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Leon

Leon's Other 260Z

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Leon    35

Tractive effort curves represent all RPMs, it's basically the engine's torque curve. Hopefully my PM helps!

 

Setting the ratios to match fuel economy and optimal TE at max RPM is probably not possible unless the engine has a totally flat torque curve. A properly done L-series will have a fairly flat torque curve but optimal ratios for max TE and max mpg will still be different. Maybe not by much, but different. Setting gears for mpg will create wider gear ratios (higher load at lower RPM = good mpg) and a deeper overdrive (again, lower RPM and higher load) than something designed for the track. To clarify, the engine operates more efficiently at higher load, a wider open throttle being the main reason.

 

I'm sure you can sense the difference when driving various cars with manual gearboxes. Economy cars are geared noticeably differently from sports cars. My Accord hates accelerating but gets great mpg because of wide ratios.

 

Sounds like your son has a great head on his shoulders and you did a fantastic job of raising him. :2thumbs:

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Leon    35

When I picked up the Z, the PO gave me a bunch of paperwork and documents along with it, including old manuals. A 1973 FSM was one of them, and despite its ravaged condition it's nice to have. Then, last week I saw an ad on CL for a 260Z FSM! The owner (REALLY nice guy!) drove up to my place last night and hands me not only the 260Z FSM but also a 280Z FSM. The generosity was much appreciated!


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Leon    35

If you ever want to sell that '73 FSM, let me know, I'd love to have one to go along with my '73.

 

Leon... your going to sell it to me... right?  (just kidding)

 

:lol:  If I decide to sell it, I'll let you guys know!

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Leon    35

It's been a while...

 

I found a machine shop for the engine rebuild, turns out every Z owner I've met recently take there engines there (Baca's Machine Shop)! I've also sent the tail-light bezels off to be re-plated about 3 weeks ago, should be another 2-3 weeks until those are back. In the meantime, I'll be painting the tail light panels and stock mirror to close-to factory color. They were painted satin black by the PO.

 

Today I paid for a Datsun Comp 3.9 R180 CLSD after searching for STi R180s for a little while. Hopefully I'll see it in my driveway within a week. Should make for a nice, classic street combo: L28 with triple 45s, late ZX 5-speed, and 3.9 CLSD. :D

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JCan    1

Leon.

 

WOW - CLSD plus 3.9:1 plus higher gear ratios from the 5 speed... very nice!

 

Regarding your tail section and grill section.  I had mine powder coated satin black.  They turned out looking just like new.  and the cost was rather inexpensive ~ $50.  

 

I'll show off a picture below.

 

Jim

 

 

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Leon    35

Nice Jim, looks awesome especially with the silver paintjob!

 

Just last weekend I picked up some spray paint from the local auto parts store, it's some sort of dark grey. I forgot what they called it but I believe it's a trim color for Nissans. It looked close enough to me when I was looking through the paint section. I figured if I don't like the color, I can just repaint! Powdercoating sounds like it might be a nice option that I hadn't thought about, so thanks Jim. ;)

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Leon    35

Diff came in on Thursday! I finally had some time to unpack it and put it up on the bench after doing some cleaning this morning. I got a tip from a local racer as far as diff shops go. Apparently, the place to go is SF Differential in South City, so I may be paying John a visit. :)

 

DSCN1832_zps2b8c8d04.jpg

 

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Leon    35

Just a little bit of progress made last weekend. I've been cleaning out the garage for months now, trying to create some semblance and organization of an actual shop (rather than a storage facility). Finally, this weekend it became clean enough to actually move the Z in and out of the garage!

 

Of course, I had to give it the long delayed "first wash"... :)

 

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The paint is in pretty good shape, but needs a good detail. (note: the car is completely dry in these photos)

 

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At this point, I'm looking for a good core P90 or P90A head to send to the machine shop. Once I have a head, I should have everything needed to finish it up.

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Gollum    23

I have a P90 but it's going to need some minor machine work. It got buggered pretty good on an exhaust stud removal. To be done right it should probably be welded and re-drilled and tapped. It might survive with just an oversized helicoil though. Make me an offer. :-)

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Leon    35

I have a P90 but it's going to need some minor machine work. It got buggered pretty good on an exhaust stud removal. To be done right it should probably be welded and re-drilled and tapped. It might survive with just an oversized helicoil though. Make me an offer. :-)

 

PM sent! :)

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Leon    35

Looks like I finally have all the parts I need. I bought a P90 and picked it up over the weekend thanks to Ray (and Alex)! Hope you enjoy the pie, Ray. ;)
 
It's complete and looks like a very good candidate for a rebuild. Not bad for $100 (plus gas money and a pie). Sure beats the crap out of those inflated P90 head prices I've been seeing. I'm not one to complain but $600 and it has a chip in the combustion chamber? LOL. Yeah, right...
 
