Author Topic: Turbocharged 6-71 Detroit Diesel Engine (Read 7007 times)

Gingercat · « **on:** May 12, 2015, 09:18:59 PM »

There is 1963 converted bus that I really want. Has a Turbocharged 6-71 (six cylinder) Detroit Diesel Engine. I'm new to all of this. I'd like to know if anyone knows about this engine. What's its reputation. The bus is very nice, already has solar and has a ton of space. But I don't want to buy a money pit. Opinions? A few friends of mine who have never owned anything like this really think its a bad idea. But dang, its pretty. They are asking $17,500. I want to be able to drive around the country, slowly, stopping for 14 weeks at a time to work, then move to the next place.

Paul & Ann · « **Reply #1 on:** May 12, 2015, 09:27:12 PM »

I would start my search for information here. http://busnut.com/home.html

Also, this couple has a bus and I believe a Detroit Diesel 6-71 that they had to have rebuilt last year. They may be able to provide some information. http://www.technomadia.com/blog/

Hope this helps.

Paul

Lawrence M · « **Reply #2 on:** May 12, 2015, 10:47:40 PM »

The 6/71 is a fine engine. I have rebuilt many back in the day. If you are thinking of buying this I would recommend getting a Detroit mechanic to remove the airbox covers and check the kits. That is an old 2 cycle engine and is easy to rebuild. Because of the age take a real good look at the intake make sure it is tight and in good condition.
But do get a good Detroit diesel mechanic to do a condition report. And while he is at it have him explain the dos and dont's with those old engines. It might be the best money you will ever spend. The inspection that is.
Good luck!

halfwright · « **Reply #3 on:** May 12, 2015, 11:13:06 PM »

The 6-71 has been around for many many years and has proven itself over and over. It came into use in 1938. The older the mechanic you can find to work on it the better.

Gingercat · « **Reply #4 on:** May 13, 2015, 06:27:28 AM »

Ok, thanks for the links. And a good idea on the condition report.

wackymac · « **Reply #5 on:** May 13, 2015, 06:29:19 AM »

Is it turbocharged or supercharged?

Gary RV_Wizard · « **Reply #6 on:** May 13, 2015, 07:04:26 AM »

That engine was made as both an inline 6 and a V6, i.e. the 6T71 and the 6V71. I think the 6T71 (the earliest model) is the one best known, but both were widely used. The old Detroits are 2-stroke diesels, a unique type that require some specialized mechanic knowledge. For that reason, some people avoid them in favor of the Cat and Cummins e4-stroke engines. Lippy says they are easy to work on, though, and I have no reason to disbelieve him.

Any old coach is a potential money pit, and diesel engines are particular ones due to the high cost of things like injector pumps. If you aren't a do-it-yourself mechanic, 12v electrician, plumber and appliance repair guy, you probably ought to avoid any old motorhome. But if you enjoy tinkering these oldies can be a lot of fun.

Lawrence M · « **Reply #7 on:** May 13, 2015, 07:42:00 AM »

One thing I will mention is they have a fuel transfer pump and unit injectors. One for each cylinder very simple to trouble shoot. A tuneup can be done by most mechanically inclined people. There should be lots of manuals around.
Don't expect to win any contest for clean air.

bigred41 · « **Reply #8 on:** May 13, 2015, 07:56:39 AM »

I noticed that you said you didn't want to buy a money pit?

Then forget this bus !! As a matter of fact forget RV'S all together!!! Definition of RV -----A hole in your driveway that you are continuously shoveling money into!!!! lol. Seriously ,if you buy the bus ,take these guy's advice and get it checked out .It is not use that is so hard on these 6v and 8v engines ,it is lack of use!!

Gingercat · « **Reply #9 on:** May 13, 2015, 07:38:03 PM »

Thanks. For Wackymack it says turbocharged. I haven't actually seen the bus, its over 1000 miles away, but have emailed and spoken with the owner. He says the engine was rebuilt 8 years ago. I am mechanically inclined, and do all the maintenance and most of the repairs on my jeep, but this is a different animal entirely. And I will be out there alone. Which makes is kinda scary.

Mavarick · « **Reply #10 on:** May 13, 2015, 11:11:38 PM »

Ginger, as Lippy said above if you do not have the experience you better get an inspection. Just about any mech that has worked heavy equip will have experience with a 6-71. They are a fine engine but very different than a Cat or Cummins. The Detroit likes to run wide open, meaning you better have earplugs because they are very noisy even with the residential exhaust kit. If you plan on doing the work on this like your Jeep etc you will need the correct injector timing tool, a crows foot wrench for the injector lines and learn how to run a rack, these are a must as you probably wont find everything on the road if you run into issues. Maybe the current owner can show you this as it is easier to see and understand rather than to read about. The engine is always a big part of the equation but don't forget there is a lot of bus left to still cost a lot of money.
As said above, if you are looking to save money an old bus is probably not the best way to do it but more power to you for being adventurous. Good luck with it.

driftless shifter · « **Reply #11 on:** May 14, 2015, 07:02:29 AM »

The Old Detroits were made to scream all day, They were popular in Fire trucks because they'd scream all day and night pumping water for the hoses, they were also popular for fishing boats for the same reason. I do love the sound of them. Most of them used a turbo charger feeding a supercharger. The chrome hump on top of drag strip engines were inspired by the use of original V71 superchargers on gas engines in early hotrod days.

