Engine bore opinions needed!

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hisandhers80s

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Madison, MS
I am not an expert, and have novice understanding what I am looking at, but 1 and 6 look questionable. I see cross hatching in every bore but there are two spots that drew my attention. See post #2 for #6 and the two concerning spots.

#1
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#2
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#3
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#4
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#5
IMG_3121.webp
 
Looks pretty tired to me. What are you hoping to accomplish?

Has it been overheated?

How was oil consumption? Blowby?

Can you feel the cylinder wear with a finger?

If it was not overheated and did not have concerning blowby or oil use and you can barely feel any wear and you are on a budget I'd recommend 220 grit dingle ball honing the cylinders just enough to restore cross hatch and running it.

The honing will extend the life of the rings, but done wrong it will make things worse.
 
Looks pretty good to me. I've had many of these apart that look about the same and don't burn oil and still have good compression numbers, actually lot of them look worse. Use to finger to feel around for a horizontal wear ridge or deep vertical scratches. What does the last cyl look like if you try to wipe it down with a rag?
 
TheBussman said:
Looks pretty good to me. I've had many of these apart that look about the same and don't burn oil and still have good compression numbers, actually lot of them look worse. Use to finger to feel around for a horizontal wear ridge or deep vertical scratches. What does the last cyl look like if you try to wipe it down with a rag?
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IMG_3124.webp


IMG_3122.webp
 
I only put 500 miles on this cruiser before I started tearing it down, but the previous owner said it was the original head gasket, and he had the records from the 100,000 miles to 240,000. There was no noticeable blow by or burning of oil, but again I did not drive it long enough to know for sure. I do know there were a ton of oil leaks (upper oil pan, timing cover, front and rear main seal). It just looks to me like someone did not change the oil as often as they should have, but again I am mostly a novice and just picked up what I know from reading on here. I will feel all of the cylinders for any grooves tonight and report back.
 
hisandhers80s said:
#6 I see faint cross hatching but also a spot?
View attachment 4093062

#1 concerning spot

View attachment 4093063
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If you haven’t already; ask yourself, "what are my goals (i.e., use case) with the vehicle?"

Answers could range from...
Make is pass someone's inspection for a quick sale. To, I want everything as rock solid as if it was new, 'cause I'm keeping it forever.

However...
Technically, each bore should be measured. I'd have a honest, experienced machinist do it. That said, Toyota did design them to be bored out. But, we're back to the question above.

Wes, Fj80oregon's opinion would outweigh most others - he's been into the guts of these, and doesn't compromise.

As a side note. When I did mine @372k miles. All my bores looked better than yours, and measured "in spec." Oil changes DO matter.
Best of luck. I envy you, teardowns are fun.
 
manofthewoods said:
If you haven’t already; ask yourself, "what are my goals (i.e., use case) with the vehicle?"

Answers could range from...
Make is pass someone's inspection for a quick sale. To, I want everything as rock solid as if it was new, 'cause I'm keeping it forever.

However...
Technically, each bore should be measured. I'd have a honest, experienced machinist do it. That said, Toyota did design them to be bored out. But, we're back to the question above.

Wes, Fj80oregon's opinion would outweigh most others - he's been into the guts of these, and doesn't compromise.

As a side note. When I did mine @372k miles. All my bores looked better than yours, and measured "in spec." Oil changes DO matter.
Best of luck. I envy you, teardowns are fun.
Click to expand...
I am building this with the plan to keep it. This is going to be an off-road rig. I have re-geared front and rear differentials with ARB air lockers and 300M chromoly front and rear axels to go in, full suspension re-build waiting to go in, Front and rear bumpers and winch to go in, and was doing the head gasket to make it last longer. That is my use case. I was avoiding taking the block out because I just had the AC system rebuilt and did not want to disconnect it and have to pay refill. I am not opposed to taking it out and having it machined but if I can get another 100,000 miles out of it like it is, then that would make sense as it would get me another 5-7 years down the road while I plan a diesel swap or full rebuild.

@Fj80oregon thoughts?
 
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Having built a handful of 1FZs now...thats probably ok to run. As others have said- you need to determine your goals. Hows the deck surface for a new head gasket? Any pitting or electrolysis?

Given the mileage you state, I'd want a look at the bottom end bearings anyhow, and if I'm taking them out to check, I'm not putting the same ones back in with 330k on them. If you're this far into it, and only need another few years until a different engine goes in....then slap a HG on it and run it. If you intend to keep it trucking for a while, then I'd pull the bottom end and go through it.

If you're careful, you can pull the bottom end while leaving the AC compressor in the vehicle and the lines hooked up. It ain't fun...but can be done. I always prefer to pull engine/trans/t-case as an assembly per the repair manual. It's actually faster for me.
 
I'm no FZ expert, but I've rebuilt a lot of vintage motorcycle engines and a few car engines and those bores look toasted to me.

The horizontal double ring grooves near the top of each cylinder look well deep enough to feel with your fingernail, plus what looks like pitting and scoring in some pix....

I would absolutely have my machinist look and measure that for a likely overbore
 
That simplifies things.
 
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