DAW

Walnut shells. Tumbling in, or blasting with I believe will freshen up a hard metal part like this without significantly changing it or abrading the wear pattern on surfaces. Double check this, but I think I read it somewhere. DAW

I would recommend a rising rate fpr as you don't trade off low speed driveability problems as with larger injectors. This is a plausable performance mod within the hp range you're talking about and it's good insurance. DAW

Choice of cam and cam timing will make a difference. With the stock cam, if you want good low-end, off-boost response, don't run it retarded from the stock index (as normal wear and tear will tend to make it). You definitely want a BOV, especially with a M/T car, and you've got to have an intercooler so that you can advance the ignition timing (and enrichen accordingly) and not get into detonation problems when the boost does come on. DAW

I'd say to run the stock turbo cam at stock cam timing, then try retarding it one notch and see what happens to your e.t. If it slows the car, then advance it one and see what happens. It's easy to reset at trackside (as long as you don't drop the chain). DAW

Do the swap with stock turbo ECU & fuel pump, get it running, then do some sort of intercooler. Even a Saab, Starion, or Volvo intercooler is better than none if you can't afford a Spearco or HKS, etc. Once intercooled, you can up the boost a bit safely. DAW

OK, I think that there are ways to know crank position @TDC without putting the timing cover and damper on each time. I believe the crank key points straight up at TDC. You can check by doing it the way you have been and confirm. If not, there is a crank sprocket mating mark that you could reference by putting your crankshaft at TDC, bend a coathanger pointer (bolted to the block) point exactly at the reference mark, and you have it. This will save a lot of time and is important for an accurate set-up because the crank needs to be brought just to TDC while turning clockwise and maintaining steady tension on the chain. If you pass TDC, you have to start over with another pass. Anytime you reposition the cam sprocket to another hole you need to do this smooth, steady pull technique to check the result. DAW

Sorry, I got that figure from my '72 Nissan 240Z factory service manual. Sounds like there's too much slack and considering the stresses of racing, why not just buy a new chain? Cam timing is too critical to have it jumping around. Maybe you can go to a parts store and hold your chain up to the new one...if they are the same, then change your mind about the purchase. DAW

Z = 13mm. ZX = 10mm. DAW

Make sure the turbo PCV is not a different part # than the n/a. DAW

There are two sets of holes for the (right side) guide. Assuming you've already set it up to take up the most slack, and realizing that the tensioner keeps tension on the chain but won't significantly change the line of the chain as it runs, if you're setting up the cam in hole #3 and the cam is still retarded per the notch it means the chain is stretched/sprockets worn or the distance between the camshaft sprocket and crankshaft sprocket is smaller than stock (due to milling of the head. Standard head thickness is 4.218 in. DAW

What sprocket hole you put the cam dowel in is not going to change the amount of chain slack; it only compensates for it in the timing of the cam. The guides can be adjusted, and if it's still too loose then you're chain is stretched or you need to shim the towers. DAW

Nothing was done to the valvetrain. The stem ht difference is equal to the amount that the combustion chamber roof was raised. DAW

Thanks for posting the pics! I'm using the original 280Z "accordian" end cap pieces, sectioned to remove the amount of distance the bumper is displaced toward the body. The stock bumper shocks and bumpers can be manipulated to displace the bumpers in (essentially by permanently compressing the shock pistons) and while it looks better than stock, it doesn't help any with weight reduction. I did this on my 280ZXT because I haven't found a suitable substitute lightweight bumper, and the ZX bumpers seem lighter than the Z bumpers. DAW

The big difference is between oiling-method for the lobes/rockers. Early heads (through 1976) had spraybar oiling setups and solid (undrilled) camshafts. Post-'76 heads oiled the cam lobes internally via a rifle-drilled camshaft and drilled lobes. You can't use the undrilled E88 cam with the N47 unless you were to swap on some cam towers and swaybar from an early head. I think the stock 280Z(X) cams are the same in profile/specs but I am not certain of this. DAW

It should be venting at high manifold vacuum (like idle). That's how it works, when throttle plate snaps closed that is when you want to get rid of the column of pressurized air between throttle plate and compressor wheel. There is no significant boost developed at idle...once the throttle plate is cracked open, however, the highest manifold vacuum drops and the BOV should close and this occurs before boost can develop anyway. DAW

The Saab 9000 intercooler bolts up fairly readily but it does lay low. The lower edge of the intercooler is a bit precarious to bottoming out and scraping. A speed bump at high speed would be a disaster! Otherwise it works fine and I've got stiffer springs and shocks to combat this problem. As to the aluminum bumpers, this work is 90% done and it works but I've turned my attention to other things...a '78 Dodge 18' motorhome to ski-bum in, gets headers, sway bars, aluminum intake, Quadrajet, cam, etc., etc. DAW

It's probably got the 280Z ex valves, but not the intakes. I'd bet on 42mm intakes vs 44mm (L28). Regardless, you've got a good thing in that head, but if it's stock Maxima L24E you'll want to get rid of the cam and the intake valve springs. Just use any non-Maxima L6 intake valve springs and a drilled Zcar (or ZX) na cam. If you decide to go with the 44mm intake valves, any '75-'78 280Z head is a good source. DAW

I think you may be able to do it if you richen it up a little and not go over 12 degrees BTDC on initial timing. DAW

The c.r. is good but the L28E dished pistons are not turbo pistons and may fail. Search for the info on blow-through Webers, but including the Webers in an air plenum/box which gets pressurized is one way. Why not have injector bungs welded to the triple Weber manifold, gut and epoxy-close ports in the Webers, and use them as throttle bodies? Overall it will probably be fewer headaches. DAW

Best solution is a staged intake; long small runner primaries, coupled by ignition intervals, staged with a short, larger runner, single plenum stage 2 manifold, regulated by airflow volume (rpm). Manifolds designed for a specific rpm range typically give something up at the other end of the range, i.e., excellent low rpm torque precludes good high rpm torque/hp. A staged intake is a way to get around this. DAW

There's no drilling, epoxying, etc., if you just use the N47 water temp sensor as-is. It has the same range of ohms/degrees temp as the cht sensor. DAW

Cut the L28E manifold just outboard of the injectors, cut a triple Weber manifold at the same distance and weld the two together, make the plenum to bolt onto where the Webers would bolt on. DAW

I'd recommend using the N47 hardware/water temp sensor in place of the cyl head temp sensor (drilling out the N47 head for a sensor doesn't sound like a good idea). Bosch thermistors are fairly standard and there's not going to be a big difference to what the computer is looking for. Run a 180 degree thermostat; not a 195. DAW

You want the valves shimmed to yield the specified valve spring installed ht (and pressure). You put in the longer valves so that you wouldn't have to buy huge lash pads. I think the 280 valves may be .100" longer than the 280ZX P79 valves and not 0.080" (check to confirm this). If so, you'll need .100" of added shims to get the spring pressure correct. You are trying to raise the valve assy (including lash pad) by the same amount you raised (shimmed) the cam towers in order to preserve the geometry. The clay method is one way to check piston-to-valve clearance, or you can install light springs on an intake and exhaust valve, rotate piston to TDC, and use a dial indicator to see how much room is there when the valve is depressed to touch the piston top. DAW

You're not going to use the crank, and it will be way overbored so don't worry about the condition of the cyl walls...it looks like a good place to start on your project. DAW