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Not that kind of visit; I'm not that lucky...yet. Not for lack of effort, that's for sure! She did help me go through the stash of bent files and cartridge rolls trying to find something to reach the last little bit of the short turn in the exhaust ports...there is a spot that I just can't get at yet and it's the last spot to do. After that, it's a little here, a little there, to get them all as close to identical as I can get them. (they're close, but they can get closer.) Port #1 was finished out completely, and match-up templates were made to make this job easier. The intake ports, being round, are much easier for me; templates are simpler and there is less port re-shaping involved overall. Exhaust ports will end up 30mm wide x 40mm tall, to match up with the header. Intakes are 38mm round; and I have 38mm templates made up from a past port job already, although they were for an E88 head...port is slightly different. P90 port is a slightly larger STR, and the valve guide bump is smaller. The lower compression ratio from the larger volume will be most welcome; as going from a 42cc chamber to a 52cc chamber will drop me from 9.72:1 to 8.1:1...much more blower-friendly!

Sounds like an awesome trip, Peter! Laguna Seca is a nice looking course...but take note that California has oxygenated 91 octane...might as well fill the tank with scummy pond water. Tuning is going to be MUCH different, so if you're going to tune the car in Oz, then ship it to the US, it'll have to be re-tuned when it gets here for the fuel he gets to use...although if he's running race fuel it won't be a problem. While you're in LA, look up Jeff Priddy and his 280ZX. He's the one street-driving the 650HP L28ET I mentioned in another thread, as well as Power By Gerolomy, who no longer does L-series headwork...they used to do some of the best L-heads in the states. Jeff's head was the last one Nathan did. Slover's Porting Service still does L-series heads, and I *think* they are in the area as well. (Trying to think of all the L-engine nifty things in the LA area...)

Been having a rough time applying some of the suggestions PMC made a while back, but I have four of the exhaust ports roughed in, just the two center ports to go. Pictures later this evening, there is a very pretty girl coming out to spend a little time this evening so little to no work tonight.

Some parts of the US have lower grade fuel, but where I live, 93 octane fuel is roughly equal to your 98 octane...different ways of measuring. A little way down the road, next town over has pump 95, which would come out as 100 octane in the Southland! Not so cheap, though.

The 680HP street-driven 280ZX is featured with dyno sheets in a few import performance mags over here, It's JeffP's over on HybridZ. It makes much more HP at higher boost levels...but most of the time, it's set up for about that. I don't even want to THINK about the money in that build... Kinetic-Sunbelt engines in GA has a turn-key 600HP+ L28ET for sale, was 12K USD last I checked. It's advertised to make 600HP minimum, and they can turn the wick up for you if you need it...with an accompanying shortening of engine life. This engine is very real as I've actually layed eyes on it and seen the dyno sheet. Electramotive raced a 750HP+ engine in the mid 80's over here...after the car was no longer competing, it was revealed that the engine made just north of 1100HP, Electramotive just chose to publish the HP at 7200RPM at that specific boost level, as that is what the car was raced at most of the time. For qualifying, they would turn the wick up...the engine was run up on the dyno to 8200-8500RPM, according to the dyno operator that worked on it. (this last bit was from TonyD, and I did a little follow up on it later...Seems to be correct, but I have no proof.) I guess the AU-US engine building hate isn't going to come down any. Was hoping to get some insight from a different perspective, but I can get along fine regardless.

Interesting. I have two heads that this was done on, plus I do it on all my "more than street work" heads. Granted, I don't do much for many, yet. I learned about the casting flash from Rebello Racing, back when I first started in Z cars. having a hard time deciding if a 36mm exhaust valve is the way to go. The seat inserts will barely hold the bigger valve, but the ID of the seat insert is smaller than the port by more than I am comfortable with. Stock valves will have the best curtain area and be the least shrouded, +1mm exhaust will be acceptable in the chamber, but only just. the larger valve will allow me to open the seat up more and remove most of the raised lip under the insert, though. Any pointers there?

