This is exactly the type of information I am hoping for. I saw pictures of what you describe from the EMC.
Some very high level racing engines designed for power and economy are now fitted with something called a concave dish piston. The cylinder heads are designed with as much squish area a...
"In my opinion, the difference in fuel economy will be almost entirely due to the weight and aero differences of the vehicle, but with slight differences due to compression ratio and barely measurable differences due to other influences of piston design"
"I most assuredly agree with Patprimmer...
jbthiel said:
"The two primary drivers of mass production piston design these days is cost and emissions, with less priority given to octane tolerance, fuel efficiency, air flow, etc."
I agree with this totally, this is one of the reasons I'm interested in learning more. Trucks are widely used...
Pat, I'm trying to relate you comments to specifications and reported performance indicators. The higher compression 5.7 engine is superior in efficiency as shown with MPG findings. This may be related to vehicle weight and aerodynamics. I am researching the two engines here's what I have found...
I’m mostly interested in the relation ship of engine design to the intended application.
The performance application is more focused on higher RPM power with an aerodynamic body style and gearing to match; this ultimately reduces engine load.
In contrast the Truck application demands an...
jbthiel
“Are you looking at two engines in particular? The LS family has at least 4 different bore sizes and 3 different strokes”
jbthiel, I am comparing the 5.7L LS1 engine that was installed in the Camaro at the end of the production run to the 6.0L engines that were installed in Trucks...
Patprimmer, can you explain this concept?
“ sporty applications will favour power density and commercial applications will favour low fuel cost and long engine life. This means lower compression than sports models”
I understand the idea of reduced compression relating to extended engine life...
Jbthiel,
I’m digesting your response. A unique combustion space is created when a dished piston is at TDC, the squish area becomes a small band and the chamber extends under some of the normal squish area of the cylinder head. With this mismatch the flame appears to have a greater distance to...
Tbuelna, The very short answer leads me to believe you’re thinking the only reason to put dished pistons in the 6.0L is to lower the compression ratio. Adding a central dish with everything else remaining the same would lower compression.
In addition squish to bore ratio is lowered with the...
Hi All,
Current GM V8 engines are available with different piston tops, performance applications like the LSx engines are fitted with flat piston crowns. In contrast many 6.0L Truck engines come with a dished piston crown.
What determines the piston design that is best for each application?
