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W111 Coupe
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Discussion Starter #1 (Edited)
Hi all,

I'm planning to take my engine apart to check wear and replace all needed items before fitting it in my car. I heared some horror stories about stipped head bolts threads in the block, and even boken/rounded bolt heads requiring grinding the head out. Is there anything to do in order to avoid such things, like torqueing the bolts a few degrees before loosening them, or hit the bolt top down with a hammer to "free" them (like with rusted bolts) before undoing them?

Thanks in adance!
 

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Buy a new quality allen head socket and the appropriate 1/2" drive extension and breaker bar. Then on reassembly REPLACE all of the bolts. Doing that I've never had a problem. (rounded heads before you even start means some cheap person scr3wed you over)
 

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Discussion Starter #3
Thanks. I have all the quality tools needed. There are signs that the heads have been off already, and the bolts are shiny stainless steel. I read somewhere this was a required replacement at some point. Does that mean I should expect less problems?
 

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1984 500 SEL euro, 1989 560 SEL, 1980 450 SL, 1981 DeLorean, 2013 F10 BMW
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When I had the heads reworked on my euro 500SEL, my technition told me to replace all the head bolts since they stretch from torque and time. We checked them against the new ones and there was a noticible difference in length.
If you're going to do the job once, do it right. Replace all the plastic and rubber associated with the motor.

Regards,
 

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You can get away with reusing the head bolts perhaps once (I just did this with no problem). However, if the heads have been off, it's wise to get new head bolts to reassemble things.

It's advisable to soak the head bolts overnight with PB Blaster, Kroil or at minimum with WD-40. When I recently removed the heads on my 560SEC, I soaked one side overnight with WD-40 and didn't soak the other side. I would say that the soaked side bolts were 25-30% easier to break loose than the non-soaked ones.

As long as you are careful and take your time, you won't strip anything.

A few tools you will need, to successfully disassemble the top end:

- valve spring compressor (you can get for $100-200 on eBay new)
- timing chain guide rail pin puller (get new on eBay for $30; don't make one yourself)
- large crescent wrench (to hold cams while loosening cam sprocket bolts)
- large 1/2" drive breaker bar (no ratchet; Craftsman makes a good one)
- special "C" offset allen key for head bolts
- low-range and mid/high-range torque wrenches

I didn't have ANY issues with stripped head bolts or any other bolts, save a very minor bolt above the timing chain housing on the front edge of the head, but that was my fault because I torqued it much too hard.

Take the opportunity to replace EVERYTHING soft under the hood -- all hoses, vacuum lines, rubber items, vacuum connectors, motor mounts, fuel lines (inspect carefully), fuel injector seals & holders, idle air distribution hoses, and plastic electrical connector ends (they get brittle). Also replace your thermo-vacuum sensors that screw into the intake manifold. Replace your large rubber air boot that attaches to the top of the throttle body. Replace your 8 rubber donut rings that mate the two halves of the intake manifold. Replace all gaskets. Replace all plastic chain rails, including tensioner rail and chain tensioner. Replace all gaskets - cold start valve gasket, tensioner gasket, intake manifold gaskets, exhaust manifold gaskets, transverse pipe copper gaskets, etc. Replace the copper nuts that attach the lower side of the exhaust manifolds to the studs.

There are a couple of excellent how-tos posted at:

Cylinder Head Removal and Replacement

http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1525150-1989-560sec-top-end-rebuild.html

Good luck.

Cheers,
Gerry
 

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Discussion Starter #7
Thanks Gerry, very helpful. The thing is that most of what you say has been done already. Here is the story: I got that engine out of a 450 SLC 5.0 which was completely rusted out. Before taking the engine out I drove the car and I noted the engine was working well, no smoke and balanced compressions even if not on top of the range. I stripped the engine to a long block but decided not to take it apart as it was working well and I was scared of stripping the threads in the block. I rebuilt the timing and put new crank seals in front and in the back as well as new oil pan gasket. I then mated it to a modified 5 speed manual transmission and adapted a 4.5 D-jet intake manifold as it was originally designed for EFI hence more adapted to my Megasquirt conversion. TB and port diameters are the same as the early 5.0. I also adapted EDIS ignition.

