'77 280Z engine rebuild

[Orangys280Z]

I just started to try and rebuild the engine of my '77 280Z recently and found a few interesting things. For starters, I don't have the original block. The one in there is N42 and the head is N47. Though I have been wondering what's the difference between N42 and N47 blocks and heads? Also, cylinder #2 and #6 had bad compression. When I took the pistons out(all of them) I wiped them off a bit with a rag. I heard some metal hit the floor and saw that 25-30% of the first two rings fell off of 2 and 6! I'll try to post some pictures of them soon.

The other day I brought the head to UTI so I could put it in the hot tank and clean it off. Well, I found out that if a spring won't compress(I was using an pneumatic spring compressor) , don't hit it with a hammer too hard because the retainers will fall out and the spring will fly across the room :stupid:. I still can't find the outter spring and one of the retainer clips. The head looks almost new thanks to the hot tank. Have some residue left from the head gasket, I'm assuming, between some of the exhaust ports.

Speaking about exhaust ports, I noticed some tubes inside the ports that went all the way to the exhaust valves. Does anyone know what's up with that? Even my instructor didn't know what was up with that.

Does anyone have any suggestions on how to rebuild a L28E? I was thinking that since I'm rebuilding it I might as well put a LD28 crank in it since some water got in the oil(that's why I'm rebuilding). Anyone know how much a good one would go for? Or would I be better off with just a L28 crank price-wise and performance-wise?

[Curtis240Z]

The tubes you are refering to are probably the exhaust liners. The theory with those heads is the liner will glow red hot and help burn up the emissions for a cleaner car.

You need to decide what you ultimately plan to do with the engine to plan out your rebuild. The longer stroke with a diesel crank may pose clearance issues with the piston and valve clearance. There is more infomation regarding this type of modification at http://www.hybridz.org

[=Enigma=]

A simple Google search revealed the following useful pages...

http://www.geocities.com/inlinestroker/

http://www.zhome.com/rnt/3.1HanveyProject.htm

Based on all the possible ways a stroker build can go wrong, this is definitely not a project for the faint of heart or the newly initiated.

Edited January 3, 2010 by =Enigma=

[Orangys280Z]

Basically, I just want a reliable engine that can take me to my school and back everyday(about 55-65 miles round trip), and still show the Honda boys that Datsun Z-cars are better then the jokes they're driving with the hot-air intakes. I know where to get a head gasket to deal with the piston-to-valve clearance issues. Also, I would like to keep it Fuel Injected, possibly upgrading the injectors if I need to.

[Curtis240Z]

May be you found some superduper thick head gasket because a stroker motor usually requires different connecting rods and pistons. I stroker motor isn't just a crankshaft change.

Sounds like a more conventional route would be to install a slightly bigger cam since you have the head off and a lighter flywheel.

[WingZr0]

Hi bro, we have the same year Z's . Mines is a newly rebuilt engine to with only 1,274 miles on it. Heres my bit of advice, the stock injectors will work more than fine so get new ones or have the old ones rebuilt. And also your head may loosen from the block, you'll see a little sipping from the passanger side head gasket. Don't trip it's just means the head bolts need to be retorqued, your head gaskets not blown. Also I would surly get a new aluminum radiator and electric fan from MSA. Pratically gurantees you won't ruin the new engine due to over heating. Thats what I have and my engine runs well on the cold side ALL DAY LONG, city or freeway.

Edited January 3, 2010 by WingZr0

[WingZr0]

BTW spring for a new water temp sensor too. If thats acting up it'll cause fuel enrichment issues causing mis fires, possible other issues and eventually the oil will start to smell like gasoline. So 30 bucks will prevent that. The cylinder head thing from earlier usually happens during the first 1,000 miles of breaking in the engine. ~Z~

Edited January 3, 2010 by WingZr0

[Orangys280Z]

May be you found some superduper thick head gasket because a stroker motor usually requires different connecting rods and pistons. I stroker motor isn't just a crankshaft change.

Sounds like a more conventional route would be to install a slightly bigger cam since you have the head off and a lighter flywheel.

I found a place that has a 2.5mm and 3mm metal headgasket. The company is called Kameari.

I heard of some people using KA24 pistons and I believe the same rods as well. But I'm not 100% sure on those clearances.

If I do go through with making my L28 a stroker and keep it injected, can I still use the stock injectors or would I be a good idea to upgrade them? If so, how big of an injector should I use?

[Orangys280Z]

That's good to know, Thanks WingZr0! Before all this happened I know my Z was overheating all the time. I still don't know how I got water in the oil though. I don't see any cracks in the head, or on the head gasket and block. As soon as I'm able to, I'll post some pictures of everything, maybe I'm overlooking something.

[WingZr0]

Well far as this part of your problem with oil in the water, if your over heating them your head gasket's blown or the block deck or head warped. When my water temp sensor was bad it felt like my Z was running hot, I mean with the hood up and looking at the engine, to the point of almost excessive. But when the electric fan kicked in at 160 degres all the heat was INSTANTLY evacuated. Pretty much saving the HG for my water is still oil free, this will work for you for sure. Your radiator might be done too cousing over heat so save yourself the the same amount of cash instead of boiling it out and get the aluminum that will work way more better to start alone by itself.

Edited January 4, 2010 by WingZr0

[WingZr0]

Lastly, if you can afford it, replace off your connector plugs. All of them. Theres about 10 or 11 of them and they are all the same as the ful injector plugs. They are the 6 FI plugs, cold start valve, water temp sensor and so forth. MSA has all those plugs at $8 each. Member Sblake can maybe help with the TPS sensor plug as its one not sold after market. Have your engine builder solder on the new plugs in place of the old ones, no need in messing around with old plugs with faulty connections, aka non working fuel injectors, on a new engine. That should take care of your minor basics . ~Z~

Edited January 4, 2010 by WingZr0

[=Enigma=]

If reliability for a car used primarily for commuiting is what you're looking for, a stroker is really not your best choice. My recommendation would be to keep it simple and upgrade your cam, ignition, exhaust, and either get your injectors professionally cleaned or replaced. Don't forget to R&R the other systems since it sounds like you'll be sparring with the Folgers punks. It would be a real shame to beat the other car between lights only to find that you can't stop in time for the next one, or even worse that you never make it because something else broke. Just my humble opinion.