1-71 Detroit Diesel (GM)

I am restoring a 1-71 power unit. When i dissembled the fan hub assembly i noticed it had a piece cast into the hub shaft to circulate oil for lubrication when the pulley is turning. There is a filling port on the pulley. Does anyone know lubricant, and quantity required? Does anyone have a service manual? I have a parts book. Al
 
1-71 Detroit Diesel

Looking for info. Name plate and stamped on my engine block is s/n 171-553 model 171G. On the flywheel housing name plate model 1-71RA and s/n A 514 Most of the 1-71 engine`s and pictures i have seen the s/n has been in the 500 rds. Have contacted current owners of Detroit Diesel to see if they have archives and info on production runs and number of engines produced. This engine has the original clevite bi metal main and rod bearings and show little wear. The cylinder liner predates the figure eight ports. They are drilled holes. When the engine was last run and shut down decades ago the exhaust valves were closed and the piston was covering the liner ports. The cast iron rings look new. This engine came from Pearl Harbor Naval Base. I cant wait to hear it run again. Aloha Al Shannon
 

Vanman

Subscriber
Re: 1-71 detroit diesel

Would love to have a 171, though of the generator set variety. Looking forward to seeing yours running :D

I believe these are "GM Diesel" engines, not being called Detroit Diesel until 1964? IIRC.

I have also heard that while all 71 series engines use interchangeable common parts, this is only the case for 271 and up, and not the 171. Don't know how much truth there is to that though.
 
Re: 1-71 detroit diesel

You are correct about the proper name. Went to Coast Guard engine school Groton Conn. in 1960.Trained on a 6-71s. Gray Marine, GM and Detroit Diesel. Have worked on 51`s,53`s 71`s 110`s and 149`s. This is my first 1-71
 

Vanman

Subscriber
Re: 1-71 detroit diesel (GM)

Wow, that poor thing. :( But at least it looks good under the rocker cover!
 

Ed Bezanson

In Memory Of
Re: 1-71 detroit diesel

Doc Have always loved the little one cylinder 71 series. I taught Auto Mechanics at Fitch Senior High in Groton, CT for 35 years. One of my students fathers had been in the Navy at Submarine Base in the 70s and he had collected about 10 GM engines and allowed our Auto Shop to rebuild a 2-71 for him. Great fun. I presently have a 3-53 out back in a shed I hope to use someday in some type of repower job.
The Coast Guard Academy is in New London across from Groton. Was the school at the Academy or across the river at Sub Base??? 1960 was the year I graduated from Waterford High School and soon after ended up in the Navy Seabees in Calif. working on Diesels in all kinds of construction Equip. Hope to see the 1-71 running again soon. Ed B
 

Vanman

Subscriber
Re: 1-71 detroit diesel

The 51 series mentioned- I believe they only made them for a few years. Those are *really* neat, being a valveless, loop-scavenged two stroke diesel. A 451 would be high on my want list :brows:
 
Re: 1-71 detroit diesel

Ed the Coast Guard training schools for the enlisted personal were at Avery Point Groton Connecticut. The training was the different ratings. engineman,electronics,botswain mate etc. Aloha AL
 

K-Tron

Active member
Re: 1-71 detroit diesel

It is not unusual to find a 1-71 with multiple brass identification tags. I believe they originally came with two brass tags, one on the side of the block (opposite the blower) and another on the top or side of the flywheel housing. Just about every 1-71 I have seen has had two brass tags in these locations. The ones I have seen and documented also have different serial numbers on each tag, including my own 1-71G. I have a hunch that GM stamped the engines serial number into the side of the block between the two stars (and also on the brass tag in that location), and the different serial number on the flywheel housing is the actual number of 1-71's setup that way. At least in my experience the serial number on the flywheel housing is always lower than the number stamped into the side of the block. General Motors produced roughly 900 1-71's. The lowest serial number I have seen is 171125 and the highest serial number I have seen is 171926; I believe the first unit was serial number 171100. My 1-71G is serial number 171449. The tag on the flywheel housing of my engine says 1-71RA A-413 15 horsepower @ 1200rpm. They are a fun engine, but good luck finding any parts for them. Very few internal parts from other 71 series engines will fit and work in your engine. Forget about the external 1-71 specific parts. I have been looking for parts for my engine for nearly a year, and I have not turned up much of anything. Can you please post some photos of your engine? I would love to see it! I really wish my engine had its original 64 hole liner in it! They are proving to be impossible to find! I am told the original 64 hole liner engines start easier, but smoke more than the engines with the later style liners. Mine has a figure 8 style liner in it. GM/Detroit Diesel made at least six different liner port layouts for the 71 series.

Chris
 
Re: 1-71 detroit diesel (GM)

Chris, thanks again for your post. I have torn down this engine, except for the removal of the cylinder head and liner kit. Upon inspection through the liner ports, it appears that the piston, liner and rings are in very good shape. The exhaust valves were closed and the piston was covering the liner ports when it was last shut down many decades ago. This unit is fairly complete with original parts. It has a bronze fuel filter housing and canisters. The primary filter is a skinner type. It has a Evans vane fuel pump. I have seen these on very old Gray Marine 64HN9's. The oil filter is a bypass type and also a skinner. The PTO clutch is the original and upon removal from the engine, I noticed the part # 3290221 was imprinted on the driven disc. Overall, internally, it appears that this 1-71 has very few hours on it. I am taking pictures of the parts prior to and during assembly. Will post as it goes along. Aloha, Al
 

gootsch

Member
Re: 1-71 detroit diesel (GM)

At one time Graymarine sold 1-71's as marine engines. Maybe parts marked as Graymarine are to be found somewhere to fit this engine.
 
1-71 detroit diesel (GM)

Evans vane fuel pump was used on early 1-71 engines. The pump shaft seals appear to be the same as the current gear pump. There are thin gaskets between the flange,body and cover. .002 thick.IMG_1032.JPG

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Re: 1-71 detroit diesel (GM)

1-71 rebuild Crankshaft assembly p/n 5152746 The journals polished up well. All are std. The old leather seals cut slight grooves on the crank seal surfaces. I may use Sleeves and oversize seals.Might just reposition seal depth. Crankshaft oil seals p/n 5150846. Front and rear seals are the same. These seals are the same size seals used on current day 71 series engines.IMG_1086.JPG

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Re: 1-71 detroit diesel (GM)

1-71 rebuild Fan hub assembly p/n5159031. Fan hub assembly has a oil fill port. When the hub pulley turns it circulates oil. The appendage attached to the hub shaft pushes lubricant to the bushing in the pulley. Fan blade p/n 3290426. suction type.IMG_1088.JPG

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gootsch

Member
Re: 1-71 detroit diesel (GM)

In the past I have used speedie sleaves with standard sized rubber seals without problems.
 
Re: 1-71 detroit diesel (GM)

The genuine detroit sleeve will fit on the shaft. Detroit now uses directional seals so i need to use a right and left hand one. Thanks Gootsch.
 
Re: 1-71 detroit diesel (GM)

1-71 rebuild. Pushrods, roller cam followers and compression release.The cam follower rollers have needle bearings instead bushings as are currently used.IMG_1098.jpg

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Re: 1-71 detroit diesel (GM)

1-71 rebuild.IMG_1104.jpg

IMG_1106(2).jpg Dipstick p/n 5152866 Note the oil level operating range. We have come a long way. My BMW does not have a dipstick. Hand crank handle and support assembly. It will be cool to hand start a series 71 engine.
 
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