Detroit 1-81

[Bill Tattersall]

I have a interesting project, restoring a Detroit 1-71. Based on the serial number, it dates to 1939. They were used by the Navy for water pumps And generators. A lot of the parts appear to be interchangeable with other 71 series engines. What I need most of all is some sort of shop or service manual. Any suggestions?

 

[Fritz Maurer]

The common '71' series manual will be applicable for much of the technical data, since it used so many of the same parts.

The 1-71 could be updated with '92' series sleeve and piston if desired.

 

[Keith True]

I took a 2-71 from a friends AC HD5 down to Power Products in Wakefield Mass years ago to get overhauled.They were the go-to guys for 2 stroke Detroits at the time.They showed us a 1-71 on display that they said came from a marina.They didn't know what it was used for originally,one of the mechanics had spotted it in the weeds while at the marina to work on something.That was in 1980.

 

[JOCCO]

I have a interesting project, restoring a Detroit 1-71. Based on the serial number, it dates to 1939. They were used by the Navy for water pumps And generators. A lot of the parts appear to be interchangeable with other 71 series engines. What I need most of all is some sort of shop or service manual. Any suggestions?

Evil bay would be one source for a manual.

 

[scootergmc]

A Detroit single is a pretty desirable engine for collectors. As has been said, manuals can be found on eBay or maybe try searching for a free download. I wish I had one to play with too.

 

[Mike(NEOhio)]

I took a 2-71 from a friends AC HD5 down to Power Products in Wakefield Mass years ago to get overhauled.They were the go-to guys for 2 stroke Detroits at the time.They showed us a 1-71 on display that they said came from a marina.They didn't know what it was used for originally,one of the mechanics had spotted it in the weeds while at the marina to work on something.That was in 1980.

I worked on one years back. FIL bought an HD5. turned out to be a money pit. I drove it a bit an my shirt was covered in oil droplets. Blower seals were shot and huffing oil. PO had a big chain and turnbuckle across the front of the tracks. Said it would throw a track once in a while. Had a Garwood blade and turned out the shaft was broke just inside the left sprocket and the frame would push it backwards. The big wishbone under the belly was missing the cap for the pin.
I did see a 1-71 at the Ashtabula Club show but didn't get to hear it run.

 

[Nordic]

The common '71' series manual will be applicable for much of the technical data, since it used so many of the same parts.

The 1-71 could be updated with '92' series sleeve and piston if desired.

Do other 71 series blocks also accommodate 92 series sleeves and pistons too? I've never heard of this before...

 

[Fritz Maurer]

Yes. They didn't change the outside diameter of the sleeve unless the block was rebored.

 

[Keith True]

The 92 series uses a wet liner,and the 71 series uses a dry liner,so I don't know how that would work.Seems I remember the 92 series o-rings were above the windows and had coolant swirling around the upper part of the liner.I know some bus boys got creative doing something like that years ago,but I lost track of their project and nevere heard the outcome.Had to have been a complicated project as a 71 series liner will fit right down inside a 92 series liner.Guys were thinking they were going to boost their 426 cubic inch 71 series engine to the 552 inches of the 92 series.

 

[Fritz Maurer]

Whoops that was the 53 with the oversize OD, sorry.
They have a 1-71 in the showroom at Great Lakes Energy Systems with a little plaque with that statement about the upgrade.

 

[piercetractor]

The 53 series was a wet sleeve engine

 

[roper4570]

The 53 series was a wet sleeve engine

A 1-71 is a pretty rare engine. Certified Detroit Diesel mechanic back in 70’s and 80’s.
Check with United Engines in OKC Oklahoma. They have a 1-71 on display.
405-947-3321

 

[MikeinKy]

What is the firing order

 

[Phill Tibbetts]

What is the firing order

1-1-1-1-1-1

 

[mechanicfred]

Did you check "Jen Sales", they have a lot of manuals.

 

[Sprint 6]

A 1-71 is a pretty rare engine. Certified Detroit Diesel mechanic back in 70’s and 80’s.
Check with United Engines in OKC Oklahoma. They have a 1-71 on display.
405-947-3321

Only made 1938-40. Estimates of around 1K built.