toddalin

It's a 600. Bores and base plate are unmodified. All parts are intact.

BTW, CarCraft had a similar rich bog on their twin 600 dps on a project. They filled the stock #25 squirters with epoxy and drilled them out to 22s and said that cured it. Then they said they realized that #21s were available and would have just done that had they known. Certainly helped me.

toddalin

After lots more measurements, I've determined that measurements don't give the full picture, and it is more important to actually see the pump shot and measure the volume simultaneously with a higher degree of accuracy. I figured there must be a better way. (There always is). This is what I came up with.

I can now very accurately measure the volume of the pump shot while observing the pattern. You guys who are losing your hair will instantly recognize this for what it is. This will "self thread" into the hole once the squirter is removed. A nylon washer seals the bottom. When you pump a shot and the volume comes to a level and does not leak down, the seal is tight. In fact, you must unscrew it a bit to let it leak down between shots. I'm using water here.

I don't know if anybody makes anything like this for the marketplace. Sure would be easy to produce and a great tuning tool.

toddalin

Well it would appear that every centimeter of tube length represents 1/4 ml (i.e., 1/4 cc). Nice! Makes it easy.

AZDoug

I still have all my hair at almost 56 (plus a bunch i didn't have 30 years ago), so please educate me on what that is.

Thanks,
Doug

toddalin

It's the dropper from a bottle of Minoxodil.

joebobbilly

that wont work but I know you wont listen anyway.

1 drop of water in a metering plate will play havoc on a holley.

You have to measure what comes out of the squirter orifices using the same viscosity fluid aka gas.

you do this by catching somehow all that is squirted

but you can't measure the volume over a given frame of time vs engine rpm etc, which makes this exercise worthless.

I bet my left one the engine is leaning out.

But you do what you want to do, after all, this is still somewhat america.

joebobbilly

and that's no HP series you have pictured there

toddalin

Did say it was an HP? I said is was a 600 dp. You said it was some big carb, not me.

Whether water or gasoline is used, the volumes don't change in a relative way. A cam that shoots less with water will also shoot less with gasoline and the relative volumes will remain the same even if the actual volumes would change a bit.

Why don't you just give it a try? This is still a democracy.

AZDoug

Never ran across a case of inbreeding before.

Doug

joebobbilly

No, you just started off this thread with a picture of a different carb than what you are playing with, which just happened to be a HP series.

Just what are those numbers on the front of the choke horn of the carb you are working on? 4776 or 4779?

FYI, the difference between a 600HP series and a 750HP series carb is slim to nothing. Don't let the numbers fool you, because the actual flow rates don't jive with the marketing labels.

toddalin

The carb mounted on on my car is a 600 dp and has the rich bog as shown in six dyno pulls on two occasions. It has had the choke horn milled off and blended, nothing more. For some reason you seem to think it is an HP or that I've shown an HP somewhere along the line. It's not and I haven't.

The carb that the dropper is shown on is a 650 dp that still has the choke horn. It was on the shelf and only serves for testing squirter volumes.

The pump cams on both carbs work the same with similar, though maybe not exactly identical results. But then are any two Holleys (or pump cams) really exactly identical and would they yield exactly identical results? I would expect there is a level of tolerance.

Tell you what. When it cools off and I get some time, I'll put the graduated cylinder on the 600 dp (with the milled choke horn) on the car and fill it with gasoline. Then I'll take it off as well as that pump cam and put it on the 650 and run water through it and we can see how much difference there really is.

Of course there is no stopping you from making and testing your own. It's only a plastic medicine dropper, a nylon washer, and 9 centimeters of photocopied ruler held on with a piece of tape.

I would certainly be interested in hearing your results.

joebobbilly

Nah, I don't think the test is necessary. I managed to put up 8 sec quarter mile times in a full body steel car with a single 750 holley.....all without data from a dyno.

But you go right ahead. If you say it's rich, then it must be.

toddalin

I put the calibrated cylinder on the car today. It has pink cams front and rear. On the secondaries squirter, in Position #1, (advertised by Holley as the lesser volume), the fuel came squirting out the top of the graduated cylinder! There had to be more than 2.5cc that came out. That's higher than listed in Position #2 (listed at 2.25cc) by Holley if you extrapolate the 50cc pump. So maybe it was the cause of a rich bog. Position #2 (advertised as the greater volume) actually squirted less fuel and took it almost to the top of the cylinder, but not squirting over.

I replaced the cam with a new pink cam and put it on Position #2 that looked to be about 2.25ccs, which is considerably less that what was on there.

I did find that Holley's don't particularly like water. It softens the gaskets and when I tried the cam from the car on the Holley that has had water in it for a couple days, the gasket failed at the pump shot orfice and I couldn't get a shot to do the comparison. I cleaned it all out and sprayed it with WD-40 and other than the failed gasket, didn't see any harm done. The pump would still shoot what was in it and the diaphragm looked fine.