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Leon

Leon's Other 260Z

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Surely a machinist would make an accurate measurement ;)

I think you would be okay with 10-1 with a hot cam, but you are in CA

I would shoot for 25-30 squish regardless of CR

 

The uncertainty is about the valves not being installed. Maybe he temporarily installed them with the old springs and hardware? I'll clarify his procedure when I pick up the engine, and I can always double-check myself once I've lapped the valves and installed new hardware.

 

I should be fine at 10:1 as long as I do a good job on the tune and minimize cylinder-to-cylinder variations. That will remain to be seen. :)

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It's a 260Z. Not a huge concern being in CA unless he gets pulled over and for some random reason the cop decides he needs to go to a ref to check on part legality.

 

As far as overall build principle. 10:1 is perfect imo if you're willing to tune it right. I plan to run MUCH higher on that on my build eventually but will also be unconventional in many ways. Right cam and the right tune and you'll be just fine.

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According to my calculations, on my motor,  46cc equates to 9.78 compression ratio and 42cc equates to 10.13.  I guess we do not know how much the head was decked prior to milling (I worried about this issue during milling with my head).  I agree that you should re-measure the cylinder chambers prior to engine assembly.  

 

I am beginning to like copper gaskets more and more.  They come in your choice of  thickness (.022,.032,.040,.043,.054,.063,.070, .086, .093, and .125 inches), they do not compress, and it allows you to build your motor exactly as you want it (noting that you can increase/decrease the gasket thickness slightly if you are shooting for a specific compression ratio.

 

 I purchase mine at Gasket works [email protected] for $135!

 

Building motors is just fun!  

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I measured the head with some vernier calipers before I took it in and the head seemed to be stock thickness (~108mm). It was in great shape and didn't look like it had been messed with. I plan to remeasure chamber volume just to be sure. I'll also measure head thickness to see how much was taken off.

 

A copper gasket sounds nice but the $135 might be hard to swallow right now! I still need to decide on fuel line routing and order AN lines and fittings which will be a pretty big expense. I'll keep the copper gaskets in mind, Jim.

 

Couple more things to cross off the list:

 

- Regrind rockers (shipped to Delta last week)

- sourcing 2mm/0.080" cam tower shims (ordered .080" 7075 shim stock yesterday :))

- sourcing longer valves (SI has great prices)

- low profile valve stem seals (FEL-PRO SS72686 bought on ebay)

- figuring out my cam and springs, lash pads may need replacement (made cam sizing spreadsheet, still need to call Isky...)

- Head gasket (will probably get Fel-Pro, maybe copper?)

- Manifold studs (MSA)

- Manifold gasket (turns out I have spares)

- Valve spring shims (TBD)

 

I'll also be going through boxes of parts this weekend and trying to inventory what I actually have.

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Got some 7075-T6 shim stock today and modeled up the shims...

 

post-3287-0-53217800-1371592002_thumb.jpg

post-3287-0-61421700-1371592003_thumb.jpg

 

I'll be cutting them on a CNC wire EDM for accuracy, plus there will be no burrs for me to clean up. Just perfectly sharp corners.

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Engine is back from the shop!

Block was bored out .020" and decked .004". It's a bit wet from a generous dose of WD40.

DSCN2069_zpsa5be364a.jpg

 

The head was shaved and got a 3-angle seat cut.

DSCN2068_zps6a6678af.jpg

 

Rods and pistons were balanced, pistons mounted (ITM flat tops), and rod bolts pressed in.

DSCN2071_zps2a2f1437.jpg

 

Today, I finally took my crank to a shop close to work who will polish it and send it off to be checked for balance. I'm including the flywheel with it to be balanced as well. Figured the crank pulley should be in balance, but I'm thinking of taking it in as well.

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New toys!  

 

I purchased some engine paint from autozone.  This paint actually cures above 100degrees.  I painted the block 2-3 light coats prior to re-assembly.  Be sure to remove the wd40 prior to paint when you do paint and prior to putting the head gasket on permanently.

 

Looks good!

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Take the pulley- they will want to balance that to the crank. The flywheel should be balanced all by itself.

Make sure your pulley is in good shape

 

Both the pulley and flywheel should be balanced all by themselves, as this is an internally balanced engine. The reason I'm not as concerned about the pulley is because it is a smaller-diameter part compared to the flywheel and "should" be balanced as long as it's in good shape. Plus, I may buy a new pulley in the near future.

 

The flywheel is an old 10lb Tilton unit and I'd like to make sure that it's in good shape.

 

Plus, I'd have to figure out which pulley I want to use from my collection!

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New toys!  

 

I purchased some engine paint from autozone.  This paint actually cures above 100degrees.  I painted the block 2-3 light coats prior to re-assembly.  Be sure to remove the wd40 prior to paint when you do paint and prior to putting the head gasket on permanently.

 

Looks good!

