'72 240Z Rebuild

[Patcon]

The video is what I'm talking about. Heat makes them come out easier. The  machine shop has a machine that heats them beside the press where they press them out. If I was going to balance. I would have someone press them out for me if necessary. Balance them at home and reassemble. I have a 20T press at the house so I can probably do it all here now. A hammer would not be my first choice...

C

[madkaw]

So the rods are different? so are the other pistons from a later L24?

Could be 9mm rods from a 73 240?

[siteunseen]

So the rods are different? so are the other pistons from a later L24?

Could be 9mm rods from a 73 240?

That's what they are then, if the '73 had bigger cap bolts.  The '73s weigh about 19 grams more.

 

Wouldn't I want less weight at the crank?  That's why I'm grinding the caps like Nissan did.

 

Man am I nervous about cutting the OE block for valve reliefs.  I did all the holes on the spare block and will post pictures of what I did and let y'all tell me which grind looks best and then try to replicate that onto the OE block.

 

I'm trying to get some outside stuff done to my property before the pollen starts.  That stuff kills me now that I've gotten older.  We only get about 2 to 3 weeks of spring before the pollen then it gets hot and humid.  But I could be snowed in. ::  

Edited March 22, 2015 by siteunseen

[madkaw]

You don't want those heavy rods, I'll take them off your hands and give you another light set;)

Post up pics and we can go from there. Staying on the conservative side is probably best. If you went overbore then you shouldn't need much.

[siteunseen]

Welp I went ahead and took the dive.  I can always get more off but I think this will be conservative enough until the machinist gets done and mocks it up.  Criticism is more than welcome, atta boys are better.

 

 

[HaZmatt]

Atta boy! 

[siteunseen]

Atta boy! 

Ha!  You get the all time "atta boy".  I love seeing things done right like you have, keeps me trying for the best with my funds. 

[madkaw]

So Cliff,

did you do the notching all with that flapper wheel?

[siteunseen]

Yes I did use the flapper wheel.  I tried making the exhaust a little bigger than the intake sides, the intakes barely scratch the bore.  I also went down at the same angle as the valves, toward the spark plug holes.

 

 

When I had the block outside I noticed a small hole in the cylinder wall.  Don't have a clue as to how it got there or what to do about it.  Taking everything to the machinist today.  He'll tell me what can be done or not done.  May end up using the .030" over F54 after all.  ITM flat tops are only $200, apparently.

 

Anyway what do y'all think?  It had good compression numbers and the walls are beautiful except for this little pimple.

 

[djwarner]

If you are concerned about the depth, try Play-Doh to make an impression. It looks like it is below the ring travel and may not affect operation.

[240260280z]

It looks like the flaw is below the top piston ring.

It is also at a the low part of the stroke so it will have no significant impact apart from some extra oil reaching the chamber.

Have the shop take a look. I am sure they could TIG it, knock it down then bore/hone through it. Some water in the block may help reduce heat effect from TIG .

[siteunseen]

Good news, you guys are right, the machinist said the same thing.

My heart fell into my shoes when I saw that pit.  It made me sick to my stomach then I got to drinking away the blues and got sick to my head. 

 

He has everything now except a piston, he said he needed one for measuring a few different things.  My short valve seals are on the UPS truck for delivery today so tomorrow he'll get those and a piston.

 

All is well in my world for a few minutes. 

 

Oh yeah, I forgot to say what he said about the .190" lash pads that came with the cam.  He said they send the thickest needed and that he has a way of milling the others down if they need to be shorter.

Edited March 25, 2015 by siteunseen