Owners of 2.2, 2.3, 2.4 motors with no balance shafts. How do you describe the extra vibration of these engines? When and how does it feel or sound?

Same question re: crankcase pressure. Is it correct to say more stroke in the crank causes more crankcase pressure?

 

my rotating assembly was all balanced there really isn't much of a difference. I don't notice it.

Crankcase pressure comes from blow-by

 

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Do that and top it off with a fluidampr. It won't be bad at all.

I have solid mounts, cams, and no b/s in a built 2.0l DSM. And its not bad at all.
The 2.4l might be a little worse, but if properly balanced and dampened it won't be excessive.

 

Wow I thought it was common knowledge strokers and no balance shafts meant more vibration. The way you two are talking it's like that is not true.

I've finally swapped my 2 litre for a 2.4 and I can tell you there is more vibration that is for damn sure.

And to the guy above saying solid mounts don't make vibration.... my friend had an Evo 6 with solid mounts and the whole friggen car shook at idle!

 

Listen up dude. You asked the question. If you think you already know the answer, lets save us all a fight here. Why post it?

I HAVE a built and properly balanced 2.0l with prothane mounts, cams that lope like a *****, and its not that bad. But, I also have a fluidampr and went to great care to balance every thing connected to that engine that spins.

A 2.4l might be a little worse, but what I'm trying to say is simply not that much worse than a similarly equipped 2.0l

Read what I'm saying. I didn't say it doesn't make ANY vibration OH NOES
I said its simply not that bad.

 

 

Man sorry I can't be bothered to tell you what I'm thinking now because I'd feel like a real poor human being if I sat behind my keyboard making personal attacks at people I don't know.

Back on topic....

The point of my thread was for people with longer stroke than standard and no balancer shafts to talk about the type of additional vibration they have incurred.

Discuss!

 

A properly balanced rotating assembly (longer stroke or not) wont have more than normal (factory) vibration. The balance shafts help elimenate the machining differances from the factory. (because we all know mitsu isnt going to spend the dough to balance every assembly one by one.) If the shafts were elimenated and stiff engine mounts are installed, you will experiance slightly higher ammounts of vibration, but nothing horrible. Just like if you install cams, you will expect to recieve a rougher idle and vibration from them compared to the factory camshafts.

 

My JAM 2.3 is smother than stock, but it has the balance shaft in it.

Jackson said there is to much internal harmonics in the stroker to take it out. Plus leaving it in helps with the longevity of the motor.

 

I would like to see difinative proof of that. I dont see how a properly built engine that has been balanced correctly wouldnt last as long as one that had the shafts in it. If anything, running the balance shaft belt is just 1 more thing to break that would take out the timing belt causing that engine not to last as long. Plus the engine with the shafts removed would be able to rev quicker and have a few freed up HP & TQ than the other. (again, I would like to have proof of that too)

 

our jam 2.3's purr...

and i prefer the oil pressure to remain similar to stock.

cb

 

CBRD.. when you say the JAM 2.3 purrs.. does that mean it basically has no more vibration than a factory Mitsu 2 litre? If there is any added vibration, where and when do you notice it?

 

This is not true. The balance shafts eliminate the inherent 2nd order vibrations found in all inline four cylinder engines. No matter how perfectly balanced your rotating assembly is, your inline four will have vibrations that cannot be eliminated without balance shafts.

 

And when and how do those 2nd order vibrations manifest themselves?

At idle? At a certain rpm range? Is it a high frequency type of vibration or more of a judder?

 

They're up-and-down vibrations, and they occur all the time, at twice the speed of the crankshaft.