zcarnut

There are two ports from each reservoir container to the master cylinder bore. The smaller front port (the “pressure portâ€) supplies fluid to the pressure side of the seal (red and blue areas) and the larger rear port (called a “compensating portâ€) feeds the volume behind the seal (yellow and green). You need to supply fluid to behind the seal so that you do not cause a vacuum to form behind the seal when the pushrod is moved to the left in the above diagram (i.e., when the brakes are applied). When the pushrod is moved to the left the seal quickly covers the pressure port so that you will build pressure in front of the seal. When you release the brake pedal the fluid behind the seal needs to quickly return to the reservoir, hence the rear port is much larger than the front.

Dan is correct. The front bumper of the 1973 240Z was extended several inches forward with longer brackets to meet the then new front bumper impact speed of 2.5mph per the NHTSA MVSS 115 standard. There was no impact speed specified for a rear bumper in 1973, hence the 1973 240Z retained a similar rear bumper like that of the 1970-72 Z cars. The standard changed for the 1974 models to a 5mph impact speed rating for both front and rear bumpers. So, the early 260Z had to meet this spec and it used the thin bumpers similar to the early cars but the bumpers were mounted to the body with the gas-assisted shocks. The late 260Z used the large 280Z style bumpers.

Yes, there are several differences: 1. The housing material changed from cast aluminum to cast iron. 2. The pinion shaft support changed from a [ball] bearing and bushing to two [ball] bearings. 3. The outside diameter of the rack support area increased, thus requiring different bushings on the front crossmember. 4. The oil filler maintenance ports were eliminated. 5. The steering ratio changed from 15.8 to 18.0. 6. The rubber rack boots mounting was changed from a rubber band to a screw clamp.

Hello Steve; Good to hear from you! Yeah, I saw those power antennas as well. I picked up my NOS antenna a few years ago on eBay as well. I have seen several on eBay since then and they always get several bids. I didn’t think there were very that many 810 owners. Maybe people think they can be used on other Datsun models(?). About the ZX steering rack swap I was working on: I have discovered a problem. Because the 810 has a tilt steering wheel, the bottom of the steering column is only supported by the recirculating ball steering box. This is done so the steering column will pivot. But when the stock 810 steering box is removed (as part of the swap) there is no support for the bottom of the steering column. So, I am trying to modify an early Maxima steering column (which also has tilt) to fit into the 810. The Maxima steering column has a pivot on the firewall support piece for the column. I suppose I could try to use the ZX steering column but it does not have the tilt function. Until I get this problem solved I won’t waste time and effort with the crossmember swap. Just broken in My old 24E had well over 200K when I replaced it and even then it used very little oil (and it didn’t even leak any oil either). Nissan sure built some durable engines.

I would try the phone book and locate a bearing/seal supply company. “HSM4 R†Is just a SKF (large bearing and seal manufacturer) suffix of a part number. Just ask the counter person for a generic CR 40x72x7 shaft seal.

Woops! Sorry about that. Terry is correct. I measured wrong. What you need is a 40 x 72 x 7 seal (again, a standard size):

The change to the stronger rear control arms occurred in 1974 with the introduction of the (heavier) 2+2 version. I have the TSB released by Nissan outlining the exact changes. This TSB was also incorporated into the service booklet “Introduction of the 260Z.†Nissan made other changes in 1974 as well: stronger front crossmember, better steering rack, beefier rear strut housing, etc., all because of the 2+2 model. Fortunately, Nissan applied these changes to the two-seater as well.

I have a .pdf file I can send you. PM me with your email address.

Another solution would be to just extend the length of the oil sump pickup tube of the L28T engine by sectioning it and adding an extension piece. I have heard of people doing this. This would avoid the metal contamination issue. However, positioning the extended tube correctly would be a concern and you may need some additional support (a brace) for the longer pick up tube.

One of the car mags (Road and Track, I think) did a L28 turbo swap on an early (1st gen) Maxima back in the early eighties. It's worth a look if you can find it in your local library. I have a photocopy of the article somewhere. I'll see if I can find it.

I have a L28 block installed in my 1979 810 which also requires a “front sump” design, and I re-located the 810 oil sump pickup tube to the front of the L28 block. If you examine the six cylinder L-series engine blocks you will see that it is cast for either a front or rear oil pickup tube location. The factory then just drilled the corresponding “boss” out depending if it was going into a rear sump (Z cars) or a front sump (810, 1st generation Maxima ) vehicle. You drill and tap bolt holes in the front boss for the new front mounted oil pickup tube and drill a new passage from it to the pickup oil gallery in the block (which runs along side the block). You also have to block off the rear sump pickup gallery with a pressed-in plug and drill a new hole for the dipstick tube at the front of the block (being very careful not to drill into the main oil gallery). Lastly, you need to plug the old dipstick tube. All this cost me about $100 at a machine shop. If you go this route, then I would recommend taking both your L28 and a spare 810/Maxima block (the L24E) to your machinist. Your machinist can index off the L24E block in order to determine exactly where to drill the needed holes.

