Optimum cruise rpm.

[bn69stang]

If a member wanted to take there fe on an extended road trip , what would be an ideal rpm cruise range ? .. Bud

[turbohunter]

Thought about this a lot since I take my truck on many long trips.
To me it would revolve around the engine you have.
For instance, with my old 360 I cruised to Montana at 2500/2600.
My new 441 I will try for around 2000. It has a heck of a lot more torque.
All theory for me now until I do it though.

[chilly460]

Definitely depends on the combo. 

Been very impressed with my current 390 as far as street manners.  750dp, Performer RPM, Edelbrock heads, Tri Y headers, 9.5:1 compression, Comp 270H. 

It would easily cruise at 2000rpm pulling a 3.00 gear and did 15mpg on one long trip I took with that gear. 

[ScotiaFE]

Optimum cruise rpm. eh
Enough to not get run over by Mary in her econo box Kia.
I've done lots of 1000 km plus runs at over 3000 rpm.
Ran the 428 with a 3.50 on a full run across Canada. Navy Base to Navy Base and back

[Lenz]

Got a feeling I'm gonna find this out pretty soon.  The only thing I haven't pulled apart on my 445 build is the rear to count ring vs. pinion teeth, don't trust the previous owner, I've changed out the entire driveline north of there and there aren't any tags to give me a ratio.  One thing for sure, we are about to have fun.  My neighbor's 15 going on 21 daughter came over when I fired it up and called what she heard "bragging rights".  The kids are alive and well .  Ya gotta love it when a plan comes together.

[chris401]

Seems big blocks will sip less fuel under 2400 rpm.

[Drew Pojedinec]

Optimum for what?

I have a 390 that cruises at 2,350, a 429 that cruises at 3,000 and had a 7.3 liter diesel that cruised at 3,300rpms
and don't anyone think a 7.3 liter diesel cannot cruise at 3,300rpms for 270,000 miles, because it can

For fuel economy, the lowest amount without lugging is good.  Your converter and cam might have something to say about all that as well.

[BigNate]

1) I agree with Drew - the lower the better if you are looking for a comfortable cruise...
2) ScotiaFE - I've gone 20 - 30 miles in an FE powered vehicle at 3000+ RPM and by the time I got there I had considered sticking a spare key through each ear-drum to make the droning go away.  It amazed me that the sound that I love so much could become a sound I was done with in such a short period of time.  Did you wear ear-buds with gun muffs over them or something?
3) Len - you don't need to pull the pumpkin and count teeth if you don't want to.  Unless you are worried about 0.01 level accuracy re the ratio - you can know where you stand by counting and comparing revolutions of the shaft and tires.  Rather than write up the details - I'll point you here:  http://www.jedi.com/obiwan/jeep/misc/gearratio.html

[ScotiaFE]

2) ScotiaFE - I've gone 20 - 30 miles in an FE powered vehicle at 3000+ RPM and by the time I got there I had considered sticking a spare key through each ear-drum to make the droning go away.  It amazed me that the sound that I love so much could become a sound I was done with in such a short period of time.  Did you wear ear-buds with gun muffs over them or something?

I`ve run into town with open pipes.
I live a fair hike from town. lol

[chilly460]

2) ScotiaFE - I've gone 20 - 30 miles in an FE powered vehicle at 3000+ RPM and by the time I got there I had considered sticking a spare key through each ear-drum to make the droning go away.  It amazed me that the sound that I love so much could become a sound I was done with in such a short period of time.  Did you wear ear-buds with gun muffs over them or something?

Exactly!!  I put 4.10s in my car to pick it up around town, so I'm now cruising 2500rpm or so just to run 50mph.  Car isn't really loud, but with Hooker Aerochambers it's not exactly quiet....tried cruising faster and it gets pretty obnoxious for long stretches.  I did 30mi up/back to Carlisle and had to run it up to 60mph to not hold up traffic, 3000rpm for a few miles was irritating.  That said, I've driven a 4.10 geared FE with very quiet mufflers, no problem at all, so the exhaust definitely has a huge impact. 

I went from 15mpg to around 8mpg in the switch from 3.00 to 4.10s so even if I could quiet the car down, I would still consider 2000rpm or so to be "optimal" with my combination.  As others have said, unless in an extremely heavy car or truck pushing a bunch of air and big tire, have to think that getting RPM down is always beneficial if the cam will allow it. 

[Ford428CJ]

In my blue beast with a solid roller 428. I ran about 2,000 RPM. Got 14mpg and had a ton of power for what I was running..

Drove it to Texas and back to Oregon... I miss it...

[chris401]

Optimum for what?

I have a 390 that cruises at 2,350, a 429 that cruises at 3,000 and had a 7.3 liter diesel that cruised at 3,300rpms
and don't anyone think a 7.3 liter diesel cannot cruise at 3,300rpms for 270,000 miles, because it can

For fuel economy, the lowest amount without lugging is good.  Your converter and cam might have something to say about all that as well.

If you said 6.0 Id call bs. No one would keep repairing and no company would keep you on for tearing up there trucks. I did run my tired 500,000+ IDI 7.3 down the devide 80mph in 3rd around 3800 rpm's. The throttle body gas engine are better for engine braking.

[My427stang]

FWIW my first iteration of my Mustang seemed to have a fixed fuel economy

433 cid, Offy Portosonic, 1000 Holley, Isky 300/250 108 LSA on 105, iron heads with 2.15/1.67 valves and a 4 speed big in out

From Las Vegas to Bishop CA - 3.70 gears - just under 14 mpg

From Las Vegas to Anaheim CA - 3.00 gears - just under 14 mpg

Both were with 28 inch tall tires, so my guess is that the 3.70s were about as tall as then engine liked and there may have been a difference between 3.70 and 4.11, but those were the numbers with the parts I had

Surprisingly, the 489 FE with more compression, heavily worked alum heads, about the same cam (sorta) EFI, a 5 speed, 4.11s gets........14 mpg LOL

[Drew Pojedinec]

If you said 6.0 Id call bs. No one would keep repairing and no company would keep you on for tearing up there trucks. I did run my tired 500,000+ IDI 7.3 down the devide 80mph in 3rd around 3800 rpm's. The throttle body gas engine are better for engine braking.

Company?  I owned the company.  and the truck was an 89 f250 with  7.3IDI and a c6 transmission.
Cruising at 65mph just resulted in that kinda rpm.  At that 270,000 miles I put a zf5 in it.  Man, that was awesome.
Best combo I've found so far?  My Galaxie has 4.30:1 rear gears and a GearVendor....  Perfect for my usage.  Tho if I were to do a lot more open highway cruising I think 3.89 woulda been nicer.

[machoneman]

Drew, with the GV unit and the 4:30's , what was the effective ratio when the GV's unit was engaged?