Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: Figoulu on April 14, 2025, 12:53:18
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Hello all
I was happy to get my engine overhauled and before putting it back in the car I checked various elements, from which the valve clearance.
Suprisingly almost none was correct, and I checked twice so happy to have made the chekings as the engine was outside
I put everything back inside the car, put oil, check again all the wires and connections and tried to start the engine.
Half a second later the engine was stuck as if the battery was dead.
I understood quickly that some pistons met some valve...
I figured out that as my head has been machined, the thickness of it is different so as the valve clearance. Actually I understand now that the original clearances were correct...
Now what to do ?
I sent an endoscopic camera. Nothing bad so far from what I could see. The engine only turned 1/2 a second.
I want to remove the head and see what to cure.
Probably I will need to cut the timing chain to be able to remove the head, unless I can remove the camshaft gear as well as the belt tensioner to let it go
Once this will be solve what shall I fear as damage ?
I assume only the head as to be checked, what about the block and the rest of it
I'm really stupid... but that's the costly way to learn
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Engine is build-in again: then I would set de clearance correct and see how the engine performs.
Alternative is, what also will happen when the engine does not perform nicely, is again a complete overhaul, as the crankshaft could be (minimally) bended, the crankshaft bearing can be “oval”, valves bended, etc…..
I know, a horror scenario. Sorry for this.
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I would not expect the skim of the head would be so much that setting the valve clearances to original specifications would cause the valves to hit the pistons. The machine shop would have had to remove a lot of material.
What I would do:
- try turning the engine by hand after removing all spark plugs
- double and triple check the engine timing: valves vs pistons vs ignition
- if engine spins freely by hand then use the starter to spin the engine briefly
- try starting it again, if the engine spins freely
Could it be that there is 'something' obstructing the free movement of the engine, such as a wrench, the timing chain, a loose bolt somewhere?
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I would not expect the skim of the head would be so much that setting the valve clearances to original specifications would cause the valves to hit the pistons. The machine shop would have had to remove a lot of material.
What I would do:
- try turning the engine by hand after removing all spark plugs
- double and triple check the engine timing: valves vs pistons vs ignition
- if engine spins freely by hand then use the starter to spin the engine briefly
- try starting it again, if the engine spins freely
Could it be that there is 'something' obstructing the free movement of the engine, such as a wrench, the timing chain, a loose bolt somewhere?
Impossible to turn the engine even with the spark plug removed... in one way and in the other way
I have no idea if something else could have blocked the engine... yes could be a nut, but nothing like a tool, I don't believe that
I guess the only way to see more is to remove the head, but there might be a way to loosen the head and remove the timing chain other than to cut it. With removing the camshaft gear ??
I forgot to mention that the endoscopic camera shows the very slight print of a valve... But I agree with you, how could the machine had potentially removed so much "meat"... so that the valve met the pistons
Before doing all this I had checked the timing and everything was well synchronised...
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What about à timing chain opened ? And blocked ?
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I would guess that the cam chain was not installed properly and a valve protrudes into the cylinder when the piston is at TDC and caused the interference. The head comes off from the engine with the engine installed. It is a hassle, but not a problem.
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I would guess that the cam chain was not installed properly and a valve protrudes into the cylinder when the piston is at TDC and caused the interference. The head comes off from the engine with the engine installed. It is a hassle, but not a problem.
Thanks
How about the chain ? How would you remove it ? Shall I remove the camshaft gear ?
As far as I remember the timing was ok. I checked it when doing my valve clearance
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Bummer to hear that. I would take cam cover off and look at the valves to make sure all of them are still in place(not dropped).
Then do like others said, remove plugs and try to turn by hand.
If nothing, mark location of camshaft to chain sprocket wheel and make sure you don't loose timing marks.
If the camshaft is in wrong position(180 degrees) off from crank, then the timing is all off.
Reset by turning the crank and camshaft independently till you line them up properly.
You said you spun the motor briefly, then you should be ok with unbent valves and uncompromised pistons.
I don't know how much you spun the motor before locking up.
Go ahead and cut the chain and remove head. New chain and head gasket is in order.
Have head and valves fixed(pressure test).
Bought a 1970 280SE with the timing turned 180 degrees off and the valves were trashed.
Got a new motor and installed it, with no problems.
That was many years ago.
Walter
1967 220SL diesel
1969 280SE
2003 Beetle TDI
2005 Honda Element
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I wouldn’t think it’s necessarily pistons hitting valves Figoulu. I believe the engine would likely still turn one way or the other in that case. Could the starter have got jammed somehow? Maybe take it off and have look. If you didn’t hear anything disastrous hopefully the engine internals are ok.
