Detroit 2-Cycles in 2017+

[Truck Shop]

Detroit 71 liners were fitted to 0.0002" and OEM coded by tenths by location of the part number stamp (stenciled on) on the liner. Correct measuring procedure was/is using calibrated dial bore gauge!
Typical to find enlarged cylinder bores located toward the top block deck area caused by 'mechanics' that non-fixed hones during overhauls.
Always measured new liners for size, out roundness and sent the rejected liners by to parts purchase source.
Wrestling VanNorman 777 boring bar on V-engines wasn't fun!

That 777 is a good machine, the old Storm was good also.

Truck Shop

 

[Truck Shop]

I never minded overhauling the two stroke engines, just were a little too fussy as to fitting sleeves. I wore two Sunnen hones out fitting liners in the 71's. Many except us old farts would forget to replace the 'pencils' at the water pump and generally another somewhere hidden in plain sight point where the blocks would get thinned out from erosion and corrosion, conversion to water filters helped much of that. The 92's I worked on were usually the complaints, not enough power meaning they did not turn tight enough even as they would pull hard, not enough noise as the turbos on those and the old 350 71's would quiet them down. A lot of people failed to check wrist pin seals adequately where a few I saw ran flat away eating engine oil, I argued often when what thought they were techs failed to torque the head studs prior to setting the heads. The old Maxidyne and Thermodyne Bulldogs were some tight long lived monsters as well, saw many make 500,000+ on original parts, just knocked to beat hell from piston slap.

Oh and when Harley went to belt drives or the earlier sealed o-ring link chains they no longer needed the 'programmed' leak to lube those chains. Better gaskets, seals and sealants did help in those older engines too. Loved Panheads, shovels and knuckles not so much.

Those early Double 00 92's were nothing more that a 71 with 92 liners. The biggest problem was breaking main caps. When the silver came out I remember removing several 00 engines
and installing silvers. The silver IMO was a good engine. When the Double 00 broke main caps you knew it because of the odd vibration and instant low oil pressure.

Truck Shop

 

[John C.]

We use to call them green block 92s and plenty of them got pulled early. As I recall Detroit had a deal on swapping them out for Silver blocks. The Silvers were a big improvement in engine life.

 

[RZucker]

Let's not forget that sickening "Klunk" when a new liner hits the lower bore. For some reason the 12V71T's I've worked with (Wabco scrapers with N80-85 injectors) liked to shift the bores in 1 and 2 left side. Had a bunch bored .010 over to cure that.

 

[Junkyard]

I used to post videos on YouTube but I eventually deleted them all because I got tired of all the dumb comments made by idiots living in their momma's basement.

I'd have high blood pressure and who knows what after reading what the trolls would have to say. Say something constructive, even if criticism. But don't stir $hit for the sake of stirring it!! That pretty high on my list of pet peeves!

 

[Birken Vogt]

If nothing else they like to scold the uploader for not warming up the engine for 45 minutes to an hour before running it at RPM above idle.

Sorry but I got places to be. Once the engine has the shakes and smoke out I am on down the road.

Also you can look at artistry of someone getting a dozer or track hoe out of the mud. The video is 10 minutes long with no cuts. Still the peanut gallery says it took too long.

 

[92U 3406]

I put a cold start video of my truck up and got flamed for cranking the starter for 25 seconds. Do we want this thing started or are we gonna dink around all day letting it roll over twice and then give it a 15 second cool down? SMH.

 

[RZucker]

I put a cold start video of my truck up and got flamed for cranking the starter for 25 seconds. Do we want this thing started or are we gonna dink around all day letting it roll over twice and then give it a 15 second cool down? SMH.

You remember the old John Deere 40 and 50 series tractors? When they fired, they went full fuel before they came back to idle. I had a car "mechanic" flip out on me once when I started my old 4430 to plow his snow. He called me everything but a white man over that. Oh... his driveway didn't get plowed that day. Tractor "didn't feel well".

 

[Birken Vogt]

Yeah the cold start videos are funny. My own procedure is, if I know it is going to start then I hold the starter on steady until it is good and running. Might not get another chance if the battery is low. Like you said there are too many who think alternating the starter off and on is a good thing. All the heat you just built up in the chambers is sinking away into the cold water jacket while you wait for nothing. Or they stop at the first sign of a cough from the engine. I set my auto start modules to continue to crank an 1800 RPM generator engine until it reaches 1200 RPM. The starter motor has an overrunning clutch for that reason and I don't want to get called out in a snow storm because it coughed and died and locked itself out for me to come and just throw a switch.

 

[92U 3406]

I'm not super keen on leaving things idling for a long time. Even at -40C I'll let them idle for maybe 5 minutes and then I'll bring up the RPM. I'm honestly more concerned about the hydraulics than I am about the engine. I like to at least get the hydraulic oil up above 0C before I really start to work the machine. Pretty hard on the hoses and seals trying to force that thick and cold oil through the system. Even if it is a winter grade oil.

