rpm range?

[69sixstang]

i am new to this six cylinder thing, I need some help from those of you that have your cars together and drive them. I have never drove my car so i have no idea what i am up against. I have the formula to figure out rppms at a certian speed speed mph x final drive ratio trans x rear ratio x336 divided by tire diameter = rpm . What i need to know now is where do these motors like to run??? my combo is 200 single 1 barrel ( larger than stock late 70s ) t-5 v-8 trans , clay smith cam 264/274 110deg, hooker super comp headers, 3.55 rear gears , dui dist. at 60 mph 5th gear .68 od 26 in tires == rpm 1850 est is that good??? to high , to low ??? let me know from you alls experiances . look like 70 mph will be about 2100-2200 rpm I want to drive this car around town and on highway both , so i need something good for both.

thanks mark taylor

 

[Rustang Racer]

Unless the bottom end of the engine has been professionally rebuilt and balanced, you probably don't want to rev the engine much over 4500 rpm. Peak torque on a 1965 200 was at 2400 rpm. My thinking is that cruising at highway speeds you would want to be near peak torque, so 3.55 is close. 3.73 would probably work well too but cost a little more gas. I had an almost completely stock 200 in a 65 mustang with a T-5 and the stock 3.20 rear end and the combo worked pretty well, but I think my tires were closer to 24in. These engines have pretty decent torque over a wide rpm range so you won't have any problems as long as you're pretty close to the right gearing.

 

[Bort62]

Crusing along on the freeway you don't want to be much over 2500 rpm or you will feel like the engine is trying to explode.

And my last engine did. 80 mph w/ no OD and 3.89 rear on 23.5" tires = dropped valve.

Closer to 2000 rpm @ cruise speed w/ a stock engine is even better.

 

[BUZZ]

Sounds like you have it set up well, 2100-2200 rpm on the hiway is good, but with your set up if you need power for passing or if its lugging while your driving around town all you have to do is drop it back to 4th gear. That should put you right into the middle of your cams power range I'm thinkin' bout 3100 rpms @ 70mph. I wouldn't change anything, that's pretty much the same set up that I'm wanting to build.

 

[sp_alloy_head]

... look like 70 mph will be about 2100-2200 rpm I want to drive this car around town and on highway both , so i need something good for both.

thanks mark taylor

don't forget to make sure your brake system is up for this type of power too. Maybe replacing the single jug M/C to a dual reservoir if haven't already done so.

 

[CZLN6]

Howdy Back Mark and all:

Here's a thought. Hook up a vacuum guage so you can watch vacuum readings at various speeds as you drive. Your set up is unique to you. Your one barrel will help your engine to build good vacuum, but the cam will reduce it some. What you'll be looking for is the highest vacuum reading at steady speeds, in both 4th and 5th gears, for best power and economy.

Keep us posted on your progress.

Adios, David