Rebuilt U20s for half a century and know it all?

[jhayden]

Watch:

https://www.youtube.com/watch?v=42f1M21yC5Y

Jon

[Solex68]

Fairlady 2000 SR311 - Showa 42 (1967)

0:00 Opening
0:30 Video introduction
1:12 Head detachment
2:04 Gasket status
4:00 Condition around the valve
8:05 Easy to fly?! Gasket myths
8:51 Yoshidaya Racing SR🏎
10:27 Secret know-how (1)
12:21 Secret know-how (2)
17:36 How to remove the head & procedure
25:34 Father, ice time
26:09 Next Notice: Cab Condition & Engine Structure

[Solex68]

Just for Shits & Giggles. Here is the episode's conversation in English. It's not perfect but sometimes the imperfections are funny too.
FYI - The time is not exact, blame YouTube for that, not me)

0:02
Oh no, this is not good. If you do this,
0:06
it will make the head gasket more likely to blow out.
0:08
Here it is, you can see that it has come out like this.
0:11
It’s burnt abnormally, and now it's like this.
0:13
It seems like it's a bit oval-shaped here,
0:16
yes, the head has been removed.
0:21
We used to race at 9500 RPM.
0:24
The dead zone was at 10,000 RPM.
0:30
Hello everyone, this is Yoshida from Car Shop 311.
0:34
This is the third episode where we’ll be explaining how to remove and assemble the head.
0:41
In response to my father's order to stop driving,
0:46
I’m overhauling the engine to restore the problematic SR.
0:50
This video is divided into three parts:
0:55

