cygnusx1

Yeah the original question was WHY did Nissan give us 1.25" intake tubes and 1.375" holes in the side of the head and what can we, should we, or shouldn't we do? ...how do we make lemonade?...so to speak, without a custom fabrication peice. To port and match the manifold interface with a bevel or leave the step-up in diameter which slows the air stream before the valve. A or B is better?

I also thought about the anti reversion properties of having a 1/16" step. I had heard about AR in the exhaust tract but not in the intake. I think Nissan may have used that step as tolerance control as well. Just making sure that there would be no step working against the intake air even if the manifold were to be slightly misaligned. Discuss....

Mad Skills. Is it just me, or is raw aluminum an aphrodisiac?

Bueller?

That is a beautiful Z! Z's look so nice in white when you add some detail like you did. I have the same baby stroller as the one on the left...and an Odyssey.

Last night I measured the intake ports on my stock P90A solid lifter version. The ports on the head are roughly 1-3/8" in diameter. Then I measured the ID of the stock manifold intake runners. They are only 1-1/4" in diameter. That is a huge difference. Now why go through all the trouble of porting the head if you are going to leave the stock intake alone? I understand that the head ports have a complex shape and the air has to contort to get around the valve but wouldn't the relatively narrow intake manifold runners be a much better place to begin your porting work? At this point with my limited tools and porting experience, all I would be able to do would be to bell out the intake runners, from about 1" deep, to a slightly larger ID to more closely match the head ports. Would that be at all beneficial to flow between the runners and the head?

I roughly measured the intake ports on the head and the runner diameter of the stock turbo manifold tonight. The P90A solid head that I have measures roughly 1-3/8" in diameter. The runners of the turbo intake measure about 1-1/4" in diameter. Would it be at all beneficial if I chamfered the intake runner exits out to 1-3/8" to match the intake ports on the head? I figure I can put in about a 1" deep x 1/16" chamfer at the runner exits to "bell" them out to 1-3/8".

What are you using for an air filter and intake tubing? When I was using the factory turbo rubber boot, it would collapse under vacuum if the steel liner was taken out of it. Maybe the ignition moduled is defective. Is your VR sensor bracket or 36-1 wheel vibrating at 4500 rpms?

Look at the bright side, the Greyhound be-heading already happened and you missed it. Good story. Waiting for the happy ending....

Some photos; Alignment tool, and 6" DIYAutotune 36-1 wheel temporarily mounted, and the fresh P90A solid lifter head all set up and ready to go. The 36-1 wheel is going to be pinned or screwed to the pulley with four machine screws around the perimeter. These will maintain alignment when I put it back on after all the belts are in place during assembly. Odd boss off the bottom of the AC bracket. I think it's an '83 bracket in aluminum. I think the '76 bracket was iron with no extra boss. Convenient spot for a threaded boss! It even has a stepped edge for alignment. Eliminating the need for a second bolt. The workspace. Our 1.5 car garage.

I made an alignment tool to center the tone wheel to the hub before I tighten the two stand-off bolts. Once the wheel is in it's final position and the VR sensor is mounted, I am going to pin the tone wheel to the pulley rim, either with dowels or tapped button heads. Trust me, when I am done, it won't move. I might have to look at my AC brackets to see why one has the boss and one does not or which is which. Luckily, the boss seems like it's in a good spot to anchor the VR bracket (yet to be fabricated).

PHASE 1: 135K mile all stock L28ET P90A Hydraulic Stock head Stock EFI/injectors/ignition/AFM Walbro Pump Begi FMU T3/TO4B Super-V trim rebuilt unit Long, restrictive, cold air intake. 2.5" DP and exhaust glass pack tail Spearco Intercooler 2.5" I/C tubing 14psi boost/65psi fuel ACT 6-puck solid disc clutch Dyno'd 265rwhp/300rwtq Runs leaner around 5500rpms. maxed out factory EFI. PHASE 2: Megasquirt II v3.0 w/4bar sensor Megaview data panel in dash LC-1 Wideband O2 Ford Lightning 42# injectors JSK Fuel rail Large cone filter intake directly on compressor inlet. Guessing 300rwhp/320rwtq No more leaning out! 15psi removed FMU for stock fuel pressure. PHASE 3: (in progress) Ford EDIS-6 ignition system in progress. Rebuilt P90A original solid lifter head w/5 angle valve job. Ported stock exhaust manifold. Gasket/Port matched intake/exhaust. Z32 5-speed in progress Fidanza 11lb flywheel in progress. ACT sprung center 6-puck clutch in progress.

