Builds 79 FJ 40 Rebuild (2 Viewers)

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OlYellr said:
I don't claim to be correct - but I believe is if for a solid backing since the head and the block meet and it isn't perfect.

First image is the gasket on the block. Second is close-up (before rebuild) of the back plate and can see how head and block not perfectly aligned (looks better on phone than screen). and even on first can see where block and head meet not smooth vertical surface. My opinion
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OK just wanted to make sure it wasn’t closing off some sort of flow that I needed. That engine looks clean!
 
I think it helps push the coolant in the right direction - part of the design. You should use some sealant on that gasket and perhaps one of the bolts that goes into the water jacket I don't remember exactly.
 
I was going to finally put in my new suspension, but forgot to order bushings for the shackle brackets…so, I made a bumper!

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Ok engine stuff…

This might have been a really bad idea but, I removed the head and tested my piston rings by adding some water to see if they would leak. 4 out of six did pretty quickly. Oil pan is off. My friend suggested lapping the valves? Idk how that helps leaks in the block. I’m considering pulling the engine and sending it off for a rebuild. Any thoughts
 
Why did you remove the head? Was it burning oil? What were the compression #'s b4 you removed the head? Is there a ridge at the top of the cylinders? Your water test won't really show anything. At this point i think measurement will determine the condition of the cylinders. A dry and wet compression test or a leak down test would've id the issues.
 
pb4ugo said:
Why did you remove the head? Was it burning oil? What were the compression #'s b4 you removed the head? Is there a ridge at the top of the cylinders? Your water test won't really show anything. At this point i think measurement will determine the condition of the cylinders. A dry and wet compression test or a leak down test would've id the issues.
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So, I had to remove the body for leaking fuel tank, found frame rot, body rot, etc. just kept tearing it down.
I did have a little smoke when it ran. Maybe valves, timing, carb idk. I have a complete engine gasket set and am painting the black and all components. Figured I check the head gasket and head.

So the pistons won’t hold water above them if the rings are good? I thought this would verify good bad rings?
 
Could have should have … Murphy’s law right.

A leak down test would be the best way to understand the rings/lower block as @pb4ugo mentioned or where a leak might be in the head. Compression too. Both are important. I had great compression and poor leak down = full rebuild.

There is a gap in the rings as they squeeze together as they move up the cylinder wall. No way to make it perfect no gap situation. So water, oil, air will pass -the % of loss is the issue.

I think the question comes down to what are you most comfortable with (peace of mind) and pocket book. This is your rig and you get to decide what right is for you.

For me, if I was that far in it and the head is getting TLC, I’d take the block to a shop and have it addressed to. I personally want stuff done so they are less likely to come up in the future. Iso i tend to pull the thread more than the average bear. Issues with my approach are time for shop to get to it. If it needs pistons, hard to get domed unless performance domes $$$$. Maybe light honing and new rings freshen it up enough. Who knows.

And… with a rock solid head, it will be better than it was before you started if you choose that is good enough.

I’m not helpful and only pointing out what I think are your choices. I guess’s you could assemble after head done and test, but if tests are poor, then what. If test good, worked out and saved time and $$.

Are you risk tolerant or risk adverse? (I’m risk adverse for the my rig in what life it had before I got it.)
 
Like @Ol Yeller ssid, It takes a dry and then a wet compression test or a leak down test to determine what's bad. Both tests will determine if the issue is in the head or the bottom end. Or just rebuild it.
 
OlYellr said:
Could have should have … Murphy’s law right.

A leak down test would be the best way to understand the rings/lower block as @pb4ugo mentioned or where a leak might be in the head. Compression too. Both are important. I had great compression and poor leak down = full rebuild.

There is a gap in the rings as they squeeze together as they move up the cylinder wall. No way to make it perfect no gap situation. So water, oil, air will pass -the % of loss is the issue.

I think the question comes down to what are you most comfortable with (peace of mind) and pocket book. This is your rig and you get to decide what right is for you.

For me, if I was that far in it and the head is getting TLC, I’d take the block to a shop and have it addressed to. I personally want stuff done so they are less likely to come up in the future. Iso i tend to pull the thread more than the average bear. Issues with my approach are time for shop to get to it. If it needs pistons, hard to get domed unless performance domes $$$$. Maybe light honing and new rings freshen it up enough. Who knows.

And… with a rock solid head, it will be better than it was before you started if you choose that is good enough.

I’m not helpful and only pointing out what I think are your choices. I guess’s you could assemble after head done and test, but if tests are poor, then what. If test good, worked out and saved time and $$.

Are you risk tolerant or risk adverse? (I’m risk adverse for the my rig in what life it had before I got it.)
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Well I do like peace of mind. I’m getting a quote on a rebuild. Thanks for all the input
 
RevISK said:
But seriously, that is crazy. Where did the bolts come from?
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That is what I was going to ask. Were those OEM?

Edit: quickly as I wait to take off on my flight. The bolts look yellow to me as if zinced. Not that that is a problem, but leads me to believe what you removed was not original- you got enough meat so removing should be straightforward.

Get some OEM that will hold up with the shear forces that snapped them. Maybe thread chase too before installing.

My unasked opinion. Stinks. I’ve been burned a few times myself.
 
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Way long time ago, I snapped a spindle bolt in the front end at like half the torque value IIRC 7psi - I'm sure it was OEM. I think I bought 5 and drilled the heads for safety wire
 
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