Bus Conversions dot Com Bulletin Board
August 21, 2014, 09:02:16 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If your computer is lost, damaged, or stolen, we will replace all of your E-Mags for free.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: [1]   Go Down
  Print  
Author Topic: Bypass blower  (Read 989 times)
Seayfam
Sr. Member
****
Offline Offline

Posts: 453





Ignore
« on: June 20, 2013, 09:14:27 PM »

I have a question for any of you two stroke guys. I'm sure some of you remember last year I bought a series 60 and was gathering up parts to do a conversion in my bus. I haven't been able to muster up the money to get the transmission and a few other parts yet. So what I'm going to try and do for now to get a little more power for all the mountains I drive in is... Upgrade my 8v92 MUI with a bypass blower. What I have is the older "green" 8v92 with 9A90 injectors and no bypass on the blower. This motor only has 60,000 miles on it and is in really good condition. (I just need more HP)

My question is.... Can I install a bypass blower and an upgraded turbo on this engine with no other modifications? What all will I need besides the blower and turbo? What should I expect to gain in HP?

Thanks in advance
Logged

Gary Seay (location Alaska)
1969 MCI MC-6 unit# 20006
8V92 turbo 740 auto
more pics and information here     "  www.my69mci-6.blogspot.com  "
wg4t50
Hero Member
*****
Offline Offline

Posts: 765





Ignore
« Reply #1 on: June 21, 2013, 02:22:03 AM »

Good subject,  Am told the bypass blower will add about 35 hp to flywheel, I used a turbo off a 6V-92 on my 8V-92 along with 9200 injectors, that worked very well, and using a resonator in lace of a restrictive muffler will be another biggie.
Always enjoyed my 2 stroke games, my toys always brung me home with a smile.
Just sayin
Dave M
Logged

MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for over 50 wpm for ever.
Central Virginia
luvrbus
Hero Member
*****
Online Online

Posts: 12222




Ignore
« Reply #2 on: June 21, 2013, 05:43:48 AM »

By pass blowers are more for fuel economy while adding hp with the right turbo Don and I can help with the turbo size,so many variations need to know where you want the torque range,high end ,low end or middle depending what one is looking for some times the mini bypass blower works the best 

The 9A90 are good injectors but I prefer the 9G90 when using a by pass blower your upgrade would just be a bolt on no biggie those old green engines are not that bad just keep pouring the oil  and keep it cool they keep on running 

I have some 92 series by pass blowers and different turbo hot housing here if you need one let me know when you head for Idaho we are going that way shortly this AZ heat is a bitch this year and it only JUNE

good luck
Logged

Life is short drink the good wine first
eagle19952
Hero Member
*****
Offline Offline

Posts: 889




Ignore
« Reply #3 on: June 21, 2013, 08:27:40 AM »

my experience is in construction and stationary DD's... leaves me with a very limited understanding of by-pass blowers... Angry

I found some info here.
http://www.yachtforums.com/forums/technical-discussion/14391-pass-blowers-92-series.html

seems like the big boys have $$ enough to sort out exactly what they want...apparently they contributed to this fellas startability problems...and he went back to 100%'s.

so where can I find more info?  educate me some please.
« Last Edit: June 21, 2013, 04:20:24 PM by eagle19952 » Logged
Seayfam
Sr. Member
****
Offline Offline

Posts: 453





Ignore
« Reply #4 on: June 21, 2013, 09:03:47 AM »

This sounds like it would be a nice and easy upgrade. I'm hoping to gain a little mileage plus a little power around the 1400 to 1600 range, if that's possible? With my gearing and the speeds I drive between Alaska and Idaho (60mph) my RPM's are always around 1500 to1600. I think my motor is governed at 1850, that or my tach is off. So I'd like to set it to around 2100 if that's a safe number for my old engine?

Clifford, I'm getting ready for the trip down and was hoping to have the bus ready for the trip. I have a good figure on what I get for mileage on that trip now and what I can pull all the passes at. It would be nice to get a comparison on a long trip like that. How much do you want for a mini bypass and a turbo? Would you ship it to Alaska? I've found some used blowers around here but I'm a little nervous about installing one without knowing the history.
Logged

Gary Seay (location Alaska)
1969 MCI MC-6 unit# 20006
8V92 turbo 740 auto
more pics and information here     "  www.my69mci-6.blogspot.com  "
wg4t50
Hero Member
*****
Offline Offline

Posts: 765





Ignore
« Reply #5 on: June 21, 2013, 09:09:51 AM »

Limiting HP for a highway engine is cooling, unlike the marine units, they have the entire ocean to cool them, so they can turn the power on and live, problem as I am aware is they tend to over do it making for a short life.  Have heard numbers of 700 hp from a 6-71TA in marine.  I am not a marine type, so going by hear-say (gosip)
Dave M
Logged

MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for over 50 wpm for ever.
Central Virginia
TomC
Hero Member
*****
Offline Offline

Posts: 6720





Ignore
« Reply #6 on: June 21, 2013, 09:18:18 AM »

Bypass Blower valve is a little misleading. When the turbo spools up to boost, the bypass valve opens around 5psi and allows enough air to bypass the blower to offset the lower pressure on the engine side. When this happens, both sides are near the same pressure, hence the pumping power loss is lowered and the blower "free wheels", but is still hooked up to the engine and turning. The idea was to get as close to not having the blower being a drag on the engine as much as possible. At first, before the bypass blower, it was thought that the turbo boost was actually pushing the blower adding power to the engine-but that was found not really to be true. Detroit really wanted to use a three wheel turbo and no blower at all. The third wheel was powered by oil pressure just to keep around 3-5psi up to run the engine mainly at idle. The response time on the turbo was really low and had reliability problems. The ideal was would have to put a clutched turbo on like locomotive engines use, but it would have been heavy and bulky.
The bypass blower is the best solution. You might see up to .5mpg better. Good luck, TomC

P.S. The last incarnation of the marine version of the 6-71TI was 485hp @ 2,500rpm. TA engines were lower since the little aftercooler was still run by the engine coolant. The Intercooler was a big affair that had sea water flowing through.
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
eagle19952
Hero Member
*****
Offline Offline

Posts: 889




Ignore
« Reply #7 on: June 21, 2013, 10:04:44 AM »

ok I understand that some device.....( for instance, if you blow up a balloon, soon enough it will burst/pop...) but if you put the balloon in a steel box and blow hard enough...your ears will pop...)
so where does the blow go...on a bypass blower system and how much of the blowers output is "bypassed...all or some.
Any pictures...is this like a waste gate in reverse ?
is it really common or a jeez that's worth it highway mod.
 what  % of mph/grade increase can one expect ? with this bypass or is it's best result on flat ground.
Logged
luvrbus
Hero Member
*****
Online Online

Posts: 12222




Ignore
« Reply #8 on: June 21, 2013, 10:15:32 AM »

There are 6 versions of the by-pass blower for the 92 series 4 different blower drives,Glenn I have a place I can buy a rebuild kit with the bearings, seals,wear sleeves and gaskets for under 70 bucks with shipping not a bad price
Logged

Life is short drink the good wine first
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!