engine probs

[davysdexta]

[hi guys i,m new to the forum .so.please be patient not so good with key board eather ,,,but i got mi self a dexter ,an she goes ok ,but quite a bit of back pressure ,,please any suggetions, i,e newliners ,n, pistons , or will rings alone do it ,,,,davy.

[Brian]

Welcome to the board.

IMHO rings would be a waste of time and money.

The Dexta engine is one of the best wearing engines built but when they get worn they need the works. I would look to fit new liners, pistons, rings and all crankshaft bearings plus a possible re-ground crank.

Add to that a new or reconditioned clutch and you are getting in fairly deep. Saying that though, it will be a tractor to last another 40 years if the rest of it is good.

[YorkshireDextaMan]

Here's just a view from someone (me) who's been B.T.D.T.G.T.TS.
You say "quiet a bit of back pressure" Tip. If you can live with it ,leave it alone, And Brian's right, he got it in there before me.
Once you start in there it will soak up money . But before you do anything ,check the block for cracks,
Jim

[davysdexta]

thanks brian, n,yorkshiredexterman,i take on board what you say , an once ur in there you don,t know where to stop, an the cost, but she does smell o burnt oil when she gets hot ,an i would like to make a good job on her ,/paint ect/ i would like to do a few ploughing matches an a couple of shows,,,davy

[dexta61]

Having read the text here and found out that IMHO did not mean Internal Motor Head Oil, I was adviced that changing the piston rings would help reduce the back pressure. Now planning to do so, I wonder what job am I taking on. Taking the engine off the tractor? and how does it work with the clutch? just slide it out?
Next would be how be take the cylinder head off and push the pistons through the top? or is it not that easy.
Thanks for your tips.

[Aussie Frank]

Hi Davy.

Just my 2 cents worth, but heavy breathing means one of two things if it has been worked hard and serviced properly, worn rings due to old age and lots of hard work or broken rings due to ether abuse, In the case of worn rings the liners will need replacing because they will be worn too. If it is broken rings pistons and liners will no doubt be damaged. In either case new liners would be wise and that means a trip to the machine shop with the engine block. Rings on their own will not solve much.

As a matter of principle I would never do up the top end of an engine without putting new bearings in the bottom end. That means check and or regrind / replace the crank as well. I saw the result of bad bearings on an engine once, you didn't need to worry about breathing as the hole that the con rod put through the side of the engine block took care of the ventilation.

The question you probably need to ask yourself, is the engine too tired to do the work you want it to do. If the answer is yes give it a proper birthday and do a complete rebuild. If it still does the job leave it alone, give it lots of work and service it properly and it may come good on it's own.

Regards, Frank.

[russelm]

I have been pleasently surprsied as to how cheap and easy the Dexta engien is to re-build.

[YorkshireDextaMan]

Agree with you on how easy Dexta engines are to do, Mark. The expense for the parts and some engineering work . IMO depends on how you view cheap.
Take and engine kit, plus oil pump, the new pipes you need to fit it.
Say £270. Some almost certain engineering work, £140 , remember the head needs the old guides replacing and the valve seats reseating, If the crank is servicable thats a bonus, there are sure to be other issues to crop up.
Remember all plus VAT, im'e up to £480. You may well get away without work on the injectors, even just cleaning them up will be £30. No change out of £550. .
No disrespect to any one on here , but that ain't cheap. would be pleased to hear from someone who can make it much cheaper, at that money it would deter me from doing another,
Jim

[davysdexta]

once again thanks guys,,, but as u say £550,is not cheap,in my book .,,i was kinda hopein to do quite a bit on mi own ,,do you need special equipment to chang the liners ,or do i need to take to a specialists ,i have changed pistons .n . rings in old mini,s years ago ,,so thought i would have a go ,,?????? davy,,,,

[Brian]

You would need to have the liners fitted by a specialist. Dexta liners have to be bored after fitting. Later after-market liners have a ridge at the top which means the liner, although being "finished" has to have a groove cut into the block for them to locate in.

You could, like me, do things slowly.

Dotty is not the finished product. I work her and find out her weak points, then repair them. I know that in the next year I will have to fit a new clutch, starter ring gear, timing cover seal and gasket, new side plates, new rev counter and drive, reconditioned steering wheel and a full paint job. Oh yes, and repair the lights and wiring.

But it won't all be done tomorrow as I also have a Super Major in waiting that needs lots of time and money, Henrietta needs repainting and Nuffy could do with a timing cover oil seal.

So as well as your engine, you have to look at all the other possible problems that you might find. If you do liners, pistons and crank, get the pump and injectors sorted, you will need a clutch and associated bearings.

Do not want to discourage you but I see so many adverts for tractors for sale, unfinished project, where the owner has run out of money, or Dextas for sale at prices in excess of £3000 because so much has been spent on them.

[russelm]

Agree with you on how easy Dexta engines are to do, Mark. The expense for the parts and some engineering work . IMO depends on how you view cheap.
Take and engine kit, plus oil pump, the new pipes you need to fit it.
Say £270. Some almost certain engineering work, £140 , remember the head needs the old guides replacing and the valve seats reseating, If the crank is servicable thats a bonus, there are sure to be other issues to crop up.
Remember all plus VAT, im'e up to £480. You may well get away without work on the injectors, even just cleaning them up will be £30. No change out of £550. .
No disrespect to any one on here , but that ain't cheap. would be pleased to hear from someone who can make it much cheaper, at that money it would deter me from doing another,
Jim

In my opinion, that IS cheap for an engine re-build.

Yes its serious wedge but in the world of engine re-builds, a bargain

[Bensdexta]

Taking the engine off the tractor? and how does it work with the clutch? just slide it out?

Fairly straightforward so long as you have an engine crane or lifting tackle - just follow the workshop manual

[davysdexta]

hi guys ,as regards my engine probs,(its a super dexta). ive heard or read somewhere just lateley,, that u can put the liners in the freezer for 23 hrs an they (SHOULD) DROP IN WITH A LITTLE HELP,, does any one out there know if this is right ,,,i dont want extra expense of machine shop ,if i can get away with it ,,,, thanks davy,,,,

[YorkshireDextaMan]

hi guys ,as regards my engine probs,(its a super dexta). ive heard or read somewhere just lateley,, that u can put the liners in the freezer for 23 hrs an they (SHOULD) DROP IN WITH A LITTLE HELP,, does any one out there know if this is right ,,,i dont want extra expense of machine shop ,if i can get away with it ,,,, thanks davy,,,,

Davy, it ain't that simple, wish it was. A good place to start is the Workshop Manual.
One thing i have'nt heard much said about on here, is . Don,t forget to Gap the piston rings, Jim,

[davysdexta]

thanks jim ,i need to find a machine engineers ,as i want valve guides pressed out ,n new ones pressed in ,,,do u know if theres any difference between p3,,144.head,, an p3,,152 head,,,,,davy .