Carb improvement

[Gaz64]

Originally Posted by Sledge

Looks like they might restrict airflow a little?

That would be correct, but only if your carb is on the marginal side of small for the engine.

So for example, a 650 DP on a 482 might lose top end, but the increased throttle response would make it nicer to drive overall.

This example would be better with an 850.

Watching a vacuum gauge at wide open throttle will tell you if you need a larger carb.

Gary

[patrickt]

Gary is absolutely right about the vacuum gauge, but, it's not as easy as you might think. Two years ago, when I was having a variety of carb problems (that eventually turned out to be a tough to spot crack) I ran surgical tubing in to the cockpit along with a vacuum gauge. I mostly wanted to confirm my power valve choice and to calibrate my adjustable Wagner pcv valve. It worked perfectly for all of that and it was actually pretty interesting just watching the vacuum numbers while I drove normally and safely. Now, my FE puts out an honest 475HP to the flywheel. Some around here call that a "weak sister." But I will tell you that it was impossible for me to safely observe the vacuum gauge, that I had hanging from a knob on the dash, while I was at WOT on the street. You might get a glance, but not an observation. I suppose I could have hooked up my son's GoPro, pointed at the vacuum gauge, while I hung on at WOT, but I didn't think of that at the time.

[Gaz64]

Originally Posted by patrickt

Gary is absolutely right about the vacuum gauge, but, it's not as easy as you might think. Two years ago, when I was having a variety of carb problems (that eventually turned out to be a tough to spot crack) I ran surgical tubing in to the cockpit along with a vacuum gauge. I mostly wanted to confirm my power valve choice and to calibrate my adjustable Wagner pcv valve. It worked perfectly for all of that and it was actually pretty interesting just watching the vacuum numbers while I drove normally and safely. Now, my FE puts out an honest 475HP to the flywheel. Some around here call that a "weak sister." But I will tell you that it was impossible for me to safely observe the vacuum gauge, that I had hanging from a knob on the dash, while I was at WOT on the street. You might get a glance, but not an observation. I suppose I could have hooked up my son's GoPro, pointed at the vacuum gauge, while I hung on at WOT, but I didn't think of that at the time.

Yes, agree there Pat.

I should have said that the gauge should be observed by a passenger or some recording device while at wide open, high rpm.

Gary