| Author | Message | ||
| JC Alacoque
Unregistered guest Posted From: 161.184.42.32 Rating: |
I have a 4-71 N in my 1957 MCI Courier 96. Runs very well. I get about 15 miles to the Cdn gallon. That would be about 13 to the US gal. Top speed about 60 m/hr, at 2380 rpm no load. It just doesn't have a lot of power: slows down up the hills. I am thinking of trading it for a turbo 4-71. Anything else would involve a lot of custom machining to make it fit. Anybody have any experience, knowledge about this? How much more HP can I expect? Would the oil bath air cleaner do, or do I need something else? Would the fuel milage increase or decrease? Or should I be thinking of swapping for much more HP, such as a DD 6V92, or a Cummins 5.9, as has been suggested to me. Any thoughts or comments would be appreciated. | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 105 Registered: 3-2006 Posted From: 67.33.248.130 Rating: |
JC, The nominal basic HP for the 4-71, 4-71E2V, 4-71E4V, 4-71N, and 4-71T at 2300RPM are as follows. 159 (80's), 127@2100(60's), 161, 202(90's). However, a 6-71e 4V would give you 241 W/70's. However, have you thought of swapping out for a 6V53N for 210@2800(50's). I probably made that as clear as looking through Diner coffee, but there it is. Dallas | ||
| JC Alacoque
Unregistered guest Posted From: 161.184.48.17 Rating: N/A |
Dallas, what is a 4-71E2V and a E4V? I am thinking about staying with a 4-71 because the swap would be easy. A 6V53, 71 or 92 would be nice, but would involve modifying the cradle, motor mounts, etc. Doable, but probably a whole winter's project for me. I know a fellow near Vancouver with the same coach who put a 6V71 in it. He wishes he put a 6V92 in it though, given the same amount of work. Anyway, I am still torn as to what to do. JC | ||
| This is Bob Unregistered guest Posted From: 63.233.6.146 Rating: |
The turbo would give the engine lots more air & would be an improvement,I have no idea if you have a left hand engine or a right,so can't recomend a 5.9 but they are good engines,if the rotation is correct for your bus | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 15 Registered: 7-2006 Posted From: 66.217.105.160 Rating: |
JC - I'm hoping someone will chime in here, and discuss the problems you'd be facing with the cooling system modifications, if you choose to go from a 4-71 N to a 6V92, or a Cummins 5.9... Not to leave out torque factors and weight. I think there's more to all this, than just swapping a few bolts. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 1 Registered: 7-2006 Posted From: 161.184.42.66 Rating: |
that's why I'm thinking more and more that a turbo 4-71 would be a nice swap. Would give me that little bit extra power to not slow down so much up the hills. I don't mind that myself, but it is the odd driver behind me without the patience... When I used to drive for Brewster's in the 70s', motorists were used to slow buses and trucks, and we used to pull over on the paved shoulder to let them by. Now that's illegal in most places. Although I still do it if I can see far ahead enough. Dieselexchange in Missouri tell me they could build me a turbo 4-71 for a reasonable price. The only mods would be an extra core on the rad, raising the bed to make room for the turbo, different intake and exhaust. Anybody had any experience with that outfit? | ||
| Bob greenwood (Bob_greenwood)
Registered Member Username: Bob_greenwood Post Number: 5 Registered: 7-2006 Posted From: 65.150.44.30 Rating: |
you just do the best you can do climbing hills,know you already know it,but get in the right lane,turn your flashers on & keep your r.p.m. s up..I think the turbo deal would probably be your best bet,it will probably give you 15 or 20 more horsepower & with the extra air,should prevent lots of black smoke ,from unburned fuel | ||
| Mike (Busone)
Registered Member Username: Busone Post Number: 312 Registered: 11-2004 Posted From: 71.33.24.110 Rating: |
I wish my school bus had a turbo as well. It will go 72 all day on the flats but as soon at it sees a hill it is all over. It will go 35 up the big hills. The black smoke is really bad the higher up in elevation I go. It does it's job hauling firewood and stuff though. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 2 Registered: 7-2006 Posted From: 161.184.42.53 Rating: |
My 4-71 only smokes some when you step on it. Last summer we were through Colorado. Driving North from Durango, over those passes at 10000 and 11000 feet altitude, she smoked quite a bit! Can't draw enough air to burn all the fuel. | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 106 Registered: 3-2006 Posted From: 67.33.248.174 Rating: |
4-71E (2V) is a two valve head and the 4-71E (4V) is a four valve head. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 3 Registered: 7-2006 Posted From: 154.11.109.30 Rating: |
Thanks Dallas, the answer dawned on me shortly after I asked you... Mine is a 4 valve with N65's | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 107 Registered: 3-2006 Posted From: 67.33.248.29 Rating: |
JC, Since the engine smokes when you get into it and you say it has N65's, is it possible that it's still on standard timing instead of advanced? The 4-71 in my old transit never smoked with N65's after we changed the timing, plus it pulled quite a bit better. Just thinking out loud here. Dallas | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 4 Registered: 7-2006 Posted From: 154.11.109.30 Rating: |
we replaced 2 injectors last year at a DD dealer, then they did a tune up (timing, valves, etc), so I'm assuming that it was done correctly. I am going to look at the air intake today up on the rear of the roof and see if I couln't build a ram air scoop that would push more air through the filter and into the blower. Sort of the poor man's turbo! I've heard of it beeing done with good results. | ||
| David Evans (Dmd)
Registered Member Username: Dmd Post Number: 62 Registered: 10-2004 Posted From: 71.125.20.202 Rating: |
Hey JC, we had a 4-71 4 valve head with a Jake set up in our 35' GM bus. It was ok up and down 95 and out to Memphis and up to Maine but boy of boy in the real hills and mountains it was almost get out and walk time. The best bet would be to get a MCI 5 with a 8v71 or a 4106, but you wont have all that room to work on the engine like you have now. If you really are attached to your bus like we are break out the $$$$$ or you can just be patient and enjoy the ride. We are repowering because we want to hit the roads out west and the mountains. Good luck. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 5 Registered: 7-2006 Posted From: 154.11.98.45 Rating: N/A |
