View Full Version : Carburator Secondary's on a 351 windsor
04-28-2013, 08:59 PM
When we re did the carburetor on our stars and stripes the diaphragm had a brass of copper fitting of some kind rather than a ball bearing. The replacement kit came with the bearing, but we did not put it in because the original didn't' have it. Does anyone know why this bearing is important and can it affect the secondary's?
04-29-2013, 11:17 AM
There are 2 configurations of secondary housings... one with a brass insert, one without. The one without uses the ball instead. Both are equivalent, and the purpose is to make the secondaries come in smoother, rather than fast/abrupt.
04-29-2013, 01:24 PM
I appreciate the response. Thank you for the help.
05-06-2013, 10:24 PM
I have a similar situation, rebuilding a 4160 600 CFM (previously rebuilt Holley # 0-80319-1) on my recently acquired 1987 TriStar with 351. My secondary housing does not have the brass insert, but no check ball either. Could be I lost it during dis-assembly without realizing it, but that would surprise me as I have looked with magnifier and see no shiny spots down in the orifice that would indicate contact from a check ball. Holley kit 703-47 did not come with new check ball....does anyone know what size I need? I have searched for hours and cannot find the check ball diameter.
05-07-2013, 10:15 AM
I went through the same process recently... had 2 carbs in my possession that I had previously rebuilt that had neither the check ball nor the brass insert. I could have lost the check balls when I rebuilt them, but I doubt it. Holley tech line said that if theres no brass insert, then it must have the ball. I suspect there was a common configuration that had neither, but at this point its just a suspicion.
In my case, I had an issue with a carb that was pulling in the secondaries too fast and easy- I couldnt hold speeds with the secondaries partially open. I went to a housing with the brass insert and went 2 steps heavier on the secondary spring and the issue is solved. Wish I could tell you if it was the spring or the different housing that made the difference.