Idles like a Rolls

[Horst]

Isn’t there this famous thing that a Rolls-Royce engine idles so smooth that a coin would stay upright?

Tried this today and I can confirm that our 151s are performing as well.

Unfortunately can’t upload a video to prove it , so here is only the still picture..

EB312511-571C-4769-8B9D-02F34B2FFA98.jpeg

[rickf]

If I remember correctly didn't you have your engine balanced when it was in the machine shop? If mine is idling low enough I can do that but as soon as it hits around 600-650 it get the mutt vibration. Whenever someone asks me about setting the idle I tell them bring it up till everything vibrates then back down a half turn.

[Horst]

First, this was of course not a dead serious post. As soon as I rev the engine a little bit, the hood will do the usual rattle...

Second, your memory serves you right. I had the flywheel and the pressure plate balanced. I also weight-matched the pistons, don't remember however how much accuracy I put into the process. Nevertheless the engine has significant less vibrations than the government rebuild A1 engine I had installed back then as an interim power pack but that is really no reference. I would need to ride in another M151 to establish a baseline how good you can be.

[rickf]

I thought you had the entire rotating assembly balanced. Maybe it was Mr. Dibbles that did that. I wouldn't want to be the machinist doing that job! Not much room to put all the weight need to balance a three main bearing engine!

[Horst]

I don't remember what I did with the crank. I had it at the machine shop but not sure if he balanced it. I remember that the shop said that for this kind of engine, balancing the flywheel and pressure plate would be a good cost-performance compromise.