There were two variants of the L24E Nissan engine used in the USA. The first L24E engine appeared in the 1977 810. Same crankshaft as the L24 240Z engine, a 25lb flywheel, 9mm rod bolts, a N47 head similar to the one found on the later 280Z except for the smaller exhaust valve and a fuel injection system almost identical to the L28 engine. This version was used until 1981 when the 810 was redesigned and became the Maxima (service code was “910"). The L24E engine in the Maxima was modified as well: the N47 head was changed to a quelch combustion chamber, the flywheel was lightened to 17.5lbs and the rods and crank were changed to accommodate a thinner connecting rod journal and the rods used the 8mm bolts. This L24E was used through 1984.

Yes. I recall a spacer was needed for the front wheels. However, the car I was putting these wheels on had the Toyota calipers, so a spacer was required anyway for caliper clearance.

Your situation reminds me of one I had. I lightened a Maxima flywheel and I wanted it balanced. The machine shop could not balance it separately. Why? Well the reason is they needed something to bolt it to. A crankshaft works very nicely. The balancing procedure is to first balance the crank separately, then bolt on the flywheel and re-balance. I had a spare crank so I was able to balance the flywheel. Maybe this what your machinist is talking about.

Machine shop. I wanted it done correctly The "wheel spinner centers" I mentioned are shown below (on a different wheel). I got them from the local hot rod shop. You get a “tower” that fits through the wheel opening and a spinner that screws on. I guess these have gone the way of the dinosaur as I was not able to find any on the internet. Summit Racing used to carry them, but their latest catalog no longer lists them.

The center opening (hidden by the plastic center cover) has to be opened up so these wheels will fit on the front hubs. To fit on the rear requires no mods but if you like to rotate your tires/wheels you might as well modify all four wheels. Once you increase the center inside diameter the center covers will no longer work as they are a "snap in" fit. I opened up the center hole to an ID of 3.75" so that the aftermarket universal "spinners" would fit. Looked very good when done (no pics, sorry). Use the Z31 mag wheel lug nuts. The Toyo ones have a different (1.5mm) thread pitch. Nice 14" x 7" wheels.

The 280ZX came with either power recirculating ball steering, power rack-and-pinion or even a manual rack depending on year and options.

You cannot. Two reasons: The input shaft on the end of the CV that fits into the diff is larger in diameter on the R200 CV axle, and the R180 axles are longer than the R200 ones.

Yes. I’m using a Z31 ECU with the turbo 280ZX distributor (for the crankshaft position sensor) and the Z31 air mass sensor. The Z31 ECU does not need the cold start injector, so I used this boss for the intake hose fitting. The later Nissan air regulator valves (1984 and up) mount directly on the intake manifold and the connection to the intake manifold is made internally in the air regulator body. So no hose is needed. You still need the fresh air hose. You can easily mount one of these later air regulator valves directly to your spacer. This is what I was going to do initially. I was even going to mount the air regulator valve on the underside of the spacer where it would be out of sight. However, I changed my mind and decided to go with a cable for the throttle control and therefore no TB spacer is needed. I adjust the idle speed by changing the stop position on the throttle lever. By swapping the factory setscrew with a fine pitch screw and spring, you can adjust the idle speed: However, adjusting the throttle stop opening affects the TPS adjustment, so you have to re-adjust the TPS after first setting the idle rpm. Also, repositioning the throttle blade has an effect on the level of ported vacuum that is used by the vacuum advance mechanism in the distributor. But the ZX turbo distributor I am using does not incorporate any vacuum advance so no problem there. I have a confession to make...The setup pictured is out of my Datsun 810. It has the air box and mass air flow sensor mounted on the side of the engine compartment. So, I am using a boot from a late 1980's Maxima (with a 90 degree bend) which fit my application perfectly.

You can disassemble the R180 CV axle and replace the center shaft with a shorter one from an R200 CV axle. The difference in lengths are: 280ZX Turbo (L side) _______________ 14 3/16 inches 280ZX Turbo (R side) _______________ 14 11/16 inches Z31 non-turbo (L side) ______________ 15 5/16 inches 280ZX/Maxima (R180 either side) ______ 15 7/16 inches All the above center shafts are interchangeable.

You re-use the stock “fast idle” valve. This is the air regulator valve that is used for the fast idle function. It is a stand alone valve needing a hose connection to the intake and another hose going to the air inlet hose (filtered, metered air supply) and also an electrical connection for the heating element inside the valve. The valve allows air to bypass the throttle when the engine is cold, thus increasing the idle speed. As the heater element warms up the valve gradually closes. There is more info about the air regulator valve in the FSM. Of course if you swap out the stock throttle body with the 240SX one you lose one of the hose connections (the intake manifold one) to the air regulator valve. However, you can make your own intake hose boss and use a suitable hose to the valve as I did:

As usual, more info can be found at Classic Z Cars.com: http://www.classiczcars.com/forums/showthread.php?t=9704