View Single Post
  #148  
Old 06-26-2011, 11:49 AM
TomcatViP TomcatViP is offline
Approved Member
 
Join Date: Aug 2010
Posts: 1,323
Default

Quote:
Originally Posted by Crumpp View Post
There is no such thing as a direct injection aircraft engine in General Aviation. All fuel injection is single point injection much like the Allied designs of WWII.

In a direct injection engine, there is almost no variation in CHT or EGT between the cylinders.

It is that temperature variation that robs a single point fuel metering system of power.

http://www.costaricaaviation.com/fli...tions_rev1.pdf

Crumpp,

At first, thx for all the excellent references you are giving on many of your post.

I understand you point on DI vs SPI (single point injection). DI has clearly many advantage and was the panacea at the time.

Viper care much abt theory and given that you run at cte regime and that the ducting are of equal length after the s/c (what is not feasible) the SPI has clearly an edge in terms of practical answer.

DI however as you has pointed out offer much more advantage on reality grounds and this clearly can be seen in ehaust temp even in today cars (Ask GrandPa about engine backslash and loud bang with carburetor engined cars before the 80's GTI went out)

Coming back on the BoB, I believed that RR had however an advantage with the s/c being inline with the engine witch simplified the routing of the air with a relative symmetry (the DB has some prob and a slight differences btw raws of left and right cylinder due to the s/c being on the port side ). This tend to makes the RR simpler ... and what is simpler is much easier to improve : a strong point for any strategical war item

Last edited by TomcatViP; 06-27-2011 at 05:37 PM.
Reply With Quote