Sm Needles

[Chickenman]

Oh and Bruce, I'm in BC.

Colten. I've sent you a PM. I'd be happy to help you tune and set up your SU's. Contact info in PM. I'm local in Metro Vancouver. We probably know some of the same people in local Datsun clubs. Richard.

Edited April 10, 2015 by Chickenman

[Bruce Palmer]

Gotta love it when helping hands reach out to one another.

[Stanley]

Finally got around to installing my new SM needles (thanks, Bruce). Previously had modded N-27's, that seemed to still need a little more polishing for top end. I usually just use the syncrometer to get them pulling the same amount of air, and then use road tests to adjust the mix. So I checked it with the old needles and both carbs were pulling the same. Checked where I had the mix nuts, the front was down 5 1/2 turns, and the rear was down 5 turns. Had made so many adjustments I had no idea where they were set. Seems like a lot but that's what it took for my setup.

 

Cleaned up the domes, etc., put in the SM's. Set the mix 3 1/2 turns down, since the SM's are supposed to be richer. Checked it with syncrometer, both pulling the same. Tried push-pin test, seemed OK. Seemed a little rich, though, so leaned them to 3 1/4 turns down. Put the velocity stacks and K&N's back on and took a little drive to grocery store. Ran bad, felt lean. Made three stops, lowering the mix 1/8 turn each time. Still ran crappy. Was starting to think it was maybe too rich. Made another stop and lowered (richened) it another 1/4 turn. Then it started to run better. Richened it another 1/8 turn. Ran it to 4700 rpm (in first, due to speed limit / cops) and no miss at 4 1/2 turns down. So maybe OK. Not much of a test, but FWIW, seems like the SM's are a bit richer than my modded N27's, but not excessively rich, at least for my car. I like.

 

Also made a little discovery (new to me, that is) about the dashpot oil. FSM says get the oil between the marks on the stick. Easier said than done; even with good light and a magnifying glass it was hard to see the oil level. Eventually I got them both about to the upper line. I was pushing up on the pistons and noticed one was harder to push up than the other. Then I noticed that after adding some oil to the weak one, it was harder to push up. By adding or removing a few drops at a time I was able to get the resistance of both pistons the same. Didn't know that. Still don't know what the best amount of resistance is, though. Need to do more tests.