Hey Guys,
I'm taking the coach across the country in January heading from Pennsylvania home to Michigan and then on to Portland. Leid mentioned to me when they rebuilt my 8v92TA that since it is dynoing at around 525hp that I need a new air filter to replace my ecolite. They said I need 2000cfm of flow. I have tried now for months to find a single filter solution for this with calls to Donaldson tech support, calls to K&N tech support, calls to Walker, Baldwin, etc. no one has been able to be helpful. They just say "install a twin filter setup" but that would require a major amount of fab work to ensure it all fits, is sealed and secure, and somehow is easy to maintain. I'd really love a single filter solution even if said filter is large. Can anyone recommend a place or person to call to actually get some out of the box thinking and help on this?
Scott I'll have to get a pic of my single filter on my series 60. If I recall it's pretty high cfm
Caterpillar should have one the 16 cylinder Cat on a generator has a big air cleaner ? where are you drawing the intake air from on your C if it cannot draw enough air from the intake a larger filter does you no good and C the factory intake is not much.Eagles you were limited because of the intake.The Houston Metro Eagles had a larger intake than the std Eagle to solve the problem
Can you fit two of your current one with a wye connection?
The high hp 8v92 calls for 8 inch piping for the intake fwiw
Are you avoiding the second filter, thinking of symetry???
Stuff your OCD in a jar, and stick a second matching, big cfm filter can and piping anywhere that it will fit conveniently. For a busnut, long pipe, short pipe, more elbows one way or another, matters not, so long as the engine can get the air it needs at the intake. The sewer pipe section of the home reno store is your playground.
One of the few things in bus systems that total creative practicality does not need to be censured.
Happy coaching!
Buswarrior
Here are some possibly choices.
https://ph.parker.com/us/en/disposable-engine-air-filters
And tubing choices.
https://www.intakehoses.com
Quote from: Scott & Heather on October 26, 2021, 10:30:26 AM
I'm taking the coach across the country in January heading from Pennsylvania home to Michigan and then on to Portland. Leid mentioned to me when they rebuilt my 8v92TA that since it is dynoing at around 525hp that I need a new air filter to replace my ecolite. They said I need 2000cfm of flow.
Scott -My 500hp 8V92 uses a single WIX 46726 air filter, which I found handles 1650 cfm flow. 6" plumbing between the filter and turbo intake. This is a completely stock system, so I would suspect that the Prevost engineers spec'd this properly. But maybe not - read on. . .
Here's some trivia you may find interesting, and then I'll circle back to your coach: Way back in the '60's, Chevy was the first domestic car to offer a turbocharged engine starting in April of 1962: the original Corvair Monza Spyder. (beat the Turbo'd Oldsmobile Jetfire to market by two weeks!) The flat-six turbo engine cranked out 150 hp from 145 cu.in, up from the original 80 or 102 hp versions. To ensure longevity, Chevy used a couple of simple, yet clever engineering details, whereas the Olds engine was considerably more complex, with much worse reliability - something that cost Olds a lot of money in warranty claims.
As with any engine, detonation can be a killer, usually by punching holes it the tops of pistons. Turbocharged gasoline engines are especially prone to detonation caused by the higher boost pressures in the cylinders compared to being normally aspirated. Nowadays electronics takes care of all this, but back in 1962 that didn't exist. Chevy's solution was to replace the normal vacuum advance distributor mechanism with a pressure-retard system that
retarded the engine timing when the turbo's boost kicked in, plus the requirement for using premium fuel. I owned three turbo Corvairs ('63, '64, and a '66), and detonation never was an issue - unless I goofed and pumped in regular.
Now the other, little-known trick that Chevy used was a special muffler. The Corvair's flat six could easily wind up to it's 6,000 rpm redline, but while under full boost from the turbo at that rpm, would start to disintegrate while on the engine dyno during durability testing. Here comes the trick muffler to the rescue. This magic device was designed so that between 5,000 - 5500 rpm, the back pressure would build to the point that at 5500, the turbine side would cavitate, thus preventing any additional boost and prolonging engine life.
What does that have to do with our 8V92s? I wonder, and am only speculating here, that perhaps MCI and Prevost, in these two applications, may have "throttled" the turbos by restricting the intake and exhaust systems somewhat, thus restricting boost and increasing longevity. Clifford mentioned the high hp 8V92s require 8" plumbing, and there's a lot of difference in the air flow between a 6" and 8" pipe - it's almost double! Some fellow busnuts have replaced the big mufflers on 8V92 coaches by replacing them with a low-restriction resonator. Reported results have been somewhat more noise, but also a drop in operating temperature due to the freer-flowing exhaust.
Depending on space availability, I'm also wondering if two of the WIX 46726 with 6" outputs into a "wye" having two 6" legs into an 8" discharge might work? But, again, like Clifford said, the air intakes of the coach might not be able to handle 2,000+ CFM? Also, would have to check to see if the turbo itself can handle a 6" or 8" intake! Another piece of the puzzle to be found, eh? Interesting challenge, that's for sure.
Sorry for the novel, and I don't know if this helps or not, but, like spaghetti, I threw this out there, hoping something might stick to the wall, or at least get the thought processes rolling.
FWIW & HTH. . . ;)
Those turbo corsair mufflers were the go to for other performance engine upgrades. Used them on my 396 Nova with Mickey Thompson headers. They were close to a no restriction glass pack and still look like a muffler. 2 1/2" inlet and outlet also. Most others were 2 1/4" max.
