Thread: V8 fuel economy
View Single Post
Old 12-26-2014, 08:30 PM   #12 (permalink)
greasess
EcoModding Lurker
 
Join Date: Dec 2014
Location: Florida
Posts: 25
Thanks: 0
Thanked 5 Times in 3 Posts



I have a vortec 4800 in the car right now. I originally chose the 4.8 because of it's stout bottom end. The first picture is of a chamber that I had welded up on the plug side and shaped like a figure 8. The added quench area should improve the engine's detonation threshold allowing for more compression with a given octane fuel. This chamber should also push more of the burning mixture into a smaller area at TDC allowing for a faster burn that will require less timing and allow less heat energy to escape through the head. I have 2 sets of heads prepared like this. One of them can be seen in the second picture. The intake port walls were left rough after porting. My thinking is that this should improve fuel atomization because of the added turbulence. The third picture is of the "somender singh groove". After the engine is together without the groove I'll get a baseline and then take the heads back off, put the grooves in the chambers, resemble, retune and test again. The groove is supposed to increase mixture motion/turbulence. I'm also going to make a set of headers with anti reversion cones to improve scavenging and decrease pumping losses. I plan to do all this with 93 octane fuel at first and eventually move to e85 when it's time to turn the boost up. The engine has 9.5 to 1 compression now with what I think is a 58 cc chamber. I haven't done a cc check on the finished chambers yet but I hope I can get close to 11 to 1. All this turbulence and chamber motion along with a faster burn and less optimal timing should allow me to use significantly less fuel and actually make more power. The car has a 6 speed manual with a .5 6th gear, 3.50/1 rear gear ratio and 315 35 r17 tires and that puts me at 2,000 rpms at 90 mph.
  Reply With Quote