| Author |
Message |
Larry & Lynne Dixon (Larry_d)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 09, 2005 - 2:55 pm: | |
Curiosity has got the best of me. I suposedly have 60 injectors in my rebuilt 871. Is this what is needed for turbo? What more does it take and what would be an approx cost. Everyone has been so good about answering my questions thot I would ask this dumb thing Thanks all larry 4905 |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 09, 2005 - 10:03 pm: | |
Larry, the turbo should be added at the time of the rebuild; there are a number of changes needed to make use of the turbo.
On the bright side, your rebuild is ideal for bus service with a standard transmission; with a light bus and highway gears, it's possible to get 10 mpg with decent acceleration.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska |
Dale L. Waller (Happycampersrus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 10, 2005 - 5:36 pm: | |
Larry,
As Tom said, there is some changes that need to be made first.
I wouldn't recommend the 60's injector for a turbo engine they are on the small side for a turbo engine.
The compression ratio is higher in a Naturally Aspirated than a turbo engine. Adding boost to the NA engine the engine won't last long. The engine has to be taken apart to change the pistons for a lower compression ratio (REBUILD).
The blower has to be changed also. A blower for a turbo engine has a different seal setup and oil drain for a turbo (depends on the turbo setup).
Then change the exhaust manifolds and add the crossover plumbing and replumb the muffler.
Then you have to relocate and plumb the air filter. Plus some other things that I missed.
To do this is very expensive and time consuming. Hate to sound so negative, but IMHO you won't gain much for the money you will spend.
If the engine is a fresh rebuild you would be better off and it's cheaper to set it up as a 318hp 8v71, Thats N65's and "A" timing if I remember correctly.
No question is a dumb question when it comes to money for a Detroit engine.
Dale |
Jerry Liebler (Jerry_liebler)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 10, 2005 - 8:22 pm: | |
Dale,
The shop that rebuilt my engine, Hillsboro Diesel in Hillsboro Or. has rebuilt many hundreds of 8V71ts &tas in their 40 years of DD experience and, in the last 30 years, ALL have used the high compression pistons. The few they did with low compression cylinder kits had poor starting complaints. Their customers have not had any shortened life complaints. To make a standard timed engine a turbo, they said the blower change is needed and of course the 'plumbing' but that's it. With a turbo N70 injectors are usually used. BTW the 'A' timing is a disaster in a GM bus because the torque peak is moved from 1200 RPM to 1600 RPM, results very disapointing hill climbing, even though the peak horspower is higher.
Regards
Jerry 4107 1120 |
Dale L. Waller (Happycampersrus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 10, 2005 - 9:07 pm: | |
Jerry,
So your telling me that adding a turbo is just a bolt on? even if you don't swap pistons.
1 New or Rebuilt Turbo
+ 1 New or Rebuilt Blower
+ 6 New or Rebuilt N70 Injectors (he has 60's)
+ 2 New exhaust manifolds
+ Crossover Piping and exhaust work
+ small parts, gaskets, oil lines etc.
+ Labor
= PRETTY DARN EXPENSIVE were I'm from. Just for at best 50 more horsepower.
Or using "A" timing that has been done for years (decades) on just about every type Detroit built.
Here is some #'s to think about
8V71 318hp + 800torque "A" timing
8V71ta 370hp + 1060torque
The TA is a turbo with AFTERCOOLER that he will have to BUY if wants that power. And if he has the correct block for aftercooler.
Hey, but not my money. If it works for you
Dale
I live on top of Fancy Gap mountain in Va. Mine climbs pretty good with "A" timing. FWIW. |
Larry Baird (Airhog)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 11, 2005 - 2:58 am: | |
I am in the process of changing from a 8V71 & 4 speed to a 8V71T (350 hp) & 10 speed in my MC-7. I can tell you even starting with a complete rebuilt 8V71T just off the dyno, it is a lot of work. For me the bell housing, pan, oil pickup, accessory drives, water pump and linkage needed to be changed. This is in addition to the dry air filter and spin on oil and fuel filters. When we got the engine and transmission removed we found out that every weld in the frame needed to be redone and don’t forget that you will need to cut a big hole in the floor to build a box around the turbo to keep the heat away from the body. With all this extra work I am happy to be doing it. Its not just fifty or so extra HP you get, you get to keep it all the way up the hill.
Good luck, and if your worried about the money, your going to spend it anyway, you own a bus! |
Larry & Lynne Dixon (Larry_d)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 11, 2005 - 11:46 am: | |
Thank you very much for all of the info, had a fellow bus owner in town offer to help, but didnot know. We are going to leave the old 4905 just the way she is, just retired have lots of time I guess. Thanks for all of the good info.
larry 4905 |
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