Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: sens on September 24, 2023, 20:50:36
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Hello,
I am removing the cylinder head of my M130 engine for an overhaul. So far so good!
To remove the exhaust manifold from the downpipes is quite a job! No movement at all!
Is it possible to lower the pipes and manifolds and remove the head without separating the two?
Or should I go for it and use more force and heat?
Any advise would be appreciated very much!
Halvor Sens
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I have done it many times leaving the cast iron manifolds attached to the front pipes. The method is a little more technically difficult and is best left for the experienced professionals. Try to use the prefered procedure and finish disconnecting the front pipes. Leave the manifolds bolted to the head for now. Gentle taps with a lead or copper mallet can sometimes free the manifold/frt. pipe connection. Do not use a lot of force with a steel hammer or hard steel mallet or the cast iron manifold can break. In severe cases unfasten all exhaust hangars so the exhaust hangs freely with some support from a stand or jack. Grab the exhaust pipes at the tail pipes and move system by hand, back and forth and up and down. Another set of hands can tap the connection with a lead or copper mallet at the same time if necessary. This method almost always works. Another technique is to use a torch to heat the connection if the equipment is available. Once the connection is free you can unbolt the manifolds from the cylinder head and remove them to continue.
If you are still not able to succeed, let me know, and I can fill you in on the alternate procedure.
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Thanks you so much!
I will follow our advise and let you know.
Halvor
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19 or 20 years ago when i pulled the motor from my 66 230 the exhaust manifold and exhaust down pipe would not come apart.
this is probably not a good method to separate but i removed all exhaust connections and let the entire exhaust hang and from the rear i grabbed the chrome tips and wiggled the entire system until the 2 separated.
this actually took several tries over a few days.
when i re installed i used some anti seize just in case i needed to separate the 2 in the future. (which i actually had to do)
good luck
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Thanks for your comment.
I will let you know!
Halvor
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And sometimes it proves impossible to seperate them without breaking the manifold.
I recently had to cut the downpipes a cm from the flange, remove the manifold and get it on the bench. Then I carefully cut slots into the inside of the remaining downpipe so as to be able to crush the remaining downpipe. After maybe a couple of hours at this I still ended up with a broken manifold.
RHD manifolds are particularly hard to source too.....
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Mmm, your story frightens me somewhat…
I undid the 6 bolts that connect the tubes to the 2 manifolds.
I will give it a try from the back of the car.
Fingers crossed…
Halvor
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The rear manifold seems to be the one that breaks most often and is harder to find in good used condition. Lots of heat and patience required in many cases.
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Thank you Dr. Benz!
Would you advise to get the cylinder head off without removing the manifold from the pipes?
Thank you.
Halvor
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Thank you Dr. Benz!
Would you advise to get the cylinder head off without removing the manifold from the pipes?
Thank you.
Halvor
Yes, I've done it that way before. In one case we left the manifolds on the down pipes and only removed the cylinder head.
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I see that removing the down pipes is quite risky…
What is the procedure to follow if you leave the down pipes attached to the manifold?
Thanks!
Halvor
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Remove everything that holds the head in place, lift it slightly, and then pull it away from the manifolds. Removing the valve rockers helps so that you won't have anything to catch the block as you remove the head.
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Thanks a lot!
I will give it a try, since I am allmost there!
Halvor
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Will the valve rockers be in the way, since they are part of the head?
Halvor
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When using this method, I use a floor jack under the front pipes help lift the head upward and easier to slide off. In addition, removing the injection pump WRD makes a lot more room to slide the head off. Although this method saves a lot of time and difficulty, installation becomes more complicated. Placement of the head and new head gasket is more difficult to achieve without damaging the new head gasket.
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Thanks for you comment!
I can understand that removing is much easier than assembly.
I think I will first try to get the down pipe disconnected without using to much force.
If necessary I will follow your procedure. I have a good lifting device for the head in place so I can move it in a controlled way.
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Sens
hi,
it probably took me 9 days for the down pipes to finally let go of the manifold.
i'd come home from work wiggle / pull / twist at the chrome tip end for a few minute then i'd leave it alone until the next day.
finally after a week or so doing this every day it finally released.
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Haha, thank you so much much for your encouraging words! Appreciated!
