NewZed

Describe your engine management system. Better details on the problem will help you also. Stomp, surge, bog, are pretty vague. Descriptions of when it runs right are good also.

Pretty sure i just read a thread from an Australian forum about carbed L28's with N42 heads used in the S130 body. There's a reference to the head also in the L6 Heads FAQ. Maybe they used a B cam for carb'ed L28's. I've wondered why the atlanticz cam spec. compilation (is that what you meant by the "book", or is there actually a book out there with cam letter designations?) skips the B. Tony D probably has details. http://forums.hybridz.org/forum/90-l-series/

It's just math. Here's some Google - http://www.onallcylinders.com/2013/05/16/what-size-fuel-pump-do-i-need-your-top-tech-questions-answered/ The typical auto store replacement pumps, like the Airtex E8312, are rated to 75-90 psi, 30 gph. He might have one on his car already. Crazy.

Kameari rocker arms. The specs are interesting, down at the bottom. Spendy. http://www.rhdjapan.com/kameari-l-type-rocker-arms-set-l6.html

You could do some math - http://www.fuel-pumps.net/fuelpumpsfaq41.html - then check specs. Of course, it doesn't look like you've confirmed that you need a new fuel pump. But you'll find out after you replace it. The pump doesn't know how much horsepower you're making, it just sits and spins, so no reason for it to wear out any faster with 10,000 HP than 10. If it worked for two months, it was sufficient.

Collecting a few more threads - http://www.classiczcars.com/forums/help-me/50052-cam-wear.html http://forums.hybridz.org/topic/111062-leons-other-260z/page-12?do=findComment&comment=1122024 later in the thread, #232 and earlier. http://forums.hybridz.org/topic/118926-engine-woes-read-on-if-you-dare/page-2?do=findComment&comment=1122036

Here's a recent thread with the similar comments about new aftermarket versus reground versus used rocker arms, from Schneider instead of Isky. Post #25. http://www.classiczcars.com/forums/help-me/50052-cam-wear.html

I'm pretty sure that these are original 1976 rocker arms, pictures. From my old cylinder head, off an engine which appeared to all original. Either 150k or 250k miles. And here's a link with a few pictures of the ITM rocker arms. The used ones are different and the ones he replaced have a Z, instead of an X. No idea if that's relevant. http://forums.hybridz.org/topic/106910-loud-tickingknocking-noise/

Leon just relayed a conversation he had with Isky about rocker arms. He said that new or mildly worn used was the way to go. Now you report that new Nissan rocker arms were "bad rockers". Any chance that they weren't actually new Nissan? What will you be checking on the rocker arms? Looks like a quagmire. Post #232 - http://forums.hybridz.org/topic/111062-leons-other-260z/page-12?do=findComment&comment=1122005

How does a bad rocker affect a valve and guide? Side loading? How would that happen? Just wondering. And did Delta do the first regrind on the rocker arms? I thought that they had issues? My impression on carbon buildup was that it comes mostly from combustion gases and fuel mix flowing over the back of the intake valve at certain times during engine operation. For example, when the throttle is closed the piston can exert a vacuum but there's no air to be pulled in. Flow stops, gases back-flow, condensation on the cold valve occurs. Same reason crud gets in the intake runners and all the way up to the throttle body. Not so much what's coming down the intake runner. No idea how to stop, except spend more time with the throttle open.

There are threads out there. Late 90's I believe, but I would find a thread and confirm first. Just search "Kia sportage 240z weatherstrip" and something will pop up.

Looks like an open R180. The wallowed out hole for the spider gear shaft is apparently what happens when you spin one wheel. Not good. Check the numbers stamped on the ring gear to see what ratio you have so you'll know what to expect from a replacement. If you go to an R200 you'll need more parts than just the diff. And thanks for playing some decent music...

Makes sense. You could probably fit narrow springs to the stock struts though, for the same purpose. The path to adjustable coilovers didn't follow from the problem.