 

[StanRUS]

U-tube critics OT example...Jason and crew cold starts

At that ambient temp...no run or blow use...no start

Detroit 2-strokes in that low ambient temp...use 'run or blow' before ever attempting crank the engine over.
How many of you guys have ever used either jell capsules?

 

[DMiller]

Gel Caps were almost useless, three to five to get some engines lit off, then there is always the one guy who stops cranking with ether in the intake then tries again to fuel knock ether lock. Old boy on that TRex needed to hit it before he cranked it to death, not too bright, guess that why he is working a scrap yard.

 

[92U 3406]

I avoid ether if at all possible. I might give it a quick shot or 2 once its making smoke but that's about it. I've been told many times that ether is like meth for engines. Once they're hooked they need it all the time.

 

[Birken Vogt]

I avoid ether if at all possible. I might give it a quick shot or 2 once its making smoke but that's about it. I've been told many times that ether is like meth for engines. Once they're hooked they need it all the time.

Probably from damaged pistons, etc. Under careful usage it should not bother anything.

I suspect the problems come from people using it on fragile small high speed high compression non turbo engines.

The key is to use the right amount to help ignite the diesel that is being injected, not so much that the engine is running on ether by itself.

If the injectors aren't injecting for whatever reason, no amount of ether is going to get it to run but some people still seem to try....

 

[StanRUS]

Probably from damaged pistons, etc. Under careful usage it should not bother anything.

I suspect the problems come from people using it on fragile small high speed high compression non turbo engines.

The key is to use the right amount to help ignite the diesel that is being injected, not so much that the engine is running on ether by itself.

If the injectors aren't injecting for whatever reason, no amount of ether is going to get it to run but some people still seem to try....

Abusers, people trying to re-start engines that run out fuel; they do not know how to use primer pump or they're to lazy!

2-stroke Detroits: long path, air cleaner, intake piping, blower (turbo) air box. I found lots of broken rings on engines that have never been ethered! My buddies always blame out of spec connecting rods (slight bend or twist) on ether usage, ditto most of those engines have never been ethered.
I use lots of ether; cleaning gasket surfaces and threaded holes if I am out of Loctite primer!

 

[kshansen]

I use lots of ether; cleaning gasket surfaces and threaded holes if I am out of Loctite primer!

Done the same myself. Two things to be aware of: first using it in a confined area, like cleaning out a differential case under a machine can give you a bad buzz and head ache(been there done that), next that stuff is very flammable, yea you knew that but we had a guy at one of our plants almost burn down a shop when after cleaning some with the ether he decided to snip off a couple rusted bolts!

And on a slightly different point being safe while using "non-flammable" brake clean can also have serious hazards.
Sure it won't burn but if heated or sprayed on hot surface it can kill you.
This should be required reading for anyone using this product:
https://envirofluid.com/info-library/toxins/tetrachloroethylene-brake-cleaner

 

[old-iron-habit]

If nothing else they like to scold the uploader for not warming up the engine for 45 minutes to an hour before running it at RPM above idle.

.

They would hate me when I start the 4-53 in my power shift Ranger skidder. Cold start procedure, per the manual is for down to +15 F. Below that they recommend a pre-heating system. Here's the short version of what it says. Insure the parking brake is set and the blade is placed on the ground. After running the engine at 1000 no load RPM for 2 to 3 minutes, engage the transmission in high gear and set the engine to half throttle to but resistance on the torque convertor until the has reached operating temperature. Seems they are more concerned about the tranny oil flow than the engine.

 

[StanRUS]

They would hate me when I start the 4-53 in my power shift Ranger skidder. Cold start procedure, per the manual is for down to +15 F. Below that they recommend a pre-heating system. Here's the short version of what it says. Insure the parking brake is set and the blade is placed on the ground. After running the engine at 1000 no load RPM for 2 to 3 minutes, engage the transmission in high gear and set the engine to half throttle to but resistance on the torque convertor until the has reached operating temperature. Seems they are more concerned about the tranny oil flow than the engine.

Using torque-engine to build heat applies to both engine and trans; I do that in Cali all the time instead of wasting time waiting for the machine or truck (any engine with retarder) to warm up.

Service trucks have block pre-heaters; per SOS oil analysis cold starts increase 'iron' wear particle count. Did not make any difference which weight oil was used 30, 40 or 15-40 or brand; higher wear rates at cold starts.

 

[OL2STROKER]

There's a few of us out here still playing with them. Here's a 12v71tt in a pulling tractor my buddy built I just finished tuning for him. Everything I own is 2 stroke powered, including my pickup. Signed up here because I bought an old dozer and stumbled onto yalls finest thread straight off!!! P.S. the symphony below is at 3500rpm

 

[StanRUS]

There's a few of us out here still playing with them. Here's a 12v71tt in a pulling tractor my buddy built I just finished tuning for him. Everything I own is 2 stroke powered, including my pickup. Signed up here because I bought an old dozer and stumbled onto yalls finest thread straight off!!! P.S. the symphony below is at 3500rpm

12Vs spinning over 3,000 break lots of parts...per modeling moments of inertia 3,280 is tops.