Xnke

It is a 2.5" exhaust, full mandrel bent and muffled. I am re-working the header to move the v-band clamp up, allowing me to swap to the 3" sidepipe. Header is a 6-2-1 equal length design, 1 5/8" primaries, 2.5 inch secondaries, total length from valve to final merge is 36".

The only material removed from the floor of the port was to remove the casting texture and blend the sides in. The old head, with this cam, manifold, and shortblock, made 8.5lbs of boost at 2000RPM and had 6lbs of boost at 1400, on throttle. Swapping out only the cylinder head, I hope to see boost drop some...this gives me a good estimate of the change in VE, since the blower VE is relatively fixed. The difference is port velocity, Tony. I can't claim to be an expert in it, but I've got my ideas. We'll see how it turns out, I'm still scrambling to find a local flowbench.

Tony, the port is all lifted...the port floor hasn't moved at all. I need to blend the sides, (I guess what PMC is calling the cheeks?) into the floor more, and clean up the surface...it's a smidge lumpy yet. The port diameter is set by the 38MM runner diameter, and the desire to get 200CFM at only 0.400" lift. It can be done, I've seen it done, and I'm trying to emulate the port job that I've seen it done with. The cam is only 0.480" lift, so no need to aim for flow higher than that. I need the port to be all in by 0.450" lift or so, and I want as much flow as I can get there.

Here are a few preliminary intake port shots. These ports are still about 1mm undersize. Stock port: After working the port to the first intermediate stage: Getting pretty close to the desired profile now: Four more intakes to go...Then the balancing.

The problem with this line of thinking is that even though you are running a small port, and thus have high port velocity, you are neglecting to do the math to figure out what this size port can actually flow. I have no doubt the engine feels torquey down low-I'm sure it does! But does it really make more torque, or is the power band just flat over 4K? Here's my reasoning: a 30mm port, with the small intake valve, certainly has high velocity...which will promote cylinder filling up to a point. But, that same 30mm port will not flow the same amount of air that a larger diameter port can move at the same pressure differential. The velocities in question are in the 200-300FPS range, once you get over about 275ft/second port velocity, power AND torque will start to fall. By 300ft/s, you'll really notice the hit. In an Ideal port, you would get all the flow you could get out of that port while maintaining a port velocity of about 240-250ft/s. If port velocity never gets to about 190-200ft/s, the engine tends to be soggy and flat...feels like a torqueless wonder. If your port velocity is over 275-300ft/s, you will feel a big rush of torque below this point, but once you get through the ideal range, torque will fall off quickly as the port starts to run into a choked flow region. It's not true choked flow, but that's the best wording I can think of to convey the thought here. In this case, a 30mm port is not QUITE too small...but smaller than optimum. You are going to hit true choked flow (the kind of choked flow that relates to sonic velocity) around 6000RPM, with a 38mm intake valve and a 0.490 lift cam.

So rather than ruin the nice 5/16" inverted flare fittings on the large, 32 row cooler, I chose the smaller, 25 row oil cooler, that had integral 5/16" hose barbs. This one is in good shape, but the black paint on the outside was peeling and this cooler fits better. I sawed off the hose barbs right behind the threaded section; as this threaded section was just a little too small to drill and tap and not quite big enough to fit anything I could find in the local hydraulic shop. I wish it had been; that would have been a better way to go. After removing the hose barb and threaded boss, I discovered that the internal passages are 5/8" diameter...with a 1/4" thick solid top plate. I drilled the top plate to 9/16 and tapped it for 3/8NPT fittings. I have a small stock of 3/8NPT to JIC-8 adaptors here that I then screwed into place, and the cooler is ready to go to the cleaning service. Total cost before cleaning: $7.86 I'll update this thread with the final cleaning cost when I get it back...These were flushed for free the last time, as a favor.

I am looking at the feasibility of re-fitting the larger stacked-plate cooler with larger fittings; the guy who scrubs these coolers out says he can get them absolutely clean inside, so metal shavings aren't an issue. I have two of these, and they are 5$ each at the local parts yard...I can ruin a few to figure this out. The Niagra cooler is going to be a cakewalk to modify...I'd do it just like any other salvaged Volvo intercooler core.

