Many years ago, when I first put a snorkel on the 455, I used a
"corrugated" rubber hose, taken off of something in the junkyard 'cause it
looked good and fit where I needed it. May have been off of some 2L
engine, for all I know. It really worked out nicely -- until the first
time I was doing about 50 mph and stepped into "passing gear". Suddenly,
beside the passee, my engine died! After that happened a few times, I
tried it with the hatch open. When that 455 ci air demand went high at
full throttle, that convoluted rubber collapsed, acting like a fully
closed choke!
Now I use "picker hose", designed to suck cotton bolls out of their shells
and deliver them to the baler.
Ken H.
On Tue, Feb 23, 2021 at 4:55 PM James Hupy via Gmclist <
> Any abrupt turn in an inlet tract will SEVERELY negatively effect
> horsepower production at high airflow. As will right angle turns in the
> inlet. The seemingly inconsequential "flow bumps" in small block chev 202
> heads were developed after endless flow bench and dyno testing. They
> account for a significant boost in flow at certain rpms when coupled with
> the correct compatible carbs, intake manifolds, compression ratios, cam
> shaft profiles, gaskets, and header diameter and tube shapes.
> When we drag raced small block chevs back in the late '50s and early
> '60s, we kept 302 cubic inch motors alive at 9000 rpms, when no one else
> seemed to be able to keep one alive for long much over 7500. Had lots of
> guys peeking over my shoulders any time I had an engine apart to learn how
> we did it. Hard earned secrets, kept mostly in my head, now as then.
> Jim Hupy
> Salem, Oregon
>
> On Tue, Feb 23, 2021, 1:30 PM Larry via Gmclist
>
> > Thinking back on this Jeep snorkel, someone out there had it on their 455
> > and ran it on a chassis dyno. Above 3K rpm it fell flat on its face.
> Whoever
> > it was running the dyno speculated that the Jeep snorkel was the cause.
> > The air coming in at 3K did not have time to straighten out after making
> the
> > right angle turn and the turbulence of the flow was interrupting the
> > effectiveness of the venturi effecting the FA mixture. They placed a 1"
> > spacer
> > between the snorkel and the carb to give the air time to straighten out.
> > That took care of the problem, and engine pulled strong to 4K. Wish I
> could
> > remember who that was, but might be worth considering that you have an
> > extra 1" there in case you have power issues. JMHO
> > --
> > Larry
> > 78 Royale w/500 Caddy
> > Menomonie, WI.
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> >
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>