Hot Rods 327 engine rpm advice needed

im planning on driving my 34 ford to bonneville this coming year ( 2000k miles one way).. Im running an all rebuilt 66 corvette 327, tri power, t5 trans with a .79 final drive, 4:11 banjo rear and 31 inch tall tires. thats is going to put me at 2495 rpms @ 70mph.

all the traveling across the country i have done has always been in a cummins diesel pick up. so you try to stay under 2100-2200.......

is the 2495 a comfortable range? should i switch to 3.54 rears and drop it to 2056 rpms? the cost will be about a grand to switch the gears. Or should i run the 411 and not worry about it?
this is my first SBC . used to a flathead in my other coupe.

thanks guys

 

If you indeed have a rebuilt '66 Vette 327 as in stock except for the 3 deuce setup then you don't want to drop your RPMs much lower then you already have. A lot depends on which '66 Vette 327 you have but it is no doubt going to be happiest in the 3K range. What you want with any engine diesel or gas is to be near the bottom of your torque band for best mileage and engine life.

Your mileage will also be effected by when your secondary carbs are starting to open as well, if you are pulling on all 3 at that RPM you may want to readjust your linkage. you want to cruse on one carb and only use the other two when you are getting busy.

 

Ive put a lot of miles on that combo ,I have the 411 in one car and the 355 in my coupe and both work good with the 327

 

I got a model a with a 300 horse 327 with a 4 barrel, 4 speed, and a quick change. Im running 3.08s in it and I like to cruise at about 80 mph or a little less, at 2800 rpms

 

its rebuilt, without to much rambling details, . stock bore, new rods, mains and piston heads, it has a mild cam and slightly oversized stainless valves. nothing special ..
so with 411 i am actually in a good range,
currently the tri power has block of plates under the front and rear carb, mainly because the guy who had it was afraid he couldn't tun it right, so he soldered the fittings shut in the fuel block and put plates under them.

 

the 300 horse to 350 horse 327s are most comfortable in the 2800-3200 range for cruising. That is where they start to climb up on the cam.

 

You'll be fine.

 

thank you. i feel alot better about this now. i really didnt want to drop a grand on 354 or 325 gears... or even worse, a quick change for 35 and newer axles, then have replace mine ..
engine numbers wise, mine is a 350 horse 327.

 

The 350 horse engine was a good engine. With the stock cam it would like a little more air then you are feeding it though that carb but it won't hurt it any, it just has a lot more potential then it is giving you now. Stock you could squeeze 375 out of them with a good tune.

All that said your cruising RPM is good and that is what you wanted to know.

 

A 4.11 with .79 overdrive is the same as a 3.24 many 327 4 speed cars in the early 60s came with 3.36s.

 

Wouldn't be too difficult to swap that trans for the proper one....a Muncie 4 speed. Then it would be perfect.

 

what squirrel said. there is nothing sounds better than high hp 327 rowing through the gears tom

 

I think you'all be fine however, you could put taller tires on it for way less than 1K. g

 

Then take the tri power off and replace with a 4 barrel & manifold.

 

You will be fine. Engine will not have any issues, and the rpms around 2500 will help mileage a bit as compared to 3000 rpm range without OD. Run the combination you have and enjoy the trip!

 

If you dropped the cruising speed to 65 mph with that combo it would be at 2287mph.
Just drive it off the tacho at what feels comfortable.

And make sure the vacuum advance is working OK

 

And remember that your car is way lighter than a 66'/3600 pound Corvette..Have you been on any trips or even around town figured your gas mileage? Just curious..And I'd put it at 80 mph and stay out of every ones way; bet the gas milage would be even better than at 70'..

 

I'll take that bet!
From 70 mph to 80 mph is an increase of 14%, this will require an extra 30% increase in the minimum horsepower needed to overcome the increase in aerodynamic drag .

 

You lost...You just got figures which you are using for across the board, I'm talking about the actual car..Now go find the OP and go for a ride in his car and take notes..

 

You are absolutely right!
The laws of Redneck Hillbilly Engineering will always Trump the Laws of Physics.

Based on your guessing abilities you've figured out his camshaft specs, BMEP, BSFC and also found some way of reducing Cd as the speed increases

 

trust me.. i love a muncie. But for some reason the locals think they are worth $1500 a pop, with no bell or shifter.. Thats OK! ill stick with my nice cheap T5 that will hold up just fine for a driver.

im running 700-16 on the back now. could only go to 7.50-16 i almost went with a set of 18's but the divco milk truck wheels are impossible to find

 

eventually the tri power will be working properly... the tri power is a vintage setup. i want to keep it that way

this car is still being built. Trying to have it done for spring time. so other than driving it in and out of the garage, its never seen the highway

 

here is the car,

 

For probably a lot less than $1000 you could change out your overdrive in the T5 to a 0.63.

 

More like $250.00..No need to change anything,,get the tri power working just to eliminate poser and go..For cruizing , never gonna be on the end two unless you trying to do an impressive quick pass...Leave it alone, work with what is there, it will work..

 

I have made the trip in the car pictured. Its much like what you have, except heavier. Before the trip, use two coats of Rainex on the windshield. You may have to drop a gear a couple times west of Cheyenne. Enjoy the trip. Keep an eye on the dip stick. An engine that never uses any oil near home may take a quart when working hard in the Rockies.

 

Phttttt

I just wanted to say that.

 

No, Don't have to guess..What ever the op does or doesn't do from asking question here...Some one with a slide rule said can't get over 150 in the quarter..Again I am talking about that specific op/car/engine and what I said was that gas mileage would be better at 80 than 70...So this redneck hillbilly [in the center of CT too!] Says Phttttt ..