Italian Tuneups: What's the longest you've run your engine at high RPM?

Why? The engine is designed for regular and has run just fine at higher speeds with regular. I'm not averse to adding some premium - in fact, I'll be filling the tank before taking off later today - but I'd be interested in hearing your rationale for doing so. Thanks!
Cheap insurance against the computer retarding timing.
 
1970 Plymouth Duster 340 which had only 21,000 miles on it. I put some performance bolt ons on the car and had a 4:56. Posi rear end with a 727 automatic transmission. I beat that car on the dragstrip as well as at home on a regular basis. I beat on it like rented mule. I am really surprised it never blew up but I changed the transmission fluid and engine oil very regularly. I ran it with open headers a lot and never was wrote up for loud exhaust. I was only about 20 years old at that time.
 
I tried it with my oil burning saturns. Meh.

What really worked though was water misting in the intake. And it was free!
 
Did you break anything? What gear were you in? Did you notice any change in the engine's performance afterward? Do you drive like that frequently?
Nothing broken. Car belongs to 78 year old in law. Never sees higher rpm. I stretch its wings about twice a year. And I am usually in 3rd or 4th gear. Don't drive the car enough to calibrate its performance afterwards. Car seems happy.
 
As someone previously stated, it helps clear the cat and related items. One mechanic at a Hyundai dealership said that he got in a Genesis driven by an older gentleman complaining of rough idle. He determined that the exhaust system was loaded with carbon and soot. He took the car out on the highway and floored it repeatedly. He said it looked like a diesel burning coal. After he got it cleared out all ran fine. Returned back to old gent who was happy with the result.
 
Once had a company outright lie to me about their financial, market, and organizational position as well as the role itself to have me leave a very high paying job in a boring industry. I was there five months and it was an absolute dumpster fire culminating in their realization that my position shouldn’t have existed in the region in first place (could have told them that after the first 3 weeks). They offered me a relocation to one of the most expensive areas in the country with no change to the comp package or a meh severance package.

Decided to take the package since I had re-engaged my previous employer in the previous weeks and knew they wanted me back. Of course they made me fly across the state to tell me this in person. I decided to rent a car and drive back home since what was I going to do sitting around a hotel with that decision kicking around my head? Ended up sitting at 4500 rpm for the last 45 minutes to an hour trying to burn off as much fuel as possible so they could enjoy paying the $10 a gallon Enterprise charged for airport refueling. That little Hyundai still did 45mpg at those rpms🤣.
 
I get concerned re ring ridge... When an engine is not regularly spun-up, the max travel of the pistons and specifically piston rings is not as high (or as low) along the respective cylinder bores
.. and when you DO spin it up, the rings can crack... when hitting the ridge. At least that's the theory. Not sure though that a moderately worn engine actually generates much of a ridge in any case...



I have not heard of this before. So piston travel increases as the rpms increase?
 
About 80% of the max RPM causes the rings to flutter in the lands which beats off the carbon and hopefully blows the carbon off the piston tops and combustion chambers.
 
About 80% of the max RPM causes the rings to flutter in the lands which beats off the carbon and hopefully blows the carbon off the piston tops and combustion chambers.
I'm curious how you know this, that the rings are "fluttering?" And how do fluttering rings blow carbon off the piston tops and combustion chambers. I'm having a hard time envisioning this. Can you help us out here?
 
About 80% of the max RPM causes the rings to flutter in the lands which beats off the carbon and hopefully blows the carbon off the piston tops and combustion chambers.
And they don't have to flutter for extended periods of time to blow carbon out
I'm curious how you know this, that the rings are "fluttering?" And how do fluttering rings blow carbon off the piston tops and combustion chambers. I'm having a hard time envisioning this. Can you help us out here?
He said "hopefully blows the carbon off the piston tops." ;) The operative word is, hopefully.
 
I have not heard of this before. So piston travel increases as the rpms increase?
Connecting rods stretch maybe a few thousands of an inch. I believe with improved metallurgy and design, plastic deformation has been minimized to the point of being negligible in most engines. Or maybe cylinders just don't wear as much as they used to.
 
Running engines at or near open throttle in the top half of the RPM range can be good, or bad, depending on how you do it. It's not just about RPM, but also at or near WOT in order to maximize BMEP and airflow through the intake & valves. Ensure it's fully warmed up beforehand, do it smoothly, keep it rolling (2nd gear or higher, not 1st) so there is sufficient airflow for cooling, and watch the temperatures. If it gets hot, shift to top gear and cruise to minimize power while maintaining airflow until it cools off. I did this on motorcycles all the time. A '74 CB-350, '78 CB-550, '92 GSX-750. Ran them hard, they saw redline on every ride, and they lasted thousands trouble-free of miles.

I also did this with a Ford Cobra V8 and a Wankel twin turbo. Same thing, they ran great for thousands of trouble-free miles. I believe that getting the valves in the upper range of their operating temperature can help keep them clean (not applicable to Wankels ;) ), and maximizing airflow through the intake and valves may wash out anything loose or liquid. An engine running at WOT peak power is moving more air than a vaccum cleaner or blower. On a new engine, the high cylinder pressures can also help the rings seat properly for better efficiency, power and reduced oil consumption over the life of the car.
 
Running engines at or near open throttle in the top half of the RPM range can be good, or bad, depending on how you do it.
Evertime I see some kid rev his engine to red line while standing still I cringe. Revving without a load on the engine is probably the best way to destroy the engine.
 
Wow, a lot of nervous nancys in here. Engine are made to be run and in my opinion work better when allowed to explore their entire powerbands on a regular basis

First of all, with any modern engine, ring ridges are a thing of the past. Better metallurgy, fuel injection, and oils have made ring ridges history.

second, an italian tune up is not putting the engine into a lower gear and just running high rpm, that really does nothing at all, besides make noise. The reason many engines benefit from an Italian tune up is exercising the piston rings. Knocking off carbon that may have built up in the ring grooves but most of all creating a better seal against the cylinder wall. High load is what presses those rings harder against the cylinder wall. It's also beneficial to do what some people refer to as reverse loading. Which could be described as once your done going wide open to redline locking the transmission into that gear and coasting down from redline, a situation which creates a long period of time with very high vacuum in the intake manifold.

This is a procedure that some have even had luck with decreasing oil consumption. I remember it being a thing with all the grandma driven 4.6 liter northstar v8's in caddies which would swill oil after being driven softly their whole lives.
 
You might notice the 2007 2.4 camry in my signature which is equipped with the notorious 2AZ-FE famous for their oil burning. After 275,000 miles and running it hard at times (not abusing) Since day on this engine has gone through a quart in 5000 miles. It doesn't burn more and doesn't burn less than 1 quart per 5000 miles.

anecdotal sure, but none of my engines have ever been oil burners by driving them hard from time to time
 
Go to a race track and get good... that will work the motor in ways you can't do on the street, period. I've run various motors at near full throttle for 30+ minutes at a time in RPM ranges that are 75%+ of redline and they're all healthy and happy. I do think it's good for them, as long as they have oil pressure, the cooling system works, etc.
 
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