I do intend to install a thermostat. The RX-7 cooler is approximately the same size as the Taurus SHO unit; but is a two-pass instead of a single pass...which I can convert the unit I have. I haven't found an RX-7 cooler yet, but i have been looking for one.

It is my intention to fit an oil cooler to my Z in the near future. I have three coolers on the shelf. Two are Long Manufacturing stacked-plate coolers, one is OEM fitment to the 1991 Ford E150 Van Transmission cooler, and the other is OEM fitment to the 1989 Ford E150 Van. Both are 10.5" wide and 1.375 inches thick. The 1991 cooler is slightly larger, and has 5/16" inverted flare fittings. This cooler has been professionally flushed, and when I removed it from service the ATF in the transmission was clean and metal-free. I removed it from a running, driving, perfectly fine truck that was being scrapped out at my employer due to rust. The cooler was about two years old, having been replaced when I replaced the transmission in that truck. The 1989 cooler is smaller, and has integral 5/16" hose barb fittings. This cooler has also been cleaned by a professional service, and when removed from the junkyard van it had very clean engine oil in it...not transmission fluid. It is possible this was fitted by someone other than the factory...although it was a factory fitted part for that year and model. Who knows? This cooler is the same width, but about two inches shorter top to bottom than the above model. The third cooler is also a transmission cooler...this time built by Niagra Fabrication, with a Ford part number on it. This was removed from a Taurus SHO. This cooler has 3/8" hose barbs on each end, and is a bar-and-plate type cooler. It is 4.5" tall, and 18" wide, not counting the end tanks. This cooler has integrated mounting points with clip nuts in it, and I can modify it for any size fitting I want on each end without as much risk of rendering it useless. It is currently filled with lacquer thinner, as I haven't had it flushed yet. It will have to go in the front of the car; but I am running out of room. Not sure if I can use it yet, I'll have to look and see in the daylight. The two stacked-plate cores I could mount in the fenderwell below the headlight, and duct cool air to them via the brake duct holes in the air dam. The long, thin one I am not sure I could do that with; I could mount it to the front of the core support and blow air down through it, but that seems like a less desirable way to go. I would prefer to mount it in the normal manner, but I don't think I have enough room unless I mount it below the core support and duct in air from the brake ducts on each side. Thoughts, ideas, Advice? Where was the stock ZXT oil cooler mounted, and how was airflow directed through it?

Who says I know what I'm doing? I'm just goofing around with this thing before I install it. Hopefully it works out well. I am fixing to go ask some questions though...gotta get edjamacated on oil coolers.

The exhaust ports I worked from a template I obtained a few years back...the port that the exhaust template was made from flowed 145CFM at 0.500" lift. Last time I managed 134 at 0.480", hopefully this time I did at least as good. The intake ports are eyeballed based on ports I've found in photos, descriptions, and comments on this and other forums. I don't have a stock P90 head to flow, and while I am trying to find a local flowbench to measure on the one I used before isn't around anymore...so far the closest I can find is a 12 hour drive plus 200$ for the work. The money, I don't care about...it costs what it costs. The shipping time is what gets to me. 38mm runners are still 4mm smaller than the largest ports I've seen...which was a 42mm port on an N42 head, on an engine turning out 370HP, naturally aspirated, at 7700RPM. The engine was run up to 8200RPM in service, but I don't know much more about it...I don't read japanese. Most port jobs I see have port sizes about 40mm...but that may be by convention more than anything. Those ports inbetween stock and 40mm seem to be clustered around 38mm as well. I picked 38mm because it should provide the flow numbers I need, without sacrificing port velocity. This port, if I can get the flare and the bowl sized properly, should provide as much as 220CFM at 0.500" valve lift. It should do this while providing port flow rates not exceeding 300ft/s until higher than 7000RPM, but still keeping flow rate above 200ft/s from 2000RPM. I would like to see 210-220ft/s at 5300RPM, up to about 240ft/s at 6300RPM or so.

The ChaseBays kit has been discussed before...it removes/eliminates the rear brakes!

