Leaking head gasket, engine rebuild

[wwheeler]

I know on my W128 220SE water pump, without any gasket it will rub. The "paper thin" gasket is well... paper thin. Paper is typically about .003" thick. Yep, not much. The green type gasket could be 1mm or about .039". Just a guess but matches what I have seen. Even if the thin gasket was .010", that is still quite a bit of difference.   

[dirkbalter]

Wallace,
you got me worried now. The "left over" one in my picture measures 0.55mm. 0.022in. Not sure how thick the one I installed was.   

[wwheeler]

As long as it spins, it should be fine. Not going to change over time once it is torqued. I am not an expert with exactly what thickness gasket is required for the water pump. I just know from my experience that with no gasket on the 220SE, it rubbed. There is a balance between being too tight and too much clearance. Too tight and it rubs which is very bad. If there is too much clearance, then the pump is not as efficient. I suppose you would want to err on having more clearance.     

[Charles 230SL]

I'm disassembling the water pump assembly in preparation for media blasting and I've found a couple of things the Group might find interesting. Those who've replaced the water pump breather pipe may recall that the pipe has a 12mm banjo bolt on each end. I noticed one of the banjo bolts on mine is 17mm (vice 12mm) and a closer look showed that the banjo bolt was home-made by a previous owner (see pic). I couldn't understand why someone would go through all the trouble to manufacture a banjo bolt, until it occurred to me that they must have stripped the threads where the banjo bolt screws into the head. Rather than heli-coil the head, they made an over-sized banjo bolt. Metric Motors currently has my longblock so I have no idea what shape the (cut) threads are in the head. When I removed the breather pipe I just assumed 17mm was the correct size and didn't bother to take a close look at the threads. I ordered a new breather pipe from Auth Classics since the previous owner drilled out the pipe fitting to accommodate the larger bolt.

Several members of this Group have removed the water pump housing so they're familiar with the washer described in this post: https://www.sl113.org/forums/index.php?topic=30823.msg223685#msg223685. Instead of the correct washer (#184 in the image) I found a rubber washer between the water pump housing and the block. It's amazing the things you find on a 58yr-old car..

[Charles 230SL]

Looks like Elring is the manufacturer of the water pump gasket used by Mercedes: https://www.authenticclassics.com/Water-Pump-for-230SL-others-MB-part-p/auth-008451.htm

[Charles 230SL]

I got a report on my longblock from Metric Motors yesterday and its worse than I thought (I guess it always is )
Looks like I'll need a new crankshaft and head. Appears the head was at some time in the past cut down below 84 mm and is now at 82.90 mm. Since Metric doesn't have a viable core on hand, I'll be getting a brand new OE head. The crankshaft has several issues including the common rear seal corrosion. I didn't realize the block had also in the past been bored to 82.5, and it now needed to be bored to 83 mm to clean up damage from some broken piston ring lands.

I'm glad Metric has the engine - the damage (above) is probably pretty routine for those guys. I know a number of members of this Group have had their 230/250 blocks bored +1.00 mm over.

[dirkbalter]

Charles,
You are going to have a 235sl now.
 

[Charles 230SL]

While the engine's out of my car I've been tidying up various peripherals (exhaust/intake manifolds, oil/fuel filter assemblies, water pump/pump housing, distributor, FIP, etc.).

I've got an early R11 fuel injection pump and while cleaning it up I noticed some inscriptions on the governor section (photos attached).

I can't make any sense of the inscriptions but as best I can tell, there appears to be a date inscribed (possibly 12/2/74). I'm wondering if the FIP may have been rebuilt and reassembled on Dec 2nd 1974.

Anyone with a rebuilt FIP recognize these markings or have any idea what they represent? I realize it's a longshot,, just thought I'd ask. 

[Benz Dr.]

I had a coolant loss problem on my car which turned out to be one of the engine side covers below the manifolds. We fixed that and then it started loosing coolant again a few months later. Turns out the oil cooler was leaking, but after 50+ years of use that should be expected. All of these leaks were found with a rad pressure tester which is invaluable for finding coolant leaks.

[Charles 230SL]

I got my longblock back from Metric Motors and I'm in the process of reassembling everything..
Metric installed a brand new OE head on my block and I just found out that the water pump housing won't fit the new head. The new head doesn't provide enough clearance to allow the water pump housing to fit flush against the block. I took a look at the old (junk) head and saw where it had been filed to permit the water pump housing to fit correctly. I decided to file the housing rather than the new head but soon realized I'll need to file the head as well. I find it hard to believe that a brand new Mercedes head won't accommodate the water pump housing. Has anyone ever encountered this?

[Charles 230SL]

The casting number on the new head is 127 016 1801 and the part number on the water pump housing is 121 201 0601.
At first I thought a previous owner might have installed the wrong water pump housing, but 121 201 0601 is indeed the correct pump housing for an M127 engine.

[austinado16]

. 

