Skipping a tooth vs bumping to the head
03-31-2010, 02:39 PM
#17
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No intention of hijacking this thread.
My truck is bone stock and for the moment I plan to keep it that way. But I am interested in increasing my fuel mileage, which I understand can be accomplished by bumping the timing. (I realize a better torque converter would help as well but that's a lot of money.)
Can someone explain to me the risks/rewards in bumping the timing? I mainly run empty in traffic, but periodically I tow a 7,000 pound trailer 150 miles through the north Georgia mountains and I have been known to load two tons of riprap in the bed and drive 30 miles.
TIA
Can someone explain to me the risks/rewards in bumping the timing? I mainly run empty in traffic, but periodically I tow a 7,000 pound trailer 150 miles through the north Georgia mountains and I have been known to load two tons of riprap in the bed and drive 30 miles.
TIA
03-31-2010, 05:17 PM
#19
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James: A 1/8" bump in timing is something all our truck will benefit from, even stock.
ZSkibo: Yes you have to pull the timing cover to take the gear off. Perfect opportunity to Kill you KDP and case bolts and front main seal as well. Leave the pump bolted to the case, and take off the retaining nut and washers. You'll have to jack the gear off or pull it with a gear puller. The bolts holding your intake horn to the grid heater are the right thread. I jacked mine off using a flat peice of steel with 2 holes drilled in them the same distance as the threaded holes on the gear. I then placed the bolts through this peice of steel and used a socket as a spacer to push on the shaft (I put the nut on the end so I didn't goof up the threads). Turn each bolt equally and it will pull the gear off the shaft. Rotate the gear Clockwise when facing the front of the engine (If I'm thinking correctly here). You'll have to turn the pump over to get it to line up the key way. It would probably be easier if you loosened the pump and took off the injection lines for all this.
ZSkibo: Yes you have to pull the timing cover to take the gear off. Perfect opportunity to Kill you KDP and case bolts and front main seal as well. Leave the pump bolted to the case, and take off the retaining nut and washers. You'll have to jack the gear off or pull it with a gear puller. The bolts holding your intake horn to the grid heater are the right thread. I jacked mine off using a flat peice of steel with 2 holes drilled in them the same distance as the threaded holes on the gear. I then placed the bolts through this peice of steel and used a socket as a spacer to push on the shaft (I put the nut on the end so I didn't goof up the threads). Turn each bolt equally and it will pull the gear off the shaft. Rotate the gear Clockwise when facing the front of the engine (If I'm thinking correctly here). You'll have to turn the pump over to get it to line up the key way. It would probably be easier if you loosened the pump and took off the injection lines for all this.
03-31-2010, 05:48 PM
#20
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Thread Starter
My truck is bone stock and for the moment I plan to keep it that way. But I am interested in increasing my fuel mileage, which I understand can be accomplished by bumping the timing. (I realize a better torque converter would help as well but that's a lot of money.)
Can someone explain to me the risks/rewards in bumping the timing? I mainly run empty in traffic, but periodically I tow a 7,000 pound trailer 150 miles through the north Georgia mountains and I have been known to load two tons of riprap in the bed and drive 30 miles.
TIA
Can someone explain to me the risks/rewards in bumping the timing? I mainly run empty in traffic, but periodically I tow a 7,000 pound trailer 150 miles through the north Georgia mountains and I have been known to load two tons of riprap in the bed and drive 30 miles.
TIA
since a small increase in horsepower can make a big difference just driving down the road. The only downside is it might rattle a bit in the morning.
03-31-2010, 07:01 PM
#21
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04-01-2010, 08:45 AM
#22
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More timing will start the combustion process earlier, and create more cylinder pressure with the same amount of fuel, often giving more horsepower. This can be a big deal for fuel efficiency
since a small increase in horsepower can make a big difference just driving down the road. The only downside is it might rattle a bit in the morning.
since a small increase in horsepower can make a big difference just driving down the road. The only downside is it might rattle a bit in the morning.
04-01-2010, 09:34 AM
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04-01-2010, 12:33 PM
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04-02-2010, 05:08 PM
#27
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Peak cylinder pressure is higher at low RPM. Burn time is relatively constant, so the lower the RPM, the lower in the cylinder the piston is when the fuel starts to burn.
04-02-2010, 06:11 PM
#30
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Thread Starter
A lot of load (timing, boost goes up, etc) and low rpm makes cylinder pressure go through the roof. Diesel are only so strong, even though they're a lot more robust than gas engines.
I talked to KTA about this, and he said bumping it to the head was about 20-22-ish last time he checked which is plenty for me.