Hot to check clutch disengagement measurement with blow proof bellhousing
hi, first, do not drill hole in bottom of bell. it's not legal. I use a gas welding rod, I bent it at 90 degree angles , to fit through the fork opening I flattened the end to .060. you can ease it in and slip between plate and flywheel. john calvert told me how to do this. air gap, is not limited to adjustable clutch.
So here are the rules, since I just went 15 rounds, toe to toe with NHRA's division 6 guy and some other guy in Glendora.
You don't need a scatter shield unless you go 11.49 or quicker. That means you can run an OE bell housing and go 11.50 and no one can say ****. I don't suggest this, but that is the rule.
The next thing follows the same thinking. If you are running 11.50 or slower, you can do almost anything you want to the scatter shield and no one can say ****. You can put a hole anywhere you want. Or two holes. Or cut part of the bottom out and make your own cover. And no one can say boo about it. The issue becomes once you modify your scatter shield, you are married to it. Lakewood charges $275.00 to install a window with cover and recertify the can and pay the freight back to you. If you do any more than drill a 1 inch hole, Lakewood won't recert it.
So if you are that worried about air gap, you can drill a hole in it. It is legal and will recert. If you have a pressure plate that is adjustable for static pressure, you can drill a 1 inch hole in the face of the bell housing. You would drill this hole from the face where the gear box bolts on out from the center so you can get an Allen wrench in there to adjust base pressure. As I understand it, you can drill one hole or the other, but not both.
Like I said, if you are that worried about air gap, drill a 1 inch hole and go.
The best deal is to send it to Lakewood and have them put a window in it. Then, if you ever step up to an adjustable clutch you will be able to tune it. If you want, I have the direct phone number to the guy at Lakewood (I'm ASSuming you have the Lakewood) and you can call him and set up shipping.
Hope this clears up the muddy waters.