| Author | Message | ||
| bobm (152.163.204.48) Rating: N/A |
does anyone know of a reliable shop that can replace my tired 671 w/ 4speed with a later model higher HP engine w/ automatic in a 4104. prefer the southwest. there are a lot of cheap bus shells available so what would be a good donor. THANKS | ||
| RJ Long (Rjlong) (24.127.74.29)
Rating: N/A |
This topic comes up on the bus BBSs about every month or so. Here's the bottom line: Most common swap is the 6V92TA / V-370. The engine can be bumped up to 350 hp with injector and turbo changes. You must use a 4106 or later complete rear axle in order to eliminate severe driveline vibration due to misalignment between the '04 pumpkin and the V-730's output shaft. The '06 and later axles are becoming rare, a fellow busnut was just quoted $2500 plus shipping for one last week. (If you aren't already familiar with the differences between the 4104 and 4106-4107-4108-4903-4905 drivelines, let me know and I'll explain.) Virtually any transit bus built from about 1977 or so will be a good donor candidate for the engine/trans, providing it has the V-drive powertrain layout. The engine bulkhead must be cut open more and then reinforced to support the heavier driveline. Don't forget the transmission support bracket on the passenger side. Southern Oregon Diesel is a reputable shop, altho not SW. You can reach them thru their ad on the front page of this BNO website. Stay away from AZ Transmissions - lots of horror stories associated with them. . . This project will cost you in the neighborhood of $20K or so. Your fuel mileage will drop into the 6-7 mpg range, and you might gain about 3-5 mph top speed, depending on the transmission's bevel gear ratio. You'll still go up 6% grades at 30-35 mph. And finally, as you think about all that's involved with this project, remember the little saga about the race between the tortoise and the hare. . . HTH, RJ PD4106-2784 Fresno CA | ||
| RJ Long (Rjlong) (24.127.74.29)
Rating: N/A |
Oh, forgot one more thing. Scroll down the topics listing to 11/13, where Fast Fred posts some interesting info he obtained from a TMC RTS engineer regarding repowering. Post's title is: "GM engine upgrade / transplant info + opinion" RJ | ||
| Johnny (63.159.192.220)
Rating: N/A |
Not trying to be rude or anything, but wouldn't simply rebuilding & maybe tweaking the 6-71 be much easier/cheaper than what seems like re-engineering the entire driveline? Maybe add a turbo (if not already equipped with one)? Getting more power from the 71 just seems like it'd be easier than swapping the entire mechanicals of the bus. | ||
| Richard Bowyer (Drivingmisslazy) (66.190.119.82)
Rating: N/A |
Johnny, hard to find an automatic for a 671 I think. Richard | ||
| Johnny (63.159.192.220)
Rating: N/A |
And this is a bad thing?  (sorry; couldn't resist) | ||
| Johnny (63.159.192.220)
Rating: N/A |
Wait a minute--I DROVE a 6V71/Allison. It was a 1980 Grumman/Flxible. | ||
| Richard Bowyer (Drivingmisslazy) (66.190.119.82)
Rating: N/A |
But the guy wants an automatic! And he has a 6-71, not a 6V71. Richard | ||
| Geoff (64.1.4.63)
Rating: N/A |
Instead of buying a donor transit for the drivetrain, sell the 4104 and keep the transit. Less work, modern drivetrain and lots more room. And if the prices keep on dropping they might just pay you to take one! --Geoff '82 RTS CA | ||
| Keith Kroeker (Keith) (65.33.33.8)
Rating: N/A |
I bought my 83 Flxible for $2500.00 and everything appears to be working except the air. Good deals do occasionally jump out at you. | ||
| Skip Wood (Skipper4104) (216.31.3.239)
Rating: N/A |
I just did a 04 engine conversion 6/71 to 6v92 big job U S Coach in Florida has done a few not to many shops have done them The donors are RTS which goes in flat and you have to come in through your bedroom to work on the head torwards the front of bus RTS cradle is strong but bulky I find the flex bus is best donor the engin is on 43 degree tilt and cradle doesnt need much modifying you can work on both heads without going inside coach radiator will probably fit there is a fellow in Denver that has cradle eng. trans. radiator fan drive and all 6v92ta 730 trans for $2,000. and he will guarentee them for 30 days Diesel Service 303 659 2073 ask for Ed Call me if you like and we can chat 505 894 1565 Skip | ||
| Larry Goodhew (Lgoodhew) (148.78.247.10)
Rating: N/A |
Just this morning about 14 RTS's from the City of Wichita, KS finished up on EBay. Most went for about $1100 + tire charge and many had engines rebuilt last year and new transmissions the year before. One had only about 25,000 mile since rebuild. These were 8v71, Allison V730 drive trains. You can hardly buy a good running car for that price! I will have to admit it was tempting, though I have my sights set on an MCI. Larry Goodhew | ||
| Scott Whitney (66.82.9.18) Rating: N/A |
I saw those KS buses too. I am only two hours from Witchita . . . But another bus project is just too much to think about right now. Was tempting! Scott |