getZ

I was wondering if anybody had an ignitor (power transistor) that had a part number that could be read. Mine is from an 81 turbo motor and is completely dead. I tested it by measuring the resistance across the base and collector and reversed the connection. They both almost 0 resistance. A similar power transistor measured almost a short in one direction and about 2k Ohms in the opposite direction which is what I expected. I tried putting what I thought was a similar tranistor in its place which turned out to be a very bad idea. I went out to grab a bite and it overheated and blew up my new blaster II coil....... oil everywhere. Okay that was a stupid thing to do. I'll attempt another transistor replacement if anybody has a part number they can read off their ignitor transistor. The only reason I attempt it is because the transistor may only be 5 bucks versus a 100 bucks for a whole new ignitor. This time I got the fire extinguisher standing by......

You can get a cable in two places that I know of: http://www.motorsportauto.com/specials.htm http://www.jagsthatrun.com/Pages/Datsun_Z_V-8.html MSA also sells adapters for different rearend gear ratios

Invest in a wideband O2 sensor and see how it is running. I'm always amazed to see the gains some people make with some dyno time and a bit of tuning. Of course that will probably mean getting a new chip made.

How did you wire the fuel pump? The output of the ecu for the fuel pump will not drive the pump. It has to be hooked up to a relay. Computer outputs do not put out enough current to drive such large devices. The ignitor is a power transistor and in the case of the z car used like a relay. The voltage at the base (ignitor input) has to always be on for the coil to have power. In reality the power is always connected and the output signal from the ecu connects the negative end of the coil to ground. It also should not take much of a voltage to drive the ignitor to switch the coil on. I can see my ignitor go on but it is only something like 2 volts. It probably only need .7 volts to work. By the way the ignitor signal does look like a pulse because it is not a steady output. When first switched on the voltage is about 3 volts and then drops down, but it cannot go to zero or the coil will not work.

What are you trying to accomplish? I assume you are adding a nine inch because you want to make the car a serious drag car. I've seen camaro guys just weld a bar across the rear "psuedo" frame rails and mount coil overs right to the bar. I'm not sure how strong those z car frame rails are, my guess is it would work, but if you really are planning to make that thing fast I would go to an after market set of frame rails and back half the car with somebody elses complete kit and consider connecting up at least a roll bar to the rear frame rails. Besides a lot of tracks make that stuff mandatory if you are really fast. Getting leafsprings to work sounds like a lot more work. I see guys doing stuff like this and they often start with what tire they want to run and work around that.

found some info doing a search with "ecu" these are mine and they are both turbo ecus: a-18 600 041 and a-18 601 042

If you didn't get the pistons yet and they are a custom order, you can order them with a press fit pin. Not sure if it's the same price or not. The cost of reworking the rods is not that much. I have a machine shop here in the US that will do the work for about a couple hundred bucks for the set. That's not just for the small end of the rod. It's for magnufluxing, hot tanking, resizing both small end and big end for out of roundness. Not sure what shipping is from your part of the world. I do have a colleages in the Netherlands who knows of a few reputable shops. Not sure if that any cheaper either.

One more thing to think about with those forged pistons. They come with floating wrist pins (they rotate in the piston and on the rod), don't think they are available as a press fit. That being the case you will have to have the small end of the rod enlarged by a machine shop. I elected not to put in a brass bushings (sleeves) and just run the wrist pin in the enlarged rod end. I guess the idea behind the bushing was it saved the rod and wrist pin from wear. Had I been able to find the brass bushings at a reasonable price I probably would have used them. My local machine shop said they talked to the guys at Top End performance and what they were doing was machining their own bushing from round brass stock. It sounded like a big added expense with out a lot of benefit.

by the way. You will have to at least hone the bores if you change rings out or they will never seat right. If they don't seat they can rotate and if the top ring is in phase with the second ring you will get excessive blow by.

As far as I know cheap forged turbo pistons do not exist. The lowest I've seen so far are around 500 dollars US. Speed costs money. How much durable power you make is directly related to how much you are going to spend. You'll get a lot of varying opinions about what minimum cheap rebuild will cost. Just remember; "You get what you pay for." Go cheap and the motor will not last. Did you ever get your book: "How to Rebuild Your Nissan and Datsun?" That book is pretty good with specs, tearing down the engine and going through and measuring bore taper, out of roundness etc. You are going to have to pull the block out to take out the pistons. Stock pistons are press fitted into the rods and cannot be removed without taking the crankshaft out.

You didn't mention anything about intercooling. There are supercharger kits for the LS series small block chevys with around 11:1 compression running 6-7lbs of boost as well. The way around dealing with the high compression is intercooling. If you are building a dedicated supercharged or turbo charged engine you'll make more power raising the boost rather than raising the final compression ratio.

