DAW

That's not a '73-'75ish 240-260Z that has a third gear switch to activate the second set of points/magnetic pick-up as an emmission control device, is it? DAW

The charcoal canister doesn't hurt your performance in any way. It does contain the car's evaporative fuel loss/emissions, both while running and parked. Do you and your passengers enjoy fuel vapors? Why not keep it, it weighs nothing and makes for a more sophisticated project car whether you're subject to smog tests or not. DAW

Oops, 7/32" on the proofread.

That's a huge difference between 1/8" and 1/4". There are 5/32", 3/16" and 5/32" in between. Best response vs loss of vacuum into lost volume is probably the 5/32" line. DAW

Why not get an orbital battery and mount it in the "trunk" and use the old battery tray to relocate the charcoal canister. There's nothing asthetically pleasing about gasoline fumes. Alternatively, you can locate it anywhere along that right side of the engine compartment rearward of the original location. The shock tower has some welded-on brackets on most years and you may have a relay mounting bracket that you could use and move the relays onto a sheet metal panel you make for the rear side of that bracket. DAW

Measure aluminum bumpers from the latest model Fiat X19s (the boxy ones that look like '77 280Z). I started this swap just as a curiosity swap and it's on the back burner, but I've fit it into place and it looks good and saves a lot of weight, probably well over 100lbs. I used the bumper shock stubs I cut off the Fiat and mounted them into the shock tubes (sans shock stubs) so they were effectively totally compressed. The aluminum bumpers are thus closer to the body instead of hanging out there like they could be used for picnic tables. I cut a section out of the plastic side "accordian" pieces to match the amount the new bumpers shorten the car length. One other nice feature about this swap is that the Fiat mounting brackets are fully adjustable and slide in a rail on the inside face of the bumper so that setting them up is easy with very little fabrication. DAW

Rising rate fpr can be used on na or turbo engines and they are calibrated for the specific application. From "How to Build & Modify Intake & Exhaust Systems" by Ben Watson: The "Rising Rate" fuel pressure regulator uses increasing manifold pressure to increase the fuel pressure. Unlike most stock fuel pressure regulators which raise the fuel pressure in a single step the rising rate regulator increases the fuel pressure at the same rate that the manifold pressure increases. Thus, the pressure differential between the air in the nanifold and the fuel is a constant. BTW, a maniflod pressure changing from -12 to -2 is an increasing manifold pressure. DAW

A rising rate fpr matches pressure to engine speed so that at high air flow through the engine, high fuel flow is provided. An AFM does this electronically, a rising rate fpr, mechanically. Adjustable fpr sets a fixed pressure which is usually higher than stock and thereby enrichens the mixture, but it is not matched to engine speed/demands for more fuel. I got the same thing from exhaust shops, although when you think about it rationally, how could adding a better tuned free-flowing engine-to-cat system which is more heat-preserving with wrap than the stock system, lead to any significant increase in emissions? They've got to go the CYA route though. I ended up buying a wire feed welder, teaching myself to weld a bit with it, then using a pile of auto-store pipes & elbows to configure a system. It was time consuming but gratifying, and the welder is one of the best purchases I've made! DAW

As long as you're replacing the fuel pump, consider getting one of the high pressure Bosch or Walpro(?) pumps and run it with a rising rate fpr instead of adjustable. After the pump and fpr, you should have your engine noticeably more powerful than it was stock. If you're seeking more power, then turn you attention to a tuned, better flowing exhaust system. If you go with headers (there are no good OEM cast manifolds for round port heads, there are a few for square port), I recommend wrapping with heat insulating wrap as it improves performance and quiets the header. I'd also recommend some long secondary pipes before they merge, and the rest of the system as 2.25", not 2.5". Unless you've got welding/fabrication experience, you would want a good muffler shop to do the exhaust and have them weld on a flange for the O2 sensor. It can go farther back from the engine than stock, but substitute a 3-wire, heated, sensor. Put the header on yourself, then dolly it, flat tow, (or open header) to the muffler shop. At this point it makes no sense to put in a cam, etc., unless the exhaust is done. DAW

