The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Racing and high performance (trucks haulin more than hay)

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-19-2010, 11:31 PM   #51
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: which carburetor!

KQQL IT
Actually, I know what you mean. You have an idle, trans and main circuit. If you land on it, you pretty much eliminate the trans circuit. That flat feel should be lean spot and flooring it will jump past it. Can be an incorrect HG rating of power valve. More than likely though a pump shot that is not quite set up right. Might not be enough. Sometimes guys will adjust the pump arm too far into the swing so they are running out of shot before the main circuit is fully taking over. Sometimes it's a carb winding up with the wrong pump cam because of an experimental previous owner.

When a guy wants to chase something like this down, the best thing to do is to get a few new gaskets and completely set the carb back up to factory Holley specs and go from there. Should be 78 jets, 31 shooters and pink pump cam on the #1 hole. JUST take the slack out of the pump arm. Don't do the feeler gauge bit.

C-10 KID
Seldom will an 850 have a better cruise range than a 950. 850s usually suck on the street because of the huge 1 9/16th venturies. Very temperamental and hard to get to not be lean jumpy. Usually just good for WOT but then again....cruising around town at 3,000 is pretty high.

Doesn't your 950 have removeable bleeds? Drilling them will ruin them. You need a precision drill set and drilling them will slow down the mix but also lean it out which might make your problem worse.

Last edited by prostreetC-10; 11-19-2010 at 11:50 PM.
prostreetC-10 is offline   Reply With Quote
Old 11-20-2010, 12:05 AM   #52
KQQL IT
At the body shop.
 
KQQL IT's Avatar
 
Join Date: Aug 2009
Location: Land of fruits and nuts.
Posts: 5,254
Re: which carburetor!

Quote:
Originally Posted by prostreetC-10 View Post
KQQL IT
Actually, I know what you mean. You have an idle, trans and main circuit. If you land on it, you pretty much eliminate the trans circuit. That flat feel should be lean spot and flooring it will jump past it. Can be an incorrect HG rating of power valve. More than likely though a pump shot that is not quite set up right. Might not be enough. Sometimes guys will adjust the pump arm too far into the swing so they are running out of shot before the main circuit is fully taking over. Sometimes it's a carb winding up with the wrong pump cam because of an experimental previous owner.


I figured it was the pump/squirter issue, never took the time to tune it out
and a 4.5 PV with 9'' vacuum at idle. and bought it new and second carb with same exact deal... the 10'' verter usually bypasses the issue
__________________
" That didnt make it any newer "
" Dont antique the equipment "
KQQL IT is online now   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:50 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com