The whole thing was ready to be started to see if everything worked OK before putting it in my '62 W111 Coupe when 48hp came with these AMG spec camshafts. I bought them and johnhef very kindly availed some 560 heads to me so that I can replicate the AMG set-up. I also have secured 11 NOS rocker arms, still looking for 5. Also got a bunch of mechanical lifters, need to find some more.

My next challenge is to increase the compression ratio from 8.8:1 to 9.5:1 or 10:1 (see my other thread). The correct way to go is to change the pistons. Ideally I should buy some new 10:1 CR pistons repair size 97mm as this is the bore of my early M117.960. Unfortunately they are very specific and I'm not sure where I can source some good used ones or NOS. MB sells them $286 each. That's $2300 which is a bit steep especially if I can reach the same result by shaving the heads. I have to take the heads out and study the shape of the pistons top. If the squish area is the same and the center of the piston deeper compared to higher CR pistons, then shaving the heads will work. If the squish area is lower I would have to shave the block, which I'm not very comfortable with. I called these guys in Belgium that race a 500SLCs and they told me they were shaving the heads, though they remained evasive (not really wanting to share precise info!)

Thanks to all, and especially to 48hp making this AMG engine replica possible.
 

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83 500SEC, 84 300TD, 86 190E 5.0 M113, 87 300D, 01 CLK55, 02 C32, 02 C320T, 03 C320T4, 03 E55
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Tribute 500SEC AMG Widebody
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u r velkome sir. look forward to more of your progress! oh, and a lil photography never hurt nobody. ;)
 

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Discussion Starter #10
Thanks. I will post pictures along the way. It may take a bit of time because the car is crying for atention on some other issues but eventually I will get there.

The pistons I'm looking for are the 10:1 compression ratio found in the 5.0L M117.965 engine. I need them repair size 97mm. Part number is 117 030 61 18 or 117 030 65 18. I've been looking on various EBays in Europe with no luck so far. I will contact Marc Van de Velde to see if he has ome. In the meantime, if you stumble on a set somewhere, please let me know.

Thanks in advance
 

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68 250S, 91 300se, 98 SL500, 450SEL 6.9, 14 CLS550 Past MB's; 300SD, 300E, 300TE, 190E, ML420
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A piston manufacturer will be able to make you new pistons.

http://www.wahlspezialkolben.de
They quoted me one complete piston inlcuding pin, rings and clips = crica 265,- Euro

They can make them to whatever spec you want.
 

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68 250S, 91 300se, 98 SL500, 450SEL 6.9, 14 CLS550 Past MB's; 300SD, 300E, 300TE, 190E, ML420
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my bad. I was reading another post and BW had recommended reading below it. I assumed it was a current article and didnt notice.

WTF would BW promote 10 year old posts?

Looking below this as I type they are recommended reading of 2018, 2015, 2011 and other old posts.
 

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'84 Euro 500SE, '85 Euro 2.3-16, '51 Euro 170S, '97 Jeep Wrangler Sport, '15 G63 AMG
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The same reason as to why the forum itself seems to be down several times a day; VS.
 

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my bad. I was reading another post and BW had recommended reading below it. I assumed it was a current article and didnt notice.

WTF would BW promote 10 year old posts?

Looking below this as I type they are recommended reading of 2018, 2015, 2011 and other old posts.
It's not always a bad thing to add info to an old thread. I did wonder though.

Anyway you've added info to a thread future users may look up to refer to, so it's of benefit.

The recommended reading thing is a bit odd. They changed it a while ago and to my mind it got odder. Perhaps it's learning as it goes..
 
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