4 cylinder vibrations

shafshak · Feb 19, 2011

hi,i was wondering if anyone noticed any excessive vibrations on your LS tractor with four cylinder engines ,when
running at high idle (pto speed) ? the reason i ask is, the kubota guys
complaining about a vibration problem on their 4 cylinder engines ,not on the 3
cylinders.thanks again and still looking

Dirt pile · Feb 19, 2011

I've run my R4041 for about 5 hrs at 2150-2200 rpm with no noticeable vibration.

LittleBlueTractor · Feb 19, 2011

Nothing like that with the 4 cylinder 28.8 hp Mitsubishi in my S3010 with the PTO engaged or disengaged at any throttle setting. If it is only happening while the PTO is engaged I wouldn't think the problem is with the engine in any case. Let us know what it turns out to be if they get to the bottom of this one.

rocknrod · Feb 20, 2011

In 1931, Mitsubishi developed and manufactured Japan's first diesel engine. The first Japanese company to recognize the match of Japanese reliability and diesel efficiency.

They even made them under Willy's License for their jeeps.
They are even using them in race cars now.
Jalopnik: Obsessed With The Cult Of Cars
They make them for marine and train applications. Ive seen them up to 4399 HP.
They are awesome engines.
I also think there may be issues elsewhere.

Although contraversial in the "forum world" the SAE international states that the vibration levels are higher for the 3-cylinder versus the 4-cylinder engines (you can buy the SAE paper here):
Downsizing of Diesel Engines: 3-Cylinder / 4-Cylinder
Of course those are real engineers taking real vibration analysis. Not forum engineers taking seat of the pants readings. So we all know who will win that argument on a forum.

Inline-four engine - Wikipedia, the free encyclopedia
"...The inline-four engine is much smoother than one, two, and three cylinder engines, and this has resulted in it becoming the engine of choice for most economy cars, although it can be found in some sports cars as well..."

[FONT=&quot]Kubota[/FONT]'s 135 HP/118 PTO horsepower tractor has a 6.1L four cylinder - Their B series "new" tractor is using a 4 cylinder.
Their [FONT=&quot]SVL75 and SVL90 Compact Track Loaders are also.[/FONT]
Wonder why?

No I really dont think it is the engine, and if it is they need to have it looked at.