1978 280z Engine Rebuild project

[siteunseen]

I bought a gallon, way too much!, of Rustoleum flat oil and a gallon of high gloss.  Then mixed 50/50 for a nice satin finish for my suspension parts but I'm thinking I'll go 75/25 for a glossier finish on my oil pan.  Looking at a ton of pictures, the oil pan has more sheen.  I used a rattle can of Rustoleum grey etching primer after a good cleaning with 220 grit sanding sponge.  Get a new copper washer for the plug while you're at it and hammer down around the edge.  I used a 5 lb sledge and a small piece of 1x4.  I've read the same about POR 15, not worth the trouble for something that'll never get touched.

I'll spray it today, next door kids played in their yard all day yesterday and they're parents are freaks when they smell something chemically. 

[Patcon]

10 hours ago, Mark Maras said:

IMO, I would add one more thing to lumens' procedure. After wire brushing and sanding, I would treat the bare metal with Ospho before painting.

^^^ Ditto, What Mark said...

[txvepr]

Taking the pistons out. Found this. Glad it didn't leave its seat. Some of the other piston bearings have wear that show up as the copper color too.

Looking at these main bearings. They look worn, but I think this would be normal wear for an engine this old. Somebody chime in!

The crankshaft spun freely in the block, so I think it is straight.

I got Parts!

 

[rossiz]

folks on the forum have had good luck w/clevite bearing sets - i went this route and all is good so far.

biggest difference in my build vs. stock comes from having things balanced. the shop did the whole rotating assembly, including crank, flywheel, clutch assy. & harmonic balancer. add to that turning down the flywheel for weight reduction and she spins up quite quickly. with the stock motor the rear view mirror would blur at 5,500 rpm, new one runs soooo much smoother all the way up to 7K.

[Patcon]

The crank turning smoothly is not an indication of straightness. These cranks are long and can be out of spec and still turn, especially with the clearances you have on those bearings. I always take my cranks to a local crank specialist. They check them for straightness, straighten them if needed, crack check them and polish or turn them.

rossiz is right, balancing makes everything better...

There looks like there is Automotive Crankshaft service in Richland Hills that might be able to help you out. Make some calls. There were 2 more in the yellow pages. Since you are in the Fort Worth / Dallas area I would suspect there are more than that.

Who is doing the machine work? vatting /  boring and hone / decking / checking the head

They can probably make a recommendation too...

[Zed Head]

20 minutes ago, rossiz said:

with the stock motor the rear view mirror would blur at 5,500 rpm, new one runs soooo much smoother all the way up to 7K.

Why are you looking in the mirror at  5,500 RPM?

To txv - isn't the crank nose key way messed up anyway?  Might want to do some math on fixing versus replacing.  Actually, do math on whatever you're attempting, there are plenty of used engines out there that just need a freshening, compared to a total rebuild for yours.  That looks pretty messed up.  The vibration fatiguing from the bad damper might have caused other problems, and might have contributed to the fractured bearing.  Who knows.

[txvepr]

I had planned on taking the block to City Motor Supply in Dallas. I'll have them do the crank too. They seemed to have a good rep overall. 

[Patcon]

 

9 minutes ago, Zed Head said:

Why are you looking in the mirror at  5,500 RPM?

That's 5,500 rpm in reverse

Good point on the crank Zed, I had forgotten about the bad keyway, the crank is pretty much stuffed anyway. When I take an engine apart, I rarely refresh, I just build them top to bottom. I hate doing a job twice and I one threw a rod out the side of a I-6 BMW motor that had been "refreshed". It costs some more but on a Datsun I probably won't have to touch it again in my lifetime.

[siteunseen]

11 hours ago, Zed Head said:

Why are you looking in the mirror at  5,500 RPM?

Flashing lights coming out of the woods and smoke are a couple of my reasons. 

I am constantly looking in the mirrors, you never know when a Mustang or something wants to get a run up on you.  If you see one coming, drop down a couple of gears and that's all you'll see of him, in the mirror. 

[rossiz]

12 hours ago, Zed Head said:

Why are you looking in the mirror at  5,500 RPM?

site has it - smoke check.

with the original motor i was having issues with oil consumption and poor AFR due to the efi system. during troubleshooting i was checking to see how much carbon was blowing out during an "italian tune up" every so often. after 5,500 RPM i couldn't see much out of the rear view mirror. the balanced/lightened motor spins up to 7K quite quickly (and makes an awesome sound in the process). it's quite addictive ;}

site has it again - w/the new motor, since there's no smoke at all, i find myself glancing nervously in the rear view looking for flashing lights...

[Chickenman]

Whatsa behind you... isa no matter!!

[txvepr]

Ugh, this does not look good. #6 piston, after cleaning. Can you see the 'X' on the piston? It looks pretty clear to the eye, but I cannot tell how deep this is. There is no sign of crackage on the bottom end of it.  

I don't think this is normal, but then again, this is my first time around.

I was hoping that I could re-use these. With a magnifying glass I could not see if these marks actually penetrate into the depth of the piston top.

Edited February 22, 2016 by txvepr