| Author | Message | ||
| Doyle Gaither (Texasborderdude)
Registered Member Username: Texasborderdude Post Number: 1 Registered: 3-2007 Posted From: 24.92.121.67 Rating: N/A |
Hi, I just bought a '78 Eagle that does not have a tach on the instrument panel. Any tips on setting one up? What's the best place to get the input? Ringgear? Is there a wireless unit available to get the signal forward to the gague? Seems my current setup is real rich and under powered. Lots of black smoke up a grade. Top speed is under 40 mph on a long 6% hill. Anyone with similar experience with this setup? Can the blower be adjusted to give more air? Thoughts, tips cost of adding a turbo? Thanks for any help... | ||
| David Hartley (Drdave)
Registered Member Username: Drdave Post Number: 734 Registered: 5-2005 Posted From: 72.189.203.211 Rating: N/A |
Check your air cleaner. It may need to be cleaned or replaced. A non-turbo engine with oversized injectors will smoke if lugged or loaded to heavily on grades. There is no adjustment that will fix the underpower issues. The only way to get more power is to replace the engine with a higher powered one. There are some shortcuts but the only real cure is a better engine and tranny combo. ie; 6V92TA ( fairly cheap fix ), Series 50 or 60 Detroit or Cummins ISM, Cat 3406 or maybe a cummins L-10 that is pumped up. There are a few 8V71's with Turbos but very rare. | ||
| Doyle Gaither (Texasborderdude)
Registered Member Username: Texasborderdude Post Number: 2 Registered: 3-2007 Posted From: 68.72.221.149 Rating: N/A |
Thanks David, You are spot on... just pulled the air cleaner, and I'd guess it was 40% clogged. I'm off to get a replacement. Don't know the injector size, but the guy that rebuilt it said it was one size up from the standard, and it will smoke if loaded on the hills... I've just learned to back off, get the right gear, keep the rps's up and enjoy the trip uphill! | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 94 Registered: 12-2000 Posted From: 75.89.20.57 Rating: N/A |
As long as you keep the rps's up around 30, you should be OK  . Sorry, it's just the AH in me sometimes leaks out! Len | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 746 Registered: 7-2006 Posted From: 64.136.49.228 Rating: N/A |
Doyle... I also have a '78...you don't say where you are on your profile... I'm in Harlingen till April..don't realy need a tach...just keep it in a gear that lets the r.pm.'s UP | ||
| Craig (Ceieio)
Registered Member Username: Ceieio Post Number: 284 Registered: 12-2004 Posted From: 207.101.213.58 Rating: N/A |
8V-71 on a 6% under 40mph seems normal to me. You are right on about backing off with the black smoke. Craig - MC7 Oregon | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 445 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
Automatic or standard transmission? Could you be lugging the engine? | ||
| Doyle Gaither (Texasborderdude)
Registered Member Username: Texasborderdude Post Number: 3 Registered: 3-2007 Posted From: 24.92.121.67 Rating: N/A |
Thanks for all the replies... just bought it from the famous Charlie Brown in Laughlin Nevada. Drove to Flagstaff, Az. over to Springerville Az, to Albuquerque NM and down home to El Paso, Texas. Just under 1000 miles at about 6mpg... but the filter was full! It's a Allison 4 speed 740 with the shift points marked on the speedo... I swore it was a 5 speed, but have been told there is a "false shift" in first gear when the transfer case gets up to speed??? I'm told that the local Cummings place has a dyno and for about $200 I can get it checked out. My first experience with a bus conversion but it's a real blast... | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 447 Registered: 10-2003 Posted From: 71.58.126.56 Rating: N/A |
Tune-up or dyno, and which to do first. Maybe popping a valve cover could be useful...someone may have put 70 or larger injectors in it or the tune is off.There is what feels like another shift when the torque converter locks up to eliminate slippage in 1st or 2nd gear depending on the transmission, but usually happens in second gear. Anyway, that is how people think they have a 5 speed. | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 750 Registered: 7-2006 Posted From: 64.136.49.228 Rating: N/A |
you will notice a WORLD of difference with a new air cleaner | ||
| Dale Waller (Happycampersrus)
Registered Member Username: Happycampersrus Post Number: 317 Registered: 7-2005 Posted From: 66.82.9.74 Rating: N/A |
If the air cleaner has been neglected, you probably need to change the fuel filters also. I agree with Bob, a new air filter should be a big difference. Before you go to the dyno, you need to do some basic maintenance to get the bus up to specs. Filters, tire pressures, check & adjust brakes, engine tune, oil change, antifreeze check, etc. Otherwise the Dyno shop will just take your $$ and tell you this stuff needs done. | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 753 Registered: 7-2006 Posted From: 64.136.49.228 Rating: N/A |
when I got my bus,it had 10 pounds of dirt in the air filter,,it's hard to get to,so,it was neglected | ||
| Steveggt (Steveggt)
Registered Member Username: Steveggt Post Number: 14 Registered: 12-2006 Posted From: 71.116.87.220 Rating: |
Hi Doyle, Hopefully your air filter will help a lot with the smoking issue. As previously mentioned, don't lug your engine! Black smoke is a good indication that you need to back off and/or downshift to keep the rpm's up. BTW, the 740 is a 4-speed tranny with a lockup torque converter, so you're kinda correct in saying that it feels like a 5-speed. Your upshift progression should sound/feel like this: You start off in first "converter"...your engine sounds like it's "freewheeling". After accelerating to around 10-15 mph, you'll feel a brief hesitation (the tranny upshifted into second), but you're still in converter. Around 25mph, you'll feel another "shift" when the engine rpms drop, but what happened was the torque converter locked up...but you're still in second! On your 2nd-3rd and 3rd-4th upshifts, you'll hear your rpms drop as well...your tranny is still in lockup. So here it is in a nutshell: 1st converter, 2nd converter, 2nd lockup, 3rd lockup, 4th lockup. - Steve | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 39 Registered: 2-2007 Posted From: 207.200.116.13 Rating: N/A |
Doyle, I think the powers that be see no reason for us to have a tach. There are only 4 gears on my 79 and if I had a tach, I couldn't change a damn thing! You are driving a commercial vehicle. They have always been heavy and slow. The 6V92 in my 89 is rated @ 350HP and doesn't do any better than 30MPH either. No smoke, no power, and the gov't is pushing no smoke hard. If you have a smoker that pulls like you say you have it as good as it gets. Back off the pedal a little on the hills. Its just like a semi. | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1201 Registered: 12-2000 Posted From: 71.195.112.181 Rating: N/A |
Doyle - Next time you log into BNO, check out the "Articles Of Interest" section. In there you'll find some tips on shifting your automatic that will help reduce the smoking and improve the performance somewhat. 30 - 35 mph on a 6% grade is normal for this powertrain combination in a coach. You will never recoup the cost of repowering to go up that same hill at 45 mph. In fact, you'll pay for it constantly in higher fuel bills, even running on the flats. Also suggest you crawl into the engine compartment and pull a valve cover to see what size injector you've got. Should be a round tag on the side of them - let us know what you find. FWIW & HTH. . . | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 96 Registered: 12-2000 Posted From: 75.89.25.194 Rating: N/A |
Doyle, I'm quite sure that the shift points on the speedo were intended for the original stick shift. Just coincidence that they match the 740. Len |
