Home
Basic Dirt Bike How-To's - Video
Dirt Bike How-To's - Video
Living The Moto Life - Video
Bike Tests | Shoot-Outs - Video
Forums
What's new
Latest activity
Log-In
Join
What's new
Menu
Log-In
Join
Navigation
Install the app
Install
More options
Close Menu
Forums
MX, SX & Off-Road Discussions
Dirt Bike Mods & Maintenance
Motorcycle Myth # 5 - You need big ports to make big horsepower
Reply to thread
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
[QUOTE="cujet, post: 1471993, member: 19501"] Always of interest. It may be interesting to note that my lowly airplane (177RG) has a 200HP 4 cylinder Lycoming engine with 5.125 inch pistons. Yet the intake pipes are 1.5 inch steel tubes with an inside dia slightly smaller than that . Sure, it's no high RPM monster, with a 2700 (3300 in helicopter use) redline. Put another way, it's a 37mm intake port on a 1475 CC cylinder. It achieves a volumetric efficiency better than 85% at full output and nears 100% VE at lower RPM's. Of note, the intake port tube diameter is not the major limiting factor. Instead, the throttle body is the restriction (by design) . It can only achieve 26 inches of mercury intake manifold pressure at full power, about 4 inches shy of the 29.92 of a standard day. Sure, by modern engine standards, those are not great numbers. But it does show a viable use for comparatively small intake ports on an otherwise good design. As you might expect, it takes just a few simple alterations to achieve a 12% increase in HP, bumping it up to 225HP. Bigger is always better? [/QUOTE]
Verification
Which ocean is California closest to?
Post reply
Forums
MX, SX & Off-Road Discussions
Dirt Bike Mods & Maintenance
Motorcycle Myth # 5 - You need big ports to make big horsepower
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top
Bottom