bschiltz Posted April 27, 2006 Share Posted April 27, 2006 I need some help with my 1979 280zx. First off, I'm 17 years old so I don't have much/any mechanical experience or garage space. I bought the car in December from my brother for $300 not realizing how much work it would be to 'fix it up'. It sat in my garage for a month or so, then I tried taking the sparks plugs out and wirebrushing them (they were blacker that all get out) and it started up. At this point, I was still fairly set on a V8 swap as the motor (as far as I could figure) had a blown head gasket ('wet black' spark plugs) and some sticky/ cloged fule injectors (read on 'zcar.com' about a clicking sound coming from the injectors). About a week ago I was messing with the car again and cleaned the spark plugs off with carb throttle body/choke cleaner. When I was putting them in, I sprayed a little carb cleaner in each cylinder (figured it'd give it a kick in the a** starting, if nothing else) and it's started several more times without cleaning the plugs. I plan on changing the oil and plugs to see if it makes a difference. So, rebuild or swap? No matter what I do, I'm probably going to have to get a shop to do it. Thanks in advance Ben Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 28, 2006 Share Posted April 28, 2006 If you don't have much mechanical experiance the you should just do a rebuild. A swap requires a lot of fabrication. Unless you know how to weld... An L28 is a pretty easy engine to rebuild. there is a book called "how to rebuild your nissan OHC engine" and its great. It has step by step pictures and instructions, its hard to mess it up. before you start read, read, read, ask questions and go slow and you will make a kick a$$ L28. Good luck. P.S. there is a lot of help on this site that can get you some more horse power for pretty cheap. Quote Link to comment Share on other sites More sharing options...
bschiltz Posted April 28, 2006 Author Share Posted April 28, 2006 Thanks zeiss. How much do you think a rebuild would cost if I do most of the work myself? I'll check out that book, too. As per the HP, I'm not realy woried about anything crazy, the car is going to be my daily driver. Too much power ( ) and gas prices realy put me off the V8 swap. Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted April 29, 2006 Share Posted April 29, 2006 with flat top pistons 20thousands over bore and a 1mm head gasket with a P79 head that will give you a nice compression raito of 8.8:1. Put on a header and 2.5in. exaust. Add a 60mm throttle body use a little better ignition, larger fuel injectors and a better engine computer and you'll have real nice 170 t0 180 rear wheel horse power engine. As far as the cost... short block rebuild ... 20thou over bore new pistons and rings $300 gasket and seal kit $100 valve stem seals/ clean up your head $100 60mm throttle body $35 at the junk yard (you get one from a 240SX) megasquirt $300 header and exaust $200 larger injectors $75 now you could go the less expensive rout and and that would be new rings and bearings $150 gasket set $50 60mm tb $35 or just check the compression in each cylinder (150 psi I think) as long as there all with in a few psi of eachother just leave the short block alone. spend your money on the exaust and throttle body and cold air induction and a better ignition. It just depend on how much money you have to spend. There are about a million different ways to build a Z engine. Good luck let me know if you have any other questions P.S. the prices are just my best guess on how much I paid a few years ago. Quote Link to comment Share on other sites More sharing options...
bschiltz Posted April 29, 2006 Author Share Posted April 29, 2006 Very cool, thanks again! I ordered the "How to rebuild your Nissan OHC engine" and "Restoring your Z car" last night on Amazon so I'm hoping those will help a lot. Quote Link to comment Share on other sites More sharing options...
bschiltz Posted May 21, 2006 Author Share Posted May 21, 2006 ok, so I've read the rebuild book and am still not realy sure about what to do. How hard is it to actually rebuild the engine? I'm good at figuring things out and working with my hands if that helps. What about getting the engine out of the car? I know somewhere where I can rent a 'cherry picker' but am not so sure about actually pulling the thing. Also, would it be best to buy a stand or can you go without one? Thanks a ton! Ben Quote Link to comment Share on other sites More sharing options...
z-ya Posted May 21, 2006 Share Posted May 21, 2006 You need to pull the engine to rebuild it or replace it. It is much easier to find a good used engine, then do the swap, than it is to rebuild an engine. If you are new to mechanics, try doing an engine swap first. Before swapping anything, I would first be sure that the motor that is in there is bad. Just because the plugs are bacl and wet, doesn't mean the motor is junk. There could be problems with the fuel injection that is causeing it to run real rich. If you know the head gasket is blown (because a professional told you), then you can replace the head gasket. Yea, it's a lot of work, but it a lot cheaper than replacing the engine. Quote Link to comment Share on other sites More sharing options...
nosebleedZ Posted May 21, 2006 Share Posted May 21, 2006 I live in eastern Tennesse which is where most zx cars were apparently sold and laid to rest. I have a friend here that could get you a great deal on a used N/A motor or even a complete turbo motor w/ all electronics for a little more. But I TOTALLY agree with the other guys, black plugs are 90% of the time not the engine, but the EFI. Have it checked before spending a dime! Quote Link to comment Share on other sites More sharing options...
