Warped Cylinder Head?

[tech71]

4 minutes ago, James Laray said:

 I can only guess that the market and the need for mechanics that specialize on the older cars is slowly fading away. 

My local machine shop consisting of (one old timer and 2 young timers) had never worked on an M10 engine but had worked on other 4 cylinder engines.

It took a bit of time, patience, polite persistence and willingness to provide printed overhaul data from factory manual but they are pretty much up to speed now. I trust them, good thing because the local go to M10 machinist is backlogged for months and not getting any younger.

I got lucky I guess that they were willing to deal with me, dropped my 4th cylinder head off yesterday

[jgerock]

23 minutes ago, James Laray said:

Following recommendations from the local BMW guys in the know @jgerock and Marshal Lytle I called Grant at Alexandria Bavarian Service located in Delray (Alexandria) which is maybe 15 - 20 miles from where I live.   I chose him because he has been wrenching on BMWs since 1977 (and the Google results shows his shop with 2002s and other vintage bimmers out front).   

 

Grant is hard to get on the phone and when you do get him he has this dry sense of humor.   He sounds like the mechanics I remember from 40 years.  We had a good conversation about how machine shops are becoming increasingly harder and harder to find.   

 

 

He sends his head work down to Memphis Motor Works in Tennessee via UPS.  

 

I was somewhat floored.   He said "if you really want to do it right, they know what they are doing with these BMW cylinder heads". 

 

So... this project is progressing from "I will just pulled the head and slap on a new head gasket" to contemplating sending the head long distance for possibly $1,000 cost (which I am willing to do).      

 

I will also call the local J & F Motors in Arlington that  Jim  also recommends.  Maybe I can keep this local. 

 

Upon reflection this type of cylinder head by BMW more or less ended by the early 90s (with the introduction of the M42 engine in the e30).   I can only guess that the market and the need for mechanics that specialize on the older cars is slowly fading away. 

   

 

 

Here is my tii cylinder head and upper cover after J&F decked it back about 2008.  I recall Grice took something to the same place a few years ago and they couldn’t get to it. Guy named Pete did the work on my parts. I saw him vacuum test the valves. Think he either retired or passed away.  Note the replaced lower exhaust manifold studs (old ones required removal for decking). This head is now at the minimum thickness.

Edited January 25, 2023 by jgerock

[James Laray]

@jgerock I just got off the phone with J & F.  They stopped doing machine work 6 years ago.    My options are like what @tech71 is working with.  Quality shops that can do cylinder heads, but don't specialize in BMW.    They range from 50 - 100 miles away for me.   Lots of driving back and forth for a "maybe" (unless you sit down with them with the BMW blue workshop manual).  So option "B" is  900 mile trip via FedEx to Memphis for best recommendation.    

Edited January 25, 2023 by James Laray

[James Laray]

Just talked to Mike with Memphis Motor Werks.  I explained that when I pulled the valve cover off, there was a swirl of green in the oil.  He said he thinks that's a crack in the cam bearing race (otherwise the coolant would have dissapated).   I get it.  If so, total loss.  

 

I plan on sending him the head, have him break it down and inspect it.   Might have find another 121ti head.   Although he said an e12 head could work.  Flat pistons, I can't see why not.  

 

[Schnellvintage]

I would try to find a 121 head.  The E12 head will give you a lower compression ratio, due to the bigger combustion chamber.  

 

fwiw,

Matt

[bergie33]

2 hours ago, James Laray said:

I plan on sending him the head, have him break it down and inspect it.   

 

Just remember, Pirate Ship (www.pirateship.com) is your best friend.  It will save you a ton of money over going into a FedEx Office or UPS Store and paying them.  Shipping a head can be expensive.

[James Laray]

@bergie33  You are the second person to mention Pirate.  Do they come and pick up you package at the house?   Where is the best place to get a box?  Will a card board box hold the head?  Should I extract the threaded studs for the intake, valve cover and exhaust?  

 

@Schnellvintage yes, I want a 121 (121ti) head because of the 9:1 compression ratio versus the e12 with its 8.5:1.  That will be the next trick if it comes to that.  I know they are out there.    

Edited January 26, 2023 by James Laray

[bergie33]

3 minutes ago, James Laray said:

@bergie33 You are the second person to mention Pirate.  Do they come and pick up you package at the house?   Where is the best place to get a box?  Will a card board box hold the head?  Should I extract the threaded studs for the intake, valve cover and exhaust?  

They are just a mirror man for USPS, UPS, etc. You print the label, put it on the box and drop it off at the carrier. 

[tech71]

1 hour ago, James Laray said:

I want a 121 (121ti) head because of the 9:1 compression ratio versus the e12 with its 8.5:1. 

Actually,  you would need 1.5mm bathtub pistons to have 9.1:1 compression.

With your flat tops and 121 head compression is 8.5:1

 

[TobyB]

I had a head corrode away into the head bolt casting once.

 

A steel sleeve, and off I went again.