Porting updates: Exhaust ports are finished, will get a final 120 grit finish before the flowbench and will get polished after. I have one intake port roughed in at 37mm, finished port will be 38mm. Progression of an exhaust port: Good shot of a finished port: I swear this port isn't as wonky as it looks...the port floor is level with the deck surface. I went and checked twice after taking this photo.

Jack....that looks like an M90 supercharger plus a T3 turbo, and a chopped up jaguar air-to-water intercooler? That's pretty dang sweet lookin!

CHECK FOR VALVE TO PISTON CLEARANCE when you reassemble. It's likely that if the cam is not very very close to where it should be, it'll hit. Any big cam like that needs to be checked, it may be that you need deeper valve reliefs in the piston. (I think this is very likely.) When you get into long duration cams, it may not hit when installed straight up, but retard the cam a few degrees and the intake might hit, advance the cam and the exhaust might hit. Even better chance with a high lift cam like that one.

That doesn't look right. Your boost line should be running UNDER the piston, so that boost pressure helps lift the puck. I think the way you've got it hooked up now, boost pressure is holding the wastegate shut.

You will have to keep up on them for a bit after the first few good heat cycles. Even with the locking tabs, I end up torquing them after the first hard drive, then again a few days later, then a week later...then they finally stay tight and I fold the locking tabs over.

Take the shaft out, drill the hub of the gear and the shaft for a pin, ream for desired pin type, insert pin. Done. I'd use a rolled spring pin, commonly called a roll pin. They are cheap, easy to get, and easy to use, and it's not like you need a huge amount of shear force there. If you're worried about it, double-pin it. It's not the dizzy that really puts the force on the shaft, I think...I think it's the oil pump that really puts the load on it. The distributor doesn't have a lot of inertial load, and not much mechanical load either...but the oil pump certainly has enough to do the job.

L-series headbolts are fully reusable after inspection. Good luck trying to buy new ones, at any rate. Old bolts harden and snap. Did you inspect the bolts for necking, stretching or other damage before trying to re-install them? Were the threads oiled as called out in the assembly manual?

A lot of shops will just polish them if you asked for a polish; they won't cut them. Not every shop has the equipment to grind the crank, but they may be able to polish the crank. My local guy doesn't cut cranks, but he can polish them with his equipment. Have to send the crank about 100 miles east to get to the closest shop that does custom crankshaft work.

Been working on this some. Crossposting from another forum. Stock port: Little better detail: About halfway done, smoothed out to judge contours and stuff: Another port, also about halfway done: I'll be taking some more shots of ports much closer to finished tonight. Yes, the ridges giant cliffs under the seats are now gone.

Yep, the 200SX box needs the rear mount moved, but the driveshaft can stay the same length when doing a FS5W71C conversion for the Z cars. Looks like the rings for 1-2 are bigger than 3-4. 2nd gear is a single-cone synchroniser, making it a Post-83, Pre-86.5. With that gear spread, I'm with Leon...it's a 1984 200SX box.

If you can't feel them, they'll be fine. You don't want to polish a journal so much that the bearings don't fit! Polishing will not replace grinding to the first undersize.

The reason for using the RB flywheel is more to get an inexpensive lightweight flywheel, plus a clutch that can comfortably hold a decent amount of torque over stock. It's not because it's really the best way to do it. Also, the larger disk lets you get that extra holding power without sacrificing clutch life...instead you sacrifice shift speed, so your synchros need to be very well setup! If I had 1200$ to drop on a flywheel and clutch, I would be using a 12lb billet steel flywheel custom made for the L locally (there is a guy here who does custom flywheels) and probably a small diameter double-disk unit...

The "stock replacement" clutch for the 350Z is the sprung-hub replacement part, since the dual-mass flywheel can't be machined. Either you spend over 1200$ on a new Nissan flywheel+clutch, or you get the Exedy/LuK replacment for the also-available solid flywheel. It's a 250mm disk, 1800kg pressure plate, and the pivot points are moved so that it feels like a stock plate would at 680kg of pressure...very similar to a stock turbo clutch.