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No need to cut the chain. Remove the chain tensioner which should take some of the tightness out of the chain.
You have a valve hitting a piston which indicates incorrect valve timing. Even one tooth advanced will make valves hit pistons. Two teeth advanced and the engine will lock up solid.
No need to remove the head if you can retime your camshaft.
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Thanks for your advice.
I will do it asap
For the Time being I need to stay away from that car…
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Check again your valve clearances. If they have increased since you set them then that is an indicator of bent valves due to incorrect camshaft timing.
If they are bent then you'll need to remove the cylinder head and renew the bent valves.
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Check again your valve clearances. If they have increased since you set them then that is an indicator of bent valves due to incorrect camshaft timing.
If they are bent then you'll need to remove the cylinder head and renew the bent valves.
Thanks a lot for the advise !
My pro went back to me and ask me to send it back to him
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We are of course very interested in what the diagnosis is, please keep us informed.
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Thanks to all for your messages including pm
At the end of the day the engine will be sent back to the pro.
When removing it from the car I will try to investigate something by just removing the rocker arm cover just to see if something obvious appears
I will post the end of the story when I know more.
For those who know the answer, do we expect the engine block/ piston / rods to be damaged or only head and valves?
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At the end of the day the engine will be sent back to the pro.
That seems the best thing to do, especially if you had not altered anything after receiving the engine from them. Good luck.
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Regarding the machine shop removing a lot of material may not necessarily the case. It may just be that the head had already been skimmed once or twice before ?
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Remove all spark plugs. Remove all the rocker arms that can be removed with the head still on the car. Next increase the clearances of the valves on the remaining rocker arms on the car until they can be removed or the engine can be turned again. Proceed until all rocker arms are removed. Next turn the engine and check the valve timing marks. Correct if needed. Next, install each rocker arm one at a time and set the valve clearance to specs.
Continue until finished, one at a time until finished or until problem occurs.
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Remove all spark plugs. Remove all the rocker arms that can be removed with the head still on the car. Next increase the clearances of the valves on the remaining rocker arms on the car until they can be removed or the engine can be turned again. Proceed until all rocker arms are removed. Next turn the engine and check the valve timing marks. Correct if needed. Next, install each rocker arm one at a time and set the valve clearance to specs.
Continue until finished, one at a time until finished or until problem occurs.
Thanks again
In the best and the worst case, what kind of damage could I expect ?
Do you think the piston / crankshaft could have been damaged or only head / valve ?
Once again the engine just try to start for one second
Secondly, how can I determine the new specs for the valve clearance ??
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I would guess that the cam chain was not installed properly and a valve protrudes into the cylinder when the piston is at TDC and caused the interference. The head comes off from the engine with the engine installed. It is a hassle, but not a problem.
This ^^. It seems most likely that whoever reassembled the engine got the cam/valve timing wrong.
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While that makes sense, anyone rebuilding an engine, or even just replacing a timing chain (or timing belt), would verify timing by turning the engine over at least two complete revolutions to confirm no interference. Certainly any professional rebuilder/mechanic should!
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While that makes sense, anyone rebuilding an engine, or even just replacing a timing chain (or timing belt), would verify timing by turning the engine over at least two complete revolutions to confirm no interference. Certainly any professional rebuilder/mechanic should!
It's not clear for me if the issue comes from a lack of control and the bad timing tuning because as far as I remember I have checked previously the alignement of the various indexes to be at TDC. And when I made the valve clearance tour, it's almost sure that previously the engine was freely truning.
this is why I guess the corrections I made to tune as the original spec made the mess, or alternatively as it has been also suggested, something like a chain link or whatever loosen screw, has blocked the rotation. this week end I will investigate because I don't hide that removing the engine doesn't please me so much... because I will need to fight again to put it back in the car... So much fun to come...
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It is true that in order to check and set the valve clearances, you would have had to rotate the engine at least to some degree (pun intended). I am thinking a bolt or other object is obstructing the rotation. Wish I was there to help diagnose, good luck with the investigation ... Do try out the various suggestions by Joe A and others.
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Since the valves are directly perpendicular to the flat top pistons on these engines, you most likely do not have major bottom end damage. The valves do not usually get bent or damaged when they are perpendicular to the pistons. In severe circumstances the valves are jammed upward breaking the camshaft or the cam support. Visual check the cam supports and camshaft closely. Next follow the steps in my previous post. On other engines where the valves enter the combustion chamber at an angle, (not perpendicular to the pistons), a collision between the valves and pistons almost always results in bent valves!