Hate to break it to you Peter...we've been doing this for nigh on 10 years now that I know of... This, combined with external water lines over #5 and #6, are how we on this side of the pond run 680HP turbo motors on the street, daily drivers. It's REALLY effective! My air hammer broke, so I am dropping the head off at my machinist's to have the guides knocked back, this 'un will be getting a TK style port job. (Last one of his datto heads I read on saw him make 204CFM intake at 400 thou lift!) It doesn't look like a US port when he's done, but I can't argue with the results. Valve guide boss removed, guide tapered, ports worked to 40MM...I'll be stopping at 38mm.

Getting started on the P90 head I picked up a while back. This is the beginning of what I would consider a full effort street port, since working the chambers much harder than this results in limited life. I have not started on the ports yet, just worked on the chambers and the water jackets. I'm getting this going now, since i pulled my N42 off to change a suspected blown headgasket, but turned out the head was cracked between cylinders 2 and 3, right on the deck surface. This is for the M62 supercharged engine; I saw 68kpa of boost before I noticed the temps just kept climbing... Valve unshrouding: Water jacket modifications...AKA "Why the hell are you drilling holes in that cylinder head?!?" Because down inside here, the exhaust port and intake port are connected with a web of casting flash. It shouldn't be there...I got in with a small drill bit and drilled and chipped out all the casting flash between the ports. Marking out for the port sizing. Intake valves will remain 44mm diameter, and exhaust valves will be cut down from LS1 exhaust valves, to 36mm diameter. The LS1 valves need to have the diameter reduced, margin thinned, 25* back-cut applied, the stems cut down by 8.3mm, and the keeper groove re-cut lower on the stem. Even with all that work, it's cheaper to buy a set of Manley LS1 exhaust valves, cut them down and re-groove, than it is for a set of Ferrea standard alloy +1mm L28 valves. The circled bolt holes will get drilled and helicoiled, as they often pull out in normal service and the threads gall up occasionally too. I use 2D series helicoils for this as they are twice as long as the normal ones.

Brake Cleaner...Tetrachloroethylene, commonly. Not sure what the non-chloronated stuff is. The UV and the heat brake it down into Phosphine, an ammonia-analog with deadly effects, and Phosgene; which was used in WWI as a war gas. Kill ya without a lick of mercy...and it's hell on your kidneys if it doesn't manage to blister your lungs into pulp. I've used the Miller Diversion 211...and honestly the only thing it had over my Jasic was a smaller box, same power, and the HF AC. I Loooooove me some HF AC though...so nice. One of these days I'll convert my Jasic and just make it so I can't blow up the inverter array with the panel knob.

Been busy with some other things; so it's a big update. Got the throttles opening up together! Fuel rail stanchions made...chunky things! Rail mounted, but not quite finished...Still needs a regulator. Feed line fitted up, and the throttle cable installed. Fuel pressure regulator housing machined and welded onto the rail, with the regulator installed. Just pop the circlip out... Pull the regulator out of the housing... BAM! ready to drop the new replacement in, OR quickly change fuel pressure in preset steps...2.5, 3.0, 3.5, 3.8, 4.0, 5.0 BAR regulators are available from Bosch...Or your local VW/Audi dealer! Starting to get the fuel lines run here: Compressor bypass vacuum control lines wrap around the cylinder head, like so... And, short some vacuum lines, wiring, and IAT sensor, this is how it should all look: Of course, we'll need more stopping power, since we're adding more going power.

This weekend I'll make the fuel rail mounts, and will get started with the fuel rail itself, I hope. All the material is here, but i've got a hung caliper on the datto and may have to split funding to rebuild the front suspension...You know, the while-am-at-it's will get me...

Only thing that has me hung up now is the PCV system. I *think* I've got a good way to work it figured out, but not positive yet. Instead of having the PCV valve on the manifold, it will be on the catch can. The catch can will have full engine vacuum on it all the time, be mesh-filled and have an oil separator in place. The PCV valve will still be fully functional; but the can will act as a vacuum resivour as well as stopping most of the crud that would go into the manifold.

So I got the counterbore made this evening, hardened and sharpened up. It's an old-style D-bit reamer, with a pilot on it. I use these things all the time in my gunsmithing stuff. Got the injector bungs counterbored and test-fitted the lower injector seals. More on the TPS sensor this weekend, when I get it fitted up.

