Project FD RX7 Restomod: Part 10 – Engine Fire Update

Project FD RX7 Update - Engine FireOwning an RX-7 is like riding a motorcycle.  It’s not a matter of “IF” (the car catches fire) but rather “WHEN, and how bad?”.  A small engine fire changed the path of our entire build, for the better?

While at Buttonwillow Raceway to test the new Continental ExtremeContact FORCE tires, Titan 7 Wheels, and baseline the performance of a relatively stock FD RX-7, I noticed some smoke coming out of the shift boot.  Then the smoke started to come out of the base of the windshield.  After popping the hood, there was a little fireball under the intake manifold that was quickly put out.  The sad part about all of this is it happened while in the paddock before there was any track time!

Project FD RX7 upper intake manifold removalOnce back at the shop, we removed the upper intake manifold to assess the damage.

FD RX7 Rats Nest

We removed the silicon vacuum lines and solenoids in the “Rats Nest”.  Some of the silicon lines were burnt.  Silicon actually melts much quicker than traditional rubber lines.

FD RX7 engine disassemblyWith the “Rats Nest” hard lines out of the way, we could inspect the wiring harness.

FD RX7 engineWhen the car was purchased, the previous owner installed a brand-new crate 13B rotary engine from Mazda, as well as a brand-new $1,400 OEM wiring harness.


  1. I see you have a Stant coolant cap on a Pettit coolant air separator tank. That cap took out the engine on my FD. Somehow the pin on the lever backed itself out and released the pressure in the cooling system while I was driving. I caught it pretty quickly but I ended up with minor damage to a coolant seal. I switched to an RE Amemiya air separator tank with a regular style cap after that and never had another issue.

  2. I keep coming back to this fantastic series to refer to the older posts and was startled to see that post #10 had arrived, but very sorry to see the subject! I thought right away that it would be the dreaded FPD leak but shoddy work is far more frustrating.

  3. If the damage is localized to only a few connectors and some wires why not open the harness up and repair it, and re-loom.

    1. It was far more than just a few connectors, and it got into a lot of wires in the middle of the loom that would require a lot of splices. You can buy this one for cheap if you want to repair and use/sell it.

    1. Good eye. Yes it does, which is why you should be VERY careful with who works in your car. Even big-name shops do terrible work like this.

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