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There is always the chance that you had something that was loose and fell into the timing chain and jammed the engine. Examine deep into the chain gallery where the timing chain meets the crankshaft sprocket. In some other case a loose part in the intake manifold can be sucked into the combustion chamber, during start-up, locking up the engine.
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You couldn’t be more accurate…
Here is a quick update…
I could remove all the rocker arms quiet easily and without turning the engine… anyway it still cannot be turned and is totally stuck back and forth…
At least (little satisfaction) it’s not my fault…
I’m gonna try to investigate but it’s quiet difficult to do without removing the head which I don’t want to do just to avoid to break the warranty…
I sent one more time the endoscope but nothing obvious. The top of the pistons are clean… just a very gentle stamp of a valve on top of some pistons
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As the camshaft is positioned, we are a TDC on the cyl 4….
As the firing order is 153 624 next cylinder to be fired is number 1.
It’s hard to say like this, but the alignment of the distributor, the mark on the crankshaft pulley and the one on the camshaft appears to be somehow consistent to be at TDC of cyl 1 if we could turn the engine more… see the red lines on the pictures that emphasizes the indexes…
It appears to me that there must be something else blocking the engine.
I think I could not do more to get the answer, in order to avoid to break the warranty of the engine but I bet it’s not because of my valve clearance tuning that the engine is stuck.
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What about à timing chain opened ? And blocked ?
Now I that I removed the rocker arm cover, I could see clearly the chain link… it’s definitely there and properly locked.
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Just a complete guess, but could the starter motor get jammed on the flywheel?
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Just a complete guess, but could the starter motor get jammed on the flywheel?
Very good idea indeed
I was thinking about to test it… remove it first and check if it could be the culprit… Same applies with the flywheel where something could be stuck around this area…
I did a complete overhaul of the starter myself here https://youtu.be/8ghKjPeb10s?si=Xv8mUc9FmKh2V1OI
… but who knows ?
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Hi François, your motor adventure is like a netflix série🙈 a cliff hanger at each end of post …!
But i think that you are close to the solution.
WE are with you on that issue.
👋🏻
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Yes I would just remove the starter, not a big job, and see if that frees up the engine.
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Good thought on the starter Bob H !
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Hi François, your motor adventure is like a netflix série🙈 a cliff hanger at each end of post …!
But i think that you are close to the solution.
WE are with you on that issue.
👋🏻
Thanks Yves 😁
Frankly spoken I’m in a way « happy » that apparently I’m not guilty with having done the valve clearance tuning even if it’s a lesson learned, for next time...
By the way in general cases, we normally compensate the head machining, by a head gasket with a thickness corresponding to the material removed, but why on our cars do we have only one ref of head gasket whatever the final thickness of the head is ?
Anybody has the answer ?
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Good thought on the starter Bob H !
Yes I would just remove the starter, not a big job, and see if that frees up the engine.
That’ll be the next step guys 😁😁 after I get my Easter lunch with my mom… she lives 200kms from my house so I guess you’ll get some fresh news tomorrow, Sunday 😉😉
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Yep…
The starter is totally stuck guys
Now I need to try to remove it. As of now I couldn’t see how to do and if it has damaged the flywheel 😁
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Conclusion: starter 1 / flywheel 0
The engine turns by hand smoothly…
Just need to put back the rocker arms and get to know the correct values even if it doesn’t seem to be problematic in my case…
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No idea yet how to fix it but it’s sold apart… anybody to tell me ?
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Replacing the ring gear is a common repair. The old one gets machined or pressed off. New ring gear is heated to expand and then pressed on. Any shop that deals with clutches should be able to do it.
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So ...good news on Easter ...
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Je l'ai fait sur une Triumph TR6. Pour remettre la couronne et selon le livre d'atelier du véhicule, il faut la mettre dans un récipient contenant de l'huile moteur et chauffer l'ensemble . La remise en place s'est bien passée. Je n'ai pas le livre sous la main mais je pourrai si cela vous intéresse vous donner les durée de chauffage et la température à obtenir.
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Replacing the ring gear is a common repair. The old one gets machined or pressed off. New ring gear is heated to expand and then pressed on. Any shop that deals with clutches should be able to do it.
Good to know. I’m gonna see with my pro how to adress this issue between he and I.