 

The M10 head's not prone to cracking on top, but when they do,

it's usually on the flat surfaces, parallel to the piston top.  The cam bearing castings

are the thickest part by far.

 

t

 

[James Laray]

 

@tech71  8.5:1 oops, that's right.  I was thinking about the M10 ti engine I had in my 2000cs with the 121 head and the bathtubs. 

 

So... if I went with an e12 head with the bigger chambers from the newer model 2002s but with the current flat tops on the older motor versus the piano tops intended for the head, how does that affect the compression?   A little less I assume. 

   

[bergie33]

5 hours ago, James Laray said:

@bergie33  You are the second person to mention Pirate.  Do they come and pick up you package at the house?   Where is the best place to get a box?  Will a card board box hold the head?  Should I extract the threaded studs for the intake, valve cover and exhaust?  

 

To expand a little (and correct my previous post), Pirate Ship is a middle man.  USPS is cheaper for large, light weight items, and UPS is cheaper for heavy items. When you get to the weight of a 4 cyl head, USPS is going to be 2x to 4x the price of UPS.  You can get boxes at Home Depot and Lowes. Get 2 heavy duty boxes of appropriate size to double box the head.  Suggest to your wife that she buy a couple new, pretty, matching bath towels, so you can take a couple old ones from her. You can tape a piece of cardboard on the top and bottom of the head for good measure.  Wrap up the head really well in 2 or 3 good size bath towels and then run packing tape around it a couple times so the towels stay put. If you can get the studs off, it will make things easier (especially the water neck long stud). Double up the boxes, place the head inside. Don't be afraid of slicing down the corners of the boxes a little so you can fold the box flaps down right against the head so it doesn't shift around a lot in the box.  Add lots of tightly crumpled newspaper to take up any extra space around it. Tape it up really well, weigh and measure it and go to www.pirateship.com and print your label. 

 

[larry_in_socal]

On 1/25/2023 at 2:50 PM, bergie33 said:

 

Just remember, Pirate Ship (www.pirateship.com) is your best friend.  It will save you a ton of money over going into a FedEx Office or UPS Store and paying them.  Shipping a head can be expensive.

Don't forget to declare value on the head....declared value both ways, to and from, make sure that on both to and from journeys that it is packaged extremely well, metal tends to eat itself out of a cardboard box... I can go on and on.. ask me how I know.. let's just say I have been in the industry for over 30 years.

[James Laray]

Update.  

 

I cleaned the head bolt holes out to remove any oil.  I also scrapped off bits of the old head gasket on the block.   I remember cleaning the bolt holes 40 years ago using a long screw driver with paper towels.  Seemed easy back then, but more daunting now in that I got paper towel at one point trapped in the bolt holes and had to configure a hook to pull it out.  I will run the bolts down in each hole to verify ease of re-application. 

 

Should I sand the block surface smooth?  Concerned about any cast off going where I don't want it. 

 

I did remove the water drain plug on the block.  There is a solid mass in the hole.  No water coming out.   I "prodded" the mass with a prope and it is pretty soild.  Noted this on other posts regarding attempting to drain the block.      Not sure what to with this.   Should I put the head back on so I can rotate the engine at the crank when attempting to drain IF I can break this mass free?   

 

Good news.  I found a trusted mechanic not too far away, Bruce Shelton (Automotive Enterprises) in Winchester (thanks Marshall for referring me).  No need to ship to Memphis, TN (from VA).  Bruce has decades of experience building M10 race engines.   He races 2002s.   A genuine guy with a couple of cool NK 1800 and 2000 sedans in his storage building.  An old "salt" and great story teller.  He has a trusted machine shop he sends stuff to.  I dropped the head off with the upper timing chain cover with him last weekend.   He's is going to break it all down and have the machine shop pressure test and see if the head is cracked or warped. 

 

I went through the receipt my dad had on the car.  He had the head rebuilt (everything) in 1991 at Eagle Imports in Auburn, AL (not too bad a shop)  at 185,000 miles.  Between he and I we've only put about 12,000 miles on the car.  Hoping valves, rockers, shafts, guides, etc. are good.   I think the car has the original cam.     

 

[eviction_party]

56 minutes ago, James Laray said:

I did remove the water drain plug on the block.  There is a solid mass in the hole.  No water coming out.   I "prodded" the mass with a prope and it is pretty soild.  Noted this on other posts regarding attempting to drain the block.      Not sure what to with this.   Should I put the head back on so I can rotate the engine at the crank when attempting to drain IF I can break this mass free?   

 

I had a large amount of gunk in that hole too -- keep trying and you should be able to free something. I think I ended up using a brass punch and tapping it with a mallet until it poked through. This was on a car that had been sitting outside for 30 years. 

 

Why would you like to rotate the engine to drain the block? Not sure I see the reason to. But, if you do rotate the crank, there's really nothing to be afraid of. Just make sure piston 1 and the cam are both at TDC before you reinstall the head. There's a procedure to follow, and you'll be double-checking the timing, too.