I built a ram air scoop yesterday on the air intake. We are going about 60 miles to camp for a few days at a lake today, so I'll see how it works. I'm not expecting great gains in power, but a least maybe no smoke. We'll see. | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 108 Registered: 3-2006 Posted From: 67.33.248.131 Rating: |
JC, Just another thought, If you still have oil bath air cleaners, you may want to clean the steel mesh inside of them. I had to do that with my 6-71. It seems that squirrels decided to make a home in the air intake plenum at some time or another... that is until the engine got started and sucked everything into the air cleaners. When I got the bus, it smoked so badly It would deplete the mosquito population for miles in every direction. I took the air cleaners apart and found the only way I could clean out the mesh was by sticking it in a camp fire. There was so much crud in them that they burned for 2 days. Now they work very well! Dallas | ||
| pat young
Unregistered guest Posted From: 70.137.196.56 Rating: N/A |
It sounds like your bus is full sized, so I would recommend staying away from the 5.9 Cummins, as I think it is too small to push your bus. HOWEVER, the only one I ever drove was a 5.9 transplanted into a Gillig, and I think rated at only 160 hp, so maybe a hotter 5.9 woud've done the trick. It was brand new, ran beautifully, but with 19,000 lbs to push around (and a lot more when loaded) this bus was possibly the slowest and had less power than any I've ever driven, including the old C180 and C190 Cummns. Also, in my humble opinion, I agree it would be better to mildly pump up your engine, or if there was room, drop a 6-71 inline into it. The complexity of swapping engines is huge, and will drive stong women to drink and men to watch Oprah. But, if a 6-71 would fit, you'd at least have an inline, probably rotating in the same direction, a lot of fun power, and at least some stuff would just bolt up or wire in without an act of Congress. Patrick, bus guy in Fresno | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 6 Registered: 7-2006 Posted From: 154.11.98.45 Rating: N/A |
Back from our little trip. The ram air scoop works really nice. No more smoke. Feeds enough air that all the fuel is used. It felt quite nice driving. Hard to tell if I'm making more HP because I was towing the boat (about 3000 lbs), and I don't do that very often. I'll be able to tell for sure next trip without it. Should I be concerned about rain water getting into the oil bath filter? The air intake was wide open to the sky before I put the scoop on, so I'm not really worried. I'll check the bath oil after driving through next rain. The way I'm thinking, the cylinders can only take so much air. The only thing the scoop does is maintain more pressure above 20 mph so the cylinders get more air when they need it: when you give them more fuel with the pedal. So I can't imagine a great hurricane through the filter sucking oil out of the bath on its way to the blower and cylinders. | ||
| Mark R. Obtinario (Cowlitzcoach)
Registered Member Username: Cowlitzcoach Post Number: 115 Registered: 4-2001 Posted From: 206.163.13.10 Rating: N/A |
By now you have received a lot of different advice about making changes. I am of the school of thought that says if it isn't broken, don't try to fix it. You indicated you have been getting 13 MPG. If you install a larger engine that number is going to go down. And it will go down farther the more you try to use the added HP. Any engine swap with the possible exception of a a 4-71T is going to require a lot of work and a lot of $$$--most likely at least $5K and going up out of sight from there. A larger engine, even a 4-71T, is going to require more cooling capacity. If you don't increase the cooling capacity, instead of going pokey slow up the hill you will be sitting by the side of the road waiting for the engine to cool off. The question comes down to how much is it worth to you to blast up the hill instead of going pokey slow up the hill? If it is that important to you it may just be less expensive and less hassle to you if you were to purchase a shell that is already equipped with the rocket engine of your choice. If you make sure the air intake is clear of obstructions, the oil bath is clean and not all full of crud, the exhaust isn't pinched down somewhere, and the muffler is still flowing correctly you will get the maximum HP out of what you have. Also, going to a DD dealer doesn't mean you had a tune-up done by someone who knows 2-cycle DD's. Setting the rack on a 2-cycle DD is more of an artform than anything else. Once you know you are getting the maximum from HP your engine it will still probably smoke when you bury the your foot in the throttle. When you see the smoke, ease up a little and you should be just fine. Happy trails. Mark O. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 7 Registered: 7-2006 Posted From: 154.11.109.30 Rating: N/A |
Thanks Mark, like I said, my 4-71 runs really well. The DD mechanic that set it up is an old school 2 stroke kind of guy that, unfortunately will retire in 2 or 3 years, and I think he did it right. That ram air scoop I built, with his blessing, works well, and there is no more smoke except in 1st and 2nd gear. I don't mind going slow. I allways wonder about improvements, you know how it is... By the way, Dieselexchange in Missouri quoted me $12000 minus $3000 core exchange for a rebuilt 4-71T! I don't think I want to spend that much money... If and when mine needs a rebuid, we'll decide what to do then. I really love my coach the way it is. I used to drive it at Brewster's in the seventies, so it is a nostalgic attachment for me. I completely renovated the inside last winter in a 50s theme to match the exterior. It draws a lot of attention whereever we go. I put on about 10 to 15000 kms on it every summer, one or two trips with a good friend who drives a '85 Prevost XL (he likes following me at 60 mph, improves his mileage), my wife shows Paint horses and my 2 boys and I follow her to the shows with it, and camping trips, etc. Lots of fun... Thanks all who wrote for the good advice. |
