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Author Topic: Serious challenges.  (Read 21202 times)
Jon Weywadt
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« Reply #45 on: September 08, 2014, 10:33:53 am »

I have a question that has been bothering me. When I took the head off to have it refurbished I backed off all the bolts on the rockers so there was no pressure on the cam shaft. Still, in order to get it out I had to hit it from the end with a nylon rod and a hammer. It did not slide out easily. Is it supposed to just slide out? Huh

Yes.

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Now that I am reassembling it I again had to hit it with a hammer (wooden) to get it back in. It does not turn easily. There is a rather large amount of friction to overcome, but then it turns fairly easy for a bit before sticking again. It has been lubricated, so oil is present in all bearings. How easy is it supposed to turn? Huh

You have something wrong Jon.  Either the head is warped or the camshaft is bent.  Since it was like this before you stripped and had the repair, if it is warped, it was warped before the repair.

The camshaft should slide in and out easily and you should be able to spin it by hand.
 
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I was surprised when I noticed that there is no bearing inserts for the cam shaft to turn in. Apparently it just turns in the aluminium that the head is made of.

Which is fine.  Many engines are like that.

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Can I just hone the bearing a little bit until the cam shaft slides in easy, or is it really supposed to be that tight a fit? Huh

No.  Don't do anything like that until both the head and cam have been measured for alignment.  You need to know what is faulty.  Imagine a bent cam - if you removed metal from the cam bores on the head you would have to take so much off to allow for the oscillation that the clearances would be too great and you would loose oil pressure.

If the head is warped, you could have the cam bearing holes line-bored but they have to be aligned with the head face otherwise as you torque the head down it will force them out of alignment again.

Years ago Dolomite Sprints had this problem where the heads were distorted and people skimmed them flat leaving the cam bearings out of alignment, and then they would snap the camshafts!  So the head face and cam bearing holes must be accurately aligned.  If you have to line bore the cam bearing holes then either they will have to be sleeved to bring them back to the original size to match the camshaft, or you would need cam bearings to take up the clearances.

Note the cam bearings are all different sizes.


Regarding the inside of the gearbox end casing, you do have to remove a little from the boss around the bolt holes otherwise the teeth of the larger gear will foul them.  You can check this easily as you offer the casing up to the new high fifth installation.

Roy

Thanks Roy.
I have tried another cam and it has the same difficulty fitting in the head and is just as tight when trying to turn it. There is no point, at which it is harder to turn the cam than another. I am therefore assuming that the cam is straight and the head is slightly warped. I will find a place that can re-bore the cam bearings.

My guess is that a previous owner did not torque the head bolts correctly, thus warping the head. Could that be thee reason?

/Jon
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« Reply #46 on: September 08, 2014, 11:44:47 am »

In the ultimate doom-scenario the block is bend.
Has happened before as Cornelis (the 2.2 guru overhere) told me.
Never seen it myself.
I don''t know if it's the case but I can imagine if it is, the head is misformed to.

Herman
« Last Edit: September 08, 2014, 11:47:29 am by Oetker » Logged

I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
northmurena
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« Reply #47 on: September 08, 2014, 12:42:08 pm »

Have also heared the rumour about the 2.2 block is bending often. Never saw one myself but maybe there is some truth behind.
Jonny, i think it´s time now to complete the V6 ;-)
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Matra_Hans
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« Reply #48 on: September 08, 2014, 03:02:42 pm »

Hi matramaniacs
The top of my 505 turbo block was also ”not flat” but I will not say that it was bended; consequently I had the top of the block planned. The same has been the case with a mate of mine who is working on a similar project in my workshop.
regards Hans
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Jon Weywadt
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« Reply #49 on: September 08, 2014, 03:46:32 pm »

Hi matramaniacs
The top of my 505 turbo block was also ”not flat” but I will not say that it was bended; consequently I had the top of the block planned. The same has been the case with a mate of mine who is working on a similar project in my workshop.
regards Hans

I already had the top planed, so I won't be able to "warp" it back to where the cam does not bind. Angry
Besides I do not know if the ends, or the middle, is bent up (or down).

The bend must be very small, since it is possible to get the cam inserted and able to turn it, even if with difficulty.

I will try to paint the bearings with a speed marker and see where the marker gets worn off.

