Quadrajet part number 7029282

[hq308]

hq,
Nothing wrong with my comprehension skills, but maybe you should brush up on your READING skills. You claimed in post 47 that there would be a minimal change in f/level, measured in thousandths, if fuel pressure changed. That is the part that was wrong. I gave you an example in post 49 of a 2 psi change [ 6 to 8 psi ] that changed fuel level 0.090".
So is Doug Roe wrong too?
I think most people would think 0.090" was a LOT more than minimal! 0.009" would be minimal.
To put the numbers into more perspective, going from the initial 0.265" float setting with 6 psi to 0 psi changed the float setting by 34%. 34% ain't minimal...

That's not correct, your example used a 0.090" different float setting to get the same fuel level, close but no cigar. You're example may or may not also include other variables such as different floats? Show me a real world example where ONLY the fuel pressure is changed and ALL other things are equal.

[kavesh]

yes.. it can
end of a small screwdriver will do the job

Thanks Smitty, that will work.

[kavesh]

Kavesh,
Are you getting nozzle drip at idle? Engine warmed up & running, use a torch to look at the tips of the brass tubes in the primary bores for any fuel dripping.

As far as I know no, but I will confirm as described here Geoff.

[GtoGeoff]

hq,
Read it AGAIN. Only fuel pressure was changed on a Chev carb, from 6 to 8 psi, 0.090" change reqd in float setting.
Those numbers came from a chart titled: 'Relation of inlet size & fuel pressure to float setting'
QJs have a very short float [ compared to say Carter/Edel ]. That is going to reduce the leverage that the float can exert on the n/seat against increased fuel pressure. So fuel level will rise more, relatively speaking, before the float can close the n/s. Hence the large numbers.

Roe covers this aspect on p. 142: ' A float shape with more material in the fuel may help to...control fuel level'

[Smitty2]

.... I changed fuel pressure from 7psi to 14psi (via a pump change) and fuel level change was zero
with the engine not running and at idle

[GtoGeoff]

Well I would remove it & put in a glass case because it is very special.