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I'll be stripping it down this week and then sending it to the machine shop (not sure whether I'll be using Baca's or Clark's at this point) along with the block, crank, and rods. It'll feel good to finally make progress on this thing.

Edited by Leon

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JCan    1

Wow!  Great find!

 

Some lessons learned from my rebuild.

 

1)  be sure to grind your rocker arms prior to reassembly.  I did not and had problems with the rocker arms not mating squarely with the lash caps and the cam.     (see pictures)  The old lash pads wore in the middle and not on the sides, the new lash pads do not have the indentation on the sides so an unground rocker arm does not sit properly on the cap.  This caused me a lot of time to find out why my engine had a loud tapping sound.

 

2)  if you are going to purchase an isky cam.  I ended up with the Isky stage II cam 715148 (see picture below).  With my SUs the car is too lopy and too loud.  This summer I am going to swap back to the isky stage 1 cam.  I suggest the stage 1 cam.

 

3)  I used cast flat top pistons on my N42, 2.8L block.  The crank/block combination pushes the pistons above deck by approx 0.025"  (0.65mm).  I purchased a custom copper head gasket which was 0.063" (1.6mm)   which gave me a gap between the piston and head of 0.037".  When I ran the stock head gasket, I believe the piston to head clearance was 0.025" which concerned me.  My resultant compression ratio is 9.83 instead of 10.2 with the Felpro gasket.

 

4)  Please find shims that are 0.040" and use two instead of four of the 0.020" shims.    I had mine custom made.  it was inexpensive.

 

Thats all I have on the head rebuild.

 

Good luck!

 

Jim

 

 

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Leon    35

Wow!  Great find!

 

Some lessons learned from my rebuild.

 

1)  be sure to grind your rocker arms prior to reassembly.  I did not and had problems with the rocker arms not mating squarely with the lash caps and the cam.     (see pictures)  The old lash pads wore in the middle and not on the sides, the new lash pads do not have the indentation on the sides so an unground rocker arm does not sit properly on the cap.  This caused me a lot of time to find out why my engine had a loud tapping sound.

 

2)  if you are going to purchase an isky cam.  I ended up with the Isky stage II cam 715148 (see picture below).  With my SUs the car is too lopy and too loud.  This summer I am going to swap back to the isky stage 1 cam.  I suggest the stage 1 cam.

 

3)  I used cast flat top pistons on my N42, 2.8L block.  The crank/block combination pushes the pistons above deck by approx 0.025"  (0.65mm).  I purchased a custom copper head gasket which was 0.063" (1.6mm)   which gave me a gap between the piston and head of 0.037".  When I ran the stock head gasket, I believe the piston to head clearance was 0.025" which concerned me.  My resultant compression ratio is 9.83 instead of 10.2 with the Felpro gasket.

 

4)  Please find shims that are 0.040" and use two instead of four of the 0.020" shims.    I had mine custom made.  it was inexpensive.

 

Thats all I have on the head rebuild.

 

Good luck!

 

Jim

 

Hey Jim, thanks for the great info!

 

1. I'm planning on sending the rockers to be reground when getting the cam reground. I've not talked to Isky yet, so I'm not sure whether they do rockers as well. I know Delta up in WA does it pretty cheap. So your solution was to have the rockers ground to fit the profile of the lash pads, if I understand correctly?

 

2. For cam sizing, I'm planning on running my own calculations to determine necessary lift and duration. I'll speak with Isky regarding it as well, especially regarding lobe separation/overlap. I'll probably have one ground to my specs, unless Isky convinces me otherwise.

 

3. Thanks for the deck height info. I'll see if I run into the same issues (F54 block with flat-tops).

 

4. If Derek (on this forum) still makes shims, I was thinking about purchasing them. I don't remember whether his are one-piece (0.080") or two-piece (0.040" X 2). I can also make my own on the wire EDM at work, if I'm feeling really frisky...

 

Thanks Jim!

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