Re: Question about what happens when the throttle

Posted by Jon H on September 09, 2003 at 15:19:21 from (69.26.18.98):

In Reply to: Question about what happens when the throttle clos posted by Ron on September 09, 2003 at 13:02:15:

You are correct,when you restrict throttle opening you get much less air in the cylinder to compress. There is a reason they tell you to take a compression test with the throttle wide open. An engine that has say 170 psi cylinder pressure at wide open throttle will have only aprox 30-50 psi cylinder pressure with the throttle closed to slow idle position. This is about the lower limit for a sparkplug to ignite the mixture and burn efficiency is terrible,this is why idling fuel economy is terrible. Notice how the newer cars are geared very high to make 60 mph at as low as 1500 rpm? This is for better fuel efficiency. If you lug the engine at very low rpm you can get much better cylinder filling, which makes for higher cylinder pressure at part throttle and better fuel economy.

Follow Ups:

Post A Followup Name: E-Mail: Subject: Re: Re: Question about what happens when the throttle Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]