z-ya

Isn't the wall thickness most important when porting the intake? It is not so important what the port size is now, but how much material can you remove without effecting the strength of the manifold. What are you trying o accomplish? Do you want to put together a spreadsheet that shows all port sizes, wall thicknesses, etc for all L6 manifolds? Or, do you have some project in mind? In the case of port matching EFI manifolds to the stock port size on N and P series heads, there is plenty of material. I have done this on N42, Turbo, and a 280ZX NA manifold. So unless you are going to enlarge the stock head intake port size dramatically, all EFI manifolds can be port matched. For my SU/EFI project, I have been able to port match it to a stock manifold gasket without the wall thickness getting too thin where the two manifolds were grafted together. This manifold will be used on either my race car and dyno tuned in August, or on the 3.1L I'm building for my 71' project.

I couldn't agree more. Microsoft likes to change things, just for sake of changing them. Vista. What does Vista offer that XP can't do? Why did they move common functions around in Vista as compared to XP? Job security? Let's keep the technical marketing department busy? A new challenge for the engineering group? What about Office 2007? Anyone try to use that yet? Yes, there are a few cool new features, but I am constantly trying to figure out how to do something that was second nature to me in Office 2003. Plus, the file format is different, so you alway have to "save as" an Office 2003 document. Another difference you have to remember. How about trying to make it easier for your customer to use your product (what a concept!)! Sorry for the vent, but have developed and support products on Unix/Linux for 20+ years, so I am biased.

Not all that pretty, but functional, and cheap. http://www.geocities.com/hrayhouston/antisurgetank.html

How much boost do you plan on running? The stock one can easily handle 15psi without detonation. Do a little searching and read up about why a stock gasket can save your engine.

What is a MLS head gasket? A metal one? Why not just use an Nissan OEM one?

What is important is how close to the sensor the fan motor is. If the fan motor is more than 3" away, you should be all set. Mounting the fan in front of the radiator will fix it for sure. As far as the water pump and alternator, I would just wait and see. If the RPM in Megatune jumps around, try temporarily disconnecting the water pump power. Next, pull the power to the alternator. Lastly, just remove the alternator belt to see if you get a stable tach signal. Hopfully you won't have to do any of this... Pete

Interesting way to mount the wheel to the damper. Nice work. Just be sure that the sensor bracket is rigid enough so that it doesn't move around at high RPM. Pete

I have had problems with an electric fan mounted too close to the VR (crank) sensor. Caused all sorts of input trigger errors, causing the engine to miss. Moved it away from the sensor, problem fixed. Pete

Have you verified the timing with a timing light? Just because you have 21 deg set in Megatune, it doesn't mean that that is the actual ignition timing. Verify that the timing you set in the timing table matches what you measure with a timing light. It shouldn't use any oil. I run multiple tack events on an oil change with a similar engine and I never see oil loss. What are they gapped to? 35 thousands is good for your engine. Yes, they look a little light, but there doesn't seem to be a lot of oil residue on them.

All that machining to use the LD block is going to cost you. And all that crank work is going to cost a lot too. After all of this work, what you end up with will not be any better than a well built L28. Since your goals are only 200HP (at the crank I am assuming), I would suggest the following configuration: L28 block bored 1mm ITM Flat top L28 pistons Stock L28 Crank Stock L28 rods Felpro head gasket (1mm) Mild street cam P90 or P79 head Mild port work (clean up) Port match intake manifold to head Header This should yield an 8.9:1 CR, which with a P series head should allow you to run on 89 octane with a modest tune. My concern is with all that machine work and part mix and matching. What will be the reliability of the end product? Yea, it will be a great conversation piece, but you can build rock solid L28 using the configuration above that will perform as well or better. Plus you will save a lot of $ in the end. Just my opinion... Pete

Put the N42 head on the L28 that has the P79 on it (flat top P79 pistons). This will get close 10:1 CR. A medium street cam, headers, intake port matching, and proper tuning can get you to 180WHP.

