Pulled the head today, and now...

[Joesprocket]

Hi everyone, hope you've enjoyed a weekend if not a long weekend for some. If you had a chance to turn your wheels I hope you did that, too.

 

Given the seized condition of the motor I decided it was best to pull the head and investigate a little further. Thought I share some pics of a motor that's been sitting since 79'. I what you see in the pics is what's to be expected. There is quite a build up of cruddy old coolant in water passages and pump. Lots of carbon build up on both piston heads and valves. A week ago I poured a bottle of water in the hot/cold divider (to see if it could reach the coolant drain plug -  it didn't) and today found water in all the cylinders which makes sense because the head gasket was pretty brittle. What a mess...but again. not sure i should expect more than exactly this.

 

I plan on pulling the rest of the motor from the car to do a full rebuild but was curious from folks more experienced if there's any advantage of trying to free the pistons now while it's secured on the mounts vs pulling it and then trying to do it? My thought is to free them now with time, penetrating fluid and wooden post and mallet. Trying to work the crankshaft nut is not showing any sign up these pistons giving way.

 

If there's anything else you see in the pics that looks like this motor is in trouble please shout them out.

 

 

Edited February 21, 2023 by Joesprocket

[Dudeland]

It doesn't look too bad.  I don't see any vertical scratches on the bores.  The head isn't torched between the cyl.  I can see TobyB is typing. So I will shut up.

 

P.S is that a crack in cyl 1?

Edited February 21, 2023 by Dudeland

[TobyB]

Pressure's on!!!

 

 

The bores look very clean to me-

 

yard it out and disassemble it.  

 

I suspect if it's stuck, the bottom end will tell the tale.

And it's far easier to hammer on the big ends, AND you

won't be as likely to hurt something.

 

t

[tech71]

Bores don’t look that bad but that cylinder head….pretty nasty and I think I spy a crack at the usual spot for 121 heads

[Joesprocket]

26 minutes ago, Dudeland said:

P.S is that a crack in cyl 1?

 

I believe the whiteish squiggly line you see in cyl 1 is dog hair. Golden Retriever.

 

[Joesprocket]

16 minutes ago, tech71 said:

Bores don’t look that bad but that cylinder head….pretty nasty and I think I spy a crack at the usual spot for 121 heads

 

Yeah, I agree. The bores are decent. Please call it out to my untrained eye if you see something that you'd suspect is a crack

[bergie33]

Just a thought... Toby and other please interject if I'm off base here. How about soaking them really good with some Marvel Mystery Oil, put the car in gear and try rocking it a bit. Maybe it'll free up. 

 

[tech71]

1 hour ago, Joesprocket said:

Please call it out to my untrained eye if you see something that you'd suspect is a crack

Actually I think what I see is on the head gasket but its in the "usual" spot.

#3 combustion chamber between exhaust valve and opening for water passage.

About 5:30, check it out there under the head gasket., use a magnifier.

All  3 121 heads I have got my hands on were all cracked there.

You were actually able to get all the Exhaust manifold nuts studs out without surgery, thats unusual.

Edited February 21, 2023 by tech71

[Son of Marty]

Hard to say with all the crap in the head but be sure to have the presure tested before spending much money on it. Putting a penitrating oil in the bores and rocking the car back and forth is not a bad idea.

[2002iii]

I would remove the starter, it might be seized inside.

 

Those pistons look pretty clean, like they got steam cleaned with coolant.

[Schnellvintage]

Squirt some Kroil down the oil hole in the block and wait a few hours. Agree with the above cylinders look ok. No. 3 exhaust side water jacket looks very thin walled.  Common area for cracks and/or leaks on 121 heads.

 

[Mike Self]

It's gratifying to see there's no rust in the cylinder bores, nor unusual scratches, gouges etc.  Given the cylinder wall condition, at 79k miles there's a very good chance you won't need to bore/fit oversize pistons.  Presuming of course that the pistons check out OK, they may just need rings.  When I rebuilt my '73's engine at 204k, the crank didn't need turning, and the cylinder wall wear was just on the cusp between refitting standard size pistons and boring to the first oversize.  With less than half as many miles, yours should be OK.

 

Three caveats:

 

1.  Your crank is a six bolt crankshaft.  While the clutch disk is the same as was fitted to cars with 8 bolt cranks (after VIN 1665200), yours has a coil spring pressure plate and its unique throwout bearing vs the diaphragm pressure plate fitted to 8 bolt crank cars.  Those pressure plates aren't easy to find, so hopefully you can get by with a new disk.  Or start looking for a 228 mm coil spring pressure plate now.
2.  Those early engines have unbushed rocker arms; they wear the rocker shafts fairly quickly, so inspect both arms and shafts when you get into the engine.  Due to this my early 2nd series '69 started running out of valve adjustment at 35k miles (I had oversize adjusters made), and I ended up replacing arms and shafts at around 100k miles.
3.  At least some of these early cars (mine did) had faulty valves.  They weren't properly heat treated, and the valve's seating surface wore away until a valve pulled up into the intake port and broke its rocker arm;  all three remaining valves (I think they were the exhaust valves) were doing the same thing.  So check your valves carefully if you're planning to re-use 'em.  

 

Finally--have you tried turning the engine over now that the head is off?  It could have been stuck due to a valve, and the rings/pistons are all fine.  A friend and I got a '75 that had been sitting outside for 16 years to turn over by pulling the spark plugs and grabbing/turning the fan!  With the fuel system gone through bow to stern, we got it running without any further dismantling.  Runs well, too.  

 

mike

[Tommy]

7 hours ago, Joesprocket said:

 

I believe the whiteish squiggly line you see in cyl 1 is dog hair. Golden Retriever.

 

I was looking at this weird looking scratch too - golden retreiver explains that

You just neet to get it out, take apart, clean and inspected every part. Then it's decisions time.

Not worth it to wrestle in the engine bay, it's gotta come out anyway.

[tzei]

Head: wash, mediablast, pressure test. Inspect cam, rockers and v/guides.

Botton end: what Toby said. Soak first with some penetrating oil. Clean deck surface well and inspect for cracks, usually around head bolt threads.

 

oh and check head straightness.

 

that’ll get you started

Edited February 21, 2023 by tzei

[Joesprocket]

16 hours ago, Mike Self said:

Finally--have you tried turning the engine over now that the head is off?  It could have been stuck due to a valve, and the rings/pistons are all fine. 

 

I was hoping for this but the pistons are still stuck in place. I'm using a combo of acetone and ATF as my penetrating oil. The exhaust valve is open on cyl 1 and intake valve open on cyl 2 - so looking for cyl 2 and 3 to be moving downward with my mallet.

 

Aside from the rings possibly being frozen to the bore is there anything else that could cause an engine not to rotate? For example, I notice the clutch pedal seems to be completely disengaged meaning I can travel the pedal all the way in and it doesnt recoil back to return. thought this might be because the slave is shot and there's not fluid in the system. I guess I'm wondering if this could be linked to the crank not turning.

Edited February 21, 2023 by Joesprocket