What is a good 440 cruising/freeway RPM ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

[skip68]

I have 2.76 gears right now and am changing them soon.  I've got a 3.23 suregrip coming from AZ. soon and I might change the gears to 3.55 but was wondering what's a good RPM range to stay in for long drives ?  Right now at 70 mph I'm at 2400 rpm.   I just want to know what is a safe RPM range to stay in at 65 mph +/- ?        Thanks,   Chuck..........

[skip68]

I aked this in the other topic but I was thinking it should be here because my engine is in the 500hp range.  Right now my rpm's are at 2400 at 70mph.  I am changing the pig soon and was thinking of 3.55's.  So, my question is what is a safe RPM range to run at 65mph for a long drive ?    Thanks guys.       Chuck............

[Ghoste]

It's a bit of a trick question.  It comes down to how much fuel useage, noise level, and engine wear you can deal with.  A 440 will cruise all day at 2000, 2500, even 3000 rpm, but they are all going to affect the three parameters above in an obvious way.  It's a very reliable engine and you can turn up even more and run it but it begins to get hard to live with on a long haul for even toughest at the higher rpms.
How happy are you at the 2400 level?  Do you want to stay there, less is better for the things I mentioned but would you go higher without it bothering you?

[skip68]

I have 2.76 gears and I need 3.91's ron says.  But I still need to be able to drive on the freeway for trips.  I could give up speed to keep the engine running slower.    I was thinking on 3.55's for gears.   Noise and fuel are ok with me.  I just want to make sure I don't run it too hard too long.  So running at 2500-2600rpm all day is ok ?   I'm sorry but I'm new at performance engines.   Thanks Ghoste.   

[Ghoste]

I have 4:10's in mine and 2500 is about 50 mph or thereabouts.  It's a slow cruise but I make the annual trek to Columbus Ohio in it which is about a 5 hour drive each way for me.  The engine is fine, the fuel costs and noise levels are tolerable although I don't know that I would want to go a great deal further.  (maybe, maybe not)  I would probably turn it a little higher but there seems to be a bump in mine where right around 60 or 65 mph the fuel use goes waaaay up (four barrel tipping in I suppose) so that is the only downfall I find.

[skip68]

    Cool, thanks Ghoste.   I was thinking that I could just drive slower if it bothers me.  I think I want to make 2500-2600rpm my target speed.  Now back to the speed-rpm calculator site.   

[maxwellwedge]

2800-3200 is a decent range for ok (not great) gas mileage. My 4.10 cars are closer to 4000 - gets old fast!

[skip68]

         Thanks.    I think I'm going to try and stay in the 2500-2800rpm range. 

[Ghoste]

4000??  God God man, how fast are you going and how short are your tires?

[RECHRGD]

I've got 3.55's in mine and as I recall 70mph is around 3000 rpm (w/ 28" tall tires) before I kick in the Gear Vendors o/d.  It's very livable at 65mph.  I only put in the g/v unit because of dreams of cruising at Viper speed.    Bob

[firefighter3931]

Good cruise rpm depends on the cam profile.....bigger cams need more rpm to be in the "sweet spot" 

Lugging an engine at low speed will chew up more fuel and load up the plugs. 



Ron

[Ghoste]

So when I do the cam swap you and I have discussed, what should I expect to happen to my "sweet spot"?

[skip68]

Right now Ron I've got that POS mopar 292-509 cam.  But, when you come down for M.A.T.S. next year we can change it. 

[mopar_nut_440_6]

Right now Ron I've got that POS mopar 292-509 cam.  But, when you come down for M.A.T.S. next year we can change it. 

I love the 509 cam. Maybe I am just old school!

I had 3.54 gears in my car and it used to have a stock 440. Got 16mpg in town or on the highway at "normal" speeds. I did find the gear a little stiff as I was still running the stock 14 inch rims and 60 series bias ply tires!!

