redmach

Well I've done some more puttering on the old 69, still can't get it to cruise like it should. To recap at first I thought it was the diff, turns out to be 3:25, posi, just what it should be. The tranny is a 4 speed toploader, also the numbers match. Next was the flexfan, a cheap aftermarket one that I replaced with the correct size 6 blade steel fan. Still the same problem. Today I even took it for a quick spin without the fan just to be sure. Still the same, maximum RPM's I dare to push it to is 3000, thats 65 MPH. I hooked up a tach to confirm what I thought was a much higher RPM, I figured it was at least 4000-4500 RPM's at 65 MPH, turns out it is 2500 at 55 MPH and 3000 at 65 MPH. Right where it should be with 25.9 in tires, right? Why does it sound like it's maxed out? It's a 351W with an Edelbrock intake and 4 BBL, pertronix ignition,headers and dual exhaust. It always starts and runs like a top, It just whines out way to soon for my tastes. I hit 4th gear at 35-40 MPH because it's whinig so high and by the time I hit 50 I wish I had a 5th gear. Is there anything I can do??? Help.

anthonydalrymple

What kind of shape are the valve spring in? What cam?

"It just whines out way to soon for my tastes." -You mean "wind out"? As inyou are applying gas but the rpms will not climb beyond around 3,000rpm? Is the ignition breaking up? It might simply be a worn out motor... Have you done a compression test?

redmach

Thanks for the reply, I still have plenty of pedal left, it just seems to be reving too fast for the RPM it's reading. At 60 MPH I should be cruising along, not listening to the engine sing like I'm still in 3rd gear. I assume it's a stock 351W, I do have the compression #'s from the last owner, I'll get them tonight.
Thanks
ps no breakdown at all, no coughing or sputtering of any kind. Runs very smooth.

anthonydalrymple

I re-read your post a couple more times & I think I now understand what you are saying.... You do not like how it sounds at 65mph, running at 3,000 rpm. You want lower rpms or to quiet the exhaust, right? Your formula is correct & the rpms for the tire size & gear ratio on your car are "right on". You can bring the rpms down with a taller rear tire. 3000rpm is not really screaming a motor, straining it, etc. My former 'vert had 3.27's, 26" tire, & the overdrive band in the AOD was bad. 3,000rpm every day on the highway until I put a T5 in it....

redmach

That's correct, It's not "loud", actually the exhaust has a nice tone to it. I really shouldn't have to lower the RPM's from 3K either. That is where it's supposed to be, the problem is it sounds like it's running 5K RPM's. Everyone says that car should just be hitting it's power band at 60, not maxing out the RPM's.
Thanks

97targa

Go under the hood while someone looks at the rpm's, run the r's up to 3,000 see if the motor seems as loud under the hood as it does on the road.
----Also if you have headers into glass packs, it will sound like your pounding the **** out of your car at low rpm's.
----Don't be fooled by matching #'s either, your tranny could be modified with aftermarket plates and gears.
----Lastly,-Check your rear end(what kind is it) stock? Gearing? If changed to 4:10 or higher(actually lower) your rpm's would fly off the charts, as well as your input speed calibration to match your gears. (You need to pull the cover and count the ring and pinion to be certain)
Alot of early on mods consisted of changing the rear gears for cheap torque. Now overpriced with $3.29 a gallon.


Reply back let us know

redmach

I have been under the hood while reving it up. Still soungs like it's whining to me. Even took the fan off to see if that was it.
I like your point about the headers though, I'm not sure what brand they are though. They are the longer style.
I jacked up the car rear and turned the tires while counting the driveshaft turns. Both tires turn in the same direction, 1 rotation per 3.25 driveshat revolutions. It's a 9" rear with no cover.It does have headers but not glasspacks. I don't know what brand mufflers they are. I can rule out the tranny because I can rev it up in the driveway to 3K and it seems like 4-5K
Thanks for the insight 97targa