when I put together my 2.3 liter shortblock I had to get rid of the balance shafts because if I didnt the rods were going to hit one of the balance shafts. I dont use the normal crank in the ams kit though. I went with the eagle 100mm crank. Also I really don't think the vibrations are bad at all. Although I dont daily drive my car I know it is reliable enough to do so. The vibrations seem to be most noticable in mid rpm ranges around 3000 rpm's. Not bad enough to complain over though. I can sit in the car and free rev the car and it does fine also. But I did take my time and do everything right. balanced the ENTIRE rotating assembly. Even the pistons. which arent usually too far off in weight of each other.

 

I have quite a noticeble increase in vibration. At idle especially. Dynamically balanced 2.3L and no balance shafts. It's unfortunately causes a perfect "sleepy time" vibration and damn near causes me to go comatose if I'm sitting in traffic.

 

So, how do you get a V6 perfectly balance? Why would an extra 2 cylinders allow perfect balancing when 4 wouldn't ?


And if its possible, how do you get a 4cly perfectly balanced?

 

2.4L stroker + no shafts + stiff mounts is ridiculous. Feels like the firewall is being attacked by storm troopers.

 

I have been contemplating if I should use balance shafts or not for my new 2.2 Magnus stroker.

I will use a Fluid damper.

Anyone with experiences of 2.2 without balanceshafts ?

regards
Gudmundur

 

Actually, V6's and V8's can NOT be perfectly balanced. When they are balanced they are optimized for a given rpm range. Because of the V design you cannot find one balance weight that will be optimal for all possible speeds. Now the inline 6 on the other hand, that's a smooth motor

 

Fiat/Lancia started using balance shafts in the early/mid 80's. To sell cars is where the buck stops regardless of make and a smoother motor might lure another sale or two (sales gimmick?) The electronics that came into use about this period are sometimes suggested as a reason to use the balance shafts, less vibration hence less interference. In the pursuit of power turning torque can be reduced by removal not to mention one less drain on oil pressure. Frictional loss merits attention IMO.

Nik

 

Even my 2.0 with no shafts + stiff mounts was a shock compaired to stock.

 

Just an update.. I finally got around to installing a fluidampr I had sitting here the last year or so and it seems to have entirely eliminated the extra vibration I was feeling from 3-4k rpm.

 

That was my question...people that added a Fluidampr to their 2.3 w/ no balance shafts. Seems crcain said it almost eliminated the issue for him. Anyone else?

 

It made a significant difference in my car at all RPM ranges.

 

we have run quite a few 2.3s now...

and from different companies... with the fluidamper and no shafts isnt bad at all.... surprised me after previously doing them with bs's.

cb