DOHC - 2.3L Duratec / Mazda L Engines Discussions and Topics specific to the Duratec 4 cylinder engines

Redline and max rpm before float

Old 03-16-2019
Thread Starter
Join Date: Dec 2018
Location: yuma Arizona
Posts: 133
Redline and max rpm before float

What is the factory, tuned, and valve float rpm's?
Max engine capable rpm at full fuel pressure
When does valve float occur on the rpm band
Old 03-16-2019
RF Veteran
iTrader: (1)
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 12,507
Not a spec that's published or even tested for, you can calculate it if you have the CAM data and spring data

2.3l Duratec In a Ranger is a Mazda L 23NS with these specs
2004+ Ranger 2.3L Duratec
143 hp @ 5250 RPM
154 lb⋅ft @ 3750 RPM

So I would say around 6,000RPM would be where you would get loss of power, about 700rpm above max HP RPM
Ranger NS23 does have a different cam than the 23EW,
The 2.3l Duratec used in cars had this spec 151 hp @ 5750 so with this cam I would expect 6,500rpm loss of power

The 2.3l Mazda L was 164 hp @ 6000 rpm so 6,700 for that model

Last edited by RonD; 03-16-2019 at 11:44 AM.
Related Topics
Thread Starter
Last Post
Exterior Semi-Tech
02-21-2019 11:42 AM
2.9L & 3.0L V6 Tech
01-28-2019 11:56 AM
Suspension Tech
08-30-2018 08:28 PM
4.0L OHV & SOHC V6 Tech
04-30-2015 11:02 PM
4.0L OHV & SOHC V6 Tech
02-17-2009 04:02 AM

Thread Tools
Search this Thread
Quick Reply: Redline and max rpm before float

Contact Us - Sitemap - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.