Xnke

Also Pete Sanders, for hosting them...I belive that's his photobucket.

WHOOO! The cam specified for the supercharger application from Isky will be mailed out monday morning. Hopefully a bunch of welding supplies will be here by then and I can complete the intake manifold soon; so I can fix the exhaust leak on the header and get a properly muffled exhaust in place. This time I have access to a 4-post lift to do exhaust fitting. Things will be slowing down soon, though, my day job is getting iffy. *Most* of the parts are made; and I need to make sure to hold enough cash back when I get paid again to grab another set of companion flanges from Cockerstar; I might have to make a new set of axel adaptors to get rid of a vibration in the rear of the car at 70MPH.

Mine is my daily, and sees 7000RPM every time I get in it. It's all about gearing.

The torque wrench won't tell you anything, on a retorque...you have to back off the bolt completely, then RE-TORQUE...the initial stiction from the properly torqued fastener will yield an errorneous reading on the wrench, with the error on the high side of the actual value.

Find the bad ground on the left side of the car. Get out your FSM and trace wiring.

Norm the 12 second SU Dude (Yep, he's real) was running an S30 into the 12's on SUs...that takes a little more than 165HP. Strokers have put down around 220HP, sometimes more, on SU's, too. They can flow enough air and enough fuel to support more than that, but I am not sure how much more. It is not possible for us to make an accurate estimate on your engine build. Not enough information given, nor is every engine built to the same specification going to put down the same power.

The water temp sensor is M16x1.5mm, not 3/8". The thermotime switch might be different, though, I don't know.

L28's are regularly bored to 89mm, it's nothing to worry about.

If the dots don't line up, that spindle shaft is either twisted or the gear has spun. I can't imagine there would be sufficient clearance even with good oiling for the shaft to spin easily on the gear, but a little slip could certainly cause the problem you're having.

Peter, How'd Gordo's engine run? En't never found the answer to that story, and that first lot you posted up looks like the one you did for him.

Re-read the porting threads here, and take a look at this photo. No sharp edges!

That electric car idea works great...as long as the load on the generator never changes. If you're driving the car, the generator load will change. Thus, the operating conditions of the engine driving the generator change. RPM might stay the same...but if the load changes, then your fuel consumption changes....

That's the highest resolution that I could find on my computer. it's horrible to read, but it is for a 1972 year model.

Meh. It's going on the throttle shaft, which is where I believe it belongs. The bigger worry right now is the PCV subsystem. It needs a decently large amount of airflow compared to say, the compressor bypass valve actuator. it is NOT a good idea to share the port with the brake booster...gasoline and oil vapors slowly deteriorate the diaphragm and I don't want to buy another one of those anytime soon. I wonder how it's done on a triple carb manifold? I have a balance tube setup already; but I would imagine that the oil vapor pulled through the PCV system would tend to be distributed unevenly in such a setup. Once the PCV subsystem is figured out, Idle control will be handled via a separate block, connected to the manifold via the vacuum log. The jig is being made to allow the injector bungs to be properly fitted to the manifold, properly being construed as "these 3/4" aluminium bosses fit this gnawed out hole in the runner, and point down the intake with minimal direct contact with the port walls." I'm led to believe that port wall contact is to be avoided for the main part of the spray, the better method being to allow as much misting to take place as possible *before* the stream/spray impinges on the floor or wall of the port, but at the same time directly avoiding contact with the back of the intake valve. The reasoning for avoiding the valve is that the intake valve runs hotter than the port wall, but even the port wall, heated by engine coolant, should be hot enough to vaporize the fuel. The hotter intake valve may at times get TOO hot, allowing partial burning of the fuel instead of vaporizing it first. Similar to how heating milk on a stove works...too much heat, too fast, tends to turn the milk....but a warm, controlled heat won't do it, even when the final temperature is the same between the two methods. This seems like a likely explanation of intake valve crud.

Because I want a THROTTLE position sensor...not a foot position sensor. For me, it's a distinction. If I could flip the throttle shaft and the TPS 180*, then the problem is obviated and I can move on. I'll experiment with that tomarrow.

That's pretty neat info, Alan, I didn't KNOW about the internals used on the LY engines, but suspected as such. I knew the block was a selected and prepped stock casting, though, you've mentioned that before and I've read about it elsewhere. And the RB20E conversions can make just as good power, Peter, just takes more work. (Just like an L could make about 400HP N/A, too....if someone had the time and gumption to make it happen. I can't do it, don't need to, but I'm sure it can be done if someone has enough money and time and skill.)