I am at day 1 now and I started the process.
The problem is to determine how much force you can apply at the end of the exhaust without braking the manifold.
Any idea??
Best regards and fingers crossed!
Halvor
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Move in all directions, up, down, left and right. Occasionally go forward and tap the connection with a copper or lead mallet.
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OK!
Thanks.
I used a plastic mallet.
So far no movement...
I will keep you updated!
Halvor
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Would it be possible to remove the studs for the manifolds and put new ones in later on when the overhauled head is in position. Then you can leave the manifolds connected to the downpipes and remove and replace the head. If you put two nuts on each stud and tightened them against each other to keep them in place, and then installed the studs with a socket wrench on the top nut.
I read on this forum that this might work.
Any comments?
Thanks!
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Or... can I put some moderate tension on the connection inspired by the picture I found on this forum.
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hi
if i remember correctly i was not that gentle pulling / wiggling / twisting / moving up and down at the chrome tips.
it took time but it finally broke loose.
some heat may not hurt if you are in a rush, especially if you are using that clamp set up in the earlier post picture
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@Sens if you do end up breaking the manifold, I have about 10 of them in good shape here with me in France where I will be for the next three weeks. So if it happens within that timeframe, I can send one in the mail. Fingers crossed!
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Plastic mallet, most likely, will not have enough mass.
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I was thinking to remove the studs as well. There are special stud removers for that. Problem likely will be to get enough access.
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@ Cees. I just came back from the Provence last week! Coincidence!!
Thanks for your offer. I hope it will not be necessary.
Best regards, Halvor Sens
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Ja17, you are right.
I just ordered a copper one.
Will be much better…
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Hi Sens,
Yes that is my picture of the clamp trying to force the pipe out of the manifold. This was on my '60 220se coupe. Like many have said here, it took about 4 days even with the clamp. The thing I liked about the clamp is that it applied constant separation pressure 24/7. I used penetrant, heat, hammering and it finally released.
The clamp doesn't have to be that complicated but used some scrap metal I had lying around. The split ring is nothing more than a wheel collar that I ordered. I then welded everything on that. I still have it and can take more pics if you need.
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Thank you for your comment Wheeler!
Another way to separate the two parts.
I will try the daily wiggling first and see what that will bring.
Thanks again!
Halvor Sens
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Hi Wheeler,
In my situation it is even a little simpler.
I try to keep constant pressure, like you said, applying moderate force on the bolt to avoid breaking of the manifold.
And of course lots of penetrant, some heat, wiggling and... patience!
Halvor
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I used this technique on the forward manifold, but I couldn't access the rear manifold connection to do this. You may have better luck.
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Good technique Halvor !
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They always say KISS - keep it simple stupid! Yes, that is a very simple solution. I hope it works and it will get there!
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Yeaaaah!!!
One down, one to go!!!!
I used M6 bolts to have more room…
Oef..
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I'm not sure what size bolts I used, but I just didn't have access to get them into the lower/rear flange. Maybe you found a better angle for your hands.
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I got 2 of the 3 in place, but it was an adventure I must say…
I will continue this week and keep you informed.
Halvor
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Still working on it…
No movement yet for number two, but nothing broken!
Patience and heat..
Halvor
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Hello again,
I should be able to cut the horizontal pipe off the front manifold under the car and remove that pipe and then the front manifold.
This will give me enough space to move the rear manifold away from the engine (to the right) to lift the cylinder head.
In that case I would leave the rear manifold connected to its down pipe.
Assembly would be possible with the connection part as shown in the picture. Diameter of the pipe is 42 mm.
This would avoid the risk of breaking the rear manifold, exercising to much force on it.
Not a very elegant solution, but low risk..
Could that work? Or am I missing something?
Thanks for your comments my Pagode-friends!!
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Try striking the front pipe near the manifold connection with your mallet. You can use a little more force since your not striking the cast iron directly.
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Hello there.
Finally I chose to cut the two down pipes and I will connect them with the two thumb connections for 42 mm.
After my cylinder head repair I want to do a revision of my rear axle. So I will have to remove the exhaust completely; that is possible if you can lift the car about 2m . I can lift the car, but not that high, so I had to cut the exhaust anyway.