/Jon
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roy4matra
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« Reply #50 on: September 08, 2014, 09:12:44 pm »


Thanks Roy.
I have tried another cam and it has the same difficulty fitting in the head and is just as tight when trying to turn it. There is no point, at which it is harder to turn the cam than another. I am therefore assuming that the cam is straight and the head is slightly warped. I will find a place that can re-bore the cam bearings.

My guess is that a previous owner did not torque the head bolts correctly, thus warping the head. Could that be thee reason?

/Jon


Since another cam is also tight, as you say, it does suggest the fault is with the head.

Before getting it line bored to re-align it, take the camshaft along too and explain that the cam normally runs directly in the head, which means there are no bearing shells that you could obtain as none were ever made.  So you need to know first if they can get hold of, or make some bearings after they machine it.  This may be the biggest problem.

As to how it happened - not sure really and there could be a few reasons, but the head bolts not being torqued down tight or correctly does not always cause distortion.  These heads are quite strong.  I have worked on some where the bolts were never re-torqued after 1,000 - 1,200 kms and have become loose, so the gaskets had blown but the heads were still straight.

If the block face was not flat it might have been the cause but then how did the head face get like that?  The block is cast iron and even more solid, so even harder to distort.  If you have had the block re-faced I hope they made sure this was square and aligned with the bores.

Roy
« Last Edit: September 08, 2014, 10:55:27 pm by roy4matra » Logged

Jon Weywadt
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« Reply #51 on: September 23, 2014, 06:14:57 pm »

----
Before getting it line bored to re-align it, take the camshaft along too and explain that the cam normally runs directly in the head, which means there are no bearing shells that you could obtain as none were ever made.  So you need to know first if they can get hold of, or make some bearings after they machine it.  This may be the biggest problem.
----
Roy

Took the head with the cam installed to the shop that fixed the cracks and did the valve job. The the cam checked out straight so he line bored the head with the cam measurements. Apparently it took off a few thousands of a millimetre in the centre bearings. No need for sleeves and the cam now turns as it was supposed to.
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« Reply #52 on: September 23, 2014, 07:13:47 pm »

----
Before getting it line bored to re-align it, take the camshaft along too and explain that the cam normally runs directly in the head, which means there are no bearing shells that you could obtain as none were ever made.  So you need to know first if they can get hold of, or make some bearings after they machine it.  This may be the biggest problem.
----
Roy

Took the head with the cam installed to the shop that fixed the cracks and did the valve job. The the cam checked out straight so he line bored the head with the cam measurements. Apparently it took off a few thousands of a millimetre in the centre bearings. No need for sleeves and the cam now turns as it was supposed to.

Still I find this strange.
The question is, what happened and what is the cause.
Could they tell you?
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Jon Weywadt
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« Reply #53 on: September 24, 2014, 11:21:10 am »

---
Still I find this strange.
The question is, what happened and what is the cause.
Could they tell you?


No, they had no idea. They say it is unlikely that the welding caused it. Another theory could be that the head was torqued wrong.
Anyway. Now it is straight and the cam rotates nicely.
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Jon Weywadt
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« Reply #54 on: September 24, 2014, 07:27:54 pm »

Now for a success story.  Grin Grin Grin

I think I wrote that when we took the head off, the tensioner for the chain could not be secured. The screw just turned and there was no feel of a spring pushing it out.

In fact, after the chain was unhooked the piston in the tensioner remained in the block, when it should have popped out if a spring was in place. My guess is that the previous owner had the head off and lost the spring down in the oil pan (where it probably still is Angry )

But now for the success. Herman graciously sent me a new spring and I have successfully installed it and the tensioner piston and secured it as it was supposed to have been. Cheesy

I first tried by lowering the spring down on a string and managed to get it into the tensioner block, where I held it in place with a magnet on a telescope shaft. I realised quickly that there was no way to then lower the piston down and engage it on the spring. There was just no room to move it around.