The reason N42/47 valves are exchanged into a P79/90 head that has had a big shave done is that they are .100" longer, thereby eliminating the need to buy thicker lash ($$) pads. One resistor is fine, it can go in either wire since it is just in series in the circuit. If you put two or more in it will just be additive which is OK to do. You can also bridge the two wires and create a parallel resistor circuit but calculating it is more involved, so I'd recommend sticking with in-line, series resistor(s). DAW

They are really cheap and sold stapled to a card, usually there are 5 or 6 to a card, all of the same value. You're looking for little tan plastic barrels with multicolored rings painted on them and a thin solid bare metal wire out of each end. There will be a selection of these cards of different resistance values, probably on pegboard type hooks. You may not find exactly 700 ohms, the closest may be 680 or 720 or 740, etc., just cut the wire, strip the ends and join the wire ends to the resistor wires, solder if possible, and tape it to insulate. Nice attention to detail on the engine, BTW. DAW

I would do the resistor, then try advancing your timing until it pings; then back it off a bit. Both the mixture richenning and the advanced timing will improve throttle response. What's the point of increasing compression if you can only run it by detuning? DAW

The head swap you did isn't a temporary solution as much as it's a budget solution. You would need to richen the mixture when you increase the compression no matter what head/block combination you run. You will have a little more ping to deal with when using the N42/47 L28 head because it isn't a high quench design as the "closed chamber" L series heads. I would just try to tune the ping out and see what you get. Your alternative is to take the P79 head you removed, shave it 0.080", shim the heck out of the cam towers, and install N42/47 valves (0.100" longer than P79/90). Or, you could use a Maxima P79 head (L24) which is a closed combustion chamber and higher c.r. than the N47 on a F54 block, install N42/47 intake valves and put it together, maybe using two head gaskets to drop compression a bit if needed. The combo you've got will work. I've been using that setup with triple side-drafts on my autocross car with good results. You become very aware of what gas stations have better quality fuel than others. DAW

The temp sensor tells the ECU how cold or warm the engine is; the cooler the engine, the richer the mixture it will need. The sensor is a variable resistor that starts out with a lot of resistance cold, and it drops in resistance as it warms up. If you add some resistance, you add some richenning across the full temperature range (which you need if you increase compression, to increase performance and decrease ping). DAW

I'm not sure which head swap you did, but if you've got an '81 280ZX n/a then I assume you put an N42 or N47 from a '75-'79 L28 and now have just over 10:1 compression. First, make sure your initial timing isn't set more than 10 or 12 degrees BTDC. Check your thermostat, you want 180 dgrees, not 195. Next, you're going to probably go out of emission specs so write down what you do in case you need to reverse it (you're probably out now anyway due to the increased compression). Splice in a Radio Shack resistor into one of the leads of the temperature sensor (either cylinder head or water temp, whichever you have), start with about 700 ohms. Remove the cover from the Airflow Meter and adjust the spring tension by two notches so that you are decreasing the spring tension on the flap/door of the AFM. Try these changes and see what you get. If not enough, then try substituting an 800 ohm resistor in the temp sensor circuit. DAW

I haven't done it myself but remember reading somewhere that a baseball bat was used (or in your case, maybe a boomerang??) DAW

Sounds like you're starting with an F54 ZX engine, 8.8:1. That's a bit high for static c.r. on a turbo engine but you can do it if you intercool it and limit boost. Volvo does this on their "low pressure" turbo engines. This would be a great auto-X engine. As pointed out above, the turbo pistons ring lands and rings are different and they are stronger, with drilled holes beneath the oil rings instead of long slots like the na pistons have. DAW

Well, that's the next engine it will have: LD28 shortblock, top end from '82 ZXT (P90, turbo, EFI and electronics), intercooler, and swap 3spd lock-up a/t for 4spd a/t from '84 300ZXT; test & tune, then transfer to Z car. The static c.r. will be about 8-8.5:1 so it will be a low-pressure turbo setup. What's fun is making the engine quick then putting it in the lighter car. DAW

