California emissions
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Joined: Sep 2004
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From: Cambria California
California emissions
I have a 1978 Corvette with a 4 speed and L82 . I recently installed a GM 290 HP crate engine and am using the Q let carb. I am considering installing a Edlebrock 1400 carb as I need to pass califoria emissions. one of my questions is will the stock air cleaner fit on the carb and will the hood clearance be a issue. The air cleaner has to be the stock unit to pass emissions.
I read a post about this engine not producing enough vacuum, I also had only 10 inches of vac. I bumped the timing to 18 degrees from 12 and vac went to 19 inches and also helped the idle somewhat but it still runs like crap. I am hoping a new carb will help.
from an earlier post on this forum about valve adjustment, I do notice when its running the valve train does not sound right like I have loose rockers. It appears that is my next project but I still need to know about the physical fitting of the carb as I want to replace the Q-jet
I read a post about this engine not producing enough vacuum, I also had only 10 inches of vac. I bumped the timing to 18 degrees from 12 and vac went to 19 inches and also helped the idle somewhat but it still runs like crap. I am hoping a new carb will help.
from an earlier post on this forum about valve adjustment, I do notice when its running the valve train does not sound right like I have loose rockers. It appears that is my next project but I still need to know about the physical fitting of the carb as I want to replace the Q-jet
Le Mans Master
Joined: Nov 1999
Posts: 5,768
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From: San Diego CA
The Factory air cleaner will fit on the engine with edelbrock, assuming you arent running anything much taller than the Edelbrock Performer.
The Edelbrock RPM will fit if you have a drop base air cleaner (but then it isnt smog legal)
You have other issues though, 10" of vacc is way too low for that engine. The 290 HP crate isnt much different from the stock L-82. It has smaller valves and a little less compression, the Cam is more or less the same as the L-82 cam and of course 290 gross HP isnt significantly more than the 220 Net that the car originally came with. That motor should idle like glass and pull no less than 16" at idle I reckon.
If you have a rattle in the valvetrain, which with hyd. valves usually isnt the case unless they were adjusted seriously wrong. I would address that first. Misadjusted valves could concievably be part of your low vacc, bad idle issue.
To be honest I ran one of those edelbrock carbs and I personally wouldnt recommend it, take the qjet to a shop that can fix em and you will be much happier.
good luck and let us know how it comes out.
The Edelbrock RPM will fit if you have a drop base air cleaner (but then it isnt smog legal)
You have other issues though, 10" of vacc is way too low for that engine. The 290 HP crate isnt much different from the stock L-82. It has smaller valves and a little less compression, the Cam is more or less the same as the L-82 cam and of course 290 gross HP isnt significantly more than the 220 Net that the car originally came with. That motor should idle like glass and pull no less than 16" at idle I reckon.
If you have a rattle in the valvetrain, which with hyd. valves usually isnt the case unless they were adjusted seriously wrong. I would address that first. Misadjusted valves could concievably be part of your low vacc, bad idle issue.
To be honest I ran one of those edelbrock carbs and I personally wouldnt recommend it, take the qjet to a shop that can fix em and you will be much happier.
good luck and let us know how it comes out.
Last edited by fauxrs; Jan 17, 2011 at 08:05 PM.