 

I got some Duplicolor engine paint at O'Reilly, Pontiac DE1610. It's about the closest you get to the stock color. I also got some self-etching primer for the block, as recommended by my engine guy. The WD will be removed and I will be cleaning everything obsessively, that's for sure.

 

Thanks Jim! :)

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I sent the P90 cam to Isky for a custom regrind today. I also heeded Steve's advice and took a crank pulley along with a couple of flywheels to the shop for balancing. I'm hoping I get my bottom end stuff back by next Friday, but I'm not sure what the timeline on the cam will be.

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No cam or crank yet, but I did take advantage of yesterday's beautiful weather to prep and paint the block right before leaving for vacation (paid the price for it via a hostile fiancee :twak: )!

 

Primed:

 

DSCN2099_zpsd54f18db.jpg

 

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Painted:

 

DSCN2101_zpscb2a8d11.jpg

 

DSCN2102_zpsd8740083.jpg

 

Also, found a brand new Nissan L28 head-gasket in my stash. I assume it's for an early L28 but I haven't confirmed.

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I'm finally ready to put the top-end together. Rockers were done by Delta in WA and the valve-train is from Iskenderian. :)

 

DSCN2104_zps0ad12c26.jpg

 

DSCN2106_zps079d4259.jpg

 

OK, more like almost ready. I've got the cam tower shims programmed up and ready to go into the EDM. I'll pop some holes into the Al shim stock and hopefully have some nice tower shims in the next day or two.

 

On another note, I registered for JCCS today. Time to start planning the trip (but first finish up wedding and honeymoon plans). :D

Edited by Leon

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Nice progress! Just get back from vacation and start working on my car tomorrow :-)

 

Thanks Takashi! I just got back from my vacation on Sunday, wish I could do that more often...

 

How's your Z doing, getting close?

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Good news and bad news...

 

The good news is that I picked up my crank, flywheels, and balancer from the machine shop today. The crank looked great and just needed a polish, the Tilton FW had to be balanced but the Fidanza didn't need it, and the harmonic damper also did not need balancing as I had suspected. This was all done as a double-check really, so it's mostly for peace-of-mind. The bottom end is ready to assemble, besides the main bearings which I ordered today.

 

The bad news is that our EDM hole-popper took a crap as I was booting it up today, so I wasn't able to make the shims... :( If I can't fix it quickly, I'll have to go the old-fashioned way and mill some starter holes.

Edited by Leon

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Painted the pulley yesterday and got my shims done today! Also, got a radio coming from Clive to round out my interior. Glad I found a nice original radio instead of the way-too-modern one in there.

 

Anyway, on to the shims. Thanks go out to the toolmakers at work for helping me out!

 

I milled starter holes into the stock

 

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Set up in the wire EDM

 

DSCN2108_zpsc4c54b41.jpg

 

The program

 

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Cutting the holes (don't mind the mistake :P )

 

DSCN2121_zpsc7e21973.jpg

 

DSCN2125_zps71d7b9b5.jpg

 

And we're done! I didn't take pics when cutting the profile unfortunately. I did make a few videos but I haven't watched them to see if they're interesting enough to upload.
 

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Main bearings should come in tomorrow and I should have no more excuses not to have this thing together. I borrowed mikes, snap gauge, and ring compressor from my neighbor. I just need a c-clamp style valve compressor and I should be set, besides the inevitable random seals and gaskets that I may have to get.

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Hi Leon.  It has been a while, was wondering how your engine rebuild is going?  

 

Hey Jim, good timing! It's been going pretty slowly...

 

Up until last weekend, it was a lot of parts cleaning, painting, and inventorying what I have. I finally spent all weekend doing engine stuff. This involved a lot of cleaning, assembly, and disassembly. I mic'd all crankshaft journals, the main bearings, and rod bearings (only did 1). From memory, main clearances were mostly .001" with a .0015" and .002" thrown in. Rods were in spec but I don't remember the number. This took quite a while, as I was getting a feel for using the mic and snap gauge. I also verified that 45ft-lb does indeed equate to .0065" of bolt stretch on the ARP rod bolts. I was going to install the crank but I found that the rear-main seal was really loose on the crank (more on that in a second).

 

Towards the end of Sunday I switched to the head and put the valves into their guides, and worked the stem seals onto the valves. The stem seals aren't fully installed yet, but that's the next job on the head. These Ford seals are a bit of a PITA to do right. Then I can temporarily install the outer springs and check the cam wipe pattern. I'm anticipating the need for thicker lash pads.

 

As for the rear main seal, it was very easy to fit it onto the crank and it had a bit of wobble to it when sitting on the crankshaft. It's a Nissan seal for a 200SX (if I remember right), but I cross-referenced the P/N and it said it works for a '79 and later 280ZX. I would think it's the right part then, but the really loose fit on the crank threw me off. Isn't the rear seal supposed to be pretty tight or does it get squished and tighten up when you install the crank into the block?

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