No I am not removing my AC for crank triggered ignition! The A/C compressor bracket has a forward facing boss on it that is tapped. I am not sure if the bracket is my 76 original or my 83 turbo bracket. I can't remember which one I used. The compressor is the '76 unit. The trigger wheel is getting mounted to the front of the two-row pulley today, using stand-offs on the two extractor tap holes. Once it is mounted and oriented properly to the VR sensor and bracket, I am going to dowel-pin it into place on the outer perimeter of the front pulley flange. I am also going to scale balance all the parts for symmetry before final assembly. I will take photos for sure.

OK the EDIS-6 swap and head swap is well in progress. EvilC came over last night and we pretty much stripped the engine bay of everything except the long block. I am going to mount the Dodge coil pack to the passenger side firewall. It looks like the Dodge coil pack uses spark plug boot connectors. So the boot you use for the spark plugs are the same that you will use on the coil side. Pretty nifty. I can keep my 8mm wires, cut them shorter, and re-terminate the coil end of them with standard spark plug boots. I am still mulling around wether to mount the 36-1 wheel in front of the crank pulley or behind it. I need to mock it up and measure some things before I decide. The A/C compressor bracket has a BIG boss right near the timing pulley. It is already tapped for a large bolt. I am going to hang my VR senor bracket on that tapped boss. Wiring....well that is always my weak spot, so I am going to go read the megamanual for the 137th time. Jumpers...grounds...shields...I/O's....arrrgh.

Hammer on end of wrench = impact wrench, in my book.

Completely horrible. I can't even fathom the feelings that you and your family are experiencing at the moment so I can only offer my condolences and just let everyone know that we want them to pull through this situation. Tears on the keyboard for a lost child.

In the factory injection and most injection systems, there is added fuel mixture when the engine is cold. If the sensor for the EFI is seeing a cold condition, the car will burn excessive fuel.

Try a clay bar kit. It takes overspray right off of paint and might work on plastics. It's not a chemical process so you don't need to worry about the plastic.

Here is some useful info with photos and diagrams. http://www.autosportlabs.net/MJLJ_V3_vehicle_installation_guide

Nice save! Similar thing happened at the local car show a few weeks ago. This young kid, way to young to be driving, is tooling around on a hemi powered bar stool. Yes, it's a fully worked, chromed out, open pipe hemi V8 with go-kart wheels and a seat over the carburetor. It has quad style handle bars. Basically, it's a hemi on an engine stand that you can drive around. Anyway, some irresponsible person has let this kid rip this fire breathing "vehicle" around the car show where there are about 1200 cars, each with an average value of $30. Anyhow the kid drives the hemi-stool up on a small 30 foot high grassy hill, overlooking the car show. He parks it, shuts it off and apparently never set the brake or left it in gear. It starts to roll slowly down the hill and this 100# kid is now standing in front of it on slippery grass trying to keep if from getting away. I was too far to do anything. It was a disaster in the making. He was losing the battle quickly and the hemi was about to roll down a 100' ramp into rows and rows of show cars, possibly with a young kid pinned to the front. As people began to notice, they ran up the hill and were able to help the kid out. It was VERY close to a major disaster, possibly ending this kids life. Accidents happen, usually due to a sequence of events that might not have looked like they were a series of mistakes, until it was too late. The kid was not scolded and continued to ride this thing like a maniac the rest of the evening. Where were the cops? Pulling over cars for little things like squeeling the tires and loud exhausts as they were leaving the show.

Seems there is a rash of 83ZXT ignition failures in the past week or so. Must be a heat wave across the country. Mine failed last week. I am switching to EDIS ignition away from the 83ZXT Dizzy because it has bit me twice already. However, I didn't know that the 83ZXT Dizzy could be upgraded with 240SX parts? That is good to know and I will look into it further. OTOH, There is no ignitor module on my coil bracket since I use MSII. Thanks.

Great info! I am still gathering parts for the EDIS-6 swap. I'll have to look at the Megamanual about the tacho pin. Didn't know it was there because I have been firing the tach from the negative side of the old ZX coil.

I might be worth trying new relays. Slight possibility of a bad connection inside a relay causing it to become high resistance once it gets too hot.

I dont get resets but I have had my car stop running with strange tach behaviors only to go back to running normally after a 25 minute cool down period. Sounds similar and I have a similar setup. It happened with a noise filter and without. Happened only twice in about 5000 miles with MSII. Best clue so far is that mine could be due to a failing pickup inside the dist. It could be plug wires going bad with heat also. Mine is so intermittent that I can't diagnose it. To circumvent, I am in the process of switching to Ford EDIS-6 ignition.

Thanks, Sidwell. Has anyone run the factory 280Z tach with EDIS-6? Does it work off of pin#2 on the EDIS-6 module or do I need to have a diode party with all three coilpacks -'s?