4.6 Dohc Swap

[johnboy89]

Update........

Ok it's been awhile since I posted but have been working on the truck. Most of the work recently has been on the headers.

Let me say that doing these has been a royal PITA. I knew it would be and that's why I waited to do them last.

I originally started with some 4.6L flanges and a set of used 302 headers. Found some BBK long tube headers locally and used those for the flange portion along with the 302 header tubing. This portion of the project set me back the most budget wise.

The passenger side is done with O2 sensor hooked up ready for exhaust tubing. The driver's is getting there still need to run tubing down to the collector.

Also have been waiting on some software for the PCM so I can flash it, then should be ready to fire it.

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[johnboy89]

It runs!!!!!!

Well I got the tuning software and created a tune for the Mazda this weekend.

Had the vision that I would like to see if it would fire. After trying several times realized I had no fuel

Digging into the problem I realized that the PCM was not grounding the coil circuit. After some help on some other forums appears I shouldn't be using the PCM to fire the fuel pump relay coil as the 98 Mark VIII's used a FPDM to run the pump.

Anyway after sorting this out I was able to get it to started Whoo Hoooo

Only ran it for a short time and one of the oil filter relocation hoses popped off. (forgot to tighten it)

 

[281Ranger]

Congrats man! Can't wait to hear about the first test drive.

 

[johnboy89]

Well it's been sometime again since I posted and figured I would make this the last update as this thread has gone on for sometime now and it's almost finished.

After dealing with some issues on the home front, I was finally able to finish up the exhaust.

I have driven it a few times and is a blast to drive. Doesn't appear at this point to be too many bugs to work out. I do hear an exhaust leak, but that's minor.

My plans for the rest of this year will be to add a posi 8.8 to it and then enjoy it.

Over next winter I may add a cobra intake and lower it some, also fix a few of the small dents on it.

I'll try and get a video of it up shortly.....

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[281Ranger]

Glad to hear you've got it on the road!

When you go looking for an 8.8 go straight for one with 4.10 gears. You won't regret it.