Turbo on the 2-71?
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=23655
Printed Date: 05 Jun 2024 at 6:39pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Turbo on the 2-71?
Posted By: JHanson907
Subject: Turbo on the 2-71?
Date Posted: 08 Jan 2011 at 1:08am
| Hey, here's a crazy idea. Would it be possible to put a small turbocharger on the 2-71 in my HD5G, in addition to the supercharger? Seen some crazy stuff being done on other diesels and this came to mind. Anyone seen anything like this? Any other ideas out there for boosting the hp a bit, without swapping motors? What do you guys think? |
Replies:
Posted By: DrAllis
Date Posted: 08 Jan 2011 at 7:14am
| I'm thinking your engine is around 70-80 HP?? I'd try a turbo from an AC 200-7000-7010 tractor if you wanted a turbo that would work. |
Posted By: Coke-in-MN
Date Posted: 08 Jan 2011 at 10:08am
|
Tag on the 2-71 in a HD5 says 48 HP from the one i have at least. As i used a later style T piston and liner in mine and upped the RPM some on governor I figure it's around 55 HP. As Detroit on their Silver Series used both Turbo and Super charger it should be possible, and that thought has also crossed my mind.
Getting the right injector size to match air charge might be one problem that would have to be worked out. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: JHanson907
Date Posted: 08 Jan 2011 at 2:27pm
| Good suggestions, both. Will look into this a bit more. There are some pretty sharp diesel guys here in Fairbanks. Thanks! |
Posted By: fglass
Date Posted: 08 Jan 2011 at 2:35pm
|
If I'm not mistaken the compression ratio of the Detroit motors are different when comparing turbo charged versus naturally aspirated engines. I know it matters on the larger cubic inch detroits, better check with the dealer to make sure you get ALL the parts that need to be swapped out to make sure it works right.
Good luck with the project
Frank Glass
upper NYS
|
Posted By: Coke-in-MN
Date Posted: 08 Jan 2011 at 2:44pm
|
On the industrial engine liners the inlet holes look like a 8 with two holes set close, on the truck the inlets are larger, slanted slot . Air flow seems less restricted. ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: TramwayGuy
Date Posted: 08 Jan 2011 at 7:44pm
| When the Detroits were Turbo'ed from the factory, the blower drive ratio was changed to run it slower. That way the blower did a little less work, the turbo made up for it as needed. The efficiency was better that way. |
Posted By: DrAllis
Date Posted: 09 Jan 2011 at 7:32am
| That is probably true, but the addition of a TO-4 from the engine sizes I recommended will definately move more air thru the engine. When Detroit did it, they had emission rules to contend with. A 2-71 engine is 142 cubic inches that fires every time around, which could compare to a 284 cube engine in theory. |
Posted By: JHanson907
Date Posted: 10 Jan 2011 at 12:35am
| Okay, so basically I should be looking for a turbo similar to that on an AC-200-7000-7010; replace the injectors w/ units built to handle the greater air volume; and possibly look at turning down the blower. All will require a bit more research, I think, but I am definetely going to try this. I have a spare 2-71, just in case...!! |
Posted By: Steve M C/IL
Date Posted: 14 Jan 2011 at 11:05pm
| Well,they made a 6-71T.Now these were 4 valve heads but would it matter?One thing no ones mentioned is the turboed engines use a metal sealing ring seal on blower shafts.I'm guessing it's probably a direct replacement for the neoprene nat/asp seals because they shared alot of parts between engines.They were building 8V71T's along with NA 8V71's and if there was a way to put a metal seal in place of a neoprene one without changing housings,they would have done it.They probably made a 2-71T late in life.The "T's" might all use cross head pistons.This all should be available info from DDA.Comp ratios,injector size etc. |
Posted By: DMiller
Date Posted: 15 Jan 2011 at 4:07am
|
If you don't decompress the engine(shorter pistons) the compression ratio change will crack the head or cook the pistons leading to failure either way. We had 318 Detroits 8V71 series with turbos in trucks, these engines when supercharged with a turbo became 350 Detroits but they had extra fuel delivered, decompressed pistons, different blower drive gear sets as well different lobe design to the blower, different sleeves and yes the inlet ports were different, and the cam timing was different. Just adding a turbo may cost more than you can imagine once the damage starts. The 350 Detroit smoked like hell cold and at a idle after sitting for a short time, very evident which ones they were in a lot while running. |
Posted By: fglass
Date Posted: 15 Jan 2011 at 10:31pm
|
That's the way I remembered all of the turbo vs non turbo differences to be.
It's not as easy as it sounds, an expensive conversion at best, but all changes are possible (if enough money is thrown at it).
FGlass
upper NYS
|
Posted By: TREVMAN
Date Posted: 17 Jan 2011 at 7:21pm
| Dont do it! The reason hd5 cats lasted so long is that they were underpowered. Hd6s didnt last nearly as long as it was basically the same cat with much more power. If you want something that can do more work, find a hd11, they were good cats too, TREV. |
Posted By: JHanson907
Date Posted: 12 Feb 2011 at 12:09am
| Evening Guys. After all this, I think I'll leave it the way it iis! Old Orange really does run very good already and is a joy to work with. Got plenty of other work to do! |
Posted By: Ray54
Date Posted: 14 Feb 2011 at 3:27pm
| Have been seeing on other sites were the 2-71 has been replaced with a 3-71.I think this was in a farming tractors rather than a dozier.Have a cousin that farms with HD9's,he has put 4 valve heads and larger injectors in 2 or 3 of them.Lots of power but now has trouble with final drives on a regular basis.I would think using larger injectors and pistons and sleeves for the higher horse power would not put an undo strain on the rest of the drive train,if you us a little common sense. |
Posted By: groanwow
Date Posted: 21 Apr 2012 at 2:26am
It seems to be a bit crazy..but its really innovative idea... you can give it a try, when you wrap up your other works... ------------- http://www.buyautoparts.com/part/replacement-turbocharger/" rel="nofollow - Turbocharger :) |
Posted By: Mactractor
Date Posted: 21 Apr 2012 at 9:56pm
| Many HD5s with 371, 371N, HD9 and dry clutch HD11 with 471N and 671, and HD16 with engine power boosted way up over HD21 spec down here. Final drive failures would only occur with the same guys who wrecked final drives on factory horsepower tractors by not keeping bearing preload up on all shafts, or putting severe impact on them bulldozing and ripping in rock. I was one of the `wreckers` when I started. Now that I know how to look after final drives and other tractor componentry, I dont have any trouble. Mac |
Posted By: HD6 Merv
Date Posted: 22 Apr 2012 at 2:36am
|
Just to add abit more to what mac said. There was special agricultural version of the HD6B called the HD6AG. same back end as the 6B and HD5 final drives; with a turbocharged 7000 engine pushing out 90hp. And is still alot of hotrodded HD5s down here with 3-71s on agricultural work still working down here after 60 years of toil; no doubt rebuilt but still pullin ! Again alot of the problems boil down to what sort of man is in the seat ! ------------- tits tyres and tracks they all cost you money |