NewZed

Good point. I didn't go that deep. On the second try, after confirming that a drill motor works, were you looking at a mechanical gauge or depending on the dash gauge? The stock sender and gauge are notoriously slow responding. Maybe you fixed the problem with the drill prime (the pumps do need priming) but went back to the bad measurement method.

I think that he means the key for gear #13. http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Engine280Z/PistonCrankshaft/tabid/1602/Default.aspx Apparently, there are three keys in the crankshaft. The illustration shows their slots.

You might have the wrong throwout bearing collar. Did you just install a new clutch (pressure plate and disc) and discover this problem?

It's been described several times that running the 8.3 CR engine (dished pistons with N42 or N47 head) in turbocharged fashion is not really a problem. Assuming Megasquirt or some other tunable engine management. So it will work. And would be much easier and cheaper than getting the P90A back in shape. One downside that you might hear about is the liners in the N47 exhaust ports and the possibility of losing one and damaging the turbo. If you don't know much about the P90A head, it would be worthwhile to ask why anyone would strip the hardware and let the head go. The simple reason is that it's damaged, either warped or cracked,and someone salvaged what they could.

The original Megasquirt was fuel only. Injections were triggered by the negative side of the coil. You should be be able to use a plain old stand-alone ZX distributor for spark, with intact vacuum and centrifugal advance mechanisms, and MS for injection. The details will be in the other MS inputs, used to determine fuel quantity per injection cycle. Edit - forgot to say, you'll still have to fix all of those crappy connections and wires to use MS. Plus you'll need to tune it, using a computer. The simplest way to get on the road if you have the stock ZX computer is to just fix the wires and run it as a stock ZX engine. The EFI harness is essentially independent of the body harness. You can even get it all done on the garage floor and start and run the engine with a battery to test. Then package it up to fit in the car, supply power, and drive,

If this was true, the shape of the combustion chamber wouldn't matter at all.

I don't know what a "jnfl" is. P90A does not necessarily mean hydraulic.

The quench discussions always seem to spin out. It's not even clear that the stock heads quench area does any useful quenching. But if you did chamber work then shaving to get compression back makes sense. I was mainly pointing out a bang for the effort issue. If you're going to work on the head, porting seems to give the best return. A set of new valves seems spendy for a small bump in CR. Not an expert, just read a lot. I could be way off.

The valves are of different length so those won't swap. The P90 might have hydraulic pivots, which would be an issue (see below). The cams might swap but make sure the rocker arms come over in the same positions. Lots of ways to go wrong.

Man, I just had a good repartee worked up...with a pun included. Datsv8r, the answer was there for a flash. Just missed it. You need to get the JTR book.

I have a couple of spare 280Z tachs in the garage. I can find out which hole has the tape on it. The problem here is that you ran out of effort in about Post #8. Crappy spelling, signs that you haven't even downloaded the free FSM's, no sign that you were aware of the Jags that Run book. No acknowledgment of the help received. That's the biggy. Did one of the screw holes you dinked with have a piece of tape over it? If it did you can save me some time. Here's another suggestion - take a picture of the back of the tach that you're working on and post it. Then someone here can point out the screw.

My impression is that increasing compression ratio doesn't buy you much, these days. It's essentially a very dated way to increase power, from back when the fuel available could handle the increased cylinder pressure. If you're running high octane racing fuel, that's a different scenario. The most effective way to get more power for the L6 engines, today, using pump gas, seems to be to either/or/and get tuneable engine management if you're running EFI, and port the cylinder heads. Over and over you'll read that the intake ports on the stock L6 heads just won't let enough air by to get the power up. Without porting the only way to get it through is with a turbocharger. That's just what I've picked up. The .080" shave and different valves is a way to get bigger valves in to the early heads, I believe. The P79 already has them.

