Warped Cylinder Head?

[larry_in_socal]

2 hours ago, James Laray said:

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.     

 

 

Just my two cents, when I was rebuilding a toyota tercel engine for my niece, I used a generic head gasket, and it ended up leaking, so I talked to my local import parts store owner, she asked me if I sanded the block. I thought that she was referring to using the black wet/dry sand paper for metal, she said no, get yourself the coarsest brown sand paper for wood. She did say that it is an old mechanics trick to place microscopic hash marks on the block so that the head gasket has something to grip to. I took her word, took a 8"x3.5" drywall flat-hand-sander, with 100 or 150 grit brown-wood- sandpaper, ran it across the head a few times, put on a genuine toyota head gasket, torqued it all down, and that engine worked flawless for several years before the car was sold due to a front end crash. 

[James Laray]

Update:  Bruce Shelton (long time 2002 race engine builder in Charles Town, WV) broke down the head and had his machinist clean it up, pressure test, and check for any warping and/or cracks.   Not warped and no cracks!  

 

The machinist did replace the brass valve guides.  The valves, shafts, rockers, springs and cam are in good shape (low mileage after previous documented rebuild at Eagle Imports in Auburn, Al).   The cam is original. Lobes look good.  Bruce installed the correct larger coolant neck on the back, spring shims, replaced a cracked rocker shaft cupped washer, a few rounded rocker adjustment nuts, and dizzy housing gasket.  He also noticed that Eagle Imports did not put a rubber washer seal on the bolt along with the flat washer for the dizzy housing.  So he did.    

 

Long story short, my woes were due to a "hardened" aftermarket head gasket installed in 1991 by Eagle Imports in Auburn.   Entropy.  

 

Now, to put it back on.  I cleaned out the bolt holes of oil.  The cam is at TDC.  I did lasso and suspend the sprocket with timing chain. 

 

As I said before, it's been 40 years since I did this (on my "hoopty" 70 2002 1669139 - why do always remember the VINs of our first love?).  I was so full of piss and vinegar back then.  Help me remember. 

 

I hate this part.  Will those sprocket bolts holes line up so I have slack tension on the tensioner side of the chain?  It is a TDC based on the hash mark aligned with the oil distribution tube. 

 

Question 1:  how much should I sand the block surface?  There is some residual old gasket crud.  I will stuff paper towels in the 2 and 3 cylinders to keep crud from falling in there.  

 

Question 2:  I know the head gasket goes on dry, but the upper timing chain cover requires gasket seal on the vertical gaskets.  This I remember.  Should I apply a thin sheen of gasket seal on the vertical head gasket area at the upper timing chain cover (in that the torque and weight is not the same)?

 

Question 3:  Do I need to torque the 4 little (10 mm) bolts for the sprocket? Can I just tighten til it feels tight? It does have the flat straps that bend over to limit the bolts from drifting.  (Why not check the Haynes manual you say -- yes, OK). 

 

A bit of reflection on this process. 

 

 I dropped the head off with Bruce in early February after careful research on finding a skilled vintage bimmer mechanic.  He has a couple of NK 1800s in his shop (one was his father's who raced it).  Both Florida green (with rust).  Very cool.  He is recovering from rotator cuff surgery and  ain't "no spring chicken".  His go-to-guy machinist wound up dealing with old guy heart issues and couldn't get to the work for a couple of months.   He profusely apologized.   I will say I was worried the machinist's doctor will sideline him. 

 

How the @#$% did Paul Wegweiser do this by flashlight in the Hawthorn hotel parking lot at the Vintage 11 year ago!   Stuff of legends. 

 

Owning vintage cars is an act of faith these days for me.  I (think) I can do everything on a 2002 except for the head, transmission, and differential.   I have in the past. 

 

This 2002 (1666179) is 54 years old.  I will be turning 60 in August.  My back challenges me these days.  My favorite mechanics and machinists are around 70 plus. The other mechanics I trust in this area always sound as if they might not be around very much longer  We are all getting old.  Entropy. 

 

Fight the good fight.     

 

  

   

 

Edited April 30, 2023 by James Laray

[Son of Marty]

Here's my way of remounting a head.

#1 lower the pistons to 1/2 way down, or up, depending on how you look at it, then I build a greese barrier around the piston to cylinder edge to prevent s#it from getting into the gap you'll also need to plug the oil outlett to the head, next don't use sandpaper to clean the deck use the course scotch bright pad wrapped around a 2x4 using long strokes until the deck is spotless no spot cleaning alowed. Then wipe the greese out of the bores.

 

#2 You'll see two small holes in the head gasket where the timing covers meet the head these need just a small dab of RTV in those holes other than that the gasket needs to be dry.

 

#3 Unless you have a torque wrench that reads inch pounds I would just tighten down those bolts well by hand and use the lock plates.

Edited May 1, 2023 by Son of Marty

[TobyB]

For #1, my variation is to use a solid scraper- not a paint scraper, but a machinist's scraper

for levelling machine tools.  Used lightly, it doesn't remove metal, just anything that stands above the surface.

Including corrosion.

 

I miss 1666365- 

it was a total beater that Mike up north took for the parts, and 

at the time, it was absolutely the right thing to do- the car was filling

up with water in the driveway.

Doesn't mean I don't miss it!

 

t

 

 

[Joesprocket]

Keeping fighting that good fight,

James. It’ll all be worth it when you can drive it to Richmond to help me with mine 😆. 
 

For real tho - you got this. Take it slow