I have a Jasic Inverter Basic 200A AC/DC/Pulse machine, a TIG200P model. I have abused the CRAP out of this machine and the WP-26 style torch it came with for a year, running it at ridiculous duty cycles and downright abusive power levels. (Yes, the internals are easily modified to allow up to 275A output...I've upgraded mine to allow up to 250A safe output) The only downside I've found so far (and this is fixable too, if you're an electronic tech) is that the AC is 60Hz output only. It's possible to convert this to a variable setup, but when you vary the AC frequency output you're actually varying the safe operating area of the inverter transistors, and you risk running them into a very unsafe area of the operating table...and if one goes boom, expect that whole bank to burn with it. When welding aluminum in a tight spot, such as welding in injector bungs on a angle-port manifold for the L, I really really wish I had the fine arc control available with variable-frequency AC output. On not so chunky aluminum (3/16" and thinner) you can fake a variable AC control by enabling the pulse mode, setting the duty cycle to 90%, and then using the pulse frequency knob to adjust arc frequency. You loose a lot of heat though, and the machine will warm up pretty good. The only other thing that bothers me is the funky gas connector on the front of the unit. I'm looking into converting mine into a water-cooled unit, by adding another output lug with the integral water line connector. As I said, I've run this machine at stupid duty cycles and power levels, welding aluminum cylinder heads, and very quickly hit the limit of an air-cooled torch. If you're not welding 3/8" and thicker aluminum on a regular basis, then this is not at all a problem.

Finished welding in those *$%&#@^ injector bungs today, those little bastards are a pain. I would have been better off boring them through 10mm and forgetting the lower o-ring seat until the welding was complete, as it is I'll have to rig up a long-pilot counterbore to re-machine the o-ring seats. Had MAJOR problems with arc wander in one spot on every bung. Might see if it can be set up in a seat-and-guide machine...that might be the hot ticket. Regarding the tuning, I DO have the option to run a hot-wire MAF sensor, there are several out there that are compatable with MS. Would it be beneficial to go with at MAF setup for load sensing, over TPS/MAP combo? The TPS/MAP combo can be rigged to run several ways...TPS as primary table, with MAP modifying, or MAP primary table with TPS modifying, or the mode that I've used before, which is used on the Ferrarri F40 system...TPS is primary, and MAP is multiplied in. In this mode, there is only one table to tune, the TPS table. MAP is linearly applied based on the current MAP value. This is the only mode that I actually *KNOW* how to use, and the only one I've been able to convert to run the spark map from the MAP value and not TPS. (this last bit seems important to me, since TPS-only won't be an accurate load metric under boost) Hoping to get the interior of the manifold cleaned up and finish-ported this week, and figure out how to accurately re-machine the injector bungs in-situ...I don't have a milling machine and I'm not sure I can rig the lathe to mill a part this large. Probably going to rig up a custom piloted counterbore from some drill rod and call it a day.

The reason I find the flat-top carbies superior is that they have a separate idle circuit. You can run a rich main needle and still lean the idle out so it doesn't smoke out the pipe in the driveway. Set the float level, turn the idle screw 1.5 turns out, set the main jet nuts 1.5 turns out, sync carbs. Set idle mix. Set RPMS to 2500RPM, adjust main jet nuts. Return to idle, re-set idle mix, BAM carbs done. Wheras the roundtop carbies tend to run fat at idle, or if idle mix is proper then they run lean up top. Needle adjustment is possible but adjusting the idle area only is a pain.