You have a situation. You're out of the Nissan spec. range. The information about how to fix your problem is out there, but even the Monroe book isn't very clear. He mentions Head Saver shims for the cam towers for heads shaved over .020", but glosses over everything between Nissan spec. and .020". His book implies that .017" doesn't need anything. Honsowetz's book says less than .030" doesn't need shims. But does say a head bent over .015" should be straightened first. Doesn't say anything about a bent head being milled. Good luck. The next advice you hear will probably be about shaving the top to bring the top and bottom parallel.

Be aware - http://forums.hybridz.org/topic/120923-got-my-head-rebuilt-and-shaved-i-fear-i-might-be-screwed-help/?do=findComment&comment=1131881 Buy the Honsowetz and the Monroe books. $20 - $30 spent to save hundreds.

Thousandths. .017". Is that combined, top and bottom, or just the bottom? Seems like a lot. More than Nissan recommends. Honsowetz recommends bending the head back to as straight as possible first, then milling. The two book, one by Honsowetz and the other by Monroe, go over this problem. There's probably a way to make it work right but may take some effort. Should have told him to tell you what he was going to do before he did it.

New ones seem to be available. What does that part do anyway?

The starter solenoid is actually a relay. A point to ponder. And if there's cooling fan for the radiator, and it's the one that comes on you should probably do something about that also. Could be that it's drawing too much current to let things work right. Shouldn't be on all the time anyway.

Pick a screw. Mark your starting point. Turn the screw. If it doesn't do anything, turn it back. This is getting sad. The internet says the hole with the screw might have a piece of black tape over it.

How do you know the walls are getting "flushed"? That would be a lot of fuel. Z31 goes up to 1989 from 1984. The ECCS systems seem to be change over the years. Fuel cut is described in some of the FSM's but overall, the 80's FSM's are poorly written. Describe your Z31 system and what you're using for inputs and someone might have some suggestions.

Cable actuation is pretty simple, in concept. Mount the ends of the sheath, tie the cable to the parts you need to move. The details can be tedious though. Here are a couple of examples and some typical parts, one's a carb but the concept's the same. A throttle blade is a throttle blade. http://www.arizonazcar.com/cableinstall.html http://forums.hybridz.org/topic/21442-z31-throttle-cable-and-pedal-swap-into-280z/ http://www.ebay.com/itm/like/390898402711

Word is that the 240SX throttle body is a waste of time. Just adding a bigger hole to feed the same small holes in the head. No actual effect, waste of effort. It's fairly well-documented on the site. Better to just add cable control to the stock throttle body. Or buy the stock parts off the internet. Message borini63, he sells a lot of parts.

My experience with people who say they don't know much about what they're selling is that they actually do know, and that there are problems and they don't want to be responsible after they get your money. Or they're selling it for someone else who wants to be even farther from the sale. Or it could actually be a decent buy, but you won't know until you find the guy that knows. The thing about modified engines is that they tend to be used hard, often breaking.

That's a lot of money for a mystery motor. Did the guy have it built or just end up with it? What are you going to see if you pull the head? Besides piston tops and valves.

My mistake. There do seem to be two (below). I've never heard (or read) of anyone swapping that plate when doing the swap but may have missed it. I wonder what would be different. Maybe more clearance for the spacer on the automatic setup. Automatic plate works for manual, but not vice-versa. Part #21 here - http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Engine280Z/CylinderBlock/tabid/1598/Default.aspx Might be available - http://www.courtesyparts.com/plate-eng-p-329396.html .

If you're looking for a simple plug-n-play harness you probably won;'t find one. You'll have to some digging, at least, to figure out what certain wires do, and some modifying. If you're just looking for a way to more power this thread is good - http://forums.hybridz.org/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/ The stock harness swap has it's own problems, there are threads out there about ET swaps. FricFrac was recently offering a harness for Megasquirt. It's the most popular customizable EFI system, on this site. People seem to like his work. http://forums.hybridz.org/topic/120766-custom-efi-wiring-harnesses-and-pre-configured-mega-squirt-systems/?do=findComment&comment=1130616