What’s This?!? And more on the YH carb...

I just noticed in the post about YH carbs something on a pic of one of the engines. While most (myself included) were busy probably looking at the fancy schmancy intake and big carb on that purdy 312 (see pic below), there's something I just noticed at the bottom of the pic. It looks like there's a garden spigot in the oil pan drain hole! What's up with that?

Is that something "home made?" Never seen anything like it.

NEXT: I guess I threw too much info. in the last reply on the YH carbs -- I knew it was kind of a long hodge podge of info. so
here it is summarized: It looks like a couple sites indicated 128 CFM for the Carter YH single barrel. Does that seem "low?"

Bruce,
No, You now have a early version of a quick drain kit! The only problem is a normal garden hose won't fit through the hull's bilge drain!!

I did notice it and actually thought it was a pretty good idea! You should be able to find some smaller tubing at the hardware and hose barb/bush it to a 3/4" straight thread female garden hose adapter.

Craig,
We need some of our "gear head" members to calculate out the CFM needs of the 312. I've never done it but I think it may just be the volume (cfm) needed at a max WOT RPM???

Where did you find the 128cfm? If you relate the two side drafts to a two bbl. carb, are they rated for around 260cfm??

I sure hope you don't have any ideas that would disappoint me - like a 4bbl. conversion???

Bruce,
I was being facetious with the quick drain!! The PO added it.

Alan,
The 312 red lines at about 4200 - 4300
I got 315 CFM (rounded figure with the 83% V.E.) using a 4200 red line and the preset Volumetric Efficiency Of 83%.

Using a red line of 4300. the CFM goes up to 322.

Am I reading it incorrectly? Is the 83% V.E. pretty much the same with all engines? What changes it? Valving?

Riley wrote: Pete, got to like the 235 hp for the 4 brl versus the 215 hp 2 1 brls. My flame arrestor just barely sticks up over the center section.

Bruce,
I've seen the 235HP figure thrown around before but never with anything to back it up. Where did you get it? When the PO rebuilt the 312, do you know if any internal mods were done on it?

I know your arrestor sticks up just above the cockpit bulkhead for looking at other Classics with the downdraft. The pictures in the brochures show that the top was close to the bottom edge of the bulkhead. Did you get any part of the original dog house?

Sorry I keep calling the Classic "yours" - I should be calling it "the boys"!!!

Pete - I did a CFM calc. myslef with only 80% efficiency entered and got about 325 CFM (from this web site)

http://www.buicks.net/shop/reference/carb_cfm.htm

But I see you mentioned the slightly higher efficiency (83%) and slightly less RPM's (4200-4300), hence the slight difference.

The 128CFM (per YH carb) number came from the 2 sites cited in the other post. One was something about Black Hawk Engineering and it seemed like they were quite knowledgeable. The other (see other post) just kind of re-affirmed it because I saw the same number (128CFM) again.

So, if the number really is correct, then, as I think you mentioned, the combined CFM would be around 260 (or exactly 256). That's what got me to thinking that they weren't doing as much as they could. Even at your lower number from your calc. of 315CFM, that seemed a little low.

I guess the bottom line was maybe like -- Hey, at a time when many comparably sized boats like Chris Craft's old inboard runabaouts were getting 185hp out of their Chevrolet 283c.i. engine, getting 215hp and the low profile to boot (with the 312) was a great thing and those little carbs fit the bill to do that.

Space, as we know with the X-55 (or any boat design really) is an important design factor and the low engine profile made the boat look very sharp (I think).

And don't worry - I'm pretty well determined to keep that engine as is. I like it's (the engine's) original look, and I like the engine box's original look AND, shoot, the Dunphy went "almost" too fast for itself "as designed" anyway when you think about it.

Maybe with some other boats it would be cool to play with the 312 (and that one pictured above I gotta say, looks pretty sweet!), but for the Dunphy X-55, I think it should be kept as is, if possible.

Oh, by the way, I thought the drain plug looked a little unusual, but I actually did think it was a pretty cool idea, if it works. Why fiddle with wrenches and pans, etc. if you could drain the oil right out in a hose?