.

I've nearly finished renovating the field, all the hard work is over, then I have to top another 4.5 acres so I'm hoping she will cope before I have the overhaul done.

Mike
1959 Dexta
I'm not retired just re-deployed

Billy26F5
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Re: Bottom end overhaul

Post by Billy26F5 »

I wouldn't recommend even trying to start the engine if it's knocking, as it will get much worse very quickly, and you might find yourself stranded just as you're finishing, Super Billy got stranded as he was returning the implement to its owners and had to be towed back home.
Sandy
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Bluebilly
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Re: Bottom end overhaul

Post by Bluebilly »

Have you thought about stripping the engine yourself? That way you only have the cost of a regrind it that is actually necessary. The crank will only need reground if it is badly scored, and you may get away with a polishing. A decent verier calliper will soon let you know if they are badly worn before taking it to a machine shop, and if you are not sure there is plenty of guys on here that can guide you along the process.
1948 E27N
1958 Dexta
Roadless 75
TEF 20
MF135 multipower
MF 165
MF 240
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Billy26F5
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Re: Bottom end overhaul

Post by Billy26F5 »

We're still doing it for Super Billy, but definitely better to do it yourself. You'll spend most of the time cleaning, so I would recommend starting to clean the outside as that dirt is much worse and can be done before stripping the engine.
Sandy
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