NewZed

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

Flywheels are the same between 4 and 5 speeds, typically, but automatics use what is commonly called a flex-plate. You need an actual flywheel and clutch for a manual. Not sure on the starter but they may be different for certain years. If Rockauto has different part numbers, they're probably different. The distance to the ring gear is probably different between the two. Google "flex-plate" and "flywheel" and you'll see what you have and what you need.

How does that affect head cooling? Seems like that would be one way to block the head port for better flow without losing heater function. The threads are the same for the plug in the block and the nipple in the head. Swap and buy some extra hose. The coolant through the core might also be cooler. My heater core pumps out a ton of heat with very little flow. I've pondered switching just for better cabin heat control.

Stick some thin plastic (like Mylar or transparency sheet [office-speak]) between the dash cap (that's what you mean by "overlay", right?) and the dash,with some lubrication, and you might be able to slip the tach out. You didn't say which year of tach you're working with. There are drawings in the FSM's of the tach backs. Body Electrical 1978, for example.

Measure the fuel pressure when it's having the problem.

Can you pump up the pressure by lifting and pressing the pedal repeatedly? If they can be pumped up and will hold, then you have air in the system and need to find a way to bleed it. If they can't be pumped up then you probably have a leaky seal in the master cylinder. Did you take the MC apart and clean it before installing it? Today's manufacturing standards are poor and rebuilt parts are often dirty,with honing grit inside that can damage the new seals.

Could be that you re-installed the calipers on the wrong sides. They're interchangeable. The bleed screw needs to be at the top where the air bubble is.

I've had good luck with MT90 also, in a 1978 5 speed. It ground in to third at high RPM quick up-shifts, with plain old Valvoline 75-90. The MT90 fixed that. It didn't fix the 1980 5 speed though. But the Swepco/ATF blend did, for the most part. I think the 1980 box might have had some rust on the synchro cones. Who knows. For the record. Notice on the Redline "Gear Oil for Manual Transmissions" page, they also list two ATF fluids. ATF/MTF fluid.

Hence "more like". 75W up to 140W is the Nissan spec for an 83 NA box, depending on usage temperature. ATF is about half the viscosity of typical gear oil. Hard to compare since they use a different spec. But Redline shows viscosity numbers on their site. Compare the cSt spec. CentiStoke is a measure of resistance of a spindle spinning in the fluid. Higher number means more resistance. Many words have been spent on these topics. Still interesting. For what it's worth, trial and error seems to work best for old worn transmissions. I use a 75/25 blend of Swepco 201 and Dex/Merc ATF in an old 1980 FS5W71B 5 speed. It had serious synchro grind at mid to high RPM shifts. Gone now, except for way high. Credit to jmortensen for the recommendation, although he uses 50/50. Everyone has their magic elixir. http://www.redlineoil.com/product.aspx?pid=51&pcid=9 http://www.redlineoil.com/product.aspx?pid=46&pcid=7 http://www.redlineoil.com/product.aspx?pid=45&pcid=7

Ouch. These engines do seem to generate the occasional odd noise that can't be identified or fixed. It kind of looks like your fix actually led to the final demise. You didn't mention any measurements or observations of old bearing quality. Or oil pressure/flow. Might have been better off to have just put the old bearings back on. Many people do just fine installing an old high-mileage motor to make a nice daily driver. The engines don't seem to show significant signs of wear until over 150,000 miles. They're super durable. On the other hand, many people seem to destroy/damage newly rebuilt engines,or parts of them, because the aftermarket parts just aren't as good and don't break-in right. It's a dilemma. Anyway, you've noticed that nobody can offer an opinion on your piston choice, because it can't be determined without knowing what the other engine parts are. Build an engine on paper first. Good luck.