Xnke

Worked out a new order of operations while I was goofing around at work, and tried it tonight. MUCH MUCH FASTER! I was able to complete these four velocity stacks in two hours, they are (I had to recalculate this) 1.3" in length, and the center two stacks are supposed to be 1.0" in length. I will machine them tomarrow evening, and get them pressed into the baseplate and welded in place. After the stacks are welded into place, I'll bolt the whole manifold minus the plenum together for documentation purposes, and to make sure that everything will seal up. Close up of how the air horns actually touch, I would have liked to have a longer radius, but this will have to work. It's all I can fit in there. Soon....Soon I will be assembling the plenum and will start measuring for the following: Throttle Linkage Injector bungs Fuel rail mounts Heat shield mounts PCV vacuum port TPS clearance. It's gonna be DAMN tight to get a stock Nissan TPS in place. I might have to switch to a Subaru TPS, they sit on the throttle backwards from the Nissan unit, and I think they still rotate the same direction. That would be an elegant solution. Idle control will share the vacuum log with the brake booster, and I'll tap into the vacuum log for the MAP sensor. The PCV vent on top the valve cover will be rotated to the passenger side, and will be plumbed into a port on the side of the inlet of the supercharger. Any blowby mist will get dumped into the supercharger inlet, and will form a coating on the supercharger rotor assembly, keeping the rotor-to-rotor and rotor-to-case tolerances tighter. Yeah, that's it.

I looked at a serpentine belt configuration, but how are you planning to run the water pump? It won't work the same as it would on a conventional serpentine setup, since MOST of the ones I'm familiar with wrap rib side on the crank and flat side back around the water pump. I am running A/C also, so it wasn't going to work for me. Anyway, this project is far from dead...just haven't been updating it here due to work on the manifold, which is down in the fabrication section.

Argh. I'm really not digging the air horn turnings. The one in the photo below took me four hours to get completed, when machining from solid. I really should try to find some 2.25" OD .250" thick tubing to machine these from...would take about fifteen minutes each, then. (But then I'd have to buy some more material...and I've got a 14" bar of 2.25" solid drilled through already...) The next issue is vacuum management. I did not provide any method for drawing manifold vacuum in the actual runner assembly...the wall thickness and the planned throttle arrangement didn't leave much room for it, and I wanted a good clean look. The FWD Maxima throttle bodies I'm using have a pair of ported vacuum ports on the front, which I don't like and don't think I can use effectively with Megasquirt. At off-idle, they would read very high vacuum, but as soon as the throttle was cracked the vacuum signal would go away, and with ITB's that's already a major issue. The steel, pressed-in tubes were drilled out of the aluminum casting, and the holes plugged with driven in aluminum slugs. These throttle assemblies ALSO have a water jacket on the bottom that comes out into a pair of 8mm hose barbs. The jacket runs under both bores, behind the throttle plates...and I am not going to be running hot water through my throttle assemblies. If I could run chilled water, or if the passeges were drilled and tapped I could run cold refrigerant from the A/C system, but that's a lot of work. And I still need a vacuum log! Instead, I've carefully plugged the original vacuum ports, and drilled through the water passage into the throttle bores with a .220" drill. The passages get all the chips blown out as best as possible, and the outer holes welded back solid. The individual throttle assemblies will have the water jackets joined together and the front of the log will get routed back to the megasquirt, and the rear of the log will be routed to the brake booster via a check valve.

I belive we have rules about posting for sale ads outside if the classifieds...let's not. Tonight's task is to figure out the order of operations for the velocity stacks. they are machined from 2.25" solid, because I scored some at the local recycler for far less than I could buy smaller material. I may also attempt to spin some horns from flat sheet, I have been wanting to try that for a while now. EDIT: why is "Tonite", when spelled correctly, censored?

Yes, a lot of people would argue that. I have the equipment and the skill to weld aluminum with an oxyfuel torch, I did it for a few years till I bought my TIG. It sucks. Gotta use a sodium based flux, which flares BRIGHT yellow, masking the puddle, so you wear an extra dark cobalt or gold shade. The good cobalt shades are very hard to find and the one I have is cracked...so it's no good anymore. The gold shades that can block the sodium flare are exhorbantly expensive. The only benefit to using the oxyfuel setup for aluminum is if you are going to be working the sheet over a wheel or with a hammer; for doing bodywork. The weld deposit is much softer, and the heat affected zone is much larger, meaning that when you start working the weld bead it doesn't crack or split, but rather spreads into the surrounding soft metal, causing a much more gradual change in thickness. It's very often used in aluminum-skinned aircraft repair. In this case, you'd be hard pressed to find a method superior to TIG for welding .500" thick plate to .065" wall thickness tubing. Even a master of the oxyfuel torch is going to have a seriously difficult time controlling the puddle on that joint...