Next attempt was to loop a thin nylon line through the spring and then through the hole in the piston. That way both could be lowered at the same time. (make sure both ends of the line come out through the end of the spring so one side is not clamped between the spring and piston)
It turned out that there was no way to get an angle on the two that allowed the spring to be pushed into the block and keep the piston aligned. Angry

The solution was to drill a 2 mm hole through the rubber of the piston near the top. Then string another piece of nylon line through the hole. As can seen below that allow for the assembly to be angled and the direction controlled. I succeeded in getting the spring inserted into the block. Grin

But because of the angled piston head you cannot push it straight into the block and thus it binds. The solution was to slightly bend the end of a 5mm bar of aluminium and use the bent end to push on the piston. I didn't bend it quite enough but enough that a slight push on top with a long screwdriver allowed it to get inserted into the block.  Cheesy

While holding tension on the bar with my forehead I was able to reach down by the engine and get a screwdriver  to turn the locking pin. IT WORKED. Grin The tensioner is now assembled and secured.
Finally cut the nylon lines and pull them out. Wink

Now to get the old spring out of the oil-pan (if it is still in there) Huh
« Last Edit: September 24, 2014, 07:34:48 pm by Jon Weywadt » Logged

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roy4matra
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« Reply #55 on: September 25, 2014, 11:04:14 am »

Now for a success story.  Grin Grin Grin

I think I wrote that when we took the head off, the tensioner for the chain could not be secured. The screw just turned and there was no feel of a spring pushing it out.

In fact, after the chain was unhooked the piston in the tensioner remained in the block, when it should have popped out if a spring was in place. My guess is that the previous owner had the head off and lost the spring down in the oil pan (where it probably still is Angry )

But now for the success. Herman graciously sent me a new spring and I have successfully installed it and the tensioner piston and secured it as it was supposed to have been. Cheesy


Give that man a medal!!  Re-assembling a 2.2 chain tensioner with the timing cover still on takes some ingenuity and perseverance.

Well done.

However, one word of caution: the two slipper pads should be close to the correct path of the chain and the curved one is adjustable.  I have found them too far away from the chain and leaving the tensioner to take up this excess slack.  When correctly adjusted the slipper removes most of the slackness and means the tensioner works closer in its body and has a longer life with less wear.  Since you have not had the timing cover off it will be difficult to tell how well adjusted the slipper pad is set.

Roy
« Last Edit: September 25, 2014, 11:11:36 am by roy4matra » Logged

Jon Weywadt
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« Reply #56 on: September 25, 2014, 12:54:33 pm »

Now for a success story.  Grin Grin Grin

I think I wrote that when we took the head off, the tensioner for the chain could not be secured. The screw just turned and there was no feel of a spring pushing it out.

In fact, after the chain was unhooked the piston in the tensioner remained in the block, when it should have popped out if a spring was in place. My guess is that the previous owner had the head off and lost the spring down in the oil pan (where it probably still is Angry )

But now for the success. Herman graciously sent me a new spring and I have successfully installed it and the tensioner piston and secured it as it was supposed to have been. Cheesy


Give that man a medal!!  Re-assembling a 2.2 chain tensioner with the timing cover still on takes some ingenuity and perseverance.

Well done.

However, one word of caution: the two slipper pads should be close to the correct path of the chain and the curved one is adjustable.  I have found them too far away from the chain and leaving the tensioner to take up this excess slack.  When correctly adjusted the slipper removes most of the slackness and means the tensioner works closer in its body and has a longer life with less wear.  Since you have not had the timing cover off it will be difficult to tell how well adjusted the slipper pad is set.

Roy

Thanks Roy. Grin

The Danish language did pick up some new cuss words in the process. Roll Eyes

I will check how the slipper pad is adjusted when I remount the chain. It should be possible to get an idea before the end cover is mounted on the head.
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« Reply #57 on: September 25, 2014, 05:05:36 pm »

When retired you can take the time to do it.
No boss is bossing around.
Well done, I'm sure I would have taken the engine out for it.

Herman
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Jon Weywadt
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« Reply #58 on: October 19, 2014, 12:30:06 pm »

When retired you can take the time to do it.
No boss is bossing around.
Well done, I'm sure I would have taken the engine out for it.

Herman


If I had a garage to work in I would probably also have taken the engine out. As it is the car is sitting the parking lot outside my friend, Jan's, house.
When Google update their street-view photos for Denmark you will see me sitting in the boot working on the engine. their camera van came down the street and turned around back in August, while I was there. Grin
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Oetker
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« Reply #59 on: October 19, 2014, 12:45:22 pm »

You're Famous now  Grin
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
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