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Author Topic: Getting ready for the road again  (Read 16882 times)
Anders Dinsen
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« Reply #195 on: May 15, 2020, 04:13:07 pm »

Not sure about your milage, but if I had the engine out of mine I would replace clutch components as well, and splitting the engine is something that even I could do and will prob save time in the long run

You may have a point there, and taking that gearbox off is probably less of a job than making that tool anyway. Also, it might be a good idea at least to inspect the clutch. I never had problems with it, so I expect it will run a while more. On a longer route, my plan is to build a new engine. I have a well prepared cylinder head which would fit a newly built engine with lightened flywheel and a fresh clutch anyway, and as that project is not on the menu now, I planned not to split the engine from the gearbox. I'll reconsider - thanks for thinking!

/Anders
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roy4matra
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« Reply #196 on: May 20, 2020, 09:10:05 am »


... First I have a few small jobs that will keep me busy:

* clean engine and gearbox
* get the crank pulley off
* remove cam chain housing
* fit a blanked off water pump housing (Jesper is helping having one made)
* get it all screwed together
* renew valve seals

And then the engine room needs cleaning, etc, etc Smiley

Best
Anders

There are a couple of things I should point out here Anders, and to anyone else in this situation.

Getting the crank nut off now the engine is out is quite easy, as long as you have access to an impact wrench (air or electric).  Remember first to unlock the lock-tab washer.  The impact wrench and the rapid rotational hammer effect it has will undo the nut without having to worry about locking the crankshaft, as the whole thing - crank, rods, pistons etc. is too heavy and has too much friction to move and the nut simply spins off.

As for the reasons to remove the nut and the crank pulley, for anyone else reading this, if it was just to replace the timing case seal, you should do that with the timing case still bolted on!  However if like Anders you wish to remove the timing case too, there are points you should note.  First the timing case is in two parts, upper and lower, and these are not only bolted to the block but there are two bolts bolting them together at the cylinder head face joint.  They are also fitted onto small dowel sleeves, which some of the bolts pass through, that lock them exactly in place so they cannot move up, down or side ways and have to come off directly away from the block.

Now this next item is important.  These timing cases were not designed to be taken off or refitted with the cylinder head or sump still fitted.

(22nd May update on next paragraph as I forgot to include the sump gasket)

The cylinder head gasket is between the upper and lower timing case, so if the head is still bolted securely on, then the clamping force on that gasket is the same as that on the head to cylinder block!  And at the bottom if the sump is still fitted you have the problem of that gasket which is much more delicate.  So these are the problems.  If you undo all the timing case bolts and try to pull either the upper or lower timing case away from the head or block, they are both stuck securely to that bit of the head gasket and have a high force against each side of it.  And that force on the lower timing case is transmitted to the lower face where it will be very tight against the sump gasket, which being cork, is a lot more delicate than the head gasket.  Whilst it is fitted and bolted, the dowel sleeves will hold the timing case in place, but as soon as you try to remove that timing case, and if you managed to get it away from the block to come off the dowel sleeves, it will tear the sump gasket owing to the force downwards from the upper timing case and head gasket.  If you managed to get one of the covers off without damaging that bit of the head gasket that will quite a feat in itself, but there is no way you will not break the sump gasket, unless the sump is off and you have already separated it from the lower timing case.  When you then try to refit that cover (let's say it is the bottom one) you would have to push it hard up against that head gasket before the dowel sleeve holes would align with the dowel sleeves to allow you to tap the cover into place, and it would not only have to try to compress that bit of the head gasket but also slide against both that and the sump gasket to go back into place against the block!  Even getting enough pressure against the gasket to align the holes and dowel sleeves will be extremely difficult, and you may find impossible.  So think about this carefully before deciding what you do next.

Finally, if you do leave the head on and therefore need to replace the valve seals with the top still bolted in place, all the different types of tools for replacing the valve seals have one fundamental problem.  They rely on compressing the valve spring, without the valve moving down.  This is so the top retainer can free the locking collets which you can then remove to take the spring off and replace the seal.  But you will find, as I have and I have done quite a number of these engines now so have some experience of this, that the collets and top retainer will be locked by the taper and pressure over time and they will be very difficult to separate, so every time you try to compress the spring, the valve will move down too.  You have to stop it moving to break the seal between the retainer and collets.

I have found that even with the head on a bench and something solid under the valve head to stop it moving, it can take quite some sharp force to 'unlock' them.  When the head is in place, getting something solid under a valve head through the plug hole is very difficult at the least!  Also it has to have the piston at top dead centre to give it something solid to react against.  So whatever you use has to be such that it is not going to damage the top of the pistons which are only alloy.  Some of these tools are designed to use the spark plug hole and air pressure blown into the cylinder to hold the valve in place.  This is laughable and I can tell you now that simply will not work with these!  The air even under pressure is weaker and will simply compress and the valve will move down, and the instant the valve lifts off its seat the air pressure drops away.

On Colin's engine we could only get some support under the inlet valve heads which are directly across from the plug holes, and managed to change all the inlet valve seals (which are the ones most likely to cause problems as it happens) but there was simply no way we could get under the exhaust valve heads as they are alongside the plug hole and you need to get something through the plug holes but then at about 90 degrees to them.

So as you have the engine out now, and all the work that this involves, it really makes much more sense to remove the cylinder head as well and do all the necessary jobs properly.  All the jobs are much easier with the engine out, and they will be completed with much less hassle, and without having to try to make things to do some of these jobs simply because you didn't want to take those extra few things apart.  You will spend more time trying to do the jobs than if you did take it apart.  So think about it carefully now before you start.

Roy
« Last Edit: May 22, 2020, 06:16:20 am by roy4matra » Logged

Anders Dinsen
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« Reply #197 on: May 24, 2020, 06:49:11 am »

I already thanked you, Roy, on e-mail, but would like to thank you again. Your post has given me several things to think of. I talked to Jesper and he confirmed that he has been successful removing the covers separately, but carefully reading and rereading your advice has made me rethink the plan. Why take the risk of doing an improper job instead of doing the job right from the start? My wife, when I mentioned your advice, said something like "Yes, that's exactly like knitting, it's better to do things right from the start!" Smiley

As my workshop is currently shed for bikes and a lot of stuff, I need to first move some things around to prepare it to accept the engine. Also, It sounds like now is the right time to get an impact wrench. Also, if I split the head off the engine, I will of course fit the polished one i had made years ago, and have the flywheel prepared. Will I be happier with that? You're right, I will, of course!

The powertrain is now as clean as I wanted it. I can now again read the "MATRA" label cast into the differential housing on the gearbox, and see that the gearbox is either cast from two different alloys, or one is eloxated and the other is not. I've mandaged to push the drivetrain to the side of the garage and will cover it with plastic so I can start the dusty work on the engine room. Things look good there, but by experience from the front, some surface rust usually shows up once I start working on it. You'll notice I still have two hoses attached to the pipes under the car. The clamps have given up so I need to grind or file them off to release hoses.

/Anders
« Last Edit: May 24, 2020, 06:54:58 am by Anders Dinsen » Logged

'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
Anders Dinsen
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« Reply #198 on: May 24, 2020, 02:28:40 pm »

Sometimes it's the little things.... A neighbor was giving away this old toolbox. The bottom was all rusty, so I brushed it down and gave it a coat of zinc, which should keep it ok for a while. Hence the wooden blocks. This one is both much more practical and looks better in the garage Smiley
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'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
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