making diesel engine run quieter

[5030]

Rob:

A big contributor to diesel engine noise is injection pressure as well as combustion chamber shape. As injection pressure rises (to meet applicable emission levels), the "clatter" gets louder.

One notable exception to that was the Caterpillar 1693 TA. It always sounded like it had a bunch of ball bearings rattling around inside.

 

[HGM]

Daryl,
Just to add a bit, the HUEI injection system used on some Cat's(& Ford P/S) have very stout springs needed to close the poppet valve, contributing to some of the noise as well.. This may be why some folks see the DI's as being noisier..

 

[IH3444]

Interesting????? My engine machinist buddy says the opposite, and my BD135 direct injection is very loud, and the NHTC48DA indirect ijection is much, much, quieter. I'll check again. He said that the precombustion chamber helps muffle the noise of the fuel oil igniteing, and then the pressure wave/flame front washes out of the release port and over the top of the piston. He also stated the the direct injection just sprays right over top the piston top, and the noise is caused by the same flame front impacting the piston top, and some slight piston skirt slap until the piston warms up and expands. Then the noise quiets down a bit.

 

[Maine_Polack]

Just my experience. I have a 65 hp, 4 cyl. Mahindra that has been giving me a starting problem since I received it last April.

A factory tech. was here all day yesterday, trying to figure out. When all the obvious things were checked out, he went to the timing. Turns out the timing was slightly off. This apparently did fix my problem, but, the first thing I noticed was that the tractor was much, much, quieter, and I couldn't smell the exhaust. Wow, what a difference!

 

[RobJ]

Well I can only offer 6 years of expierence of working with these engines. The diesels I worked on came in a pre-cup or direct. Basically the same engine but with different heads and pistons. We dynoed a lot them with a water brake dyno or some were used as gen sets. We loaded them with a water ground tank. They were Deutz diesels all using Bosch systems. The pre-cups rattle just like my Kubota.

 

[SkyPup]

</font><font color="blueclass=small">( Rob:

A big contributor to diesel engine noise is injection pressure as well as combustion chamber shape. As injection pressure rises (to meet applicable emission levels), the "clatter" gets louder.

One notable exception to that was the Caterpillar 1693 TA. It always sounded like it had a bunch of ball bearings rattling around inside. )</font>


Each injection event on a modern high pressure diesel injection system is about equal to firing a .22 Magnum rimfire round in energy and speed, thereby resulting in the greater amount of noise emissions.

 

[5030]

HGM:

Caterpillar isn't using the Hydraulically Actuated Unit Injection on their new engines. They have went to compound turbocharging and paid the EPA fine for particulate emissions. However, next year, 007, Cat will have to add an EGR system like DDEC has in place now along with particulate traps in the exhaust header. MB as well as Volvo have the EGR also. DDEC's EGR units are causing a bunch of headaches and the fuel mileage is down the toilet as is Caterpillar. My '06 Cat is right around 4.5 and so are the Detroit's. Of course, the consumer will pay for the difference in the long run. The benchmark of '07 will be that the exhaust will be cleaner than the intake air....but at what price?

Cummins of course is out of the Class 8 market, concentrating on smaller vocational units and stationary power. The rub is that it will all spill over into the consumer marketplace with diesel pickup trucks and car engines being outfitted with the same gadgetry.

The thing that just astounds and amazes me is that the engines made for the agricultrial market have no such emissions gadgetry and still meet Tier 3 and eurpoean standards while using non electronic injection, no EGR and no catalytic conversion units in the exhaust tract.

I don't know the answer but it seems to me that the large displacement diesel engine builders either cannot or will not accept design changes that will make their engines emission compliant and still maintain a reasonable level of efficiency.

Physically, if you took a fully dressed DDEC3 engine and placed a fully dressed DDEC4-5 engine beside it, other than the distinctive green colored block and domed valve cover, the engines don't look or sound anything alike. Caterpillar on the other hand, other than the huge compound turbo assembly and the air to coolant heat exchanger don't look or sound all that different. I can't really comment on Volvo or MB physically, I just get close up and personal with Cat and DDEC.

In light of the '06 emission requirements affecting engine longevity, DDEC has reduced their warranty on internal engine components, camshafts and injection parts. Caterpillar has went to a subsidized warranty.

In our shop, I used to never see a green motor in for repairs. They were always yellow. Now green has outpaced yellow and MB is a strong contender too.

 

[RalphVa]

I used to turn my old 220D by hand using the fan. Think the manual on my 240D says to use a wrench on the driveshaft pulley. Did my 220D valve adjustment a couple of times myself. Have always had a shop do the 240D. Get it done about every 2-3 years.

Guess that diesel clatter is injection ignition clatter, from what other folks are saying.

I remember an old Chevy pickup once that came into our service station, clattering away. My dad adjusted his valves for him, and it idled gentle as a lamb. This was before Chevy went almost exclusively for hydraulic valve lifters.

You're supposed to do the valves stone cold. My dad did the Chevy's while it was running. You'll end up with more clearance cold doing them warm or hot in most cases because the valve stems will expand more than the overhead valve hardwear above the head. It's also kinda nasty doing them while the engine is running. Think my dad was looney in some cases. He'd grab hot spark plug wires in his bare hands, too. He's 86 now.

Ralph

 

[Posterboy]

5030

"Cummins of course is out of the Class 8 market"

Where did that come from?

 

[5030]

Tim:

Cummins Engine could not make the cut as far as emissions requirements were concerned for 2006 and unlike Caterpillar, they declined to pay the fine and continue making non-compliant engines.

DDEC, MB and Volvo were all compliant in '06 though for '07 more advances in emissions control (and the corresponding loss in fuel efficiency) will have to be made as well as changes in the fuel delivery system to accomodate '07's ULSD fuel.

Speaking of ULSD fuel, I wonder how agricultrial engines and tractor engines in general will act on the new fuel. The sulfur is a lubricant for the injection pump and injectors and the absence of it will probably have a detrimental effect on those components. I know for certain that Mr. Lucas and I will become good friends.

Cummins Engine still builds engines, however, not in the class 8 on road arena. Personally, I've always considered the new generation Cummins engines to be glorified boat anchors just like the 2 stroke Detroit engines........just an expensive way to burn diesel fuel..... /forums/images/graemlins/grin.gif