'78 Turbo V6 carb on ebay

I too would like to find this out......

Turbo Carbs have many differant features than those made for the N/A's. I had written before they are not a direct fit for the N/A's. So I too assume that the CFM's may be different for the Turbo carbs. If only someone can confirm this since I installed a highly modified '83 Turbo Carb on my N/A. :confused:
 
I have been able to collect a few Q-jets here and there. It looks like the early carbs are 800 cfm and the electronic carbs are 750 cfm. The difference is in the primary barrels.

It is a little hard to see the difference. If you have Roe's Rochester Carb book, look on page 109. There are two good pictures of the primary bores. The 800 cfm doesn't neck down as far and has a noticable "bump".
 
Thanks Rich,

Never thought to look.....Now that I know I'll look at both my '82 N/A 4.1 Q-jet and the '83 Turbo Q-jet to see if there is any differance at the bore.

My '82 4.1 intake has a 750 CFM print casted on. Perhaps this is a clue.....:D
 
I belive the casting are for the 800 CFM , But on the carb's that are on turbos the secondarys are limited on their opening so it flow 570 CFM , this is where doug Roe book shows you can trim the "tang" to have it open more to give more flow.

But go to big and the car will buck & miss (I have tryed this) . What I did was drilled and taped a hole and inserted a screw than you can adjust the total CFM , If you go to big you can adjust it so the blades do not open has much , to small then you can adjust it so they open more. (50° angle on stock , hot rod tech artcile suggested 70° ) I found 70° to much . But every car is a little differant.

I had the same problem with the big holley , these cars seem to like a total carb size around 600-650 CFM.

Thats my two cents.
 
Top