Do you think that the spring perches will leave more room for the wheels if they're adjustable? Have you thought this through?

Get the Kia Sportage weatherstrip. The repro stuff tends to be too thick, according to numerous reports around the web.

You can't learn this stuff from a phone. You'll need a big screen and time to read. http://forums.hybridz.org/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/ http://forums.hybridz.org/topic/38461-240z-260z-280z-turbo-swap-guide/ https://www.diyautotune.com/tech_articles/how_to_megasquirt_your_280zx_turbo.htm

There's a guy who recently snapped the tensioner head right off of the shaft. It was extended and cocked when he put the chain back. He had the same problem getting the sprocket back on as you. Pretty sure that if you get your eye just right or use a mirror that you can see the tensioner, with the valve cover off. If you see a lot of the shaft you might have a problem. You might try rotating the engine backward, but it could be too late. The half mm extra in HG isn't going to matter.

There's a useful picture on page EM-20. http://www.nicoclub.com/FSM/280z/

You only need a modified propeller shaft. http://www.jagsthatrun.com/Datsun-ZX_Order.html http://www.jagsthatrun.com/Pages/Parts_DATZX_MountingInstructions.html

In Post #16 you said the engine was running well, the only remaining problem was the jittery/cutting out tach. I missed the follow-ups to new problems. Primary resistance is between the coil + and the coil -. There's a really nice drawing in the FSM, very hard to misinterpret. Secondary is what you measured and should be very high. Like about 10,000 ohms, also shown in the FSM. So you measured the wrong thing, or reported the wrong spec. (1.4 ohms) but still got a bad number. I wouldn't assume that all of those things are related to one source. You need to figure out how to measure the right things first. No offence.

Ohms aren't drawn, they're just there, in the way. FSM says 0.84 - 1.02 for coil resistance, looks like you're using the 75 coil, not the stock 82 280ZX? You didn't say what the new coil had either. Did you measure with the coil connected or disconnected? If connected, then you were also measuring resistance through all of the other wires connected to - and +. Parallel circuit. Disconnect the coil before measuring primary resistance. What problem are you working on, the jittery tach problem? Put a condenser on the line, it can't hurt. Worst case, it's a useless piece of electronica on the circuit. The advance problem is a whole different thing.

But you probably know a lot more now. Broken stuff makes you smarter. You should check your timing, not so much the advance number but the quality/consistency of the light. If the mark is jumping around and seems retarded you might need to switch the wires. It will run with the wires backward but the trigger won't be consistent. MSD says violet is positive and most people say that the red from the VR is positive. So you would have yours backward. Red seems to be positive for the GM HEI module hookup, but who knows for sure what the MSD module needs. http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions1/6425.pdf

Check the wring diagram before going crazy. Here's a nice one - http://www.classiczcars.com/forums/open-s30-z-discussions/36494-free-full-color-wiring-diagram-1976-280z.html The obvious - bad bulbs. Second - bad connections. I had one get hot enough at the bulb to melt the socket allowing the contact to loosen and break the connection. Check the grounds. If you had a short the fuse would blow. Sounds like you have a broken circuit instead.

Have you removed the blower and cleaned it yet? Also the heater core. Lots of crevices to hide in there. sounds like you're hoping to clean it up without taking it apart but that's probably not going to happen. I found 1/4" of mouse droppings on top of the glove box in a parts car I bought, along with a blower housing full of mouse nest. Any little ledge where they can sit in safety is going to be a latrine.

This is fascinating and I hope it works. But is it really that simple to draw up a head on a computer, cast it, machine it, and have it work correctly right off the bat? A scan of the exterior of an existing head doesn't show internals that may have been designed to distribute and accommodate loads, in use and cooling/heating cycling. I would imagine that in the automotive world, there would be many trials, tests, failures, and redesigns before the final product was locked in. Seems like someone's going to need to offer up a test engine, and break a few heads before this is done. Eeyore