VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 04-14-2021, 08:34 AM
Vans101 Vans101 is offline
 
Join Date: Apr 2016
Location: San Jose
Posts: 72
Default Different IO-540 Oil Sump Designs...Why?

It seems that Lycoming has (at least) two different oil pan designs for the IO-540.

The first design is a system where the intake tubes are cast into the oil sump so this means that the engine oil is dripping down on to the outside of the cast intake tubes that run through the oil sump.

The second design has two separate cavities for the oil sump and intake system where the oil sump is its own cavity above and the intake cavity is a completely separate cavity below.

Does anyone know why they would have the intake tubes run through the oil sump?

Was one a first generation design and then they changed their thought process or was it a carbureted engine verses a fuel injection engine design??

Do they still make both systems?

What are the advantages/disadvantages to each design?

Anyway just curious if anyone has any intel because it seems like such different thought processes.

Thanks
Reply With Quote
  #2  
Old 04-14-2021, 01:24 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,955
Default

For a long time, carb'ed auto engines would run an exhaust passage through the intake manifold with the purpose of heating the air fuel mixture after the carb. The advantage is that heating helps to better atomize the fuel, with more even air fuel mixing, and provide smoother running engines, especially in cooler weather. The down side is that warmer air contains less O2 for a given volume than cooler air, due to differing densities and therefore slightly less power production for a given displacement.

FI engines can better atomize fuel and this practice generally went away with port-based, FI engines.

200* oil constantly flushing over the intake plenum will add a decent amount of heat to the air fuel mixture.

Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019

Last edited by lr172 : 04-14-2021 at 01:33 PM.
Reply With Quote
  #3  
Old 04-15-2021, 09:20 AM
Vans101 Vans101 is offline
 
Join Date: Apr 2016
Location: San Jose
Posts: 72
Default

So was one design used for carbureted engines and the other design for fuel injection?

For the engines that have the new aftermarket "cold aid induction" how much performance gain is there for the mod?

Is the mod available for both the intake tubes in the oil sump and the intake system below the oil sump designs?
Reply With Quote
  #4  
Old 04-15-2021, 11:48 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,955
Default

Quote:
Originally Posted by Vans101 View Post
So was one design used for carbureted engines and the other design for fuel injection?

For the engines that have the new aftermarket "cold aid induction" how much performance gain is there for the mod?

Is the mod available for both the intake tubes in the oil sump and the intake system below the oil sump designs?
The cold air sumps, I believe, were developed to allow folks to extract a bit more HP, by eliminatng the heating. I suspect that they have a larger plenum area and this is the primary reason for the increase HP. Pure speculation on my part. The std sump has a very small and inefficient plenum relative to the auto world. Unclear if there is still enough warmth to help with carb'ed engines. To be clear, the difference is not night and day, especially with summer temps. You may not even notice the lack of heat with a carb.
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 01:59 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.