Inliners International Forums General Discussion Hi Performance Flowbench experts, what's a good figure?

As mentioned in the Mopar section, we're doing a serious project on an Australian Hemi 6 engine.

Working on the flowbench yesterday, my nephew found that with 0.58" lift in standard configuration the inlet port flows 193cfm.

What are good figures for an inline six in the 250 cube category? And what do those translate into in terms of horsepower?

Ray, i've noticed that the standard used in Oz for flow testing is much different that in the US and other places. We use 28" here, so make sure your #'s are in that same unit of measure. A mildly ported and prepped 250/292 head can flow in the 260 CFM range @ .500 lift pretty easy at 28".

IMO,our siamesed port head would not be a good comparison to an individual port cyl head as far as head flow.

Ray Bell
Maybe compare to this?

http://www.classicinlines.com/alumoverview.asp


MBHD

That's helpful stuff, thanks guys...

Please keep it coming.

Ray, you've probably gone the calculator route, but just in case, here's a set that I've found particularly helpful.

http://www.wallaceracing.com/Calculators.htm

Thanks for that, I'll pass it on to Ben...



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Guys
I like the 'Calculators' site. Do you know of a site formulated for the inline 6? I don't know which calculation are only for the V8 or which could be used for the 6.
Mike

Most of these will ask how many cylinders your engine has. As long as you have a port for every valve they work quite well. We don't get into trouble until the siamese ports come into play. To my knowledge no one has came up with a way to model them. For the most part, that only hurts when we try to get into the "tuned" intake and exhaust lengths and volumes for a particular RPM.

If the calculator doesn't ask how many cylinders, just use the actual engine size and other data, but multiply the result by 1.333.

According to Bell, the port area of a siamese intake should be 2-3% higher than the area of the intake valve as a minimum.
For a 1.94" valve (common for Gen-3 L6) that's about 3.04 square inches, equal to a rectangle 2.03" × 1.5" or a round port 1.97" ID.

OK, header calculation
use 1.33 on 6 CI , and tube size and length is now correct.
On the collector results, use same length but reduce DIA/area by 1/4?