What is your analysis about the reason it went like this ?
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So ...good news on Easter ...
Yes indeed… I agree.
I’d like to take this opportunity to warmly thank all of you with leads and supportive comments. It’s been a pleasure to post and receive interesting answers. Special thanks for those who pm me and of course for the ones who got the right clue @Daveb and @BobH 👍👍👍👍
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Je l'ai fait sur une Triumph TR6. Pour remettre la couronne et selon le livre d'atelier du véhicule, il faut la mettre dans un récipient contenant de l'huile moteur et chauffer l'ensemble . La remise en place s'est bien passée. Je n'ai pas le livre sous la main mais je pourrai si cela vous intéresse vous donner les durée de chauffage et la température à obtenir.
Thank you. The best is for me to see directly with the pro who might send me a new flywheel while I would send him back the damaged part. Once again I would like to understand how all this could happen ?
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As of tonight I removed the intake and exhaust
Removed different connections
I have left for tomorrow:
- gearbox support
- rear axle connexions
- power steering pump
I’ll remove the engine from the car and separate the gearbox.
See you tomorrow for the next steps!
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What a job already made👍, keep on!
And stay safe …🏋️
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Ring gear is easily removed with a dull chisel. Keep hitting on the ring until it starts to slide off of the flywheel. Place the new ring gear on the flywheel after heating with a torch and it should pretty much drop into place. Once it cools it will be more than tight enough.
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That’s great news, no engine damage!
But may I direct you to reply #8 in this thread? 😉
Maybe ask your mechanic if the starter may have caused the problem. Otherwise it might happen again..
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By the way in general cases, we normally compensate the head machining, by a head gasket with a thickness corresponding to the material removed, but why on our cars do we have only one ref of head gasket whatever the final thickness of the head is ?
Anybody has the answer ?
Is it because the extra clearance can be taken up at the ball studs?
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That’s great news, no engine damage!
But may I direct you to reply #8 in this thread? 😉
Maybe ask your mechanic if the starter may have caused the problem. Otherwise it might happen again..
Yes sorry this one fell off the radar. Message #42 correctes 😁 Thanks for having given the right lead after only some messages 👍👍
My idea was to try to use the starter again once the engine is outside. I don’t see the problem to try again if I can properly stabilize the engine. I want to know wether the starter or the flywheel ring is the problem.
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Ring gear is easily removed with a dull chisel. Keep hitting on the ring until it starts to slide off of the flywheel. Place the new ring gear on the flywheel after heating with a torch and it should pretty much drop into place. Once it cools it will be more than tight enough.
For this job do I need to remove the flywheel from the crankshaft? I guess yes
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Is it because the extra clearance can be taken up at the ball studs?
Could be but as any other system you can compensate as well
My question is now how much would be the good clearance… my pro do not answered yet… if I could measure with a gauge the journey of the valve and compare it with original spec it could be the solution. But as it is engineered I think I can’t
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Thank you. The best is for me to see directly with the pro who might send me a new flywheel while I would send him back the damaged part. Once again I would like to understand how all this could happen ?
If you think about it, the flywheel is sitting there, minding its own business, and it's suddenly assaulted by the starter gear, flying out of nowhere, it's bound to get a bit bruised and beaten over the years. Added to that, if it's true that the engine always comes to rest in one of a few positions (i don't know if that's true, but sounds reasonable), then the same few teeth on the gear ring will be subject to the wear and tear. Added to that there is no lubrication, like with most meshed gears. Perhaps your starter wasn't making good contact with the gear ring before you refurbished it, good video by the way, and perhaps that caused more damage to some of the teeth.
I think the gear ring is made to be sacrificial, a bit like the iron rim on a cartwheel, hence why it can be replaced, not bad if its lasted over 50 years!
Just make sure the starter makes good contact with the new gear ring when you assemble it again
So glad it wasn't too much of a problem for you!
