Zed Head

Engineering type nerd talk but I took a GDT course long ago and Fidanza's concept makes me nervous. Stacked error (wrong term, can't remember, probably stacked tolerances). Are you supposed to have that plate skimmed before usage or just bolt it up and go? Make sure that you understand well how it's supposed to be used. Even if Fidanza is confident it wouldn't hurt to have it checked.

Piston availability has varied over the years. Here's an old post about alternatives. Takes some extra work. https://www.zcar.com/threads/honda-xl500-pistons.45301/ Datsun Spirit has possibilities too. Expensive of course. https://www.datsunspirit.com/shop And Rebello might have something. Haven't seen much written about what's happening there, but if he's still building engines he needs pistons. http://www.rebelloracing.com/nissan1.htm

Are you losing spark or injection? The resistor is part of the 280Z tachometer circuit. Here are the instructions for the Crane modules. People often have problems when they use aftermarket ignition on the 280Z EFI systems. Not sure why. I have had odd problems with loss of injection if the ECU doesn't like the tach connection. https://static.summitracing.com/global/images/instructions/xr700 instructions.pdf

Edit - It might be just a partial conversion. Just realized that you did not read the CL ad. If you read it you'll find - "Nice V8 scarab conversion with engine still intact." https://datsunforum.com/the-scarab-legend-the-original-hybrid-datsun-z/ "As time has passed, the number of legitimate Scarab conversions have become cloudy – Some claim less than 200 “factory” Scarabs were ever produced, while others put that number upwards of 270. Adding to the confusion, many “customer cars” were converted by Scarab – and even more were converted on a DIY basis by owners in other states, as over a thousand conversion kits were sold during the life of the company with an approximate price tag of $1200. Some customers opted for all of the upgrades, some just wanted the V8 swap..."

The engine seems to be in the Scarab position. Jammed against the firewall.

Some sources call it the Auxiliary Air Regulator. AAR. If you look closely at where it attaches you should see a plate underneath it with heating cooling lines attached.

That would be because the coolant plate underneath the AAR has heated up. That means that the valve is not binding. All signs point to no electrical power through the AAR heating coil. Unlikely that a vacuum leak would disappear when the engine warms up. Just trying to be helpful.

This video just popped up. Interesting results.

The math is correct. That's about all that can be gleaned from your post. You'll want to match the pistons to the heads, not the block, to get the desired CR. The L28 was used for small and large combustion chamber heads, the pistons were changed to achieve the desired CR.

His problem is with the AAR, not the thermotime switch. The AAR has power as long as the fuel pump has power.

You can also stick a Noid light in the connector and start the engine. The light should stay on when the engine is running.

It's on the same circuit as the fuel pump. Looks like it grounds through pin 34. You can test the whole circuit at the ECU connector. The FSM instructions describe how to use the Start circuit to actuate the fuel pump relay to provide voltage. But you could also just disconnect the AAR and test for voltage at the AAR connector with the engine running. The AAR should get power when the fuel pump does and the fuel pump only gets power when the engine is running.

This is a sign that there is no electrical power at (edit - actually should say "passing through". The ground side must be there also to complete the circuit) the AAR plug.