bschiltz Posted May 21, 2006 Author Share Posted May 21, 2006 I was a little unclear, I guess. It's more than the plugs which makes me think the head gasket is blown. When it runs at idle, the oil pressure gauge reads zero untill you rev to about 2k RPM. Also, when you check the oil with the dip stick, it's very runny and about 1/2 inch over the 'full' mark. Like I said, I think it's a blown headgasket, but haven't had anyone look at it yet. Thanks Ben Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted May 21, 2006 Share Posted May 21, 2006 Hey Ben. I believe in the "how to rebuild your datsun nissan sohc engine" book it has a section in the front detailing how to determine whether or not your engine needs to be rebuilt. For a blown head gasket you want to check cylinder pressure (you can get a gague at the parts store for about $20) if you have two cylinders right next to eachother that have low pressure then you probably have a blown head gasket (example... cylinders 4 and 5 have a psi of 45 and 55 but the rest of the cylinders have a psi of 160). check each of the 6 cylinders for equil pressure they should all be within 10psi of eachother I believe that if you get a minimum of 150psi accros the cylinders then the bottom end is just fine and doesn't nessarily need a rebuild. Another easy check for a head gasket leak is green coolant in your oil. Drain the oil in to a pan and let it set for about a half hour if you have green water bubbles floating on the top of your oil then you probably have a blown head gasket. Other indications for an engine rebuild are: how many miles does the engine have on it? If it has 150 thou + you might consider a rebuild. Also is it an automatic transmission or is it manual? if its an auto, the engine might be in better shape because its harder for the driver to abuse the engine. Lastly and most importantly ... the main reason that I recomend an engine rebuild instead of a swap is because of what you want to do with the car. In your first post you talked about putting in a V8, this would imply that you are looking to make some pretty substaintial horse power. If you swap an old engine in you might have problems with that engine a few thousand miles down the road. also any mods that you do on it to increase HP would not be as effective as they would be with a fresh rebuild. Keep in mind that the most RWHP (Rear Wheel Horse Power) that I have ever heard of comming out of a "slightly modified" L28 is about 180. With the heaver ZX body thats not going to get you a 12 sec 1/4 mile car... more like a 15sec at best. That is not to say that A 200 + RWHP N/A L28 cannot be built, but it is to say with "bolt on mods" it is unlikely to be built. If you wan't real HP out of an L28 then Turbo is your only option. There are two kinds of Z owners ... the first kind loves the Z car and enjoys the drive but when it comes to the mechanics of the car they would rather spend the money and have it fixed by a shop than get there hands dirty. There is nothing wrong with this kind of Z owner! The second kind of Z owner is the kind like myself and many, many others on this site, we dream about our Z's, we can't wait for the weekend so we can install the new part that is going to give us 2.5 more RWHP. We don't mind the Exaust smell, we visit Z forums online 2 or 3 times a day to help others with there Z's. Rebuilding an engine is not only a challenge but its FUN! For us the Z isn't just a car its a hobbie. What kind of Z owner are you? As to whether or not you have the skills to rebuild your L28, well... 3 years ago I barely knew how to change the oil on my car let alone rebuild an engine. I did what you did, I bought the books, did my research, studied, read, studied some more, made a bunch of mistakes, and I have learned how to do just about everything on my own. I am no super genius (as you can tell my my numorus spelling errors) but I have a passion for my Z. If you have a basic understanding of tools, you like a challange, and you don't give up easy, you can rebuild your engine! If you have ever built a model (car, airplane, ship, whatever) in your life, you can rebuild your engine. If you can hook up aduio and video equipment then you can rebuild your engine. Should you rebuild your engine... well, thats up to you. What kind of a Z owner are you? Good luck we are always here to help with whatever you decide. Matt- P.S. A turbo swap is more complicated but if your gonna take it all apart you might as well put it back together the way you REALY want it! Quote Link to comment Share on other sites More sharing options...
bschiltz Posted May 22, 2006 Author Share Posted May 22, 2006 Right, Thanks all of you for the help. I'll check compression and go from there. NosebleedZ, Thank you very much for the offer, I'll keep that in mind. I'm going to be the second kind of Z owner...Wish me luck Ben Quote Link to comment Share on other sites More sharing options...
CerebralSponge Posted November 13, 2008 Share Posted November 13, 2008 "How to rebuild your Nissan OHC engine" and "Restoring your Z car" Sorry to kind of thread jack, but does anybody know if this book includes the l28et? it say's through l28 so I'm assuming it covers all models. I know it's basically the same but I'm looking to rip open an engine for the first time and want all the info to be there. P.s. This threat is great. Quote Link to comment Share on other sites More sharing options...
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