| Author | Message | ||
| Austin Scott Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 402 Registered: 9-2006 Posted From: 209.156.24.114  Rating: N/A |
Simple question... Can a 671 blower be geared differently to get more boost? My thought process... Everyone adds turbo to an engine to add boost to the engine. The blower already adds boost to the engine. Other vehicles that have blowers/superchargers will change the pulley size to increase/decrease the amount of boost. Could something similar be done to the blower on a bus to increase the blower boost? I know it is not that simple but I thought I would raise what I thought was an obvious question.... . | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1860 Registered: 10-2003 Posted From: 71.58.71.157  Rating: N/A |
there are a couple of gear ratios that would help to increase your boost, however adding a turbo is much more efficient in creating more horsepower in this application. BTW, turboing your 4104 is worth the effort; it made mine run like a 4106 | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 369 Registered: 9-2007 Posted From: 24.183.21.246  Rating: N/A |
Austin,the short answer is yes. The blower drives can be changed to increase boost. I had it done on my 8V71 back in the 70's. The mechanic used "white tag industrial 75 injectors and changed the gear drive on the blower to increase the output. The changes made a big difference in the power of the engine, but I didn't keep it long enough to know what it did to the durabilty. John | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 642 Registered: 10-2006 Posted From: 72.66.171.142  Rating: N/A |
What did it do to your fuel mileage John? | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 452 Registered: 2-2001 Posted From: 74.143.99.106 Rating: N/A |
Certainly it can be done, but the turbocharger is more efficient because it uses exhaust gas volume to create boost. It takes horsepower to turn the blower even at stock speeds. And the turbo is kinder to the engine because it creates very little boost under light load conditions. And turbocharged 2 cycle Detroits have lower compression ratios than non turbo engines. | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 370 Registered: 9-2007 Posted From: 24.183.21.246 Rating: N/A |
Laryn, It didn't seem to make a lot of difference because that Detroit never got very good fuel mileage from the day I bought it new. I did have to be careful with the temperature and how hard I pushed it in the hills though. It would turn the manifolds and the bottoms of the stacks red hot so you could see them glow at night. I never had it Dynoed but I would estimate 350-375 hp instead of the 318 it was designed for. (Message edited by bigrigger on March 03, 2010) | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 434 Registered: 10-2004 Posted From: 173.77.219.254  Rating: N/A |
It boggles the mind thinking about sitting on top or slightly behind a Detroit back in the day in a long haul truck. I drove a Transtar (not with a Jimmy) for a short period but it was pretty wore out, and a R-600 with no a/c in Fla for 4 years. But nothing like the ride of any new trucks with all the nice comforts, making a tough job a little easier to bear. You truck drivers should start a thread about back in the day for us. amazing. |