1931 Carburetor Side bowl Drain Valve Seat
 

Does anyone have a method to lap a 1931 Model A Ford carburetor side bowl casting where the drain valve "petcock" seats? I have an original casting with a new drain valve petcock and it leaks just a little bit.. I was thinking maybe there was a Dremel grinding stone bit, but not sure if one exists.. Checked Steve Pargeter's restoration book and didn't see anything..

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Is this what you need?
http://www.model-a.org/dremel_911.html

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Lap with tooth paste

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Thanx for your response.. I have the Dremel 911 grinding stones already and they work great for the fuel line ferrule seat.. The petcock drain valve is smaller and has a point..

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Good idea toothpaste is gritty.. The only problem is the petcock is threaded once it seats I can't lap it in with a spinning motion.. Do I need to get a another new petcock drain valve, grind the thread's off and make it into a lapping tool?? Thanx for your suggestion

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Get a drill bit that just fits through the threads, put some valve lapping compound on the tip, then spin it BACKWARDS to lap the seat.

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Thanx for the tip!! I'll try it this weekend

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Great tips here! Thanks for sharing!

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

The 911 stone works good on the gas inlet, but is to big for the drain valve on the sidebowl. Clean it up real good and place a drop of silver solder on the tip and then fit to seat.

Re: 1931 Carburetor Side bowl Drain Valve Seat
 

Thanx Carb Guy, briphaeton, Gary WA and Tom Wesenberg.. I agree with Jason in Texas that these are all great tips in this thread!! I have been rebuilding original Model A carburetors (obviously all with no side bowl's)!! for about 20 years as a hobby and thought I had all the carburetor rebuilding problems solved until my Dad gave me his indented firewall 1931 coupe last year (which he finished restoring in 1968 the year I was born).. I don't know how far back the Ford Barn Forum search goes, but was surprised that no one else had this question or problem.. Thanx again, Joe