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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Justin Swartz on February 25, 2021, 07:29:15 PM

Title: 8v71 turbo or supercharger?
Post by: Justin Swartz on February 25, 2021, 07:29:15 PM
I have 1 supercharged and may buy 2 with turbos. Trying to figure out which one I am hoping to keep
Title: Re: 8v71 turbo or supercharger?
Post by: Nova Eona on February 25, 2021, 08:10:32 PM
Is it a true super or just the standard roots blower they all have?  Turbos are generally preferred when the option is there, only reason I know of people going with a NA/Roots is if they absolutely prize reliability above all else or just started out with one (like me).  If it's a true super, I've got no input and will defer to others with more experience.
Title: Re: 8v71 turbo or supercharger?
Post by: Justin Swartz on February 25, 2021, 08:15:45 PM
Well, it has a blower/supercharger of some sort on top of the engine. The two busses I just found are turbo
Title: Re: 8v71 turbo or supercharger?
Post by: Justin Swartz on February 25, 2021, 08:17:02 PM
They both run fine. Just trying to get more experienced information
Title: Re: 8v71 turbo or supercharger?
Post by: richard5933 on February 26, 2021, 03:26:48 AM
The Detroit Diesel two-strokes engine, by design, cannot suck air through the cylinders and need the blower to push air in. That thing is not a super-charger, it's just the blower pushing combustion air into the cylinders.

The turbo will be on the exhaust plumbing and use the exhaust flow to spin a turbo, and the turbo fan will push incoming fresh air into the blower under pressure. These are what will increase performance, but they will also increase the need for engine cooling.

Please give us more details of the bus you have vs. the ones you are considering. A turbo alone wouldn't cause me to choose one bus over another, as there are lots more factors involved here. More information is necessary.
Title: Re: 8v71 turbo or supercharger?
Post by: Justin Swartz on February 26, 2021, 03:55:37 AM
Learning something new every day. 2  81's and 1 82' MCI MC9's
Title: Re: 8v71 turbo or supercharger?
Post by: richard5933 on February 26, 2021, 04:04:15 AM
More important is the condition of each. A bus with a turbo that has been driven a million miles with poor maintenance would be much lower on my list than a well-maintained bus with fewer miles and no turbo.

Have you seen and inspected these buses or are you working only from what you're seeing posted online?
Title: Re: 8v71 turbo or supercharger?
Post by: Justin Swartz on February 26, 2021, 05:37:42 AM
Both of the turbo buses are retired school buses. I have been looking for a transmission for mine and a friend came across the two buses. After speaking to the owner im getting both buses for less than a transmission would cost. One has all the seats and the other was used for tailgate parties and events. I plan to look them over thoroughly just before I drive them 800 miles to where I am. Was just looking for a more educated opinion about the two differently induced engines.
Title: Re: 8v71 turbo or supercharger?
Post by: luvrbus on February 26, 2021, 10:49:14 AM
If it a 2 stroke Detroit it will have a blower under the turbo,turbos add power and a cleaner burn than the N/A engines,blower or supercharger it becomes a super charger when you add it to a 4 stroke,my neighbor is a world figure in superchargers I sell him all my old 2 stroke blowers he turns into superchargers  for the racing crowd.Me personally I would prefer a 6v92 TA over a 8v71 N/A (non turbo) any day of the week     
Title: Re: 8v71 turbo or supercharger?
Post by: Utahclaimjumper on February 26, 2021, 11:57:20 AM
 The main difference between a "blower" and a "supercharger" is the gearing. A blower replaces only ambient air pressure,,that's why two stroke detroit people call them "normaly asperated",, a super is geared much higher as in  "overdrive" to accomplish higher than ambient air pressure as desired for the application..  This is what you see on fuel dragsters that blow up under the extreme high pressures.>>>Dan
Title: Re: 8v71 turbo or supercharger?
Post by: chessie4905 on February 26, 2021, 04:50:24 PM
Or don't blow up.
Title: Re: 8v71 turbo or supercharger?
Post by: Utahclaimjumper on February 26, 2021, 06:36:48 PM

Only a mater of time.>>>D
Title: Re: 8v71 turbo or supercharger?
Post by: luvrbus on February 26, 2021, 06:55:35 PM
They don't really put out more air pressure than the standard blower on the Detroit engine around 20 to 30lbs,When I rebuilt Van's blower I got new silicone seals from my neighbor and installed those instead of the crappy after market seals offered today
Title: Re: 8v71 turbo or supercharger?
Post by: dtcerrato on February 26, 2021, 07:44:19 PM
Dean's Blowers in Washington State rebuilt ours. I sent him up a truck parts blower for trade on his labor. He converts them for Gasoline drag machines and is really good. He doesn't believe in replacement of stock seals he uses  upgraded turbo seals. Does nice work & is very knowledgeable.