I have to replace both header gaskets on my 05 with Edelbrock SC and E85.
3 years ago, I had motor rebuilt with forged rods and pistons.
One shop did engine work, another pulled and reinstalled engine. Engine works great.
I had many problems with the other shop. Mainly loose connections.
After breaking in engine, and trying to datalog so Lito could tune, I ran into 2 major problems. First was the car would drive around town beautifully, but as soon as I went WOT to datalog, it would misfire. It turned out that the positive battery cable was not tight on alternator. No problem for normal driving, but vibration of WOT caused wire to move. Took a while to figure that out.
Then, when I got my first good datalog, Lito said to check exhaust and accessories for something loose because he was getting high knock values that should not exist with E85. I checked everything and only found a loose wire on starter, and over tightened knock sensors. Torquing the KSs properly reduced the knock values, but they were still higher than normal. Car ran with no problems at track days.
Fast forward to this week and I’m taking things apart to replace gaskets. This is the top stud and nut for cylinder 8. Next to firewall on drivers side. It’s a real MFer to get off.
Stud was too long, and shop just tightened it up to the point it bent in header tube. I know this had no effect on performance of header, but I’m sure this is where the ghost knock was coming from. With everything in place, it was impossible to see. In the photo the nut is just started on thread to show dent. Header is not off yet, so I hope it didn’t wear a hole in tube. Find out next week.

3 years ago, I had motor rebuilt with forged rods and pistons.
One shop did engine work, another pulled and reinstalled engine. Engine works great.
I had many problems with the other shop. Mainly loose connections.
After breaking in engine, and trying to datalog so Lito could tune, I ran into 2 major problems. First was the car would drive around town beautifully, but as soon as I went WOT to datalog, it would misfire. It turned out that the positive battery cable was not tight on alternator. No problem for normal driving, but vibration of WOT caused wire to move. Took a while to figure that out.
Then, when I got my first good datalog, Lito said to check exhaust and accessories for something loose because he was getting high knock values that should not exist with E85. I checked everything and only found a loose wire on starter, and over tightened knock sensors. Torquing the KSs properly reduced the knock values, but they were still higher than normal. Car ran with no problems at track days.
Fast forward to this week and I’m taking things apart to replace gaskets. This is the top stud and nut for cylinder 8. Next to firewall on drivers side. It’s a real MFer to get off.
Stud was too long, and shop just tightened it up to the point it bent in header tube. I know this had no effect on performance of header, but I’m sure this is where the ghost knock was coming from. With everything in place, it was impossible to see. In the photo the nut is just started on thread to show dent. Header is not off yet, so I hope it didn’t wear a hole in tube. Find out next week.