Really, the only big tool I used was the lathe, and I only used that for turning the form for the cone. the TIG welder you aren't really going to get around needing if your are going to fab aluminum sheet, though.

Reading through Monzter's intake manifold thread, I got the itch to do something similar. But I don't have access to a big CNC nor the 90+lb chunks of aluminum bar to get the thing done his way. I started out with some research, learning how dual-plenum intakes work, and the acoustic tuning done to match intake runner diameter, runner length, and port length together for a desired torque peak. This is the result: Manifold ID: 38mm Manifold length: 265mm Total intake runner length: 395mm This should produce peak torque at 5300RPM, and support enough airflow for 300 horsepower or more. Plenty for the task at hand. Started with the dual-plenum assmebly. Didn't get a lot of photos of this part, but I didn't really want to buy any 4.125" diameter tubing...so I scrounged some up from the scrap bin: Trued up, welded together, and most of the powdercoat stripped: Side lopped off, getting ready to cut the slot down the bottom of the primary plenum: This is the stock rack area...notice that wooden baseball-bat looking thing? That used to be a cheap table leg...turned it in the lathe from 2.5" diameter down to the smallest diameter I could comfortably turn using an offset tailstock. I would have liked to taper down smaller, but it would have made some of the other work more difficult, so no big deal. Here I've wrapped the table leg with flat sheet aluminum, and am working it into the finished conical shape...not quite there yet: The dual plenum assembly: This is the interior slot, it's 13mm wide here, and will finish up at 16mm wide after cleanup: Cutting up runner tubing...38mm ID, 41mm OD, runner tubes are 7.100" long. Layout: Holesawing the port openings...they're cut on a 15* angle, and stepped to provide a positive stop for the runner tubing.. Close up shot of the port openings...this is one of the errors I mentioned. That port is about 1.2mm too low in the flange. The goal was to lift the port up in the head, as it is now they are centered up. I'll probably weld up the lower edge of the port in the finished manifold, and lift the topside some. Here's the finished flange, with the full profile chopped out with a hacksaw and Thanatos, the Destroyer Of Worlds. (That'd be the name of my big electric die grinder...) Flange bolted to one of my cylinder head cores, with the front and back runner tubes welded up. This is the point at which I miss the opportunity to fix mistake #2. Runners 2 and 5 welded up, this is where mistake #2 becomes not-easily-fixable: Fitting runner #4 into place, #3 and 4 are angled, but are two-piece runners. The transistion will get blended inside the runner tube and if I need to, I'll weld the outside of the tubing to build up the wall thickness in areas before sanding it back, this will let me contour the inside of the runner correctly. See where I mentioned mistake #2? This is it. The center two runners are shorter than the outer four by 0.060". This happened because the welding distortion that occured when I welded runners 2 and 5 into place pulled the jigging plate into a bow, and I didn't check for flat before I started work on the center two runners. No worries, once the braces are in place then I'll have the manifold milled flat and it'll all work out fine. Here's a shot of the whole works: Some more angles: Another oops caused by mistake #2...can't get the bolts in because the flanges are too close...: Nothing a little time with a screwjack and a few wrenches couldn't fix. Had to be done anyway because the throttles didn't bolt up to the jig plate! Took four hours for me to straighten things up right... Had to slap together a custom Intake Manifold Straightener Widget to get everything lined up right. Anyway, that's it for this weekend. Current runner length is 9.5", which is 1" short of the target. Once the manifold is decked and I have a final runner length, I'll cut the air horns to hit the target runner length.

Those look suprisingly similar to the Sumitomo S12+8 calipers that we use still...Wonder if the pads are similar? Anyone got photos of a set to see?

More duration and lift. Overlap is a red herring! Intake valve closing is the event you need to pay attention to, to stave off detonation. You can retard the cam one degree by slipping a tooth and then moving to the #3 position; thats -9*, plus the 8* from the #3 hole...or you can slip a tooth then add back four degrees by going to the #2 hole.

i've started having that problem on my L...it'll seep a little water, but only if I let it sit for a week or so. If I am driving it daily, then I don't see any seepage at all...and it's all on the passenger side of the engine block. Mostly right above the boss for the block serialization.

