DBA 5029

Topic: DBA 5029 (Read 740 times) previous topic - next topic

DBA 5029

July 12, 2019, 08:52:18 am

Not to start a what's best filter discussion . Just a question about the Donaldson Blue DBA5029 air filter. Does the small end have the gasket and hole so your filter minder works?

Re: DBA 5029

Reply #1 – July 12, 2019, 10:01:09 am

Hi Bruce, no, it does not. Carefully remove and save the gasket as you will need to use it on the new Donaldson. As for the vent hole, use a punch...do not use a drill bit as this will leave metal shavings in the filter.

Re: DBA 5029

Reply #2 – July 12, 2019, 10:52:29 am

Here is a photo of our DBA5029. I used a new razor blade and like Peter posts, carefully removed the old gasket, used silicon to glue it in place and then took a punch and gave it a whack. Nice filter!

Pierce

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Reply #3 – July 12, 2019, 12:09:19 pm

That is what I did too. I used double sided carpet tape. just takes a few minutes. Pierce, I thought your vintage coach used the inside to outside version?

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Reply #4 – July 12, 2019, 12:48:56 pm

Think Foretravel used whatever housings were readily availible at the time,so your filter will match the housing,same years may have different filters.

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Reply #5 – July 12, 2019, 12:57:27 pm

No, outside to inside. The original had an inch of dirt, twigs, small pebbles from the behind the tire intake. Wish I had taken a photo. The replacement sucked in water spray from the tires and partially collapsed. This is why I'm changing to the later style air intake. Will post photos when done. All coaches with the behind the rear tire intake should change location.

The 2-cycles will use up filters over twice as fast as the rest. Also reason for stock 5 inch exhaust.

Photos of partially crushed filter attached.

Pierce

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Reply #6 – July 12, 2019, 02:21:50 pm

Here is a side by side showing many glue points on the Donaldson 5029 compared to the Brand X as well as the label from the box.

Pierce

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Reply #7 – July 13, 2019, 12:35:13 am

Thanks for the replies!

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Reply #8 – July 13, 2019, 09:16:53 am

Quote from: Pierce & Gaylie Stewart – July 12, 2019, 12:57:27 pm

The 2-cycles will use up filters over twice as fast as the rest. Also reason for stock 5 inch exhaust.

Since the question about the air cleaner has been answered, may I diverge from topic a bit?

Having trouble grasping the concept quoted above.

Are you saying with twice as many power strokes per mile, the 2-cycle diesel inhales twice as much air as the 4-cycle? Does the 2-cycle diesel also use twice as much fuel per mile? I thought 2-cycle diesel fuel economy was close to the same as the 4-cycle engines.

If it takes X amount of fuel to produce the power required to move the coach down the road, then I would think the quantity of air required to burn that amount fuel would be the same, regardless of engine design.

Or does a 2-cyle diesel inhale twice as much air as it actually needs to burn the fuel, and "wastes" (exhausts) the left over air?

Re: DBA 5029

Reply #9 – July 13, 2019, 11:45:57 am

Chuck,

Really excellent question!

Yes, your last sentence says it all. Unlike a motorcycle 2-cycle, the 2-cycle diesel has to have air forced into it to even start plus it has no exhaust cycle so the roots blower pushes lots of air out the four exhaust valves in the head. No intake valves, just holes/ports in the side of the cylinder. Remember, there is no set air/fuel ratio, the engine only needs fuel enough to overcome internal friction and the accessories to run at idle. The 4 cycle wastes one whole revolution on the exhaust stroke along with the energy required for that stroke. Unfortunately, the roots blower is only efficient at lower RPMs and rapidly loose efficiency at the RPMs build. That's why the 2-strokes have so much torque at low RPM and while they can turn higher RPM, they loose efficiency.

Here is a quote from a trucker: Detroit Diesel 71 - 92 series fans | Page 7 | TruckersReport.com Trucking... Firing every revolution makes them only sound like they are turning high RPM when there are not. "The screaming Jimmy" is around because the ear tricks the brain.

