- Thread starter
- #141
OK just wanted to make sure it wasn’t closing off some sort of flow that I needed. That engine looks clean!
Builds 79 FJ 40 Rebuild (1 Viewer)
- Thread starter Stevens79FJ40
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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.
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- #143
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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- #144
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
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
pb4ugo
SILVER Star
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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- #146
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?
OlYellr
SILVER Star
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.)
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.)
pb4ugo
SILVER Star
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.
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- #149
Well I do like peace of mind. I’m getting a quote on a rebuild. Thanks for all the input
OlYellr
SILVER Star
Also happy to share what I did for engine stuff if you want/need. Finished mine Oct of 2023. somewhat fresh in memory
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- #151
Quote on rebuild was $5k, I’m not ready for that. Decided to clean the head, lap the valves, prep mating surfaces and paint the block and head
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- #152
Idk how? 5ft lbs torque broke off every bolt got my oil filter bracket. I thought it was the torque breaking at the proper setting. 
All 4 snapped off? How many shop beers were used to prep for this job?Idk how? 5ft lbs torque broke off every bolt got my oil filter bracket. I thought it was the torque breaking at the proper setting.
View attachment 3774677
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- #154
Unfortunately zero.
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- #155
RevISK
SILVER Star
There's your problem.
RevISK
SILVER Star
But seriously, that is crazy. Where did the bolts come from?
- Thread starter
- #158
Came from there. They looked perfect. Came out no problem
OlYellr
SILVER Star
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
