spiralmax

[xxalexx at ix.netcom.com]

> Wow, those who don't know the past are doomed to repeat it. When I was racing
> Flattrack Triumphs about 15 year ago this I saw this idea. There were
> companies selling inserts for intake manifolds, and even mesh screens in the
> base gaskets to increase turbulence. I heard you coud get them at Fairs from
> about 1930 along with the snake oil.  Suzuki as I recall even cast turbulence
> vanes into the intake ports. We ground them out when we went looking for
> power. Unless you have over ported ported the heads and intake to a point that
> the fuel is puddling in it, it is a joke. They might help on low velocities
> like at idle.
> 
I was head of engine dyno dept. at Carter Carb. in late 70's.
We did alot of work inserting struts in carb to improve 
cylinder distribution which improved performance.  At WOT idle rpm  
some engines would have up to a 4 A/F spread.  The best
method I developed was drilling holes in throttle shaft, to eliminate
puddling.  Upstream vane(s) did little for distribution and did not 
repeat between test engines.  4 cyl. carb engines were rather  
sensitive to air inlet resonance and upstream intake dimensions on 
fuel curves.  When looking at test results make sure there is a large
number of tests done so a analaysis of variation can be none.
A trick for making a widget device look good is test a old worn
out car, it is highly probable that one  baseline and retrofit test 
will be grosely different either good or bad.  
alex peper
68 Truimph Bonneville, 820 Routts, Sifton Cams, Barnnette clutch,
R-tappets, Joe-Hunt Mag, stock Amals.