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So The engine is out.............on it's own. I know I'm a wimp and I'll pay for it later.

Nicely settled on it's stand. 

Now I have the lump in front of me I am starting to wonder if my "diagnosis" was right. I thought the orible noise from it came from the little end bushes rattling about or rather the gudgeon pin rattling about in the bushes. Now I'm not so sure, The bushes are still a good tight fit in the con rods and the pins "seem" a nice fit in them.

The liners, big end bearings, pistons gudgeons and rings are less than 500 miles old but I didn't change the little ends. Now I am not at all sure I need / needed to.

Now the questions.

How tight a fit should the pins be in the bushes, I can stand the pins square on top of the con rod bushes and they gently slide in would that be about right?

How can I tell if the timing chain / tensioner is warn? The teeth look to my inexperienced eye look fine, can I measure the deflection like a fan belt?

How come I can't get my measuring thingy to give the same measurement twice.

I am sure I'll be back with more dumb questions later, but answers the the above would be great for starters.

 

David

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Hi David,

Now the questions.

How tight a fit should the pins be in the bushes, I can stand the pins square on top of the con rod bushes and they gently slide in would that be about right?

The pins need to turn in the rod little end. They may be  a little tighter in the piston but not a lot. A good push fit is normal.

Are the rod bushes worn at all.

How can I tell if the timing chain / tensioner is warn? The teeth look to my inexperienced eye look fine, can I measure the deflection like a fan belt?

The chain is normally tested by laying it on its side and then lift at one end. The chain will arc. The amount of arc is the crucial point. Look at the WSM

The tensioner may have deep grooves worn in it. If it hasn't then press on . If it has then change it. The Moss ones work fine.

The cam gear wheel should have a small amount of flat on each tooth and the profile of the teth should be uniform.

How come I can't get my measuring thingy to give the same measurement twice.

Phase displacement due to drugs is common.

I am sure I'll be back with more dumb questions later, but answers the the above would be great for starters.

 

Roger

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Thanks Rob

I do have a lot of oil about, will clean up better and try the same trick again.

Stuart

The pins turn easily in both the little end and in the pistons, they certainly don't bind. my original "guess" was that the little end bushes that I did not change last time had to be a little worn and was / am quite prepared to replace them

Will look at the chain test trick in the WSM tomorrow, I can see the logic in that. Once the chain is off it will be easier to inspect the teeth.

Not resorted to chemicals .......................yet, so I will put it down to a lack of experience and a cheep gauge.

 

Thanks David

 

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If your measuring thingy is a micrometre there is a skill to using them, there may be ratchet with preset tension at the extreme end, use it.

Otherwise develop a "modulated touch" whereby  you barely "stroke" the micrometre barrel, using the friction from your fingers and thumb skin to turn the barrel and evolve a reliable constant torque for reliable readings. Also the difference in angle or inclination of the micrometre or part to be measured can impose a different loading upon the micrometre "anvils" (where it touches the part). Which can again give inaccuracies in measuring especially when you are trying to differentiate between various grades of sliding fit where the differences will be numbered in a couple of 1/10s of one thousandth of an inch.

If you didn't replace the small end bushes last time just replace as a matter of course, if there is a noise after rebuilding you will curse not having taken the sure method.

Mick Richards     

Edited by Motorsport Mickey
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Now well outside my comfort zone.

Removed the crankshaft today, one of the big end bearings is in a bit of a mess so I will have to have the whole thing reground and let them supply new new bearings to fit the reground crank,. while they are about it will get them to change the little end bushes as Mick suggests.

I am now left with a still very heavy lump of block which if I can get in the back of the car I will take up to the machine shop as well and get refaced and I suppose while I'm about it I might just as well get the head skimmed. (in for a penny etc.)

Am I missing anything, Is there anything else I should consider while I have the engine out and in hundreds of bits in dozens of bags.

Thanks for all your help and patience, I am sure I will be making a pest of myself when It comes to putting all back together again.

David

 

 

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Hi David,

       unless you have done it in the last 5 or 10 years I would get the machine shop to pickle clean the block. Thios will remove ALL the crud in all the nooks and crannies

and will help cooling on the new engine.