I used a sabre saw and it was an easy and safe , 5 minute job!
Pipes and manifolds are away now and now I will continue to remove the head.
I read something about the hidden screws. Are these the ones in the two pictures?
Best regards and thanks again for all the support!
Halvor
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Mine had welded themselves together as well. There wasn’t enough stud sticking through the manifolds to fit a lock nut on so I put weld onto the stud ends and then used the manifold stud nuts to wind the studs out of the head. (The weld stops the nuts unscrewing off the studs) Fit new studs with an Allen key hole in the end when reassembling
I hope this helps
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Yes Halvor, those are the two hidden bolts. Remove the chain rail and bracket first to make the one below easier to access.
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Hello,
The adventure continues...
Any idea how to remove the bolt from the camshaft sprocket?
Block the sprocket through one of the openings with a wooden support?
Or is there a better trick?
Or use the special wrench I found on the internet?
Thanks so much for helping me!!
Halvor
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Do not block the movement through the holes in the sprocket. The cast steel is easily broken. Put the box end of a 22mm wrench on the bolt head and give the other end of the wrench a firm blow with your new copper mallet! A battery impact tool is also excellent. You should notice little or no reverse movement of the engine.
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Thanks a lot!
I have all these tools, so I will give it a try!
I might buy the camshaft wrench later if it will not work...
Thanks again, Joe!!!
Halvor
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And Yesssss!!!
The head is off! A hit with the copper pallet made the cam sprocket bolt free and the rest was relatively easy.
Thanks for all the support!!
Halvor
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Hello again,
I inspected the Cylinder bores this morning.
It is clean that the engine made its km's or miles.
The surface of the bores looks more or less polished; you can see some taches on the picture, but in reality you don't feel anything. No scratches or whatsoever.
You can feel the ridge, caused by the top piston ring. Diameter bore is 86,5 mm; so factory spec.
Of course a total overhaul of the engine is the best solution, but my plan was to overhaul just the cylinder head to avoid smoking after idle.
In fact the engine runs smoothly and I will just use it for some trips in our neighbourhood.
Or is this a bad idea and should I go one step further and go for the total overhaul. Or is there a step in between?
Or stick to the first plan?
I am sure I am not the first playing with this dilemma!
Thanks for your comment!
Halvor
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I think you’ll need inside micrometers to read the wear accurately. You’ll need to take fore and aft and side to side measurements at several locations along the bore.
What were your compression readings prior to pulling the head? Were you burning oil? There is a way to tell the difference between valve stem leakage and oil scraper rings.
I pulled my engine recently and sent it to Metric Motors. Unfortunately it was trashed beyond repair, I did know there was water in the oil. Even the crankshaft was too far gone from water corrosion. Turns out the previous engine rebuilder did a terrible job, among other things they glued the sprocket to the shaft.
Metric Motors ended up getting me another block. I had already had bought a new head a few years ago. Very little was salvageable.
I now have a chance to clean up, repair, and paint the engine bay, which I’ve needed to do since I bought the car 23 years ago. It’s a big job but I wish I had done it years ago.
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Thanks for your story: ups and downs, I can see that!!
Before repair, I measured the
Compression.
Compressie sept 2023 (kg/cm2)
1: 13
2: 12
3: 10,5
4: 10,5
5: 11,5
6: 11,5
Not fantastic, but remember there is a lot of wear in the valve guides…
I think it will improve once the the cylinder head repair is done.
Halvor, the Netherlands
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Normal compression on a 130 (280SL) is 10-12 atu (roughly kg/cm2).
With a difference of no more than 1.5 atu between cylinders.
If I were you, I would take the motor to a specialist for evaluation and than decide on the necessary work to be done. Kevin already pointed out the procedure for properly measuring the cylinders and the minimum tools required.
You don't want to do this kind of work twice.
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Normally A M130 engine with less than 150K miles just needs the cylinder head rebuilt and a new timing chain.
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Thanks for your comments,
guys!
I will ask the guy where I will bring the cylinder head.
I think I will attack the cylinder head first and then rebuild the engine. The chain does not shows any play, but since I am there…
Overhauling the total engine is better of course, but a much, much bigger project. The risk I am willing to take is that I need 2 head gaskets in the end…
I wiil keep you updated.
