DAW

I posted earlier and couldn't find the hoodscoop article I wanted. Aaron found it and here it is...http://www.240sx.org/links/installs/hood/hood.htm food for thought. DAW

Not sure, but this may be the reason the F54 block is recommended for the big overbore (vs the earlier N42 block). Which was yours? DAW

I want to know the maximum overbore for the LD28. I don't have the money to pop for sonic testing just to find out. However, on visual examination of the cyl bore wall material in the rear-most block water jacket vs that of an L24 block, it appears that there is a lot more material there vs the L24. How much over 84.5mm can the LD28 be bored? DAW

Did you get the hoses? These come with some great molded curved hoses that have a built-in taper at the intercooler ends. For $8 you can't go wrong. I was bought a compact intercooler from a JY once for about that price...the guy thought it was some kind of heater box and I didn't argue. There is an interesting electronic feature built into the Audi unit and I'm not sure if it's a temp sensor or a pressure sensor. It might be a means of limiting boost if intercooler temp is too high. DAW

Thanks. I'm going to rob a spare turbo of one for now and order several to have on hand. DAW

So I'm installing an intercooler on my '83 280ZXT together with an adjustable wastegate actuator and a BOV, and after the umpteenth time of removing, repositioning, and reinstalling the compressor housing of the T3 I managed to "snakebite" the compressor O-ring, cleaving it in two. I've searched and I have some inquiries in to turbo remanufacturers but I thought I'd ask out there if anyone knows of a good source for small parts without being sold a rebuilt turbo when all I need is a gasket? Thanks. DAW

My experience with the Monza exhaust from Victoria British is that I was happy with the quality but it was way too restrictive. The system for 240Z would have made a great "Twice Pipes" if you tied two together to make one decent exhaust system. You'll be wanting a higher flow system than the Monza if you're going to make some power. I understand what you're talking about re the "Euro" sound. I lived in Southern Italy for a couple of years and I loved to drive my Alfa Romeo GTV with dual Weber DCOEs, if nothing else, just to hear it rev. I was researching some info on BOVs recently and came across a soundmaking device that would produce a BOV-type "whooosh" between shifts for an na car that wishes it were a turbo...now that's desperate! I'd love to package that Euro sound, or figure out how it's done, it looks like they use a lot of little resonators rather than single, huge low-restiction mufflers. DAW

I would transplant an L28ET with all the stock hardware/ECU/fuel pump, relay etc, then intercool it with whatever (Saab, Volvo, Starion) source, 1st gen Eclipse BOV, and sell the stock L28E. Bang for the buck, I don't think you'll do better than that. DAW

Use only the 9mm bolt Nissan rods; not the 8mm. DAW

You need to verify it yourself and it's easy to do. That way you can ask yourself, "do I believe what I'm told, or my lying eyes?" Warning though, adjusting the cam timing is easy but you must block the timing chain when you reposition the sprocket or you will lose the chain and make a lot of otherwise unneccessary work for yourself. You can't disturb the crank once you've blocked it, so you would turn the cam a small amount using a large adjustable wrench on the square lugs on the cam so that you can slip the repositioned sprocket onto the cam dowel. DAW

There's an article available on line describing a step-by-step method of fabricating such a hood mod. He does it on a 240SX but I think it could work nicely on a 240-280Z. I can't find it but maybe someone else has saved it, or search "hood scoops". DAW

yo2001, that doesn't work out. L28 crank uses 130.4mm rods and 38.1mm pin ht pistons. A 140mm rod would required a pin ht of 28.5mm. Possible, but that's mighty low, even for a forged piston, and it leaves hardly any room for piston rings (maybe it was an L24 crank?). I'm interested because I have some Nissan 140mm rods, but they have 23.5mm pins, and I'm always searching for pistons with a low pin ht in a useable bore size. Does anyone have the specs for pin ht on the RB series pistons? DAW