Consider fitting the Christian Marks rear crank oil seal.  Do not fit any similar unless it is a Christian Mark seal. - there are cheaper ones out there.

Roger

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Couple of points David, make sure you remove the liners before taking the block in for decking etc, also the machine shop should be advised you don't just want the block dropping on a Miller and skimming ad hoc, but the top surface made parallel  to the line of the crankshaft.

Also if you do ask them to "pickle" the block you'll probably damage the integral camshaft bearings (which are replaceable) but will pull out and then new ones pulled back in when the block is clean. 

Then you can start fitting the crankshaft and spinning to make sure it's not bent ( yes they do, even if not heat related). The spinning should be able to be done just with the fingers of one hand and will equate to about 1/3 rd lb ft ( well my fingers do anyway ), but you can measure it with a torque wrench or Spring balance placed at 12 inch from the centreline of the crank. If it's more it may be worth clocking the crank without any main caps fitted to see where the resistance ( bend) is.

Mick Richards

 

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A damn good clean is a good idea, not only to help the cooling but also I suspect it will make reassembly a rather nicer task.

On the subject of rear oil seal I'm glad you mentioned that, of the two types available It seems one needs the crank to be machined, not the end of the world as I am having work done on it anyway. The other (no machining required) is a little more expensive, but needs a special tool to fit it?

 

David

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Hi David,

     whether the block is deep cleaned or not make sure that the plugs either end of the oil gallery are in place and are tight.

I would not go down the machining of the crank oil seal - bridges/boats being burnt.

If you use the Christian Mark seal then various places and forum members can help with the tool.  The TRShop do a loan of the tool and I have one.

Fitting new cam bearings is relatively easy. You need to be careful that the oil holes are in the correct place and the locking screw holes line up before putting the lock screw in.

 

Roger 

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Crikey Mick if I go in and start asking for the parallel stuff they are going to think I know what I'm talking about, and nothing could be further from the truth.......

I'll ask how they ensure that and let them tell me. I will try the turn by hand crank test but heaven only knows what I would do if it does turn out to be "bent".

Roger I understand the logic of not removing the crank scroll, lot easier to take off than put back on :rolleyes:. so will go with the Christian Marks seal. (from the TR Shop).

Thank you for your time and interest. David

Edited by david c
opps wrong name
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Hi David

               Balancing the rods and pistons can reap benefits with a smoother running engine and not difficult or expensive to do.

                Cheers Richard

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16 minutes ago, david c said:

Crikey Mick if I go in and start asking for the parallel stuff they are going to think I know what I'm talking about, and nothing could be further from the truth.......

I'll ask how they ensure that and let them tell me. I will try the turn by hand crank test but heaven only knows what I would do if it does turn out to be "bent".

 David

Then you talk to us David and I'll give you the contact who will straighten it (with hammers ) so that it is within tolerance. I had a 4 cylinder crank which after grinding and nitriding bent (not uncommon, the heating up stress relieves the cranks 100s of thousands of conrod impacts from engine running) by 10 thou between centre main and the nose of the crank. It was sent back to the machine shop who returned it 48 hours later with no bend...NO bend, I had to check my DTI, I thought it was broken ! Counter intuitively I'm told the large bends straighten easier than the small, trying to remove the last 1 thou is sometimes a difficult task. 

As I said, removing engine and gearbox together is not the impossible task it at first seems when compared with some of the other tasks. 

Mick Richards 

 

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Hello Malbaby

It had crossed my mind....................and I'm pretty sure it will again.

But at the moment I think I can do this, not quickly, but apart from the crank shaft stuff I have managed to change the pistons and liners a year or so back.My biggest problem I think will be to get the valve / ignition timing right but with some care. the workshop manual and some help from the forum I think it should be do able and it certainly keeps the little grey cells working.

Thanks for your interest and best wishes to all in Aus.

 

David

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Hi David,

                       regarding the valve timing.

If you use a standard cam and the original cam wheel then it will have the timing marks from standard.

If you use a new cam (Newman PH1 etc) then you will be given an angle to set it up to.

For this you will need a timing disc

Something to set TDC accurately

And a DTI to set the cam initially.

Not complicated but take some care.

 

Roger

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