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For this job do I need to remove the flywheel from the crankshaft? I guess yes
https://www.bing.com/images/search?view=detailV2&ccid=iVpqPNmc&id=1638BD6E5052AC06B6B32E939AD307CC12A4BEA1&thid=OIP.iVpqPNmcqpf9CPdyjjqS2gHaEK&mediaurl=https://i.ytimg.com/vi/ruNBZFYEbek/maxresdefault.jpg&q=how+to+replace+ring+gear+on+flywheel&ck=247B547937658A194FB3E9BF961E22A7&idpp=rc&idpview=singleimage&form=rc2idp&mode=overlay
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https://www.bing.com/images/search?view=detailV2&ccid=iVpqPNmc&id=1638BD6E5052AC06B6B32E939AD307CC12A4BEA1&thid=OIP.iVpqPNmcqpf9CPdyjjqS2gHaEK&mediaurl=https://i.ytimg.com/vi/ruNBZFYEbek/maxresdefault.jpg&q=how+to+replace+ring+gear+on+flywheel&ck=247B547937658A194FB3E9BF961E22A7&idpp=rc&idpview=singleimage&form=rc2idp&mode=overlay
Easy 😅😅😅
Thanks 👍
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Countdown to lift off…😁
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I like the Trabant thing.
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I like the Trabant thing.
A souvenir from my hungarian period when I lived in Budapest. Such a car would cost 150€ complete… they were useless because they couldn’t pass the pollution test and couldn’t be driven anymore…
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Tell me about it... my father owned two of them.
Ok, not to ruin your thread, sorry.
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Nothing too much
When I lived there we could ask any kind of decoration… as a symbol of an era I decided to ask to get a front to remember those days in my garage…
By the way… perfect landing
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Rocker arms back. Clearance given by my pro: intake 0.15 mm exhaust 0.20mm which is now set up even if it’s not totally logical to put + 0.02 for the exhaust and +0.07 for the intake…
Saw also the gear… definitely it has lived because there is at least one more damage done previously… a cheap savings my pro did…
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Before I remove the flywheel I wanted to test my starter and see if I can activate the rotation of the engine and let the oil pressure rise up
https://youtu.be/SDMJsD6YD3o?si=XqcFypwCF1eBC13v
As you can tell the pressure is ok at least drops of fresh oil falls on the rocket arms I guess the oil circuit is about to be fully under pressure
But you can also hear a bad repeating noise…
To make sure it was about my damaged flywheel and the interaction with the starter I made a slow motion video and marked the 2 damaged gear with red line on a tape located just in front of them. I got immediately the answer…
https://youtu.be/zegj6UV4rvQ?si=H8r7YPl343zk3R2J
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FIGOULU:
Loving this serpentine journey you are on , and your documentation and pics….both entertaining and informative. ( I thin you are in the final chapter now?)
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FIGOULU:
Loving this serpentine journey you are on , and your documentation and pics….both entertaining and informative. ( I thin you are in the final chapter now?)
I try to make it live and tell a story from A to Z to make sense and interest... So frustrated to see posts without the final solution
So... Yes, the parcel has been sent yesterday to my pro who is in Germany.
With all those events I wanted to make it to the safe side and bought a new starter just in case mine was not 100% reliable and could possibly be part of the trouble.
Apart from that I have ordered couples of very last missing parts / or to be replaced to be able to get back very soon with a running engine.
I dont but the pressure on myself and gave me a 3 weeks time to get back the flywheel from my pro with a new gear and the last missing parts.
I'll give you the next episode for sure untill this engine runs and the car drives !
Thanks for your interest
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Rocker arms back. Clearance given by my pro: intake 0.15 mm exhaust 0.20mm which is now set up even if it’s not totally logical to put + 0.02 for the exhaust and +0.07 for the intake…
Saw also the gear… definitely it has lived because there is at least one more damage done previously… a cheap savings my pro did…
.003 intake and .007 for exhaust.
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.003 intake and .007 for exhaust.
Yes those are the original value for the valve clearances but provided that the head has been machined I guess we cannot stand with the original values and possibly run the risk that piston and valve get married against theit own will :o
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Not likely but this how you check:
turn your crankshaft over to 5 degrees ATDC on number one cylinder. Pry the intake rocker down until you feel it hit the top of the piston. If you have a dial indicator you can use that to check liner movement or you can see if a .040 feeler gauge will will slide in between the rocker arm and the cam lobe. If it will easily slide into place you should be good to go. If the gauge is too tight try a thinner combination until you find a size that fits. Less than .035 and you may run into trouble.
Only the intake valve can hit the piston during normal operation. Intake valves are supposed to be set to .050 mm recession which is the amount the valve face sits below the parting surface of the cylinder head. If you have your valves sitting at parting surface level this is the real problem.
.002 for your exhaust is far too tight and you can risk burning out the valve.
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Yes, go with the original specs as Dan suggests. The factory allows for the machining of engine parts within specs and it should not effect the valve adjustment.
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Thanks all for those important info
I will check that as the engine is still outside and for some days / weeks again 👍👍👍