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81ZX NA + MSII + N42 + 2mm MLS HG + ...


naviathan

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This car has become an ongoing project. It's become more than the simple head gasket change I intended it to be, but that seems to be the way things go in my garage. Things start out simple and end up a full on project.

 

Some Background!

 

My 81ZX DD has been down for going on 9 months now. It started after a trip to Myrtle Beach with wife to visit family. I got stuck in traffic and she over heated a bit. Never pegged the gauge, but came very close several times.

Well drove it home thinking it was fine because it acted like normal. After every long trip I like to check and change the fluids. The oil was goop. I realized I was getting coolant in the block and I knew what had to be done. For me this was a blessing in disguise and I knew it. YAY! Upgrade time! If the car was going to be down it would be better than ever when it came back up. I immediately purchased an MSII kit online and put it together. Ok time for a new cam as well and I just happened to have one I was saving for a stroker project, but I figured it would serve well in my DD for now. After pulling the head I realized it was badly warped. Straight edge showed a huge gap and the cam was difficult to turn in the towers (required a large set of channel locks). Fine I have another head. An N42, I'll throw that in the machine shop and put the new springs, cam and rockers in it and go to town.

 

And I couldn't be more wrong. At the time I didn't realize the N42 would up the compression. That wasn't the start of the problems though. First I ripped the nose off 5 of the cam lobes. So one performance cam down the drain. Turned out the valves that were in my N42 were too short....Yeah not sure how that happened. The engine I pulled the head from came off a 76 and the valve seats were steel, meaning someone had done some head work at one point. I'm not sure why they would have put shorter valves in, but it really screwed my engine up. So cleaned engine, replaced cam with stock :( and replaced the valves with some stainless ones I was saving. Up side is my machinist identified the valves and can get them for me for less than half what I paid from Arizona Z Car. Anyhow, put it back together, installed MSII and universal harness, locked distributor and cranked it up. Took a while to get the base timing set, but she eventually came to life. And ran like crap. The AFRs were all over the board and she had no power. Then she popped the head gasket. Pulled the head again and by this point I was 3 months into the project and leaving for Iraq.

 

Welcome to today. I'm not home yet, but my 6 months in Iraq is almost done. I've realized my error with the head and now have a plan to throw in a 2mm MLS head gasket, some ARP head studs and get some good high octane gas in her so she can actually run with the high compression. Next up, getting home and starting over again...Wish me luck.

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  • 1 month later...

The head is off and I'm buying parts. Things have been very slow with this build, but I have a very good excuse, my son Jayden was born on May 15th. I'm picking up a porting kit from Summit with my ARP head studs and I'll update when I start on the porting.

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I'm all excited now I just received my 34# 14mm injectors (thanks abes!). Then I placed an order with Summit for a valve spring compressor, port and polish kit and ARP head stud set. Next I ordered a "Stage IV" Camshaft (.495/.495 Lift with 290/290 duration) and a 2mm MLS Head Gasket from MSA. Last but not least I email pallnet about one of his rails with all the trimmings for the new injectors.

 

Before anyone says anything about the MSA camshaft I bought it out of convenience only. If I was really taking my time here I would have sent a cam out to be reground.

 

YAY!!! I can't wait.

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Ever have one of those moments that makes you feel like you've wasted so much time and effort for nothing at all? I just did.

I received an email from Jon at Motorsport auto about my order. He informed me that my cam was shipped, but my head gasket was on backorder for an undetermined amount of time. I'm sure this is already well known around the forum and I should have searched, but apparently they get their gaskets from Nissan, who has stopped producing them with no eta for reproduction. Anyhow, I had ordered a 2mm head gasket from MSA back in 2005 for my 77 project that I've hardly even dented the surface of. Well I could never find the 2mm head gasket from that order and of course by the time I went looking for it, I was too late, the order was months old because I was in Iraq at the time. Well fast forward to today I asked Jon if they might have shipped a gasket in a box sized for a body kit (being that the body kit was the only box I hadn't opened). He says it's possible. Low and behold, I cut open one end of the massive box my body kit is in and there it sits, like it was waiting for this moment, a brand new unopened 2mm MLS head gasket. To top it off, all the ports that were blocked by my previous gaskets are now open with this gasket lined up. It's thick, very well made and just make me smile to think about how my engine will run once this fiasco is complete. Anyhow, I felt like a fool for never looking inside the box, but I'm kind of glad I didn't somehow.

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  • 7 months later...

I haven't updated in a while so I guess now is a good time. The N42 head is toast. I tried porting it myself and cut into the water jackets. Sadly I thought porting an L28 head would be like porting anything else. Well despite the porting guides on the net you do not want to cut into the short side radius of a L series head. Lesson learned, maybe one day I'll find a way to repair it or find another N42 to work with. For now I've pulled the E88 from my 77. Interesting thing that 77. It has a 260 block and head that were both bored to a 2.8L and had new seats and valves installed the same size as the N42. Good thing too because I was able to swap my swirl polished stainless valves right over. So, I made some port measurements this time. Come to find out, the E88 ports are so much larger than the intake runners that the only thing I can think that really needs to be done to them is smooth the walls down. So, maybe one day in the future, but for now I haven't the time. I have all my parts in finally, including the .220 and .260 lash pads I was waiting on. Time is not my friend however. Any time I do have is spent with the many other projects I have going on. So, maybe by summer I'll have my Z back...Maybe.

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