Removing the head, 2. Revealing the secret to preventing the head gasket from blowing out, and 3. How to remove the head.
1:04
I’m sure everyone is eager to know the condition of the head gasket, so we’ll start with removing the head.
1:10
Let’s get started.
1:12
Now, I’m going to lift it up here.
1:16
Even though I’m lifting it, my hand is getting caught.
1:24
It seems like it’s stuck.
1:26
What’s happening here? What’s going on?
1:33
Here we go.
1:35
Let's align it a bit to the center.
1:39
The head has now been removed. I’ll place it on the tray.
1:56
It looks better than I expected.
2:06
Oh, this part is out of place.
2:11
Hmm, what do you think?
2:13
We’ll start by checking everything, including the gaskets.
2:17
We’ll examine the head gasket and other components carefully.
2:24
It looks like some water might have gotten into this area.
2:30
We’ll also check the head's and cylinder block’s surfaces for warping.
2:37
These head bolts are quite dirty with sludge and rust.
2:42
This might have prevented even torque distribution when tightening the head.
2:45
In our shop, we always re-thread all the bolt holes.
2:49
We re-tap the threads on both the block and the head to ensure even torque.
3:02
We also repair the threads for the cylinder head.
3:06
This ensures even torque application.
3:10
If you don’t take care of these details, you might think you’ve tightened the head bolts properly, but they won’t be secure.
3:16
This part is a bit concerning.
3:19
Ideally, the gasket should be perfectly round, but it seems a bit oval-shaped here.
3:30
It might have leaked from here into this area.
3:36
Let’s inspect it closely.
3:40
Now, here’s a quiz: where is the crack in the head gasket?
3:50
We’ll check each part carefully.
3:54
In the past, it was common to see the valves in this area completely corroded and messed up.
4:02
This is the number one issue; the aluminum around this area would be completely corroded.
4:09
It’s not as bad this time, though.
4:16
The threads for the spark plugs were heavily rusted, but we’ll repair those as well.
4:20
The spark plug holes are rusted, but we’ll fix them.
4:24
These smaller ones are the exhaust valves.
4:27
This is the number one exhaust valve, and this is number two.
4:34
And this is number three.
4:37
This one is number four. Each one is burnt differently, with some being completely black and others burnt only in certain areas.
4:48
If they were all equally burnt, that would be normal.
4:51
But as you can see, some are pinkish, while others are completely black.
4:58
The first one, as you can see, is heavily corroded.
5:05
The valve itself is corroded. You can see the Nissan mark here.
5:14
This one says “Exhaust” (EX).
5:18
You can read “EX” clearly here, but on the first one, you can’t read anything because it’s so corroded.
5:31
So, without a doubt, this valve experienced abnormal combustion, which led to corrosion.
5:49
If you look closely, you can see some brown discoloration around here.
6:05
It’s not black; it’s more of a brownish color.
6:15
This indicates that compressed air leaked into the water jacket through this part.
6:30
This engine has run for several hundred kilometers, but due to minimal leakage, the valve corrosion is limited to this extent.
6:35
In more severe cases, the entire area around the valve seat could be completely corroded.
6:47
You can see some corrosion around here, too, though it’s minor.
6:50
The rest of the combustion chamber is blackened but not corroded.
6:58
The carbon buildup here isn’t as bad.
7:02
[Music]
7:06
Other areas of the combustion chamber show different patterns of carbon buildup, indicating that some oxidation has started.
7:16
The valves are oxidized, but it’s not too bad.
7:25
I’m relieved it’s not worse; we’ve seen much more severe cases.
7:28
If you notice radiator water leaking or bubbles forming in the tank, don't keep driving the car.
7:42
The car might seem to run fine, but please don’t continue driving it in that condition.
7:47
If you encounter these issues, stop driving immediately and have the car towed.
7:56
That concludes the explanation of the head.
8:00
End.
8:03
Yes, yes. As has been said for over 50 years, SR engines have a reputation for blowing head gaskets easily.
8:17
If you push the engine to 7000 RPM regularly, the gasket will blow.
8:25
I bought my SR 51 years ago and used to drive it at full throttle all the time.
8:29
I blew the head gasket about three times a year back then.
8:35
From that experience, I learned how to prevent head gaskets from blowing and developed some know-how.
8:46
In our racing shop, we use this knowledge to build engines that can run at 9500 RPM without any issues.
9:03
By the way, our dead zone was at 10,000 RPM.
9:13
[Applause]
9:21
This legendary Yoshida Racing engine is still carefully preserved.
9:29
[Music]
9:45
Even after all these years, the head gasket hasn’t blown, and the engine hasn’t overheated.
9:53
For those who came to see our classic car at the Tax Classic Rally, you know that our engines can run at 9500 RPM without issues.
10:06
Back then, even works drivers wouldn’t push their engines past 7200 RPM.
10:11
They were told that 7200 RPM was the limit.
10:18
But we made engines that could run reliably at 9500 RPM.
10:23
I’ll explain the know-how behind it now.
10:26
We re-tap the threads for the head bolts like this.
10:28
These are the threads where the head bolts go in.
10:36
If the threads are rusty, the head bolts won’t apply even torque, which is critical.
10:46
We meticulously clean and re-tap all ten bolt holes.
11:00
This attention to detail ensures a high-quality engine.
11:15
You can’t build a good engine by just slapping things together.
11:23
It takes time and care to build a reliable engine.
11:31
We do this for each bolt, one by one, and it’s this accumulation of effort that creates a great engine.
11:36
We also check the surfaces of the head and block.
11:40
If there’s any sludge buildup, we clean it out completely.
11:46
We also clean all the bolt holes.
11:50
After cleaning, we’ll re-tap all the threads.
11:56
This level of care makes a difference in the engine’s performance.
12:06
If you cut corners, you’ll end up with a subpar engine.
12:20
We’ll also re-tap the head bolts.
12:23
These bolts are covered in sludge and rust, which we’ll clean off before re-tapping the threads.
12:29
Since these head bolts are no longer being manufactured, we have to restore them carefully.
12:40
Once the threads are cleaned and restored, we’ll explain how to reassemble the head properly.
12:51
This is all part of our know-how, and I’ll be sharing our secret techniques with you.
12:57
The head has been placed back on.
12:59
When attaching the head bolts, we use a special spray to prevent rust and ensure even torque.
13:24
This spray is applied to the threads before assembly.
13:29
This isn’t engine oil. It’s important to use the correct lubricant.
13:47
Engine oil should not be used here, as it can cause slippage and make the head gasket more likely to blow.
13:50
This special lubricant ensures proper sealing and torque distribution.
14:22
When assembling the head, the threads should be clean, and a special lubricant should be used, not engine oil.
14:25
If engine oil is used, it can cause the head gasket to slip and eventually blow out.
15:14
The engine oil can also seep into the gasket area, leading to leakage.
15:48
It’s important to avoid using engine oil on the threads to prevent this issue.
16:18
Instead, use the special spray to ensure a proper seal and prevent oil from seeping out.
16:25
Our engines can run at 9500 RPM without any issues, thanks to these techniques.
16:30
We’ve never had a head gasket blow, even at high RPMs.
17:11
This level of care and attention to detail is what sets our engines apart.
17:24
If you don’t take these steps, you’ll end up with a lower-quality engine.
17:50
It’s important to take your time and do everything properly.
17:55
If you rush through the process, you won’t get the same results.
18:18
Now, let’s move on to removing the camshaft.
18:25
We’ll start by removing the camshaft bolts and then move on to the head bolts.
18:34
It’s important to remove the bolts in the correct order to avoid damaging the engine.
18:46
We’ll remove the camshaft tensioner first.
18:58
Be careful not to drop any bolts during the process.
19:04
Now that the tensioner is removed, we can move on to the camshaft bolts.
19:21
Don’t remove all the bolts at once. Start with the tensioner and then move on to the camshaft bolts.
19:31
Once the camshaft bolts are loosened, we can remove the tensioner and then the head bolts.
19:46
Make sure to remove the bolts in a crisscross pattern to avoid warping the head.
20:05
Once the bolts are removed, the head can be lifted off.
20:28
Be careful not to drop the bolts during the process.
20:39
Now that the head is removed, we can inspect the gasket and other components.
20:50
The head gasket should be inspected for cracks or other signs of damage.
21:00
If the gasket is damaged, it will need to be replaced.
21:31
It’s important to clean the surfaces of the head and block before reassembly.
21:46
Make sure the surfaces are clean and free of any debris.
22:22
Once the surfaces are clean, we can begin reassembling the engine.
22:46
Reassembly is just as important as disassembly. Take your time and make sure everything is done properly.
23:24
Once the engine is reassembled, we’ll perform a test to make sure everything is working correctly.
23:45
If everything checks out, the engine is ready to be reinstalled in the car.
24:12
Remember to take your time and do everything properly to avoid any issues down the road.
24:43
Once the engine is reinstalled, we’ll perform a final test to make sure everything is working correctly.
25:06
And that’s it! The engine rebuild is complete.
25:28
Thank you for watching. We hope you found this video helpful.
25:46
If you have any questions, feel free to leave a comment below.
26:28
And don’t forget to subscribe to our channel for more videos like this one.
26:39

[Solex68]

And for those who have never seen them, here is the YouTube channel: https://www.youtube.com/@carshop_311

[MattC]

Watch that guy all the time! Captions are a must.

[jrusso07]

Knee pads...brilliant!

[Stick]

I think I just watched all of the Car shop 311 vids (for 311)... great stuff and learned a lot.