Halvor
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It's very importaont to have the bores measured properly by someone who knows what they're doing. A compression check isn't sifficient.
The absolute best way is to measure manifold vacuum with the engine running but of course, you don't have that opportunity now.
Did you manage to seperate the 2nd manifold from the downpipe?
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Thanks for your comment!
Yes, measuring the vacuum in the manifold is difficult now…
As indicated above I did not insist separating the down pipe and the manifold; I was afraid to break it.
I simply cut the two down pipes and I will reconnect them later on.
Suppose the diameter of the bores is to high, that would mean a complete engine overhaul, right? The big thing…
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Hello again,
I measured the distance between the ridge and the bore itself by inserting a feeler gauge in the small gap. (see picture)
I know that you will tell me that this is not the correct way to measure this, but at least it is an indication. ;)
I was able to insert a gauge of 0,05 mm, meaning that the bore diameter is at + 0,1 mm approximately.
And that is far too much, since Haynes tells me it should be lower than 0,022 mm!
I am afraid I will have to go a few steps further than just the cylinder head overhaul.
The wear of the valve guides indicated already to me that the engine had made its km's.
I my reasoning correct?
Thanks for all your support!
Halvor
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https://www.youtube.com/watch?v=VXiN1lNZ7TY
Also, get yourself a workshop manual aka BBB and read up on the chapter. (00-5)
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The top of the cylinder bore does not wear since the piston rings do not travel all the way to the top. If you thoroughly clean the carbon off the cylinder at the top, it should measure out to the original cylinder diameter. Lower in the cylinders, is where all three or four rings travel in every stroke and this is where most wear occurs. The wear may also occur more on one side of the cylinder than the other. Cylinder bores can actually wear oval and the rings adjust by wearing themselves to fit, as the cylinder wears. Just installing new round piston rings in worn oval shaped cylinders usually results in an engine which uses a lot of oil. So evaluating the condition of the cylinders is critical. It seems that the factory uses very hard rings, and the cylinders are worn out of spec before the rings are depleted. This seems to happen around 150K to 200K miles with conventional oil. Longer engine life can be achieved with modern oils, good maintenance and good driving habits. One quick way to evaluate the wear of the piston rings is to examine the bottom cast iron oil control ring. It has a double ridge and the valley between the two ridges almost disappears as the two ridges wear down. By this time the cylinders are usually worn beyond factory specs also. As you realized, the factory does not allow much cylinder wear before calling for a cylinder boring with new pistons. If your engine has less than 150K miles consider just reconditoning the cylinder head first. 90 percent of the time, most oil consumption problems and compression problems are cured or made much better.
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Nice Video Dirkbalter!
Thanks for the link.
I have access to the link https://vdhflipbooks.de/books/WHB/WHB1959-Band-1/#94.
In fact that is the BBB chapter you mentioned.
Indeed, I had studied the pictures about the different defaults in the cylinder bore.
In my case no scratches or so, but a polished surface and a diameter probably out of spec...
Best regards and thanks again.
Halvor
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Hi Joe,
Thanks again for your very helpful comments!
I think I will go for the head repair first, knowing that in fact the total engine is due.
However, my goal was to solve the oil mist problem after idle and that wil probably be solved after the head revision.
After that I have some other projects for the car: radiator, rear axle overhaul, etc.
So step by step will bring this beauty back to where it belongs!!!
Halvor.
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Yup, if you can read German, the flippbooks are better than the single volume BBBs that are available now.
Good luck
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Hello again!
After inspection of the cylinder head by the machine shop they strongly recommended a total overhaul of my engine.
I found however an overhauled 280 sl engine, done by the same shop for reasonable price. The engine was sold by the guy from whom I bought the car 5 years ago. I have great confidence in him.
So I will do the swap in the near future and I will let you know.
Thank you so much for all the support so far!
Great forum!!!!
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I’m curious how they can tell how the rest of the engine needs to be rebuilt without seeing it. I guess if the valves are all good and there’s burnt oil all around they can deduce the oil scraper rings are shot.
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It is an assumption, but I think they are right.
In fact they will not do the head only, just the total engine.