Exhaust Stud Size

[Satisaii]

I have pulled my hotside setup too many times and the three long studs that hold the SC bracket on are stripping out of the head. Does anyone know the size of these for a 99 (M10 1.25 or 1.5)? I might also need to go with helicoil inserts. Any opinions on those?

[Tom @ Fast Forward]

Most of those are M10 x 1.5

Heli-coils, if installed properly, are just fine.

Here is my "if installed properly" story. :)

In 1989 we replace the aging Mooney 201 with a Mooney 210. We had it about a week and flew from Detroit to Waukeegan Illinois. Taking off out of Waukeegan, we were on IFR back to Burr-Macomb airport in Michigan. We were under the control of O'Hare center. About 15 minutes after takeoff we were about 10-12 miles out over Lake Michigan. The radio conversation went something like this:

O'Hare: Mooney 77 x-ray, climb to 5000 ft and maintain heading.

Dave: O'Hare, this is Mooney 77 x-ray, request permission to do a 180 and return to Waukeegan.

O'Hare: Mooney 77 x-ray, maintain direction and procede to 5000 feet.

Dave: O'Hare, this is Mooney 77 x-ray. No, we need to do a 180 and return to Waukeegan.

After the third back and forth:

O'Hare: Mooney 77 x-ray, is there a problem?

Dave: This is Mooney 77 x-ray. Well, O'Hare, our oil pressure reads flat zero.

O'Hare: Mooney 77 x-ray, are you declaring an emergency?

Dave: O'Hare, 77 x-ray. Not at this time but we would really like to turn back to Waukeegan.

Then O'Hare gave us permission and turned back to Waukeegan. Waukeegan cleard the traffic and gave us a striaght in as there were no winds to speak of. Back on the ground, we took it to the service center. Turns out Lycoming had a problem with the oil pressure regulator threads and did the approved FAA fix. They installed a helicoil and put the oil pressure regulator. Well, when you install the Helicoil, you break off that tab. The guy who did it didn't bother to recover the tab and it got stuck in the oil pressure regulator keeping it open. We had flow but no pressure.

They are great devices but have to be done correctly. Needless to say, a "strong" letter went out to Mooney and Lycoming both.

The good news is that the prop never stopped turning and no damage occurred. ;)

[Satisaii]

Lucky that tang did not end up in the oil pump.

I just put some delrin motor mounts in and had to remove the header (of course.) When I went to reinstall it, I had chunks of aluminum on the ends of my bolts. Considering that I will be getting a new header made next month, I figured maybe I should go ahead and redo those bolts. Or I could just warn the guy who is going to make the header and have him do them.

Anyways, I will be passing through there when taking the Miata back to Austin on October 15 to get that header done. Depending on the time I get there, I night give you a shout.

[Tom @ Fast Forward]

The doors are always open and the spare beds are always made. Just let us know.

We could always talk PCBs. ;) We have a running model now.

[Satisaii]

LOL, maybe I should come up sooner then next month. It would be a business trip then.

[Tom @ Fast Forward]

No rush. Our current prototype PCB guy is slower than molasses in January. Hopefully, I will have a 'almost ready for production' PCB by the end of the week but not holding my breath. Come when you can. The porch light is always on. Kind of like Red Roof Inn. ;)

[Satisaii]

Why don't you tell me when you want to talk PCB's and I will come out. After all, it will be on my bosses' dime. And that is as good as ay to do a trip.

[Tom @ Fast Forward]

Anytime you want.

Should have the next version PCB next week? Maybe the week after?