A 2mm head gasket would increase the head volume and lower the final compression ratio. A simpler way of thinking of this would be to imagine the volume of the cylinder at the bottom of the stroke divided by the cylinder at the top of the stroke. Increasing the gasket thickness changes the volume of both, but because it is a much greater percentage of the volume of the cylinder at the top of the stroke the compression ratio goes down. Not sure if that was any easier to understand or not. Anyhow, the lower compression allows you to get away with more boost, which is why a lot of people run it. Apparently this change does not adversly change the valve train geometry. I only say that because I have heard of a lot of people have done it with no problems. It adds .8mm to the original deck height, like making the head thicker instead of shaving it. I know there are shims for the cam tower, but I haven't heard of anybody shaving down the cam tower after adding a thicker head gasket. That's just my 2 cents.

I have a similar situation, a 1mm headgasket, but with custom forged pistons that were supposed to give me a final compression of 8.0:1. The timing chain I put in was brand new and seemed a little tight. I'll let you know how it goes. I'm almost ready to break my new motor in. Hopefully this weekend. I had the same concerns about the head gasket thickness affecting the timing. I think spec for shaving a head was something like .2mm and a stock gasket compressed was at 1.2mm so you should be just on the edge of what my book specs (How to Rebuild Nissans). Off the top of my head a full point of compression is worth somthing like 10% more horsepower so you are looking at something like 1.5% increase in power. You will probably see greater horsepower changes with a change in the weather.

I don't know why I didn't look there before. It was less than five bucks at motorsport.

this might be a dumb question but where can you get a replacement dipstick tube for an 280zx engine? My original tube was mangled taking it off before the block went out to the machine shop. I was going to swipe one out of a junkyard, but they don't come out so easy either.

okay, since you're to cheap to buy a manual. from "How to Rebuild Your Nissan Datsun OHC Engine" by Tom Monroe L28 cylinder head bolt torque 65ft-lb/9.0kg-m 14 13 10 9 6 5 2 1 4 3 8 7 12 11 front of engine from "1981 Datsun 280zx Turbo Service Manual" valve clearance mm (in) ::::: hot ::::: intake .25 (.010) exhaust .30 (.012) ::::: cold ::::: intake .17 (.007) exhaust .24 (.009) *note this is not for an 83 which has hyraulic lifters (so I've been told) You can get the first book listed from MSA. I had to search for the factory manual. I think you can get those on CD from Nissan.

over the last year I have only seen AZ car forged pistons as 1.0mm /.040 inches for an overbore. Have the engine bored out and you should be good to go.

bastaad525, You need a metric adapter if you want to run AN connections. I'm installing the same filter adapter plate as well. You can get it at summit racing or several other mail order speed shops. It is a 18mx 1.5 to 10AN. I did the same thing but it is definitely not the el cheapo route, but man does it look good. Two 18mm/10 AN adapters and 10AN elbows ran 70 bucks.

The first set of pistons look very strange. I don't know why you would ever chamfer the outside edge of the piston. You would create pockets on the outside that keep a good even burn throughout the chamber. It looks like some kind of attempt to raise the compression. Flat tops or the dished ones would work better.

I couldn't find the post for this, it was a side topic in a posting a while back about putting a bung in the fuel sending unit on a 240z tank to use as a fuel return line. Well I did it. I'd post the pictures if I could figure out how to attach the pictures. First, it sounded easier then it was. The space to put the hole is not very big. Unless you want to relocate the tack weld that the lever arm is mounted, the spacing leaves little room for error not to mention the chance of breaking something is very good. I used an air tool inlet as a bung and welded it on to the cap after cutting the quick disconnect end off. Another point in doing this keeping the unit cool while you weld so you don't melt the solder (which can easily be resoldered if you unsolder or break it). One other point, I drilled the fitting out as not to be restrictive. I thought about using a pipe threaded AN style fitting, but getting a jam nut on the back is really tough. My car came from Tuscon if your car has a lot of rust I think getting the sending unit off is next to impossible. If you are looking for an easy way to create a return line you might think about using what some of the mustang guys were using to convert the early fox bodies over to fuel injection. A short section of pipe with a bung welded on it and clamped the fuel inlet pipe at both end, much simpler at least without actually trying it. It took me about a day to finish mines, including droping the tank.

does anybody have preference of alchohol over water (for the car not for you). My understanding is water has a greater capacity for absorbing heat in the combustion chamber but alchohol does a better job cooling the intake charge.

sweet! Now, how do you mount the m62?

that m62 sounds interesting. I'm curious to see how it fit in there. Why carbs? They are easier to install, but more finicky to keep in tune. I saw another way to seal the carb without sealing the entire carb, but it required better throttle shaft seals and just a top hat. How do you deal with the airfuel mixture under boost with a carb, just by rejetting. If you run 9lb of boost can it keep up? Then if you bypass the supercharger will it run way rich?