First, let me say I don't advocate street racing but this pompous ass just got to me. I was driving the engine that I'm transferring into a '72 240Z this summer. It's in my "mule" right now, an '82 Maxima a/t. It's a street engine not a race engine, an LD28 shortblock with an N42 head and 280Z EFI and 280ZX ignition. 10:1, headers and custom exhaust. So, this jerk is riding my rear bumper as I'm slowing to stop at an intersection in a small town. We were both turning right onto an open four lane highway with a 60mph speed limit, but apparently this guy was in a big hurry and going into a road rage because he was too stupid to know that a constant red arrow on a traffic signal means that you stop and wait for green. If it's a flashing arrow, you stop, then go if it's clear. By then, I knew what was going to happen as soon as there was a green arrow and we turned...he was going to swing out into the other lane and stomp on it, leaving me and my pathetic old Maxima in his dust. That's not how it went though, because I nailed it as he came around me and off we went. He was probably glancing in his rear view mirror to see how far back he left me, he saw me in his side mirror just slowly falling back from his right quarter panel. Not at all what he was expecting! We were well beyond the speed limit when he got off it and I shot by. In the end, he had beaten me by a couple of car lengths, but clearly I left his ego in my dust and I'm sure he won't be telling anyone this story and is confused about what happened. DAW

HIGHRPM, do you know if the 2.3 will bolt-up to the early style Saab drivetrain (longitudinal engine)? Do any of the Saabs have LSDs? Do you know of anyone who has built a mid-engine Saab powered car? Thanks. DAW

Racer X, I had been looking at transplant engines on paper and the Suzuki V6 looked good re power/wt. It was a while ago so I might be mistaken, but I think the dohc V6 in the late model Isuzu Trooper was another. Re the Saab, I'm interested for another reason. The older ones were longitudinal engine fwd and the later ones transverse. I want to know if the turbo Saabs had LSDs. I'm toying with the idea of one in my 510 (instead of the backseat). For a Z engine, I've wondered about the new GM inline 6 (but one I looked under had a front sump oilpan), and about Volvo rwd engines. The 2.3L turbo 4 in my 940 Turbo wagon pulled strong and looked almost too small under the hood for that kind of power. I drove one in Italy that had a 2.0L dohc turbo which was also impressive (European spec engines aren't offered in the states, but many are tuned for more power per liter. There's some sort of tax law which is heavy for engines over 2 liters). Another Volvo rwd engine possibility is the 3 liter dohc inline 6 they offered just before the fwd cars came out. Does anyone know about these engines re wt., front vs rear sump, and power tuning potential? DAW

With such a large investment in drill bits, why not take the bar to a steel supply shop or large machine shop and have the holes laser cut for about $50? DAW

I agree with Mike C. And apply as little shock force to the overall header as possible. Personally, I would cut a gap in the nut with a torch then separate the the remainder of the nut away from its bolt with a chisel, either hand or impact. DAW

I was fitting one to my '76 Z when I found a Saab 9000 intercooler which is similar but seems to fit better. I used a big Mercedes aluminum radiator with electric fans and decentered it to the pass side to allow the air intake hose to pass through next to it. This allows both intercooler hoses to go through the round openings in the radiator support. I have a '72 front bumper so was able to cut the bumper shock housings where the intercooler fits between them. My main concern is ground clearance. I think it's OK but I'm going to fabricate some sort of guard for peace of mind. DAW

I know that NISMO recommends that only the 9mm bolt-rods be used for competition. I thought about using a set I have anyway, but I came upon a freshly built L28 with L24 rods and Sterling pistons (#12149P which have a lower compression ht. than stock to allow use of 133mm rods) which had a hole in the block where #2 rod cap and fragments of the broken ARP 8mm bolts went through. Seeing one convinced me. DAW