Bill

Utclmjmpr · « **Reply #12 on:** May 17, 2015, 01:48:48 PM »

A turbo'd 671 of that vintage is a very rare bird, most likely it has a blower as most did to provide the air intake needed for combustion. If it actually is turboed it should have the turbo pistons installed, if not it will be known as a "smoke turbo" and set for a low boost input to the blower.>>>Dan ( 1962 GM 4106 with 8V71 owner 14 years)

Utclmjmpr · « **Reply #13 on:** May 17, 2015, 04:36:57 PM »

Paul,, Technomadia's engine was an 8V71 V8 568 CI.>>>Dan

Gary RV_Wizard · « **Reply #14 on:** May 17, 2015, 05:21:31 PM »

Frankly, I would prefer something a bit more pedestrian than the old Detroit. You should have plenty of choices among older diesel coaches with no slides, and I would want to be able to spend days inspecting it up close rather than fly in and have to make a snap decision. And get something that was easy to find parts for and fix. I know some folks love the old Detroits, but parts and expertise for it are less common than Cummins or Cat.

Paul & Ann · « **Reply #15 on:** May 17, 2015, 06:09:46 PM »

Quote from: utahclaimjumper on May 17, 2015, 04:36:57 PM

Paul,, Thechnomadia's engine was an 8V71 V8 568 CI.>>>Dan

Thanks Dan for the information. I didnt remember which engine they had, but do remember reading about their engine overhaul.

Paul

Lawrence M · « **Reply #16 on:** May 18, 2015, 09:00:07 AM »

Quote from: Gary RV Roamer on May 17, 2015, 05:21:31 PM

Frankly, I would prefer something a bit more pedestrian than the old Detroit. You should have plenty of choices among older diesel coaches with no slides, and I would want to be able to spend days inspecting it up close rather than fly in and have to make a snap decision. And get something that was easy to find parts for and fix. I know some folks love the old Detroits, but parts and expertise for it are less common than Cummins or Cat.

I have to agree with this as much as I love the old Detroit's.
Lawrence

RoyM · « **Reply #17 on:** May 18, 2015, 10:58:20 AM »

We saw a lot of them on logging trucks in the 60's. They had a unique sound and were LOUD. The driver was kept busy shifting as the power band was very narrow.
As was mentioned, this unit is really not very suitable for an rv. By the time the dust settles, you will likely have enough in it to buy a nice more modern unit without the service headaches.

Utclmjmpr · « **Reply #18 on:** May 18, 2015, 05:38:54 PM »

The often repeated mantra among bus converters is "do it your way" many folks do a wonderful job to.>>>Dan Gingercat,, which make & model "bus" are you looking at? most older buses used the Detroit.

Gary RV_Wizard · « **Reply #19 on:** May 18, 2015, 06:22:05 PM »

Yeah, but how many old bus conversions success stories do you actually see & hear? The relatively few are widely known and praised in bus nut circles, but you actually find few of them in use around RV parks. Hanger Queens, most of them! There are a lot more of the old GMC motorhomes with the front drive gas chassis in actual use than there are bus conversions. I love to tour them, but don't want to rely on one for my home.

On the other hand, an old Vogue or Foretravel is still a marvel, solidly built and as reliable as a mechanical beast can be. Also vintage Country Coaches and older Monacos. Other brands too, but those are the top of the lines.

mistere · « **Reply #20 on:** May 19, 2015, 07:57:53 AM »

Being a 2 cycle, probably turbo and blown intake system. it is possible to get a runaway engine. It happens if there is an introduction of oil (fuel, crankcase etc) into the air intake. Any oil will become fuel and since the air intake is always wide open if there is enough of a oil leak it will keep the engine running. There is a drive link for the blower which is designed to fail before engine damage occurs. If there is a kill switch on the dash, it will be a damper that blocks air from getting into the engine, thus shutting it off. It sounds
worse than it is, just be aware of the intake air blockage method.

Lawrence M · « **Reply #21 on:** May 20, 2015, 03:05:38 PM »

I can't remember if you can install spring loaded rack to these old 671's.
I have updated a lot of 16V149 Detroit's. It makes it a much safer unit virtually eliminates a runaway.

Gingercat · « **Reply #22 on:** May 29, 2015, 08:02:30 PM »

The fellow doing the selling couldn't answer half of my questions, as he had only had the bus for a year, and only been in it about 6 months. I was often talking over his head about it. So I decided to let it go, since I couldn't get any real info from him about it. Just as well now that I've learned that my 2014 Beetle cannot be towed on a dolly but would need a trailer. Sigh. This is all going to take longer than I thought.

driftless shifter · « **Reply #23 on:** May 30, 2015, 10:23:37 AM »

Gingercat. I think you my be mistaken about your Beetle. If it is front wheel drive it can indeed be towed on a dolly, a manual transmissission can be flat towed a max of 50 miles at 50 MPH, an automatic cannot be flat towed, Flat tow and dolly are two completely different ways of towing.

Bill

Lawrence M · « **Reply #24 on:** May 30, 2015, 03:17:24 PM »

Quote from: Gingercat on May 29, 2015, 08:02:30 PM

The fellow doing the selling couldn't answer half of my questions, as he had only had the bus for a year, and only been in it about 6 months. I was often talking over his head about it. So I decided to let it go, since I couldn't get any real info from him about it. Just as well now that I've learned that my 2014 Beetle cannot be towed on a dolly but would need a trailer. Sigh. This is all going to take longer than I thought.

The decision you made is the correct one. I know you will find something. Good luck in your search!

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Author Topic: Turbocharged 6-71 Detroit Diesel Engine (Read 7007 times)