Good to know. 15.5" from the back of the valve to the runner opening, so we're a little longer than the 13" you mention. Header is this one, built in my garage. Total length to final merge is 34", primary length is 20". All tubes are within 1/8". Header tubing is 1.625", 2.5" collectors, and is mated to a 2.5" exhaust. Header was intended to be mated with a 3" exhaust, however I haven't managed the packaging constraints yet. Camshaft is a Isky custom profile; 0.480" gross valve lift, 280* seat-to-seat duration, 232* duration at 0.050" lift. Lobe separation angle 113*, intake open 25* BTDC, closes 75* ABDC, exhaust opens 71* BBDC, closes 29*ATDC, Overlap 54*. Camshaft has not been delivered yet, but has been ordered and a core delivered to be ground. I will be calling tomarrow to see where it is. Hopefully it'll be better for the application than the current cam, which is a similar lobe profile cut on a 107.5* lobe seperation angle. Current cam has shit-for-all vacuum at idle, and was generally a poor choice for a street application. Compression ratio is *supposed* to be 9.7:1, however I am reading conflicting reports from my construction logs. Compression may be lower than desired, however that can be easily, if expensively, fixed. Current engine is 79mm stroke, 88mm bore, 133mm rod, 9.32cc dish in piston, and moderately ported N42 head, shaved 0.030". Calculations showed that this *should* have put chamber volume at 42cc, however I need to measure the head thickness again and be extra certain. If I'm lucky, then the compression will come out at about 9.0:1, and we'll see what we will see. Target boost is 8PSI, intercooled. Compressor will be 65% adiabatic effeciency from 2000RPM til 6500RPM, dropping to 60% or so at redline. Volumetric efficiency of the compressor will be 88% or higher over the same range. Hoping to get at least 80% volumetric efficiency over this rev range in the engine; if I manage that then I'll put the power goal to the ground. (assuming the transmission will handle it!) As far as the tuning goes, the Hybrid Alpha-N mode I mentioned uses both MAP and TPS to gauge load, using the same math the Ferrari F40 used. I've used it prior to this, and it's pretty slick, just takes more time to tune properly. Initial tuning will be done on some carefully chosen roads that have (measured) grades of 3%, 7%, 10%, and a 12% grade, each about a mile long, in a straight line. It's pretty easy to setup passes on each grade at incremental throttle position, then move to the next grade, so tuning is slow, safe, and steady. I think I can get at least 85% of the tuning done this way, before shelling out the money for dyno time. It's a 4 hour drive, plus fuel costs, plus 185$/hr to use the dyno, plus lunch for the dyno operator, so I like to make that time count.

Yep, done it before. At the specific power outputs we're looking at here, it shouldn't be an issue. That said, I am fully willing to accept ANY advice from someone who has worked with the GTR boosted system at the level you have. A GTR though, is a whole 'nuther beast. You're looking at 600HP minimum, I'm looking at 300HP maximum....the max this particular supercharger (eaton M62 from a series 1 3800) can push is about 270RWHP. I would have to move to an M90 to get more. As it is, I'm running a short-runner, large-runner-diameter, large-throttle-plate intake that requires a LARGE throttle cam (we're looking at a 5:1 ratio of pedal-to-throttle motion at the early part of the cam) to even be remotely drivable. Tip-in is awful. Idle vacuum is 55kpa best case, and the engine cruises at 75kpa. WOT is reached at 82% throttle position. Don't shift up under 4000 unless you really want to baby it. (makes in-town driving a pain.) 4000RPM and up and this intake really shines....below that and it's a terrible compromise and tunes very, very similar to ITB's. ITB's with charge robbing. Worked perfectly fine for a track car with a head the flowed a little better than mine does; but on my daily no, it's causing me headaches. If I'm going to drive with all the issues inherent in ITB's, then I might as well pick up the one benefit to them. Also, MS now has a new load system specific to ITB systems....I plan to give it a shot. If the new load sensing mode can't handle boost, then there is always Hybrid Alpha-N mode, which I have used before and it works very well. Got any tips on preventing standoff or reversion? I'm worried that the straight-shot runners might cause problems with that. Thinking about porting the head to 39mm or 40mm (careful, careful!) to get an anti-reversion step, as suggested by Racer Brown in the article reproduced on Datsport. Head is a P90, and I've done a little port work before. I still need to practice some on my exhaust ports, but I think I've got the intake down. Flowed an E88 head casting to 221cfm at .540" lift, and only lost a very few cfm under .300". The P90 port looks like it'll take less work to get there.

The original inlet of the throttles has a 90* turndown on it, that goes to the OEM nissan airbox. I thought about trying to figure a way to use it but it was going to be a lot of trouble for less than optimal usage. I left them at the junkyard in the passenger seats of the Maximas I pulled the throttles from. The engine management is handled by an MS1extra controller, and an EDIS ignition controller. I am currently running this on the car now, and about 95* of all the bugs are worked out. The new installation will let me fix all the remaining bugs, which are mostly wiring related. The wiring harness will be split into a cabin harness and an engine harness, as to make the wiring much much less convoluted. Also, the harness won't have to be wrangled out of the car each time the engine gets removed. Every time I go out to the shop to do some welding, it's so cold my breath fogs the mask and I can't see what I'm doing...