[Charles 230SL]

..seeing that the area of contact on the water pump, is just a flange with a bolt hole..

thanks Todd, but the area of contact is where the water pump breather pipe attaches (see photo).  I ended up filing both the water pump housing and the head. The additional clearance provided by the gasket and the washer (#178 and #184 in the image below) should now permit the pump housing to fit correctly.   
thanks,,charles

[Charles 230SL]

I completed installation of the engine ancillaries - the new engine started effortlessly and it runs smooth and quiet. I got it up to operating temperature then shut it off and re-torqued the head. All that remains is to recharge the AC and install the hood..

[Charles 230SL]

So far I've logged 570 miles on the new engine and it runs beautifully. Yesterday I re-torqued the head, adjusted the valves, and changed the oil; all uneventful. I noticed all (12) valves were too tight but I guess that's normal considering new valve seats, springs, rockers, etc. I adjusted the intake and exhaust valves to .003 and .008, respectively.
The distributer housing gasket has a slight oil leak/seepage and its frustrating seeing oil on a freshly rebuilt engine. I ordered a new distributer housing gasket from MBUSA but it'll be the weekend before it arrives - for those who've replaced this gasket in the past, did you use gasket sealant on one side or both sides? I didn't use sealant the first time but I certainly will this time. I've got that notorious AC plate to contend with, so I don't want to have to do this job again.

[Charles 230SL]

haven't posted in a while so thought I'd provide an update..I've logged a little over 5000 miles on the new engine and it runs like a top! I can't say enough about the quality work done by Metric Motors. I drive the car several times during the week and to my folk’s house every weekend. I always enjoy driving through Warm Springs, GA (see pic)

With the old engine (before rebuild) I'd grown accustomed to cleaning up oil on the garage floor from leaking front & rear crankshaft seals - the new engine doesn’t leak a drop anywhere!

[ja17]

Looks very good also. I noticed you upgraded to the rotary AC compressor with the single belt also.

[Cees Klumper]

All's well that ends well, you went through a lot but now you're definitely getting your money's worth. 5,000 miles since October is more than most of us put on our Pagoda's in 5 years!

[Charles 230SL]

 

All's well that ends well, you went through a lot but now you're definitely getting your money's worth. 5,000 miles since October is more than most of us put on our Pagoda's in 5 years!

Thanks guys, it’s become almost a daily driver for me.. Spring came early this year so I took the hardtop off a few weeks ago.

[Charles 230SL]

hello all, I haven’t posted in a while so I thought I’d bore a few folks..
I now have 12,679 miles on the new engine and it runs perfect. I drive the car every weekend and several times during the week. 
As many of you know, the Valve Adjustment Tour has an excellent section on re-torquing the head (part of the 12,000-mile Plan “E” maintenance schedule for Type 190) and I’ve referred to this section several times over the years I’ve owned the car.  I had planned to re-torque the new head at the 12,000-mile mark but after an email exchange with Mike Elias, I decided to forego the re-torque and only adjust the valves.
Per Mike, “You do not need to re-torque the cylinder head at 12K miles. As long as it has been done twice already (at warm up and again at 500 miles) you’re good to go. However, it’s a good time to do the valve adjustment. Be sure to keep the oil fresh; change it every 2500 – 3000 miles … Castrol GTX Conventional Oil 15w-40 or 20w-50.” I asked Mike if there’s an interval he’d recommend to re-torque the head (i.e., every 15K, 20K, 30K.. etc. miles)? Response: “We can’t find any reference in our books for re-torquing the head gasket beyond the initial warm up and first service for the 113 chassis type - Not needed unless the engine got hot or sat for a long period or there is some symptom related. Valve adjustment every 12K miles (15K KM) is published in the tech data.”
I realize there are differing opinions on this but based on dialog with Mike, and since I re-torqued the head after the initial warm-up and again at 570 miles, I decided to pass on re-torquing the head bolts and just check/adjust the valve clearances.

[Vander]

Mike Elias does an amazing job building Mercedes engines, however when it comes to re-torqueing cylinder heads on our cars the tech manual does a great job not only mentioning the procedure, but citing the sources from the factory as well as including the thought process and interpretation of said material.


I will continue having Metric Motors build my complete engines when needed. But I will also continue to re-torque all of my cylinder heads hot, and adjust my valves cold upon purchase and every 12k miles thereafter.

[ja17]

More modern Mercedes engines use "stretch style head bolts". Modern engines do not require re-torquing the head since the stretched bolts continue "pulling down".  Stretch bolts will maintain the torque, even if the head gasket shrinks or compresses over time. The engines in all the pagodas do not use stretch bolts. If the head gaskets shrink, or compress over time (usually the case), the torque will decrease. In my experience over the last sixty years, it seems that the pagoda engines with the least amount of head gasket problems have had their heads re-torqued along the way. Modern head gasket design and materials have improved over the original head gaskets. Try not to use New Old Stock head gaskets so you get the advantage of improvements made with newer production.