*************************************************************************
Fuel consumption test 2
I repeated the test on 01/22/2006 again with no trailer with even better results. Again, I drove to a local economy fuel station and toped of the tank with 87 octane regular fuel. I was sure to get the tank full to the top of the spout. I then completed the same 50 mile round trip. The tank was again toped off taking 2.139 gallons. The resulting 23.37 MPG is real and nothing more than outstanding for this truck!
**************************************************************************
Fuel consumption test 1
On 01/21/2006 I conducted a fuel consumption test in my Suburban (no trailer). I drove to a local economy fuel station and toped of the tank with 87 octane regular fuel. I was sure to get the tank full to the top of the spout. I then completed a 50 mile round trip on a long straight flat road. The tank was again toped off taking 2.3 gallons. 21 MPG tops my all time best of 17 MPG for this truck!
*******************************************************************
With engine repairs complete it is time for testing! The unmodified factory computer is in place managing the fuel and spark. The O2 sensor has been replaced as well as the spark plugs and fuel filter. read more: http://somender-singh.com/content/view/54/37/I have located problems with the engine and have began repairs. The major problem was a bad temperature sending unit for the engine computer. The computer was sensing a cold condition and enriching the fuel delivery to compensate. The thermostat was also changed to the original design of 195 degree. The engine is performing better than when new and fuel economy is going up! Next week I will be checking the operation of the O2 sensor. If it is measuring high O2 the computer could be enriching the fuel delivery to compensate.
Observations:
I drove the Truck every day this week to check it out. An engine shimmy at idle was traced to a leaky EGR valve. I fixed up that issue and the engine idles smooth @ 600 RPM. I know it would go lower but GM decided to put a tamper proof plug over the idle adjustment.
Power is defiantly up; it accelerates to 60 MPH effortlessly at low RPMs. Remember I’m dealing with an 11 year old truck with 160,000 miles on it. This thing is actually fun to drive; the additional torque seems to make the 4 speed automatic work better.
Before the modification I monitored the engine temperature closely, it was running at 165 degrees F. After the modification it’s down 15 degrees. I’ll be changing the thermostat because on cool mornings this week the engine never got above 120 degrees, it seems to like more heat, I will try a 180 degree thermostat.
I pulled the plugs to look for the tell tale signs of detonation, at over 10:1 compression there’s none to be found.
I’m monitoring fuel consumption and planned on having honest numbers for you. I need more time to sort things out to be sure I report actual findings. . I’ll continue to drive it every day and report numbers soon.
What was done:
I located a set of heads that are identical to the ones on my Suburban (pictures below)
I then modified these heads, milled 0.050" and cut the grooves. The chamber size was reduced from 64cc to 58cc
I pulled the original heads and installed the modified heads
The only changes done were the mill and the grooves, nothing more.
Max out of Minimum
This project named “Max out of Minimum” will be developed to produce the maximum amount of benefits that can be realized with the minimum amount modifications to the engine. This project will turn the focus to testing reductions in fuel consumption in daily driven V8 Trucks. This country cannot do with out Trucks, but 13-15 MPG is no longer acceptable!
A comparison of the cylinder head squish area and the piston squish area clearly displays how the manufacturer decided not to take advantage of all of the available squish area of the head thus reducing squish percentage and compression by installing the dish pistons. This presents a perfect opportunity to find out how well this simple groove design will perform despite the lack of Squish support. We will be able to see what can be accomplished by pulling the heads, making a few small modifications and reinstalling them, putting in the least effort, nothing more!
Using a 1/16" ball end mill I cut the initial grooves with a die grinder mounted to a hand made fixture that is designed to cut a straight line. I cut them 0.040" deep because the deck is very thin, when deck thickness allows, I cut deeper (0.0.60" to 0.080"). I cut the initial grooves parallel with the deck surface. The groove finishing is done with a hand held hacksaw blade and a thin triangle file. I contour the bottom of the floor into the combustion chamber cavity and widen to groove to 0.125" at the cavity.
The heads are casting number 14101083. Here are the specs I found for the heads:
Cylinder head assembly used on 285 hp 350 engine (P/N 12353641). This cylinder head assembly includes 1.94" intake valves, 1.50" exhaust valves, valve springs (P/N 3901068) and valve spring caps (P/N 14003978). This cylinder head has 64cc chambers. The cast number for this head is P/N 14101083 or 14096217. This cylinder head has 1987 and later intake manifold bolt pattern. The center two bolts are at a 72º angle.
 The information I found on the pistons show a 10cc dish.  With this information I calculated the compression ratio, the results follow... Production engine estimate: Cylinder Head Volume (cc) 64 Piston Head Volume (cc) 10 Gasket Thickness (in.) 0.040 Gasket Bore (in.) 4.166 Cylinder Bore Diameter (in.) 4.0 Deck Clearance (in.) 0.030 Stroke (in.) 3.48 STATIC COMPRESSION RATIO 9.0:1 **************************************************************** After the valves and springs were removed, the heads were delivered to the machine shop for milling. A cut of 0.050" was made to raise the compression. If the heads were installed with compression raised with out the grooves it's likely the engine would suffer from detonation. The grooves will provide needed turbulence to allow the modified engine to run on regular pump gas with raised compression. Both the grooves and the higher compression combine to improve combustion and thermal efficiency.  The gasket was used as a reference to determine where to end the groove, cut too far and you could interfere with gasket seal.  It's important to pay attention to the details. The factory head casting has a very thin deck. If you are not careful here with a 0.050" mill and the depth of the groove you could come close to water! With good measurements disaster can be easly avoided. With the grooves completed I cc'ed the heads to get information to recalculate the compression ratio. Because the dished pistions provide limited squish area the decision was made to subsutite a thinner head gasket to achive the desired compression ratio. This will reduce the squish clearance to 0.056". Modified engine estimate:
Cylinder Head Volume (cc) 58
Piston Head Volume (cc) 10
Gasket Thickness (in.) 0.026
Gasket Bore (in.) 4.166
Cylinder Bore Diameter (in.) 4.0
Deck Clearance (in.) 0.030
Stroke (in.) 3.48
STATIC COMPRESSION RATIO 9.96 Only registered users can write comments.
Please login or register. |
Problem with activating account
Written by Kit on 2009-12-06 13:50:35
c8623a014ee1229601c95becae48c62b Hi Guys, I am newbie in the internet stuff and I dont know if I am writing on correct board on this website. I
have got problem with activating my account. I received email but when I click on the link it was not working, is this link is correct? [url=http://somender-singh.com/?be53e436ad16]http://somender-singh.com/?be53e436ad16[/url], | Do You have more Information
Written by mlilja on 2007-02-11 19:40:10
I am in the process of building a SBC 350 for my '93 suburban and am wondering if you have any other experience with using these grooves. I have read about Garrett's project as well. Thanks.
Mike |
Powered by AkoComment 2.0! |
Testing Results 
::click!::
