Well, that took longer than I expected. Got the 17mm bolt head, Dremmeled off the shaft, and drilled off center. Tight slip fit and positioned just right.

Here are a few pictures of the new fabricated stop as well as some pictures that show the amount of vac needed to overcome the spring tension of the flappy with the spring wrapped around 2 times. Starts to move at 6 inches of mercury and and is fully open at 11 in Hg of vac.

Does this look alright now?

Thanks to Mrmerlin for pointing out a piece of information I was unaware of. After all of the work on the intake refresh, I want this thing to work and work like it did when it came out of the factory.

 

final fitting is to check the flap inside of the intake, make sure it isnt binding in its bore, when the intake gets hot and if this piece isnt on then the flappy can bind shut, it may work when you do the start test but it should also be checked when the engine is at operating temperature.
i think that if the flap is held open with a small piece of wire (placed between the bore and the flap) then the stop is installed you will be good to go

 

About .030 in that range?

 

Careful adjustment of the securing screws prior to this had shown no binding with the disk moving freely when vacuum was applied.

With the addition of the "stop", the flappy disk is held open just a hairline crack and only requires the vac pressure to overcome the spring tension. Seems to operate very smoothly and opens completely.

 

The answer to the original question is:

Single wrap of the spring, not two.

 

On mine the choice is a quarter wrap being the first opportunity to put it under tension...second chance being the first one to have a full wrap but it consists of 1 and a 1/4 total wraps.
That's where I put mine. 1 1/4. Maybe my spring is stretched out to the point of being that way

 

I guess this is more accurate in my case as well. I started with the option of either 2/3 of a wrap or 1and 2/3rds. I went with the later and think this will work well in my case.

 

Every one that I have checked, start to open at 3# vacuum and fully open at 5#.

 

Nice repair.

That vacuum is high for the flappy. Greg Brown's earlier post about a single turn is right - if you check the archives and nichols, the flappy should be open fully by 3inches vacuum.

 

Alright. Will disassemble and remove one round of spring tension. Thanks.

 

I removed one round of the spring and now the flappy starts to open at 1 inHg and is fully open by 3 inHg. I appreciate everyones input here.

 

When I took mine apart today it did not even have one turn on it, more like 1/4 turn, and it was working before we pulled the motor.

My guess is the spring has stretched, my stop was gone also and I do not think the intake has ever been off.
from the shape of the arm where it should hit a stop it obvious that something went there at one point.

 

This is GREAT info! I did not have the stop on Virginia when I disassembled the intake (I even have pictures!) and it was not in the valley. However, Virginia had it's intake removed by the PO's mechanic so no telling what they threw out. I had NO IDEA there was supposed to be a stop there - in fact I don't even remember seeing it in PET (but now I'll have to check again when I get back home from travel).

My intake R&R procedure currently doesn't include any discussion of this part (much less a picture!) but I will update it to include the discussion and if I can borrow a picture from 928autobahndreamer and find a way to fit it in, I'll include a picture of the fix (THANKS for jumping in on this one, Stan).

As far as the number of wraps for spring tension, I tested the before tension (pictures included on the first page of the R&R post) and found the flappy would begin opening at 3" and be fully open at 8". But, again, the intake was taken off by the PO's mechanic so I don't know if that's factory. I would also like to update the Intake R&R post with the recommended spring tension so I'll work on that as well. It will probably include a discussion of recommended vacuum to first move the flappy and expected vacuum at flappy fully open. I will try a test on Idaho - I'm certain that's a virgin intake and has low miles - and see what vacuum it's flappy begins to open and what vacuum it's fully open just for fun.

THANKS for the great discussion and new information (new to me, anyway). I'll get back with my findings (as soon as I get some quality shark time back at home!)

 

Sorry. Could have done a better job than "single wrap of the spring"...although I thought this would be clear.

How about: Lowest possible tension that is possible?