Head Gasket Questions!

[nkopp]

OK, it's been a busy couple of weeks but have been chipping away at this the last few weekends.

On the engine numbers, the chassis was paired with L24-089xxx from the factory (March 1972), but currently is fitted with L24-138xxx (looks like late 1972 from the zhome registry). So not an L26, and looks like someone has modified it. 

I have everything as cleaned up as I can get it without getting out some kind of grinder. I blew air through all of the cooling jacket and got quite a bit of junk out. Is this going to be clean enough to put back together? Once I get her running, I'm thinking I can put in some EVAPO-RUST and a filter to clean it out a bit more. Seem reasonable?

I did notice some damage on the head for cylinder 3. Is this something to be concerned about?

I've been reading up on timing, and I think I have it where I need it. Cylinder 1 is TDC, the cams are at "bunny ears" and since I can see cylinder 6, I set it exactly between the exhaust and intake strokes. The gold links on my timing chain fit with a bit of slack in position 1 and I think I can force it into position 2 with a little elbow grease (and a rubber mallet). Haven't gotten into the distributor yet, but that seems straightforward enough. How does all this look?

Last question, is whether I should spray the new gasket with copper spray. I have seen several people say to use it, but others say to listen to the instructions on the gasket itself, and this one says no sealant. I already chased the head bolts and have the torque numbers pulled up. Anything else I should think about?

Thanks as always!

[Racer X]

Follow the instructions on the gasket.

Do you know what a degree wheel is?

If so, do you have one and know how to use it?

Dialing a cam in ensures optimal performance.

 

Oh, and the damage in the combustion chamber looks like there had been detonation in that cylinder. Didn’t you mention a turbo in this engine’s history?

Other than a modest disturbance of air flow, and slight difference in chamber volume, and the appearance, if the valve is sealing, it doesn’t hurt anything being there.

 

[nkopp]

I saw a video with one, yes. I don't have one, though. Worth grabbing it sounds like?

[Reptoid Overlords]

I rebuilt an L28 some time ago that is not currently installed in my car.  I used a Fel-Pro head gasket and used no spray.  It  has slightly over 2k miles on it with no issues.  I also recently used a Fel-Pro head gasket on my 1991 Mazda B2200 pickup with no spray.  It is holding up fine after several hundred miles of daily lovely Seattle driving. 

[Racer X]

7 hours ago, nkopp said:

I saw a video with one, yes. I don't have one, though. Worth grabbing it sounds like?

Depends on if you can use it effectively. The cam can be installed and timed without one, but the upper sprocket has a number of marks and dowel pin positions to allow advancing or retarding the cam position relative to the crank. 
 

Since your engine has been “built”, knowing the cam grind data, lift, duration, lobe separation, and the optimal timing of valve lift relative to piston position is something that should be considered during assembly. 
 

Getting it “right” will make a significant difference in how well the engine runs and performs.

[Zed Head]

15 hours ago, nkopp said:

The gold links on my timing chain fit with a bit of slack in position 1 and I think I can force it into position 2 with a little elbow grease (and a rubber mallet).

Not sure what you mean by "slack".  Choosing a sprocket position depends on the relationship of the notch and groove.  A picture of the chain tensioner will give a clue on chain wear.

No offense, but you're still working with a hodge podge of parts.  But if it ran before it will probably run again.

[nkopp]

By slack, I just meant that with the cam sprocket on position 1 and the gold links lined up there and on the crank, there was some slack on the tensioned side. Meaning that the cam would fall behind the crank when it runs and the slack is pulled out. In position 2, it's very tight.

I'll see if I can snag a photo of the tensioner later today to see what wear looks like.

The hodgepodge of parts is definitely on my mind. I mean is should work, right? Only one way to find out?

Edited December 19, 2022 by nkopp

[Zed Head]

The colored links are just there for assembly.  To evaluate wear you want to put the crankshaft at zero on the damper puller (TDC), tighten the chain on the tight side, then see where the notch is.  Everything starts with the crankshaft.

But, regardless, it will still run with the cam at 2.  The torque curve will just be shifted to lower RPM.

[nkopp]

Whelp, I put it mostly back together today. Working on the timing cover and water pump tomorrow and hoping to refill with fluids with crossed fingers. 

Looking at cold valve adjustments and then re-wiring with a Painless kit after this. Which will (hopefully) lead to compression testing and fuel system. Any other stuff I should keep my eyes out for in these next steps?

Thanks for everyone’s help here!

[Racer X]

9 hours ago, nkopp said:

Whelp, I put it mostly back together today. Working on the timing cover and water pump tomorrow and hoping to refill with fluids with crossed fingers. 

Looking at cold valve adjustments and then re-wiring with a Painless kit after this. Which will (hopefully) lead to compression testing and fuel system. Any other stuff I should keep my eyes out for in these next steps?

Thanks for everyone’s help here!

Gonna be tricky getting the front cover on with the head and oil pan on tight.

[nkopp]

Ah 🤬

Edited December 27, 2022 by nkopp