Interesting idea for butterfly shaft bushings..

[Blake]

Hey everyone..


i came upon a post on one of the cadillac forums earlier today while looking for an efi manifold..  its in regards to the bushings on the carb.  here's a summary of the posts:

Note:  this posting is from the drag racing forum where these guys easily get 700+hp from a pretty mild engine..(turbo charged)



guy #1: "If you ever have trouble with your throttle body stickin, hard to press on gas or not wanting to return all the way... I fixed mine by putting a roller bearing on each end of the shaft.."

guy #1 response to "roller bushings?": "Yes , I used the roller bearings instead of bushings..they work perfect.. after about 2 years they got a little dirty and needed a shot of carb cleaner, but thats it.. if you want to do it , I'll  find the number I used, got it somewhere..."


another guy #1 response: "The reason I did not re-bush was ... the hole was only , if I remember right , a few thousands worn..just enough to make it stick..
now if the hole is a few thousands bigger than the shaft when the throttle body is new, everything will work fine.. because the shaft is only making contact at the very bottom  lets say 10%...but as soon as it wares the contact area gets bigger and bigger and after just waring down .004 you are maybe at 40%..and that much contact wants to lock on the shaft.. so I though that re-bushing would only prolong the problem... so I tried putting in  B-65 TORRINGTON   roller bearing... now ware in not a problem ..I had to clean them after 2 years with carb cleaner.... I maybe all wrong but thats what I think...when I bought the bearings they were less than $3 each but that was over 3 years ago..."

Someone else found a link: "I found a website pdf file that shows the bearing and the dimensions, now I know what you are talking about:

http://www.industrialsupplyco.com/Catalog/brgneedle.pdf#search='B65%20TORRINGTON'"


Now mind you, the carb they are talking about are the 800cfm early rochesters..  but the link the guy provided seems very helpful in giving dimensions for the bearings.

Just an idea i thought i'd pass along.  i know rebushing the rochester carbs arent that hard and apparantly the needle bearing conversion wasnt that hard either, so i dont see why one couldnt do the conversion for us.

A quick look on mcmaster carr showed a wide variety of sealed bearings for about 4 bucks each.  when i chem-dip my carbs this week (hopefully) i'll see if i cant take a measurement of the bushing area.


just thought id throw another idea around that might help some people out.

Blake

[Lucky]

if your going to pull the butterflies & seals out, be carefull of the screws that hold them in. in addition to being possably corroded, some of them are staked in 7 easily break off. fun huh?

I won't tell you about the need to properly position the butterflies when reinstalling, as another q-jet lover, i'm sure you understand.

flip that air cleaner cover over for me!!

--Lucky