They are thoroughly covered on this site in other posts. The LY head is a nissan competition part, quite uncommon as far as bits and bobs go, and was installed on pretty much a factory bottom end. There was race prep done, yes, but the block is a regular P30 or N42 block selected for uniformity. I am not clear on the cam timing system...the LZ heads were gear timed, but they are for the 4-cylinder engines. It's a two-valve, crossflow head. Not unlike a Z-series head, actually, at first glance.

Just a bit. The problem with your theory of length being the predominate factor doesn't jive with the results I have seen, both in the Z and in dozens of other cars. The manifold lengths seem to be whatever packaging constraints demand, with a trend towards longer runners, but universally the runner diameter-engine displacement method predicts the torque peak with much greater consistency. I'll have to do more research. As for the runner length, I've been using a simplified version of the Chrysler formula, which is supposed to generate a second-wave reflection length based on torque peak desired and intake valve timing.

Got the plenum assembly back from the machine shop, and have it mocked up. Not bad! And this will be irritating. Argh. Anyone got any ideas for a more compact potentiometer type TPS that will fit the nissan shaft? Or even one that has the connector body flipped 180* or so?

The stock intake, at 32mm ID, is definitely a feature that needs to be addressed. It's not so much the flow rate, as it is the acoustic tuning that is the problem, in my opinion. Torque peak RPM is seriously impacted by the diameter of the runner, and to a little lesser extent the length of the runner. By playing with the runner diameter, peak torque can be moved around, and then once you decide where you want peak torque to occur, you can set the runner diameter based on that. (Hint: for a 176 cubic inch 6-cylinder engine, peak torque will occur around 5300RPM with a 1.76" average runner area, or 5850 RPM for a 1.95" average runner area.) Once runner diameter is set, you can reinforce that by adjusting the runner length from valve head to plenum to narrow or widen the torque band. 5300 RPM would be 2nd wave tuned with an intake length of fifteen and a half inches, valve to plenum. The stock L28 fuel injection intake, with 32-34mm runners, is set up for peak torque to occur between 4000 and 4200 RPM. I seem to recall a characteristic torque curve for turbocharged L28's being mentioned before. The problem is that now the runners should be about twenty inches long to match the length to the torque peak. It is possible to fit this into the bay...that's 16" from the cylinder head to the plenum. Wrap them around an LD manifold or the P65 casting and I bet you're pretty close. I've got a hunch that this length-to-diameter mismatch results in the "5500RPM out of breathness" for the L28ET that is often mentioned. The stock cam is probably engineered to match up pretty well to these characteristics, too. By placing peak torque low in the relative capabilities of the engine, you are sacrificing horsepower for torque. Without making a single foot pound more peak torque, move the peak up 1000RPM and gain horsepower. You can adjust for the move with gearing, if needed. On the other hand, if you are going to stick with the stock gearing...a 4200RPM torque peak would be rather appropriate.

I have the dimensions, I'll get them posted here. EDIT: Here you go!

Tony, every fel-pro printoseal gasket I've installed lately has been magnetic...it is, as indicated on the package, of "MLS" construction. Steel shim, viton sealing rubber on both sides, thick orange viton sealing rings printed onto both sides. The steel shim construction has been the reason I haven't retorqued the headbolts. I don't see the 70ft-lbs of each headbolt compressing that steel shim.

It may or may not have adequate baffling inside, but that's easy enough to fix.

The belt speed depends on the driving pulley's circumference, and the RPM. Belt orbiting is a lesser problem for thick belts, such as V-belts, than it is for flat belts, such as poly-v, flat, or cogged (timing) belts. To combat belt orbiting, you would ideally have idlers or driven pulleys on alternate sides of the belt, such that the belt would wrap over the driven pulley, then over the idler on the backside of the belt mid-span, then over the drive pulley, and under an idler, again on the backside of the belt mid-span, then over the driven again. This way, the belt does not bend the same direction twice consecutively, and belt orbiting is better controlled.

Year, make, model? There are a few different pans out there. (front sump from a Maxima, rear sump from the 280ZX, mid sump from the Z, 6qt/7qt pans, ect.) If anyone actually knows, how can one tell the application difference in a 6qt and 7qt pan? I can't even find the difference in part number from the book, but I definitely had two different volume oil pans in the mid-sump configuration for the L24/L26/L28. One is the same size as what is on my car, and requires a 6qt fill volume to reach the correct level on the dipstick, Plus a 1/2qt for the filter, and the other pan (that was punctured near where the #1 rod would damage it) was considerably deeper...25mm deeper in the sump area, IIRC. I couldn't find a spot were it has been modified, but I don't have easy access to the pan anymore...It's on a running engine two hours northeast of me.