Yes, a 30A relay should handle both pumps. If you are running a pump that requires a lot of power, you can always add another relay.

Why not just add a sump to the stock tank or add a small surge tank. Your going to have to cut the crap out of you nice restoration to install that plastic Summit cell. You are going to loose your spare too, right? Unless you are going racing, the stock tank is the way to go.

Glad to hear it works! My initial concern was that you are now powering three coils through a tach that originally powered only one stock one. Since they are not firing at the same time, this should not be a problem. But, your modern wasted spark coils do use more power. Again, I don't think it will be a problem because I know many people that run hot coils through the stock tach. Pete

I've had the best luck with OEM Nissan gaskets for both turbo and NA header applications. Copper gaskets should work very well. I think if you look at cost, the Nissan OEM on e is the best. They are made by Ishino gasket, and you can find them in the aftermarket.

I've seen late 73s that had the voltage tach. Pete

Vista is not hard to use, performs faily well (not quite as god as XP), and will run Megatune fine. So why screw with some virtual machine software that is probably more work than it is worth. I know the ones that run on x86 based Macs are flaky. The tought 100% compatibility, that its until you try and use it. Cygnusx1 is dead on. Just about any laptop will run Megatune. Even though I have an Intel Centrino based XP laptop, I don't use it for tuning. I have this old HP Omnibook 900 (PII 333MHz), that is nice and portable. I run Windows 98 on it, which is very fast on one of these. And it has a REAL RS-232 port (don't have to use on of those USB converters). I'm on my second one. The first one I got for free (broke the screen during a dyno session), the one I have now I got for $29 on Ebay.

You mean Megatune, right? It runs fine on Vista. What is Windows 7???

Before you put the head on, did the timing tab align with a mark on the damper when #1 was at TDC? If so, turn the crank so the mark on the damper aligns with the timing tab as when you had the head off and #1 at TDC. Align the marks on the oil pump and oil pump shaft. Then turn the oil pump shaft just a couple of degrees counter clock wise (looking down the oil pump shaft towards the pump). Then insert the oil pump and shaft. The couple degrees is just to compensate for movement when the oil pump shaft gear aligns with the crank worm gear. It just needs to be close. The final timing adjustment is done with the distributor. If you are running aftermarket engine management with direct fire ignition, then it doesn't matter how you time the oil pump shaft because it is only turning the oil pump. Pete

Are you guys just yankin' my chain or what?

You are missing my point. The 70-72 tachs are CURRENT sensing, not VOLTAGE. I am not going to educate you here on the difference between current and voltage. You will need to do that on your own. All modern tachs are VOLTAGE sensing. To build a circuit that will properly OR (logical) CURRENT from three different coils would be very difficult. An easy thing to try is to power all three of the coils from the black/white coil wire. This will provide power to all three coils THROUGH the wire loop on the back of the 72' tach. So each time a coil fires, a current pulse will flow through the wire loop on the back of the tach, causing the needle to deflect. If this doesn't work, get 73-78 tach. Then you can either use the tacho output or the circuit below if you are using all of the outputs from MS: Pete

Your 72' tach is a current sensing tach. MS is not compatible with it. as per my original post, you can get a 73 or later S30 tach, and use the tacho output from the MS. Are you using a single coil? If you power it from the factory black/white wire, your 72 tach should work (as long as you are not using an MSD).

Just found this thread. I've been thinking about this for a while. I came across the GSXR throttle bodies a while ago, and love how they are modular. What about the slightly shorter runners for the inner TBs, would this cause issues? Pete

You get out of something what you put into it. If you want people to actually get something out of this write up, try putting a little more effort into it. Making it more organized, with schematics, pictures, and of course words from the dictionary would be extremely helpful. Sorry to get on your case, but given the time it will take for me to interpret your writing, I could dig in an figure out the actual wiring. It would be easier to look at the factory wiring diagram that understand your description. Pete

Wow very nice!