cygnusx1

I might have a set coming available soon. I'll let you know when I get them later this week, unless you find them elsewhere first.

That sucks that they gray out the TW when you select EDIS... With Megatune and the old version of firmware that I run, I can adjust the trigger angle fine in the software. Contact DIY Autotune, or Matt Cramer for advice on that issue. A timing light is ESSENTIAL here. Go get one.

Maybe they short stroked cylinder 6 because they knew it ran the hottest.

Here are the chambers as they came out of the motor. 5000 miles of street, and two track events. No obvious signs of chronic detonation in my inexperienced eye, correct? Could I have an intermittent detonation from something, well.....intermittent? Chamber #4 worse case fire ring burnt, and pushed out to the cooling port: Chamber #1 for reference:

Let me translate my own post. A P90A/H with a solid kit installed, including a correct cam, is equivalent (performance-wise) to a P90 that came with solid posts. I don't know if they varied the coolant chamber design between the two heads.

What's not cool about this?

The engine is built and the head is torqued. I will drop it into the car next week and begin the break in. Fingers crossed. It's my first motor so I am second and third guessing myself at every step. The timing marks are dead on, top to bottom. After searching locally for an "A" cam and coming up short, I decided to leave the turbo cam in place. It's probably a good idea to break in the motor with the cam that was used to create the existing tune anyhow.

By diverter valve, do you mean recirculating the blow off? If so, then yes, you install a valve to vent before the TB back into the rubber boot between the AFM and the turbo inlet. Thats how I originally did mine when i had to run the AFM. I used a PVC transom fitting in the side of the rubber boot. I spent a lot of time on a bench grinder, shaping the back of the PVC fitting into a smooth rounded shape so it didn't obstruct air flow too much. Then I tightened it up using a sealant. Worked great. Through-Wall Fittings www.mcmaster.com

Welcome back and you won't need a fan when the nose is in the air!

I just want to add that when you follow the "just turn up the boost" mentality, what happens after a certain point, is that the restricted flow path will cause the air to "bunch up"; and at that point you are beginning to make more heat than flow. Heat is the result of trying to flow 10 pounds of air through a 1 pound path...so to speak. The analogy could be trying to push a sponge through a funnel. Pushing harder on the back of the sponge will cause it to bunch up and compress further, in the wrong direction, making it all the more difficult to fit through the bottleneck..."heat".

It seems like plenty of expensive port work has been done to it, so you need to compare the price of porting a new head to match, with having the one bad chamber welded and re-cut. If it's just one chamber, it might not be too expensive. However, the cheapest is to let it be, give it a GOOD tune, and then have the dyno/tuner dial it down a few notches for safety margin. Also check that injector, if that's the only lean chamber?

Wow! Putting my subwoofer to the test! Love the throttle response.

My urethane air dam is very rigid. Must be different levels of quality out there. Mine is about 18 years old now.

Best of luck with the surgery, recovery, and readjustment of your life around your new challenge. You will find ways to work with it. Use you're inventiveness. You might design custom levers, handles, triggers....etc for all your toyz so you can continue to enjoy them. Don't be too ashamed to ask for help initially. I know it's very difficult for me to ask for help if I can't do something. I don't know about you but, I am way too "DIY Stubborn" sometimes.

Darn, I was swapping the E31 "A" cam into the P90 head when I noticed that the dowel pin hole on the old "A" cam is completely surrounded by a crack in the casting. Hoping Joe has an "A" cam in his attic so i can go pick it up and resume progress. The engine should have been in the car today but I'll hold off until I locate another cam.

I think Ford was over here reading the Aero threads...

Joe, how slow does it crank with a full charge on the battery? Does it turn "steady and slow" or does it lump over "fast-slow, fast-slow" like a high compression motor. If it's mostly steady slow in both cases, with the plugs in AND the plugs out, then there is some internal resistance to spinning that is greater than the resistance from the compression. I still think you should be able to "feel" if the engine is too tight by putting a wrench on the balancer bolt. If it's tight enough to slow the starter down, then you will feel it. I can turn my motor over a little with just two firm hands on the pulley; with the plugs in it. It's much easier to turn by hand with the plugs out. What accessories are driven by the engine... Alternator, A/C, pumps? Are they free spinning? Is the starter good? Might want to drop the pan and have a look. Does it have a magnetic drain plug you can inspect?

If it runs at 500rpms at all, then you do have spark, fuel, and compression. Now you need to bust out a timing light and watch the crank pulley while someone keeps the car running. If you don't see the timing mark, mess with the trigger offset in MS "+ and -" until you see the timing mark on the pulley. Then just put it at around 20-27 deg BTDC at idle by fudging offset numbers, trial and error. Make sure your firing order is correct, and make sure your injector banks are on the correct cylinders. My map alternates banks if I recall.

If it's turning over really slow the compression test may be moot.

Joe, I would take the plugs out again and turn it over by hand with a wrench on the crank pulley. Compare what it feels like to a known good engine. I am thinking spun bearings or a bound up cam if it's turning too tightly. A side note...old fuel? My car fired up and ran with three cracked pistons and a heap of coolant in one cylinder.

I thought of a better way to share my msq. Watch in full screen so you can pause and take the numbers down if you need them. Megasquirt/Datsun - Fuel and Spark map Built in Megatune (www.diyautotune.com) EMS: Megasquirt II Firmware: 2.687 MAP: 4 bar sensor Wideband: LC1 Innovate Idle contoller: none IAT: GM Coolant Sensor: 280ZX Head Temp Sender TPS: 240SX Injectors: Ford Lightning 42# high impedance 440cc Turbo: T3/TO4B hybrid Intercooler: 18x3x11 Spearco Engine: Datsun L28ET F54/P90 (stock long block) Throttle Body: 240SX with spacer Exhaust: 2.5" downpipe and back BOV: Vented TurboXS Ignition: Ford EDIS-6, 36-1 trigger wheel, dodge coil pack. Car: 1976 280Z Flywheel: Fidanza Boost: 18psi Knock Sensor: none This map is NOT dyno tuned, but is street and track tested. Untested under severe loads past 5500 rpms.

Wow. That's some very impressive work and dedication! Welcome.

For me it's about the scraping on the road every time I pull in or out of my driveway. No paint will hold up to that. Besides, I like the two tone look up front. To the OP, I think dark blue with the matte black air dam would look great. If you want it to shine, just spray on some Armor-All.

My machinist settled on just under 0.003" for my ITM's (cast) which is looser than stock, but then again, I do run 2.5 times the stock boost. Dimensions measured at the skirts, like you said. Maybe I am opening a can of worms, but technically, the difference between the bore and piston should be divided by two. Clearance all the way around. However books only spec the difference between the piston and bore, not really the clearance. Unless you push the piston all the way to one side in the bore.

It matchers the tires, unpainted.