Idle adj. During break in
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Melting Slicks
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From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Idle adj. During break in
Those of you with new crate motors did you have to tweak your idle up or down as the engine broke in ? I thought the engine would loosen up and the idle would increase gradually requiring turning it down. The opposite seems to be happening . I had to tweak it up twice to maintain 900 RPM. Does the rings seating and compression increasing cause that ? I only have 200 miles on the '77 with a new 383 stroker.
And yes, if you are wondering if I am OCD at least when it comes to the Vette!
And yes, if you are wondering if I am OCD at least when it comes to the Vette!
Last edited by BPHORSEGUY; Apr 11, 2020 at 03:16 PM.
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Those of you with new crate motors did you have to tweak your idle up or down as the engine broke in ? I thought the engine would loosen up and the idle would increase gradually requiring turning it down. The opposite seems to be happening . I had to tweak it up twice to maintain 900 RPM. Does the rings seating and compression increasing cause that ? I only have 200 miles on the '77 with a new 383 stroker.
And yes, if you are wondering if I am OCD at least when it comes to the Vette!
And yes, if you are wondering if I am OCD at least when it comes to the Vette!
Curious, whose crate is it ?
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Melting Slicks
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From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
I have checked for vacuum leaks. I will recheck floats but they were fine. The water temp is 170-175 and oil pressure varies between 30-55 lbs from idle to 4000 RPM. I have only needed to adjust the idle screw maybe 1/8 turn.
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Melting Slicks
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From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
I have been playing with the mixture screws. The 2 in front were open about 1 turn and the 2 at the back only about 7/8, I marked the original positions when it came back from the shop. The carb is a Quick Fuel Predator 650 and according to the supplied instructions the mixture screws should start at about 1 1/4 turns or 1 1/2 if that doesn't work. So it is setup leaner from the shop then what I would expect from the directions.
Except for chasing the idle a little bit the car starts great hot or cold and runs very strong!
Except for chasing the idle a little bit the car starts great hot or cold and runs very strong!
Last edited by BPHORSEGUY; Apr 11, 2020 at 07:31 PM.
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Melting Slicks
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From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
OK...I rechecked the float levels and found both near the bottom of the windows when they should be 1/2 way up on the arrows of course! They were fine 10 days ago, Just things bedding in? Any way it seemed to idle stronger and I will report back after a test drive. It is Easter and all!
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I have been playing with the mixture screws. The 2 in front were open about 1 turn and the 2 at the back only about 7/8, I marked the original positions when it came back from the shop. The carb is a Quick Fuel Predator 650 and according to the supplied instructions the mixture screws should start at about 1 1/4 turns or 1 1/2 if that doesn't work. So it is setup leaner from the shop then what I would expect from the directions.
Except for chasing the idle a little bit the car starts great hot or cold and runs very strong!
Except for chasing the idle a little bit the car starts great hot or cold and runs very strong!
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Last edited by BPHORSEGUY; Apr 12, 2020 at 04:06 PM.