So being the avid Ford enthusiast, I went out and purchased a rough Mustang for a good price, a California emissions 1999 Mustang GT with 160K miles on it. You could say this was a "barn find" because it was literally found in a barn, but its not in that great of condition. The previous owners didn't take good care of it, but they were an older couple so the vehicle is completely stock - stock exhaust and not even a cold air intake on it...
Why was it so cheap? Well once the engine warmed up you understood why. A loud ticking knocking noise was evident after about 2 minutes of run time. Now we know why it was stored in the barn for a few years. After closer inspection it seemed the noise was coming from the front cover area so I drove it home and figured oh well.
Once I got it into the garage, I tore apart the front end. I'm pretty comfortable with modular timing systems if you didn't notice. Ah yes, an easy find - a bad timing tensioner on the right bank. Since I was there, I decided to order up a set of Comp Cams 262AH. The cheapest I found them was on Amazon, but they come and go as far as availability. I figured "why not!". I also ordered all new Ford timing components.
That's when things went kind of south for me. The cams installed with ease, but I noticed all my timing components were wrong even though I looked them up by VIN. Based on my year, I should of had a Windsor block but mine was a Romeo. I didn't think much about it and just got the stuff that fit the Romeo block. Everything was honky dory for awhile.
A few mods later, a buddy of mine wanted to run my car. He drives a self turbocharged Honda Civic pushing maybe 5psi of boost. I figured what the heck, Ill run him. We raced from a dig and from a rolling 20 and in both cases the Mustang barely won but that poor old 4.6L gave its all - I now had a rod knock. I spun a rod bearing. I get it home, rip the engine out, and tear it down and find something rather bizarre.
The block had been changed. I did have a Romeo block, and based on the casting numbers, it was out of a 1997 F150. The heads were the original Windsors that came with the car. That created some unique set of problems and advantages. Since it was a NPI block with PI heads, it created a compression ratio of around 10.5 to 1. I should have been running premium, but I wasn't aware. The other issue was that those 262ah grind cams were not to be used with a NPI block. Every single piston had marks from kissing the intake valves. Apparently its a wide spread issue with the NPI blocks but doesn't bend the valves because the intake valve actually hits the piston on its way down. The fix is regrinding stock valves and removing the lip or going with aftermarket valves.
So I decided to take this project in a new direction and install a different engine. Read on to continue...