A while back we had a fuel system discussion where I mentioned the idea of high RPM pull over enrichment from the accerator pump squirters. Some guys had a difficult time buying into the idea that such a thing occurred.

While web searching for other things I stumbled upon some really cool videos down the throat of a carb while its on the dyno - - the seventh one down (4412) clearly shows the fuel flowing from the squirters. The other vids are very cool too...some really cool stuff!

http://www.ryanbrownracing.com/Video.html

 

Barry that right up in the the popularhotrod mag you ? 1975Ford posted it in another thread.. http://www.popularhotrodding.com/eng...ine/index.html

If so man.. way cool, makes a working man feel like he has a chance in hell at any fun with one of these if so desired.HAHAA Just saying it was some great reading.. makes me wish I had more time and $$ to tinker.. But ole Bush and the boys keep me on the straight and narrow (straight to work/narrow budget after taxes) LOL

 

Back in the bad old days of the '60's it was known about and either you left the squirter check ball/valve in or not depending if you needed the extra fuel of not.

 

Very cool. I had no idea the squirters were more than just a temporary supplement. That would mean that a tightly tuned engine might require a main jet change to accompany a squirter size change.

Good info.

-Scouder

 

Only if you leave out the check ball/valve under the squirter. otherwise there should be no pullover. That's why the check ball/valve is there.

 

That could be one reason for the check ball, but it's not the only one. When I rebuilt my holley, I noticed that the seat for the check valve (in my case it was a pointed brass slug, not a ball) was on the bottom of the valve. I did not note if there was a seat above the valve in the squirter body. I also noted there was no spring to position the valve on the seat. So only the weight of the brass slug would seat the valve. With the air flow past the squirter there would be a vacuum that would suck the slug up. If there was a seat above the slug, then yes, it would impede or stop the flow of fuel in the pullover process. But wouldn't that same seat on top of the slug also prevent the squirter from actually operating? As the pump acted and pushed fuel through the valve, the slug would be lifted and seat aganst the top seat if there was one present, sealing the passage. If the slug or ball was heavy enough, the vacuum above it might not be sufficient to lift it from the lower seat and thus it might prevent pullover.

Near as I can tell, the function of the check valve is to stop the backflow of air to the accelerator pump when the throttle is closed. This way, the accelerator pump is forced to fill with fuel and cannot suck air backward through the squirters. And you would have a more reliable pump shot when the butterflies open.

 

Yup - that was me in Pop Rod - - they did a nice piece and I really appreciated it. And Supercab has the check ball function nailed

 

[Elvis voice] Thahunk you. Thahunkyouverymuch. [/Elvis]