Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem
Another Idle question
richie49:
Cliff
I finally got it to idle in gear.But it isn't going to work.The idle is 1000 in gear and is so rough that it would not be any fun to drive.So I'm pulling the engine and swapping out the cam as soon as I get the funds to buy new parts. After I get it back together I'll have to see if the carb will work with the larger idle tubes and down channel restictions. Always something. Is there any suggestions on general cam specs, looking for a new cam more suited for the engine.
Richard richie49
Cliff Ruggles:
The cam isn't really too big it's just ground on too tight for LSA, so too much overlap and without increasing the compression ratio to offset the lack of "squeeze" at low rpms the engine isn't happy about it.
I've never built an Cadillac engines so no direct experience but have done quite a few "strokers" at or near 500 CID using Pontiac blocks. We've found that the big long stroke engines love 114LSA with the ICL around 109-110.
Assuming your compression ratio is around 7.5-8.5 to 1 I'd want closet to 230 @ .050" and around 280-290 seat timing. It will idle much smoother than the 108 LSA cam and make "locomotive" type power from right off idle to about 4800-5000rpms........Cliff
richie49:
Thanks Cliff
I'm looking into different cams now but that suggestion would help idle which is what I'm looking for.Whenever I get one and get it together I 'll reply on this thread .No telling how long this will be .
Richard richie49
Cliff Ruggles:
I don't have any direct experience with Cadillac engines so wouldn't know any specific part numbers.
What are your goals for the project?
You mentioned pretty much a "stock" low rebuild with a cam change. What is the application, drivetrain specs, etc?
richie49:
Cliff
I didnt see this post so Its a late or long off reply opps sorry.The goal is a daily driver with a little bit more than stock power.I dont wont or need 1000 hp.
A littl rumble at idle is ok but not so if I have to fight it. The car is a lightweight corvair,turbo 400 with a shift kit,a 8.5 rearaxle with 3.08 posi gears.
I had another cam that was 280duration,112 lobe seperation,528 lift 225 at.050
that was messed up when the engine lost oil pressure.So I believe I'M going back to those specs. most people have been telling what to do about the cam in it right now ,saying the carb is wrong and the distributer isnt working right and theres nothing wrong with cam,and all I have to do is tune it and it will be a smooth running engine. No matter what timing I put on it It isnt a good idle. You sent me the parts to help fix the idle ,tubes jets and jet rods. It does appear to be running on idle cicuirt no drips.I dont belive its going to idle better no matter what I do so out comes the cam for a more pratical cam
Richard richie49
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