Author Topic: Head Removal. To proceed or not to proceed  (Read 37356 times)

Jonny B

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Re: Head Removal. To proceed or not to proceed
« Reply #75 on: March 11, 2016, 15:53:14 »
Very nice indeed. What is the red around the four cam bearings?
Jonny B
1967 250 SL Auto, DB 568
1970 280 SL Auto, DB 904
1966 Morris Mini Minor

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #76 on: March 11, 2016, 17:38:38 »
Jonny, Assembly Lube. It goes on all contact surfaces. Unlike oil it stays put until you run the engine. Don't want a dry start.
Tyler
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
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Benz Dr.

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Re: Head Removal. To proceed or not to proceed
« Reply #77 on: March 11, 2016, 18:35:13 »
I spin the engine over with the starter, spark plugs removed, until I get full oil pressure. Almost no load on any moving parts. I tried using an electric drill once and it almost broke my arm when I hit oil pressure. :o I figure the starter is a bit safer.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #78 on: March 11, 2016, 18:58:32 »
Dan, Going to do that as well. With the valve cover off until I get flow to the cam oiler tube. Going to break in the cam @2500 RPM once it starts so I want that little bit extra insurance.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

rgafitanu@gmail.com

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Re: Head Removal. To proceed or not to proceed
« Reply #79 on: March 11, 2016, 19:20:48 »
Tyler,
I have a question, maybe I am getting this wrong (BTW the post is great I wish you to enjoy it once finished). You (they) took 0.003 from top and 0.003 from the bottom of your head. While skimming from the top drops the position of the camshaft wrt everything else (since the bearings are on the skimmed surface), skimming from the bottom reduces (only) the volume of the combustion chamber. In my mind, in order to correct the camshaft positioning I would shim it only for the top skim 0.003. If you are shimming the camshaft for the total 0.006 aren't you overcompensating, possibly affecting the valve kinematics? Or maybe I am missing something.

Radu

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #80 on: March 11, 2016, 21:22:14 »
Radu, Yes and No. Keep in mind my valve seats were ground so the valve stem height is actually a slight bit higher than before.
You want to shim the cam towers to bring the cam back to the height before the repair (measured from the block) so the total shim thickness would be as close to what was milled (top and bottom) as possible. This allows the timing chain to ride in its original path and keep the valves in time. If you were to leave out the shims or cut the measurment in half, The cam timing would be retarded as well as the possibility of the tensioner maxing out. As far as valve/rocker geometry, this will be made up with the correct thickness thrust washer pieces that sit on top of the valve stems. This determination is made last after the cam, rockers, and ball studs are installed. Hope that makes sense.
Tyler
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

Pinder

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Re: Head Removal. To proceed or not to proceed
« Reply #81 on: March 12, 2016, 15:27:41 »
I used the same assembly lube. It worked out great. I also cranked the engine until there was oil visible at top. Spark plugs removed when that was done. Looks like your making great progress.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.
1997 Corvette C5 Silver. automatic
2015 BMW 320i xdrive
2021 Mercedes GLS450 Silver

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #82 on: March 12, 2016, 15:41:55 »
Pinder, Getting there. Im taking my time and detailing components as they go back on the engine. Cleanup, paint, and aluminum cleaning takes way longer than the actual repair.  ::)
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

Pinder

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Re: Head Removal. To proceed or not to proceed
« Reply #83 on: March 14, 2016, 16:22:58 »
Yes takes time but worth the effort. especially if you cleanup the manifolds and valve cover plus the intake throttle body. I also cleaned up my wiring harness. I found lacquer thinner works pretty good to get the gunk off on the wire harness.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.
1997 Corvette C5 Silver. automatic
2015 BMW 320i xdrive
2021 Mercedes GLS450 Silver

erickmarciano

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Re: Head Removal. To proceed or not to proceed
« Reply #84 on: March 15, 2016, 02:21:53 »
just removed the head and a few exh valves have a whitish crust on them
What can this be?
Thanks
« Last Edit: March 15, 2016, 03:19:52 by erickmarciano »
1994 E500 W124
1971 280sl
1989 Porsche 930 coupe
1988 e30 m3
2001 ducati mh900
2006 ps1000
1962 Vespa GS160

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #85 on: March 15, 2016, 03:42:47 »
Erick, Mine looked almost identical. Its ash. Most likely from burning oil.
My valve guides and seals were the culpret.
Check out the photos of them on page 1 of this post
« Last Edit: March 15, 2016, 03:58:03 by Tyler S. »
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

erickmarciano

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Re: Head Removal. To proceed or not to proceed
« Reply #86 on: March 15, 2016, 13:23:42 »
Got some ban news
Car ran amazing till I got bored and decided to remove the head for a little oil burning
The head has never been cut but one of the combustion chambers has been re welded . Does this look critical?
Would you reuse it or use an alternate head that measures 84.6?
Thanks
1994 E500 W124
1971 280sl
1989 Porsche 930 coupe
1988 e30 m3
2001 ducati mh900
2006 ps1000
1962 Vespa GS160

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #87 on: March 15, 2016, 14:39:44 »
Have the machine shop pressure test the head and then make a determination. If it was welded properly I dont think its anything to worry about. It must have burned a seat sometime in its life if it has never been decked.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

erickmarciano

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Re: Head Removal. To proceed or not to proceed
« Reply #88 on: March 15, 2016, 14:42:01 »
Great.  It has never been welded showed a local Mercedes wiz
He said the same thing burnt seat
What would cause that whole area to be eaten up?
Thanks
« Last Edit: March 15, 2016, 18:06:01 by erickmarciano »
1994 E500 W124
1971 280sl
1989 Porsche 930 coupe
1988 e30 m3
2001 ducati mh900
2006 ps1000
1962 Vespa GS160

Benz Dr.

