Running engine at 800-900 rpm in neutral

[Duffy1]

I was informed by one of our club model A gurus that it was not good to rev the engine up in neutral. He said you need to have the engine under load when running higher rpms. Appreciate your input .Thanks

[Patrick L.]

Someone says that you can't run the engine at 900 RPMs in neutral. Really. I think someone is pulling someones leg, I'll let you determine which one.

[1931 flamingo]

Did he happen to say why?? You can't believe everything someone tells you, but if it's on the internet it has to be true (chuckle, chuckle).

Paul in CT

[Tom Wesenberg]

1000 RPM is OK, but other than a quick blip of the throttle I don't like to go high revs in neutral. When the engine is under load it's compressing more air, which helps to cushion the sudden direction change of the piston at the end of the stroke.

[Jordan]

I would think it would be better to run it at a fast idle than a slow idle.

[700rpm]

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Why would you want to do that for any length of time?

[Bill Steiner]

Does not make sense. I can see no reason this can do any harm. Bill

[Duffy1]

I need to charge my AC which requires the engine to turn about 800 - 900 rpm before the compressor starts working .

Tom ; Thanks for the informative response .

[160B]

Originally Posted by 1931 flamingo

Did he happen to say why?? You can't believe everything someone tells you, but if it's on the internet it has to be true (chuckle, chuckle).

Paul in CT

State of disbelief, you can't put anything on the internet that isn’t true; I know I heard it on the internet!!!

https://www.youtube.com/watch?v=rmx4twCK3_I

[Jim/GA]

Won't hurt a thing.

[Mitch//pa]

has others have said maybe the guru bumped his head

[CarlG]

I wouldn't call 800-900 rpm "Reving-it-up". 1500-2000 would be!

[Purdy Swoft]

800-900 RPM would just be a fast idle. Some performance cams need to idle at that rate.

[MrTube]

Both of my 2012 cars idle at 750rpm. Before anyone attacks modern engines, these little 1.4 liter engines peak torque at 1700rpm and hold it to 5500rpm so I wouldn't say they are bad.

Anyway, my feelings are the model A's engine could run at 1000rpm 24\7 with no load on it with a little timing advance and the proper fuel mixture.

[modelAtony]

My engine builder of inserted engine told me to button it up, crank it , if no leaks idle up to 1400 rpm and let it run for 10 hrs while keeping a close watch on it . His directions to me were after that, it is now fully broke in . Fooled me but he was correct. Pushing on 55,000 miles in 4 years have fun modelAtony Lafayette, LA

[Mad Mac]

After I had my stock engine reconditioned professionally I imagined I heard a bearing knock so I took it back to the reconditioner. After listening to it for a while at slow speed in neutral he increased it to maximum revs and held it there for about 10 seconds. I was horrified and thought he was ruining a new engine by doing that. He then looked at me and said "Nope, nothing wrong there". That was about 20,000 miles ago and she is still going strong.

[ctlikon0712]

"The thing about quotes on the internet is that you cannot confirm their validity."
Abraham Lincoln

[40 Deluxe]

Originally Posted by Tom Wesenberg

1000 RPM is OK, but other than a quick blip of the throttle I don't like to go high revs in neutral. When the engine is under load it's compressing more air, which helps to cushion the sudden direction change of the piston at the end of the stroke.

Two questions about the "cushion of air" theory: What about when you're running say 40 or 50 MPH and back off the throttle to slow down? You're at high revs with suddenly no load on the engine, and you do this dozens of times on every trip!
Next, what about the exhaust stroke? On every other revolution of the crankshaft, your pistons are coming up to top dead center and suddenly changing direction without the benefit of any "cushioning" effect!