Those look fine.

That's pretty cool...bet they only let them run the one time like that.

There is absolutely nothing at all wrong with that head. It has the same ports as the later N42, already has the larger exhaust valve, and the only difference between that chamber and an N42 is the spark plug boss. One benifit of that head is that it's already as unshrouded as you can get, for an unmodified head. Also...everyone hates on them, so they're cheap! If you are looking to control detonation with a cam, then run a longer exhaust duration, longer intake duration, and LOOK AT THE INTAKE VALVE CLOSING TIMING. Close the valve a little late and it'll bleed compression off at lower RPM. It'll actually help cylinder filling at higher RPM, but the main benifit in this case is lower dynamic compression. This exact mechanic is why I can run Kentucky 87 octane on a dished bottom end with an open-chamber N42 that has been shaved to provide 9.7:1 compression, and STILL run a full 36 degrees of timing with no tendency to ping or knock. Just set the valve closing event to bleed off some of that compression from idle to about 3500 RPM, and you can avoid a LOT of detonation.

Are you running the cam off the lobe? If the wipe pattern shows about 1.5mm or 2mm from the edge of the pad, it's fine.

Yes, that is what he is referring to. On the S130 I'm told that it also contains the proportioning valve. If it doesn't, then that particular car DOESN'T have one installed...there's nothing between that block and the rear brakes but a 'T' fitting right before the line splits to feed the left and right calipers. As far as either of us can tell, it's all factory installed lines...we certainly haven't replaced any of the hardlines.

Look at it this way: If you can't see it, it was never painted. If it was never painted, it'll surely have developed at least a little rust in 40 years. If it's developed a little rust in 40 years, then what about the places that developed a LOT of rust??

Sure you can. It's done all the time by the guys who take a P90 or P79, shave the head .080", then shim the cam towers up 0.080", then they run the longer valves to match. Did you number the rockers before you dropped them off?

I have a lightened stocker in the floor next to me...chucked it up on the lathe and cut it down to 18lbs...225mm flywheel. Was dissapointed in the weight reduction, but it's as thin as I'd feel comfortable with. I'll end up buying a CrMo unit eventually.

Is your car a hydraulic lifter car? If you have a lifter laying down on you, then it won't matter. Even if you can't hear it ticking yet, if it's going soft, then you WILL see a crazy wideband signal. Is the LC-1 throwing error codes? If it's not, then I would start looking for exhaust leaks, bad lifters, misfires, and ignition noise. You ARE running suppressed plug wires and resistor plugs, RIGHT? if the LC-1 isn't throwing codes, then look at your tune. The VE analyzer won't do it all for you...you have to give it a reasonbly nice tune to start with before it can start the refiniing process. DO NOT enable EGO correction until you have your tune as good as you can get it. It'll mask tuning errors and cause you no end of trouble. Use it ONLY after you have gotten your tune as good as you want it to be, and then use it to compensate for mediocre gasoline, weather changes, ect. That's what it's there for...it's not a bad-tuning-corrector.

They are split from 69-70, 71-74.5, 74.5-76, then 77-78. The window glass from late 70 to 76 is generally interchangable, though.

the MSA radiators are Champion radiators...they're exactly the same unit sold on ebay.

Just remember that you WILL have to adjust the valves several times the first several weeks of running. Probably the first 8 months or so, before they settle in. Leave yourself enough room to do several valve adjustments...The lash WILL GET TIGHTER AT FIRST. Then it'll level off, then in a few years you'll start to see it open up.

Waiting on material to show up now, it'll arrive thursday. The new intake manifold will be a junkyard sheetmetal version of Monzter's spectacular CNC machined ITB madness, using runners that will be 10.5" from the cylinder head face to the end of the velocity stack, 1.5" ID, and angled up about 14* from perpendicular to the cylinder head face. It's going to be a tight fit, obviously, but it WILL fit in an S30, and a single-throttle version will be fitted to an S130 for a turbocharged application.

You have a bad fuel pressure regulator. I fought this EXACT issue with my stock regulator for almost six months before I replaced it with a new unit and it workes perfectly now.

Check the aussies. They seem to have gotten more of these than we did in the states.