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Re: Head Removal. To proceed or not to proceed
« Reply #89 on: March 16, 2016, 02:12:12 »
We weld up heads quite often. The water ports in the head will often corrode away and will need to be replaced. Sometimes the head will have corrosion around these water inserts so that would need to be welded. If the head is straight a very minimal cut would be needed to clean everything up.

 I'm thinking a coolant leak in the head gasket caused it to corrode the chamber and maybe enough for the valve seat to come loose. We have had to weld the seat recess back in, machine a new area to accept the seat, and then install a new seat. After the seat is installed it would need to be cut to fit the valve. Only someone skilled with the proper machines can do this sort of work. Maybe not rocket science but not easy to do either.   
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

erickmarciano

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Re: Head Removal. To proceed or not to proceed
« Reply #90 on: March 16, 2016, 03:39:43 »
Thanks for the reply
The piston is pitted for that cylinder
Car ran great. Compression was 150 except the one with a lose guide at 130
Should I leave it like that?
Thanks
1994 E500 W124
1971 280sl
1989 Porsche 930 coupe
1988 e30 m3
2001 ducati mh900
2006 ps1000
1962 Vespa GS160

ja17

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Re: Head Removal. To proceed or not to proceed
« Reply #91 on: March 16, 2016, 04:27:01 »
Erick,

The stock thickness is 85mm. 
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #92 on: March 16, 2016, 06:41:56 »
That was either caused by a lean burn or detonation. Probably a result of the burned exhaust seat. Double check your injectors after the repair. That single cylinder could have been running lean do to a bad injector.
I have seen engines put back together and ran with that kind of pitting. Its a gamble. Personally, I wouldn't run it like that. If it goes and you ruin the block then you will be out of pocket way more then you will be fixing it now.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

Benz Dr.

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Re: Head Removal. To proceed or not to proceed
« Reply #93 on: March 16, 2016, 18:40:18 »
That's a 280 block - are you putting it in your car? That piston isn't in great shape.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Pinder

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Re: Head Removal. To proceed or not to proceed
« Reply #94 on: March 17, 2016, 12:12:48 »
If the engine is already out of the car it wont take too much more work to put new pistons in. second repair pistons are relatively cheap on the internet for around $650.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.
1997 Corvette C5 Silver. automatic
2015 BMW 320i xdrive
2021 Mercedes GLS450 Silver

Tyler S

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Re: Head Removal. To proceed or not to proceed
« Reply #95 on: March 18, 2016, 00:33:40 »
Lots of progress. Installed the new ball studs, rocker arms, rocker clips, and 3.5 mm thrust spacer shims. The valve geometry is almost perfect. The ball studs are exactly at the middle of their travel and the rockers are uniform and parallel. I can't believe how much tighter everything is with new parts! The old spring clips could almost be removed with your thumb nail.
What a joy it was setting up the valve clearances for the first time after assembly. My knees are killing me.  :'(
So as it stands I am now back to where I started with the original project of replacing the manifold gasket.
Still lots to do but I see an end soon. Replaced the starter with the higher cranking amp one since it was easily accessable with the manifolds removed. Also replaced the battery cables.
New water pump, oil pan, oil pump pickup screen and gasket, side cover plate, every single seal and gasket with the exception of the rear main.
Cleaning up and painting all the ancillaries and brackets before they go back on the car.
A few days before contact I hope. The pile of "Star" wrappers is getting excessive :o
Happy Saint Patty's Day! 
Tyler
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

Pinder

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Re: Head Removal. To proceed or not to proceed
« Reply #96 on: March 18, 2016, 00:46:12 »
Looks Fantastic Tyler! I admire your attention to detail.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.
1997 Corvette C5 Silver. automatic
2015 BMW 320i xdrive
2021 Mercedes GLS450 Silver

ja17

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Re: Head Removal. To proceed or not to proceed
« Reply #97 on: March 18, 2016, 05:05:28 »
Eric,

Water in the combustion chamber can also cause the pitting in the piston top. I have never seen the pitting cause any problems.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Benz Dr.

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Re: Head Removal. To proceed or not to proceed
« Reply #98 on: March 18, 2016, 17:01:34 »
It will eventually fill up with carbon and look like the rest on the piston tops.

 I would polish off any sharp edges to avoid any places where you could get a glowing piece of carbon sticking out from the top of the piston. Not much of a problem with our cars but it is a big problem in 190SL's that tend to run on after shut down from this exact situation.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

erickmarciano

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Re: Head Removal. To proceed or not to proceed
« Reply #99 on: March 19, 2016, 02:38:21 »
Thanks for the encouragement
1994 E500 W124
1971 280sl
1989 Porsche 930 coupe
1988 e30 m3
2001 ducati mh900
2006 ps1000
1962 Vespa GS160