Bastaad525, I think you should look into the cam timing more closely, given the type of problem you're facing. First, what hole the cam is in on the sprocket matters only in re to where the cam is actually timed to. In other words, what you really need to know is where the index line on the front cam thrust cover lies in relation to the V-shaped notch on the cam sprocket. Factors at play here are chain length (stretched vs new vs new replacement not to spec, etc), sprocket (crank and cam) wear, cyl head thickness, over or under-shimming of cam towers. The wild card is whether your replacement cam pin is identically placed at manufacture to the Nissan cam you removed. This last one requires a degree wheel to confirm. You'll be able to compensate for any discrepency easy enough, but you'd have to check it first. Leave the dowel in hole #2 where you have it and check the line/notch position. Always rotate the crank smoothly to #1 cyl TDC position to keep chain tension on. You may find that you have selected #2 hole but the cam is timed closer to stock location or even retarded, especially if the head has been milled but not shimmed. From your description, it sounds like you may be looking for some cam timing advance to help driveability and low-end power, so consider the trial & error tuning route and advance to hole #3 if you don't have a degree wheel. With flat-tops and a milled N42 you don't have an endless piston-to-valve clearance so you don't want to be off too much in either direction. DAW

If you can't get rid of dieselling, until you sort it out you could try to rig up an Idle-Stop Solenoid. This setup was OEM on Z28 Camaros and 396SS Chevelles in late '60s, early '70s when high performance engines met emission controls. The solenoid is actvated with ignition switch "on" and the running idle speed is adjusted by turning the hexhead rod that comes out of the solenoid and contacts the throttle linkage. The usual idle speed screw is backed way off. With the solenoid unplugged, the usual idle screw is set so that the engine won't idle anymore and dies (like 400rpm). With the solenoid activated, you can set idle at 800rpm and when you shut it off the throttle plates snap nearly closed and this prevents the engine from dieselling. Maybe you could find one of these in a JY, I think GM used them extensively even on economy cars back then. DAW

The Maxima 4N71B wouldn't be suitable for any performance application (but it would be an option for a retrofit upgrade on a stock 240-280Z with an A/T), but it is the source for the bellhousing to adapt the stronger 4N71Bs to the L6. I'd like to know if anyone has facts as to which 4N71B is the strongest and why. I've heard it said that the Starion is a good donor but what about the 300ZXT and RX7, & Mazda 929? They have similar hp or higher curb wts so why wouldn't they be built similar? Are there other worthy sources like Mitsubishi trucks, Monteros? How does the A/T failure rate compare on all these sources? Anyone out there with good experience & knowledge that could do this comparison with other than heresay? I have a 4N71B from an '84 300ZXT that I plan to install in a '72 240Z but I'd reconsider if there's a better source at reasonable price/availability. Thanks in advance. DAW

An intercooler never hurts; it can only help. DAW

I'm certainly not well informede on A/Ts but I think this is a good topic thread to update once in a while. There's a concurrent related post in "Drivetrain" re a member's quick L28ET with a 4N71B. As to your situation, I know you'd be able to upgrade the 3N71B (Jatco) trans in your '72 by going to a 3N71B from an '81-'83 280ZXT as it has a higher stall speed torque convertor (and maybe beefier internals; anyone?). There's a 3LN71B from the '81-'83ish Maxima that has a hydraulically-locking convertor that in itself is a step up from your non-locking convertor trans. When the convertor locks up, it's feels and drives like it shifted into a higher gear. The '84 Maxima had an electrically-switched lock-up convertor 4sp A/T with the bellhousing you need to bolt onto your L28. Then there were the A/Ts on the 300ZX(T)s which were 4spd A/Ts with electrically or hydraulically locking convertors; and the turbos have higher stall speeds than the na cars. The same Jatco trans is used in Starion/Conquests and some RX-7s. It would be very helpful if anyone has some facts as to which applications offer the best/strongest internals (# of clutches,etc), as well as some stall speed comparisons, and if the Maxima L4N71B bell housing bolts onto all of these options for adapting to the L6. Presently, I'm using a 3LN71B behind a 2.8L L6. The trans is from an LD28 and has a lower stall speed than even the na L6 (and much lower than the turbo applic.). It works great for the street but the engine is set up for a lot of low-end torque (83mm stroke) and I doubt it would work as well with less low-end torque. Maybe admin could shift this to Drivetrain? ha DAW