[NYCMille]

Good question to which I have 2 answers and take from them what you will:

My '68 - MR. ANGRY - has a mild 440, something like a 470 lift cam, rpm intake, headers and an 800DP on top. I also run a GV OD unit. I've run this car across the country 3 times averaging 80-90mph. My final drive ratio is .64 so 80mph is a about 3k. Keep in mind that Chrysler put these 440's in EVERYTHING and they are a pretty bullet proof engine as long as you don't get too nutty with the build. I've been running my 440 between 3000-4500 for over 32K now, plus I road course the thing and it's never given me a lick of trouble. Keep them mild and you'll have GREAT reliability. Also, when I say I cruise between 3-4.5k I mean I do this running 500-700 miles in one day so the engine will be spinning like that for 8-12hrs at a time.

My '69 Daytona has a 471 stroker and a keisler - granted in 5th gear at 3000rpm is 106mph which I obviously don't cruise at but I wouldn't hesitate to run it at 3k-3.5k all day long if the opportunity presented itself.

Just my 

[firefighter3931]

So when I do the cam swap you and I have discussed, what should I expect to happen to my "sweet spot"?

The 112* LSA by nature has a broader powerband so the sweet spot is also wider. Anything over 2000 rom will be pretty nice with that cam profile....you won't need to buzz the engine up to find it, but it will be happy everywhere. 


Ron

[firefighter3931]

Right now Ron I've got that POS mopar 292-509 cam.  But, when you come down for M.A.T.S. next year we can change it. 

No problemo Chuck....i'm in. 


Ron

[acelondon]

Hate to steal the thread, but: Does any body have a way to get a Charger(small block) under 2000 at highway speeds?
My Chevy S-10 is at 1800 at 70. Its a 4WD with a 4.3L V-6 in it, so my 318 should have the power do it too. I hate the fact that im at 3grand on the highway. i was told the car has 3.23 gears. 727 auto. Im looking for a 4/5/6-speed overdrive of reasonable price.

Gear Vendors Over-Drive is out of the question. I just simply will not spend that much on something like that when i only spent 1200 on the car!

[Ghoste]

The S-10 almost certainly has an overdrive gear in it though.

[acelondon]

yes it does. Im looking for an over drive tranny (manual) for my charger. That dosent cost 6000$

[Sublime/Sixpack]

        Thanks.    I think I'm going to try and stay in the 2500-2800rpm range. 

I think you'll be happy with your 3.23's.

[mauve66]

the original unit in mine was 3.23, was very pleasant at 75-80mph from colorado to missouri

[Charger-Bodie]

yes it does. Im looking for an over drive tranny (manual) for my charger. That dosent cost 6000$

Ya gotta pay to play!

[mauve66]

        Thanks.    I think I'm going to try and stay in the 2500-2800rpm range. 

I think you'll be happy with your 3.23's.

i posted to the other thread you had on this, if i remember right with the 14 inch tires and the 3.23, i was about 2300 at 65-70 mph, but that was a long time ago.............. in a land far far away were my charger actually moved everyday under its own power................ oh sorry...............

[flyinlow]

my 440 turns 3000 rpm at 70 mph in third. 2000 rpm in overdrive/lock up. .....a518 trans

3000rpm and under cruising should not be any problem. I would not run a street car engine at more than 2/3 of it redline rpm for an extended time.

[maxwellwedge]

4000??  God God man, how fast are you going and how short are your tires?

Near 70 MPH - F70-15 Polyglas - I did say near 4000 - probably 3800-3900...Who knows if the factory tach is reading right but it sounds near 4000 as well.

[skip68]

I think I'm going with 3.55's

[mikesbbody]

have a play with this    http://vexer.com/68rt/speed.html

[mikesbbody]

I forgot to say, I have 3.55's in my Charger Auto, 28 tall tires, and it doesnt rev too much on the highway.
I cant say how high because my Tach doesnt work 

[mauve66]

chuck, don't forget to change the speedo gear in the tranny also

[skip68]

chuck, don't forget to change the speedo gear in the tranny also

Thanks Robert.     I need a new speedo cable anyway.  I put a new one in but I messed up and had it against my manifold so it melted.     I just use my GPS to watch my speed.   

[skip68]

    Thanks Mike, I think 3.55's it is.