Good. I'd like a professional (or even semi-professional) builder's thoughts on it; our pros back at Hybrid have gone into retirement/hiding for now...they're hard to come by, anyway. These injector bungs look like shivere. Two of them are going to need touchup machine work, which bites. Maybe I'll get some heat in the shop tonight and see about welding up the rest. Here's a little extra about the project:

Got all the bits straightened and machined flat, here's the mockup fitting to make sure I haven't totally goofed up: Going to have to fit up a throttle shaft extension here to correct for this... More photos of ugly welds this evening, I'm having a rough time of getting the injector bungs welded into place.

I've got this posted up on HybridZ too, but figured you guys might like a look at the job. I am currently running a hybrid intake made from an L28 fuel-injection intake lopped off about 1.25" from the head, then welded to the twin SU intake after the flange was cut off. The SU's were replaced with a pair of Mitsubishi Eclipse throttles, so it's a twin 50mm throttle system. This works fine, from about 3500RPM and up. Below that, I think I'm seeing bad reversion effects and charge robbing on some cylinders, as the car has to run extremely rich at idle and will foul plugs on four cylinders, while the other two remain quite fine. I've swapped injectors around a few times, and the plug fouling doesn't follow the injector...Note that the engine will only foul plugs at idle, once you're driving it keeps them clean. Leaning out the idle results in poor running and lean snaps. All this goes away at higher RPM. So, to eliminate charge robbing and to improve the overall cylinder-to-cylinder distribution in preparation for 8-10lbs of boost, I've started a new manifold project. Here's the outline: The manifold is a fabricated aluminum part. I have the ability and facilities for aluminum castings up to 20lbs on site; and *may* work with that eventually, but not for now. The runner ID is 38mm, and was chosen based on where I want peak torque to fall. I don't buy into the "manifold length is the torque determining feature" because the data shows otherwise. Manifold length should be chosen to complement runner ID in my opinion. For an L28, 38mm ID runners will provide a torque peak at 5300RPM, and will have a port velocity of 200ft/second to 520t/s from 2800RPM to 7000RPM. This is within the ideal range, although on the bottom end we're starting to see the velocity drop off. To complement this, a runner length of 15.5" was chosen, as this is close to the 3rd wave length for 5300RPM, and has usable nodes from 3800 to 7400RPM, coinciding nicely with the goals of the project. The absence of charge robbing will be pushed for by making this an ITB intake, using throttles from a FWD VG30e Maxima, as they are plentiful in the parts yards, even if they are a little oversize. I'd prefer 40mm throttle plates, but these are 45mm. They'll do. At 10 bucks each, I'm not going to shell out nearly 400$ per each from Jenvey for 40mm units. Injector ports are currently being fitted, and it's a right pain in the rear to get the TIG torch down in the tight spots. It's currently giving me fits, but hopefully a gas lens setup will help with this...it's on order. We'll start here, with the plenum: Yep, those are fire extinguishers... Then we press a table leg into service, wrapping it with aluminum to form a secondary plenum assembly from 2.4mm sheet: Got them welded up, the main plenum pulled pretty good in the middle. Fix it later. Fitting up the throttle plate/velocity stack plate: Laying out the cylinder head flange: The runner tubing is fit into hole-sawn holes, cut with both a 38mm and a 41mm hole saw in a drill press. The ports are cut in at a 15* angle, and if I had done my math right, they would line up with the bottom of the OEM port. They don't...I'll have to lift the manifold about a mm. Well, let's have a go at it, shall we? Yep, welding moves. A lot. 2mm! Before straightening up, this is the "concept" shot. Now, that's done. Let's get started on some "velocity stacks"....I hesitate to call them that, because they don't have as much radius as I wanted. Not enough room between the throttle bores. But, they are tapered in, and have a 1.5" radius cut into them. I really don't like the thin edge there, but they're already in and I can't change it now. Plenum assembly! I'll put up the rest of the main runner assembly in the next post.