addballer696

Im planning on going on the hot rod power tour this year and will be driving my 77 corvette for hours on end on the interstate. When going 65 mph my rpm's are at 3600. Should I be worried about running my engine that high for that long?

forvicjr

If its dependable around town chances are your good,just watch your temp and oil pressure, and let it eat!

Fay vette

Thats high for 65. My 77 run 2500 to 2600 at 65 (350 turbo tranny). I don't tirn 3600 until about 77 or 78 mph. You sure your trans is operating properly and shifting into 3rd gear? I had a problem 2 years ago that it was running 2nd gear only and thats about what it was turning at 65 when I had the problem. $1,350 rebuild and its shifts great now. Search some of my old post on it.

Those are nice wheels, what kind are they? Where did ya get um?

FRSTR90

At 70, my engine use to turn about 3200rpms that is with a 3.55 rear end. Sounds like you might have a 4.11 in the back..

Bowerss2

milo30

That's about what mine turned. I drove it from Texas to Chicago and had no problems. If it's mechanically in good shape, the oil pressure and water temp is good you shouldn't miss any gas stations where ever you are going.

Fay vette

http://forums.corvetteforum.com/c3-t...ate-speed.html

Here is my old thread on it.

7T1vette

To answer your question... Yes. You should be concerned about driving long distances at that elevated engine speed. Engine wear is a function of engine speed, operating temperature, load, etc. etc. Thus, your engine will get a lot more 'wear' during highway runs than it needs to do. Your cooling system will be doing more work and you will be burning a lot more fuel just to make the engine rotate more.

Now, should you be concerned? Well, if you don't mind the noise, the poor fuel mileage, the extra heat, and the reduction in engine life...NO. Since you have a very 'low' rear gear for performance purposes, your solution is to 1) just deal with it, 2) change the rear end to a 3.36 or lower ratio, 3) install an overdrive transmission.

P.S. If you choose to go with "Door #1", you might want to consider using full-synthetic oil in your engine. It will perform better and last longer at higher temperatures (internal) and improve engine life as compared to organic oils.

Lee H

Put a real good tune-up on it, set of fresh hoses and go. It'll be a blast.

addballer696

Thanks for all the advice, i would love to switch out my gears, but don't have the money right now. Forgot to mention its a 4 speed and hits every gear so thats not an issue. Never had an problem with oil pressure or engine temp so I guess ill take my chances, drive around 60 mph and keep her on mostly highways. Thanks for all the help.

toddalin

Do an oil and filter change just before you go.

C3 4ME

First of all, are you sure your tach is reading correct? Mine in my 79 was reading a little high on a 5 hour road trip last month. It was showing right at 4K running about 75mph, and I verified it was reading high. I'm pretty sure I was running around 3-3500 rpm the whole way, and that didnt' bother me at all. Temps were fine, oil pressure was too.

Lon Wayne

Nutin to it we use to fill the old 455 ? big block fill it with food and men and drive for 20 hrs straight .just stoping for fuel.did the trip 3 yrs in A row. 70&75 all the way never had a tach if we did Im sure we would have covered it so we would not the RPM. Ohio to Daytona .1000 miles each way.Its A Chevy.

Lemans Blue 69

For what its worth, 69 with close ratio tranny and 3:70 rear end. Factory. At 65 I'm turning 3000 RPM, at 80 I'm turning 3500 RPM. I'm the original owner and never had issues. Change oil on a very regular basis.

toddalin

Speedo needs calibration.

If you're turning 3000 at 65, you're turning about 3,692 at 80. If you're turning 3,500 at 80, you're tuning 2,844 at 65.

KTKelly

Last I had the 69 (350/350 4spd) at 65 I was turning somewhere around 3200...


Rear tires were a bit undersized (265/50-15) so that would have had some small amount of effect.


Didn't hurt anything but my pocket....

thegazman

I have a 79, L-82 with a 3:70 differential and I run around 3500 rpm at 70 mph. Great around town, but not a good trip car. My next project is an overdrive transmission.

joewill

i am sure there will be lots of 4.11s and 4.56s at the power tour. mine had a 4.56 when I bought it. I would not put it on the highway, just took the back roads and always kept it under 55. I couldn't live with that. so it was was one of my 1st projects to put a 2.73 in it.. now 2000 rpm at 60.
you don't have to do the entire power tour. just do some of it. if you like your gears, keep them. but several posts above tell you the consequences..

power tour is pretty cool, I missed them 2-3 years ago when they went close by.. I regret not going.

Brown78

I just wrote a paragraph on you Delmor. And it just disappeared. To the abridge version.
Hope to see you at the TRPT Don't waste your money on a gear change out. I went from 373's to 308. The little change wasn't worth the money. I installed the Keisler TKO 5 speed. Now at 85 mph I rev 2400 rpm's The road God loves me and so dose my 78 Vette. I've put 40,000 miles on in 3 years. I do a lot of driven. Didn't build it to set and look at her..

wbelleau

My C3 1976 Corvette runs very well under 60 miles per hour. However, when I hit above 55 miles per hour. I will be pressing the gas peddle and it sounds like my corvette is not getting gas to the engine. It will accelerate and stop accelerating while I am pressing the gas peddle going above 55 miles per hour on the interstate. Does this make sense? I am an amateur when it comes to working on cars. In matter of fact I have been paying a mechanic to fix my car. Does anyone know what I have to do to fix this?
I have replaced the fuel pump already.
Does my engine need to be rebuilt?
Like I said it only acts up at 55mph to 60 mph plus.

What part of the motor is in charge of going high speeds?
What all should I get looked at?
What all should I get replaced?