After watching Steve's U Tube video on how to clean up a spray needle, I'd like to give it a try. My question is, on the wooden block "holder", does anyone know what the angle of the 2x4 should be cut at? Thanks, Dave
That's a great question!!
I didn't measure the angle. I just cut it to match the shape of the needle.
Maybe I'm over thinking this but, the taper on the needle seems to be important. To much/ little angle, and the adjustment would be way off? As this is my first Model T carb rebuild, I'd like to get it right. Thanks, Dave
A short stubby angle will make the adjustments very sensitive but a long taper just means more turns needed to fine tune the mixture. Use the long taper and you should be happy.
don't overthink or lose sleep on this. Follow Steve's lead on this.
You want to end up with no ridge or ring on the needle, and a sharp round hole in the jet (purchase a new one as they're cheap).
Thanks everyone. Replaced: spray nozzle, fuel valve, choke and throttle plates, and gaskets. Have a swivel top needle that is worn but will work with a little attention. My build is 70 miles away. Been bringing parts home to refurbish during the week. My wall of finished parts is growing and my stash of parts needing attention is getting smaller. Waiting on cool weather to start the rearend, then the engine. I appreciate the replies, and I'm sure more questions will need to be answered. Thanks again, Dave
No measuring needed. Make a line on paper. Lay the needle shaft on the line. Lay a ruler across the line, matching the angle of the needle point. Make a line along the ruler. There's your angle. Cut it out and use it to mark the angle on your block. Cut the block and drill the hole parallel to the bottom of the block. Done.
After dressing that inlet needle don't forget to mate it with the seat by tapping it with a small tool and hammer. That's the way to get best surface fit of the tapers, for secure seating. Fig. in Service Page
Know this thread is on the longer spray needle, and that can't be seated with hammer, but thought the importance of the stubby float inlet needle seating is an add to this thread. That needle is often rough on its taper even when new and needs the manual seating method.
Paragraph 884 and Figure 434 are for the inlet needle. Don't try to tap the threaded spray needle.
Placed an order for carb parts, requested the original style and the rubber tipped fuel valve was shipped. Such is life. Don't think tapping on the rubber tipped valve is needed?
Nope. Sometimes these stick. You may want to hold out for a metal one, but it will likely need to be polished. Mine have come "rough 'n' ready" - obvious tool marks.
The steel needles are no longer being made.
I installed a Viton tipped needle in an NH about 10+ years ago and so far, no problems. That being said, I don't put on near the miles that most of you do, maybe they were better back then, wouldn't surprise me. Back in the '60's-'70's when we first found out about them, they worked great in our "high" performance cars. Of course, that was before we got this CRAPPY fuel shoved down our throats. No doubt, the Viton isn't as good as it used to be either, not much else is. Dave