The big brother in the railroad locomotives of our 92 series 6V-92TA is the EMD710 (710 cubic inches per cylinder) is almost exactly the same as our engine and has anywhere from 8 to 20 cylinders. To get away from the roots blower loss, they have gotten rid of the blower completely and have the turbo directly connected to the engine with gears and a clutch. The clutch is engaged to start the engine and bring it up to temperature and then disengaged so the turbo does all the work. Getting the 2-cycle to meet Tier IV emission requirements in the railroad industry is difficult as the 2-cycle puts out more of certain types of emissions. The 20 or 16 cylinder could no longer be used as the tray holding the particulate filters and catalysts would have taken 16 more hours to remove as it was installed above the engine so any engine work was very costly. They have gone to a shorter 12 cylinder version with the emission package at the end.

So, the two cycle has advantages and disadvantages:

Pros:
Lots of low end torque
Glass smooth from idle to max RPM
Instant power even when cold as no wasted exhaust cycle and compression heating of incoming air from the roots blower.
Much lower EGTs so no risk of piston or valve failures like 4 cycles.
Four exhaust valves in the head to evenly distribute heat evenly across the head.
Lower EGT means less exhaust manifold cracking potential.
Equal MPG with other 4-cycle coaches even with the blower loss.
More efficient liquid cooled aftercooler rather than remote mounted intercooler that is susceptible to cracking, etc.
Military specs so more reliable and direct drive possible for all accessories (but not the way Foretravel installed it).
Much higher horsepower available with only more fuel injected.
Less accessory vibration and cracking like dip sticks, etc.

Above is the reason Mercedes purchased Detroit and is still producing this engine today. They had the $$$ to take over any company but chose Detroit Diesel. They now produce the most reliable 4 cycle and 2 cycle engines along with the new cutting edge transmissions.

Cons:

Harder to smog.
Harder to cold start because of the way Foretravel installed it.
Shorter air cleaner life, especially with the air intake placement. When the air cleaner gets wet, the positive displacement blower pulls an incredible amount of suction.
Poor fuel mileage with high horsepower versions in fire service or marine use.
Larger exhaust pipe/muffler needed to handle the increased amount of air.

With new opposed piston 2 cycles, increased efficiency along with low emissions, two cycles will have a bright future even as electric vehicles start to dominate the market.

Check the opposed piston (no valves) 2-cycle engines in the 2019 Ford pickup trucks. Video at this site also: Achates showcases 2.7L, 3-cylinder opposed piston gasoline compression...

Pierce

Re: DBA 5029

Reply #10 – July 13, 2019, 11:53:30 am

Thanks, Pierce. You have (as usual) provided a excellent answer to a puzzling (for me) technical question.

Re: DBA 5029

Reply #11 – July 13, 2019, 12:06:12 pm

Chuck,

You are very welcome. My explanation is flawed compared to the video below. It's very, very old but aside from the diesel explanation, it has quite a few nostalgic photos and videos. It gives a good animated explanation of the 2-cycle/4-cycle difference.

And, I love 4 cycle diesels also having owned quite a few.

Be sure to start this from the beginning.

https://www.youtube.com/watch?v=pfIcR0kB0LA

Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 10, 2025 ...

DBA 5029

July 12, 2019, 08:52:18 am

Re: DBA 5029

Reply #1 – July 12, 2019, 10:01:09 am

Re: DBA 5029

Reply #2 – July 12, 2019, 10:52:29 am

Re: DBA 5029

Reply #3 – July 12, 2019, 12:09:19 pm

Re: DBA 5029

Reply #4 – July 12, 2019, 12:48:56 pm

Re: DBA 5029

Reply #5 – July 12, 2019, 12:57:27 pm

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Reply #6 – July 12, 2019, 02:21:50 pm

Re: DBA 5029

Reply #7 – July 13, 2019, 12:35:13 am

Re: DBA 5029

Reply #8 – July 13, 2019, 09:16:53 am

Re: DBA 5029

Reply #9 – July 13, 2019, 11:45:57 am

Re: DBA 5029

Reply #10 – July 13, 2019, 11:53:30 am

Re: DBA 5029

Reply #11 – July 13, 2019, 12:06:12 pm

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