The MCI C has the 8 inch piping with the plastic reducing housing across to the turbo if stock ,Tom (LVMCI) just purchased the parts for the air system the one was rusted out the plastic was cracked everywhere.It is a well engineered system unless it has been cobbled up,lot of people because of the location inside do cobbled it up for space not implying Scott cobbled his up .Tom is still trying to catch his breath for the parts $$$$$ the special inline 8 inch pre cleaner was very pricy
Thanks for the ideas and links. I have already purchased some piping and rubber hose connectors from intake hoses. I am not concerned about the symmetry of two filters as much as the ease of swapping in new ones. My stock intake ducting (which travels to mid way up the side of the coach and intakes through a grill up high) is all custom since the coach has a roof raise, and a completely redone body. I suspect it won't flow enough air through all that even with a high flow filter. A single filter with high flow rate will suffice and I can plumb it in and change it out when necessary. Twin filters are going to be a pain to squeeze in there and swap out.
BW, do you think it's safe to use PVC pipe in a hot bus engine bay? I don't want to dust my brand new engine....
Quote from: buswarrior on October 26, 2021, 02:21:45 PM
Are you avoiding the second filter, thinking of symetry???
Stuff your OCD in a jar, and stick a second matching, big cfm filter can and piping anywhere that it will fit conveniently. For a busnut, long pipe, short pipe, more elbows one way or another, matters not, so long as the engine can get the air it needs at the intake. The sewer pipe section of the home reno store is your playground.
One of the few things in bus systems that total creative practicality does not need to be censured.
Happy coaching!
Buswarrior
Here's the setup I have now. Ecolite ducted to the intake up high. Not ideal but it works:
With the factory pre cleaner at air cleaner they could draw more air if needed it was a good system
Quote from: Scott & Heather on October 27, 2021, 08:45:48 AM
Here's the setup I have now. Ecolite ducted to the intake up high. Not ideal but it works:
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You will get it worked out but the piping looks like 6 inch to me
Hi Cliff,
Yeah it's I think 7". If 8" is what is specified then I'm not big enough. I guess I need to either make a 2000 cfm ecolite work or break down and get twin filters. If I pull air from the engine bay is that a bad thing? I can't get anymore air from the upper intake as those holes are already as large as they can be at this point.
Carve a hole in the side wherever it works to feed the other filter. Some of us carved into the sides of the MC8 above the air cleaner for similar reasons, air intake was totally crap even for stock installs...
I would avoid inhaling hot engine room air.
Performance temperatures of the various plumbing pipe materials online scatter gun:
https://www.engineeringtoolbox.com/plastic-pipes-operating-pressure-d_1621.html
Close proximity to heat would need a little protection, otherwise your engine room is a windy place, and the pipes are inhaling cooler outside air.
Happy coaching!
Buswarrior
another hole probably will work. Do some thought how to avoid ingesting rain into filter.
I don't mind carving another hole, as much drama as that is, but the original hole/ducting on the drivers' side actually invades the bedroom (ducting runs inside bedroom between engine bay and radiator bay) so that is going to be drama for sure. I don't want to just cut a hole in the engine bay area because that will pick up rain mist (as you know these coaches throw a TON of spray on wet roads) in copious amounts...so I'm still working on this...
My bus has a Donaldson water separator mounted in the intake stream before the air filter. Unfortunately, the water separator is quite large. Mine is mounted vertically and the air intake is up by the roof.
To bad they tossed the pre cleaner and vortex on your bus here is a photo for one that LVMCI replaced that was rusted out and the 8 in to 5 in reducer from the air cleaner to the turbo.MCI missed the boat on cooling but they did do a great job on the air supply for the 8v92 all 8 inch piping.For some reason my photo of the backside showing the 8 in on the vortex will not post
does anyone know what the airflow is at the top of the bus? If there is a clean flow of air across the top, it seems maybe a scoop up there down into the engine bay could provide much needed cool air.
remember the old Flxibles with their air scoops? Could mount some decent areodynamic looking rectangular enclosure on rear of roof to satisfy air needs. Unless height clearance is a problem. Some city buses have something up there, maybe for hvac though.
Eagle tried the air scoops at the back on the roof in the 80's for a short period of time wasn't a good idea I guess because they stopped and went back to side intake,
The side intake must not have worked well, they only appeared for a couple years in the early 80's. I have one on my 82 Model 10.
All this talk about air flow, but no mention of the pressure drop . . . a 6" pipe can flow 2000 cfm, but it will be at a higher pressure drop than a 8" pipe.
The parker filter I use is listed at 2000 cfm, but no delta P shown
The donaldson exchange is listed at 1500 cfm at 5"H2O.
Also, length and elbows add to the restriction (effectively making the pipe 'smaller' ).
If I was wanting to increase the flow rate & decrease the pressure drop, I would add another filter in a good spot - If 4" pipe is all you can fit in, that will still help.
Quote from: kyle4501 on October 29, 2021, 04:54:14 PM
All this talk about air flow, but no mention of the pressure drop . . . a 6" pipe can flow 2000 cfm, but it will be at a higher pressure drop than a 8" pipe.
The parker filter I use is listed at 2000 cfm, but no delta P shown
The donaldson exchange is listed at 1500 cfm at 5"H2O.
Also, length and elbows add to the restriction (effectively making the pipe 'smaller' ).
If I was wanting to increase the flow rate & decrease the pressure drop, I would add another filter in a good spot - If 4" pipe is all you can fit in, that will still help.
The last time Scott posted about this I took photos of the 134 Detroit engineering bulletin showing all the restriction factors on different sizes pipes,elbows and wyes it should be here somewhere