Set your idle as low as possible to get rid of dieselling, without going so low as to load up at idle. So what's going on with the cooling system? You're running hot since the top-end rebuild...is there now a lot of pressure in the system? Is a cylinder leaking compression into a water passage (at head gasket seal)? Is there a hairline crack in the reworked head? Assuming you increased compression with the head work, you have a new set of mixture requirements (richer), and timing parameters. Either or both of these being off will cause detonation and/or dieselling. Until you get it sorted out, don't let it run-on, hold with the brake and engage the clutch on shut down, and decrease idle speed. DAW

Turning over generally refers to cranking (starter turning the crank). It sounds like maybe your car fires but won't run. If this is the case, make sure all coil primary wiring is intact because if you have a ballast resistor, it is bypassed while cranking, then used for running mode. Check the voltage at the pos side of the coil while cranking, and then while ign switch is "on". Maybe the ign switch or wiring is at fault and it fires but won't run. DAW

What does it weigh?

"Ported" vacuum is a signal source at the throttle plate from a slot that is masked at closed throttle, then gradually exposed during throttle openning such that the resultant signal is roughly proportionate to the degree of throttle openning. So you can see why that wasn't working well...you wanted just the opposite type of signal, and more of an all-or-nothing type signal rather than gradual. As to the vacuum fitting/connection, I would try to approximately match the lumen of the fitting/hose of the BOV. If you mismatch to too large a fitting, you'll lose responsiveness of the BOV and defeat its purpose. If the mismatch is to too small a fitting it could lead to increased turbo lag because the vacuum in the top of the BOV won't be able to release quickly if it has to flow through a tiny orfice/restrictor. The turbo will freewheel until the BOV has the signal released so pressure is allowed to build again in the turbo hoses. There's a single fitting in the top of the manifold, about 1/3 of the way from the front that is about the size of the BOV port. That would be a good vacuum source for BOV signal. It would be best to find a metal Tee port that threads in to replace the single port connector. DAW

The SUs don't have accelerator pumps, so if the chokes aren't set right starting can be difficult. Try (careful!) ether (starting fluid) to see if it will fire. Since you didn't need to disturb the ignition system, it should spark like it did when parked for the carb swap. If it fires on ether but won't keep running, then start tracing back the fuel supply to each carb, i.e., fuel pump/lines flow, float chambers, the fine mesh screens at the inlet-needle-seat, etc. Check that the pistons in the carbs lift OK using one finger, and drop when released. DAW

Think about what the BOV is for and you can figure out how to plumb it. The vacuum signal to the canister diaphram is wrong. That signal is ported vacuum and that's not what you want so reverse that hook-up and start over. You want an intake manifold vacuum signal to your BOV, take it right off a manifold fitting using a tee. When you let up on the throttle, the plate closes and the manifold signal shoots right up as the cylinders are sucking against a closed chamber (the manifold). This opposite of this condition is happenning simultaneously on the other side of the plate as the wound-up turbo is suddenly faced with a pressurized column of air it created which has no where to go now, and works to try to stop or brake the compressor wheel from turning. The BOV vents that pressure and allows the turbo to stay spun-up so that you'll have pressure availablr when you reopen the throttle (at which point the BOV vacuum signal falls and the BOV stops venting). Vented air from the BOV should be rerouted into the system since it is metered air which has some proportion of fuel matched to its passage through the AFM. If you do vent it into the PCV intake, then do it as close to the large air intake hose for the turbo as possible, and use a "Y" fitting to direct it into that larger volume air hose rather than into the smaller volume PCV (valve cover-connected) hose. DAW

You're right re the engagement of the distr onto the tang of the shaft, but you could move the wires around by one cylinder interval on the cap if it's off by that much. DAW

How many degrees is one tooth worth? You could figure out which way it needs to go, pull out the distributor, rotate the crank by one tooth's worth of degrees and drop the distributor back in. That would be faster and easier (and less messy) than dropping the pump. DAW