Someone probably stuffed the thread and tried to repair it.

Worst case a tig welder would be able to apply some new material, redrill it then retap.

It should be easy enough to fix.

Did you win this head on Yahoo! Auctions recently? I saw a head for sale a day or 2 ago?

Thanks Chris , Gavin !

I hope the work will be easy . Also I am praying the head pass the leak test .The S20 is sometimes notorious for crack around valve sheet ring.

This one is not the auction one , but the seller is the same person from the auction one .

Kats

Hi , my No.2 S20 Engine is confirmed for its good condition.

I couldn’t stop myself doing this , taking a picture of the S20 gears location. I guess Alan would took same photo when he was rebuilding his S20 . People would always ended up doing this !

Note : the two chains are original , it has old type shape. We say it is Hyotan shape . Nissan provides still now but they are oval shape. Although in the illustration , the chain looks oval type.

Kats

Edited February 24, 20196 yr by kats

A chain tensioner is adjustable manually . Don’t tight too much , no chain noise isn’t good , some noise is good for the chain.

I tried to display the electrical ignition system , but I didn’t want to open the plastic bag because I have got the used complete set from the seller of the spare engine.

Note : S20 comes with Mitsubishi components such as a starter/ an alternator/ a distributor/ a voltage regulator / a transistor ignitor.

Kats

 

The pistons, I found a cool thing , original pistons are numbered on top face , from 1 to 6 . On the other hand,  a new piston which I have  is supplied from Nissan is not stamped on it . 

Cylinder liners are NOS . The original pistons are very nice . But I am wondering can I put original pistons into the each corresponding cylinder even if I use a set of new cylinder liners?

Kats

 

Kats

A common trouble of the  tensioner , as the bolt pushes the the collar, a plastic bush inside of the collar gradually collapsed, finally the gear scratches the collar, then break it . 

My spare engine’s tensioner  has slightly worn out ,  so I will replace it with a NOS one .

And the chain guide which is located between the camshafts , there is also a common trouble of cracking at the both sides of the ends .  As the chain goes to be flexible, bounces on the guide , it makes the guide stressful.

Courtesy Mr.Watanabe ( owner of PS30-00063 ) for the pictures which show a damage for each parts.

Kats

 

Edited February 24, 20196 yr by kats

Hi , I looked at the cylinder block , now I understood how S20 is made . I see now water line , oil line , and each holes has each purpose.

At the rear end of the block , “B73” on it . This is stamped on the every crank cap .And this code must be on the left side of the block with a brush paint which is made by quite bigger strokes . I haven’t seen it yet, so that will be my next challenge.

And the oil pan , it is bigger than the L-series Engine. Max is 6 litter, I am feeling this Engine becomes nicer about oil pressure when the oil quantity less than 5 litter.

Kats

Edited March 2, 20196 yr by kats

Is this intake valve stem guide modified ? For better air flow ? Ex valve guide looks normal .I doubt some hand work was done in the past . I feel same thing when I viewed from In / Ex port , it has slightly grinded around the hole for the stud bolt . I need to check my NOS head .

About the front gear housing cases , they have a same number for each . My spare has “15” on them , because these cases were bored at the same time . 

Kats

Edited March 2, 20196 yr by kats

1 hour ago, kats said:

 

Hey Kats,

Do S20 engines have sleeves in their cylinder bores? 

*Edit actually I went back through the thread and saw they do indeed have sleeves, unlike the L-series.

Edited March 2, 20196 yr by Gav240z

Yes Gavin , S20 engines have sleeves in the cylinder bores , that is why it is very good for cooling the engine.

This video is my favorite , just enjoy of the S20 music. I want to drive my Z432 like this ! But maybe I can not .

What I will do is,  I will use a racing alternator , a rcing starter ,

and an oil cooler system , and hopefully a set of racing cam . And an earliest gear driven oil pump which makes strong mechanical sound !

The driver is Mr. Kurosawa , this was taken in 2001, at his age of 61 years old. Wonderful racing driving , he was a chanpion of 1969 Japan Grandprix driving Nissan R382.

He said at the end of the video , " Our factory race cars were very sharp coming up torque "boom! " from 7000 to 8500 rpm compared this car . However this car has the same sound and feeling , this car reminds me of my old days  " .  

Kats

 

 

Edited March 3, 20196 yr by kats

Hi , now Nostalgic Hero vol.192 is on sale , this time featuring Fairlady Z .

I found this unique device , an aircraft type over head console for Zs . 

I remeber this was so fascinating on cars not only for sports car but also for sedans etc . It was like everyone wants to put it on their roof .

Was this type of console popular in other countries back in 70s and 80s ?

Kats

 I don't ever remember seeing one of those back in the seventies.