Edelbrock 1407 off idle bog

78Delta88

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May 23, 2022
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No primaries are smaller, which handles idle and off idle to cruise. Secondaries handle acceleration to wot, added to what was started with primaries. If any loss at all it would be way deep in RPM ... 5500 to 7000 if at all. Just recall the lean condition of the 750 was basically due to the previous set of primaries were too large, resulting in too much air that needed more fuel to balance things out.

One of the reason I like the Spreadbore on a street car. Smaller primaries, very good low speed manners. Large secondaries are there when power and speed is needed. The largest Holley is 650, the largest Q Jet is 830 to 872, there some contention on this, these are found on Cadillac and large (455) Olds and Buick.
 
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Baker7888

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Dec 3, 2021
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No primaries are smaller, which handles idle and off idle to cruise. Secondaries handle acceleration to wot, added to what was started with primaries. If any loss at all it would be way deep in RPM ... 5500 to 7000 if at all. Just recall the lean condition of the 750 was basically due to the previous set of primaries were too large, resulting in too much air that needed more fuel to balance things out.

One of the reason I like the Spreadbore on a street car. Smaller primaries, very good low speed manners. Large secondaries are there when power and speed is needed. The largest Holley is 650, the largest Q Jet is 830 to 872, there some contention on this, these are found on Cadillac and large (455) Olds and Buick.
Thanks. I think i need a little more seat time on the 600. I am contemplating changing the clutch pedal geometry as engagement comes in like directly off the floor, although it’s adjusted correctly. I did shorten my fork linkage as the pedal was originally way too high at rest. I think this is part of the issue. All this stuff is fairly minor, i am just trying to make it a more perfected package with better manners
 
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78Delta88

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May 23, 2022
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We still know Edelbrock has a bog issue out of the box. So after driving a bit, still might not be bad idea open up the pickup tubes like in the 750. Just drive for a bit and see how it does.
 
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Baker7888

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Dec 3, 2021
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Maine
We still know Edelbrock has a bog issue out of the box. So after driving a bit, still might not be bad idea open up the pickup tubes like in the 750. Just drive for a bit and see how it does.
I could try the already drilled primary boosters off the 750, no?
 

78Delta88

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May 23, 2022
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Might try, but I think the boosters might not fit. Was thinking of that after I mentioned it the other day..., The new bore is smaller.
 

Baker7888

G-Body Guru
Dec 3, 2021
665
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43
Maine
Might try, but I think the boosters might not fit. Was thinking of that after I mentioned it the other day..., The new bore is smaller.
Gotcha. What about accelerator pump squirter? Go larger or stay with the same?
 

Baker7888

G-Body Guru
Dec 3, 2021
665
115
43
Maine
Might try, but I think the boosters might not fit. Was thinking of that after I mentioned it the other day..., The new bore is smaller.
So the 600 seems to be a hit. Got a little seat time today. The other thing i did was adjust the clutch so it is engaging closer to mid travel versus right off the floor like it was. The problem with this is my throwout bearing may not have the proper clearance. Unfortunately i have bigger issues. This knocking noise has been driving me nuts. I have it traced to inside the bell housing with a stethoscope. So the transmission needs to come out so i can investigate. The transmission leaks like a sieve, literally, so i will have to address that as well. I think i have another thread about the clutch rattle noise so I’m gonna head over there ….
 
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