3k to 5k rpm.
comp cam

 

I have a rebuilt 460 in my '79 F350. Loaded to within 300 lbs. of it's GVWR, and it usually tows something around 2400 lbs. (see signature...)

The engine has factory stock everything, except:
-Holley 670 Street Avenger carb
-MSI ignition module and racing grade wires
-Performance cam and lifters
-Headers

The truck is 2WD and has Dana 60 rear with 3.73 gears. I am running 235/85/16 tires.

I run 87 octane fuel and timing is currently set at 8 degrees. Any more than this and it pings like a s.o.b. and gets real hot.

I regularly get 10.8 US MPG on the highway at 65 mph. I would sure love to get better mileage. Thought about running premium fuel but the difference in cost matches the difference in MPG gain, so this really gets me nothing (I can go the same distance for $100).

 

hey all, i got a 1984 f-250 with a stock 460 and stock manifolds and some really choked up exhaust, i was wondering if went with headers and dual 2.5" exhaust would it get me more mpg along with more power?

i got 4.56 gears in the rear and i do quite a bit of freeway driving turning about 3500 at 65mph.... just a thought, appreciate it if anyone knows anything that could help

i was also talking to a guy that said this year of truck has retarded cam timings which also choke it down and its got a smog pump on it....i'm getting about 5-7mpg right now, very pathetic....

Thanks,
~BLaCkSiLo

 

Change your gearing or add o/d. 3.5 k is too high for cruising.

 

yeah, well, how would u do that, it's a 4 speed, get a new tranny installed?

 

If you don't tow a lot of weight or have big tires, I'd look into some 4.11's or 3.73's to get the revs down. That should help your mileage a lot. Then go for the exhaust, etc.

Could add an overdrive unit, but they tend to be a bit pricey for me at 2k plus for a Gear Vendors. But you'd have an 8 speed.

 

Hey Guys,
I'm into FE's and I know that will probably make you guys tell me to shut up, but they are both Ford Big Blocks and I personally think that they are both great engines. Mine has been bored .060 over and is on it's second buildup (before it was a stock reman. bored .060 over. That makes it about a 402. Anyway though I know a 429 and 460 are bigger but I definately think a guy should be able to get 15mpg with a 429/460. I knew a kid with a 1/2 ton 2 wheel drive that could get 15 relatively easy when it was tuned up. It was a 77 with a 4-barrel smog motor but still he got it. I would think that with higher comp. ratio you would do slightly better, right size cam, descent heads, and a lot of time tuning the 4 barrel in. It should be doable, My instructor in my auto-mechanics class at college said that years ago he built 2 mild (cough, yell at me if you will) chevy 454's. They were both in suburbans, (one in a 2wd and one in a 4wd) and the one in the 2wd could get 20mpg! I know it sounds darnright unbelievable. The one in the 4wd got about 18 with full time 4wd! He said they pocket ported the heads a little and used some mileage/RV/torque type cams made by a company called Racer Brown, with a Quadrajet (spreadbore), and I think he said dual exhaust. What I am getting at here is that these engines are almost identical in displacement as far a cubic inches are concerned and trust me, my instructor is a very laid back, quiet, and really honest guy. Granted he is more of a Chevy man but has nothing against Fords for the most part. My 390 (402) with 8.5:1 compression, headers, dual 2 1/2 exhaust, Thrush glasspacks, Cast iron T-code four barrel intake, Edelbrock Performer Plus cam degreed straight up, true roller timing chain, Holley 600 cfm single feed vac. secondary, K@N filter, Pertronix ignitor, Bosch Platinum plugs could get 14mpg driving at 60 mph and being very light on acceleration. (FE's 390 and above were never noted for good mileage either). Now I know thats with some mods but to me that somewhat stock and the 4 barrel Holley needed a little tuning. When I bought it, it had a 2 barrel, stock reground cam (which are garbage, trust me we miked the lobes and some were way off from factory specs) stock manifolds, single pipe with rv type muffler, points, stock air cleaner and filter and 10w-30 oil and he said if you took it easy and kept at 60mph or under you could get 15. He was 75 years old and very meticulous and honest. So I for one think 15 with a 429/460 is definately within reach if not slightly more like 16. All that stuff comes down to fine tuning, exhaust flow, spark, comp ratio (not much but you would think it would help), engine temp, weight of engine oil (I think syntheic oil in the engine along with everything else would definately help) fan clutch, flex fan, electric fan, power steering takes power too, tire size and gear ratio, vehicle weight.....the list could go on for a long time. By the way he said that both of those 454's were in 3/4 ton's and as we all know, if a chevy can do it, a FORD can do it a heck of a lot better!!!

 

Hey Lectrocuted, you must be in to HEAVY METAL and obviously MEGADETH!, Great band and wish Dave wouldn't have slipped back into his old habits because that is how he got the compressed radial nerve (in the drug rehab that he checked himself into after his relapse) I still think he is the man but it just made me shake my head and say man this stinks, One of my favorite bands has gave it up. Oh well though, their older stuff was the best even though some of the newer stuff was good. I am a Frosh. in college in the auto mechanics and even though they were a little before my time in a way they still kicked butt.

 

Yea, I seriously get 15 average going right around 60mph- I'm sure the gears (3.54) tires (315's), the cam and the low stall speed converter, along with religiouly easy driving style all contribute to my good milage in such a heavy truck. Also making sure it's aligned, and brakes are in good order and not dragging. Heck, my old 300 six in this same truck got over 18 with a bunch of performance mods. Too bad I dropped a valve

 

460s are good but i like the 429 (which the same block as the 460) i have an F600 with a 429 and high compression heads on it. about a 11 or 12 to1 compression ratio getting 16 mpg loaded with 1 ton of fertilize. It is putting out about 575 horse. I am running it on Propane and have the mixer tuned to my specs. you have to have the timing precise though (to the half degree) or it doesent run that good. Dont try running that high a compression on todays gas though. The person who had it before me busted a rod because of low octane gas.

 

15 seems pretty good, I have a 77 f150 4x4 with a 460, c6, 3.73's, and 33 inch tires. i get 8 mpg no matter what i do. loaded, unloaded, uphill, down, 8 mpg. I have a friend with a 77 3/4 ton chevy and a 350, he gets 8-10 mpg, and with half the torque.

 

I must be doing something wrong. I run a D1VE engine with 4bbl (from a 77F250 460 & C6,) but I run a "built C5" and 2.90:1 x 31 spline, 4 pinion 9" , on tires with 31.5" diameter. It's in a 66 F100 on a 79 F150, trailer special, SWB frame. I average 17 mpg. On a trip I can beat that by almost 2 mpg. if I behave myself.

I scale 3190lbs "wet", run consistent 12.60s in street trim w/ closed exhausts [2- 1/2 " all the way back]. I'm clicking 2650 @ 70mph in D. with throttle valve at WOT, upshift from Intermediate is at 92 mph +/- I have +12 mph if I "kick down & 80 mph. I run an SCJ hydraulic cam, cast iron exhaust manifolds (gained about 2 mpg with them!) the 780 cfm Motorcraft 4V I mentioned. I also run a windage tray in pan. & a Cloyes accu roll chain & sprocket timing set with a "Blue Struck" FoMoCo Duraspark Module & Distr. Except I do not run 2 piece top & 9mm wires, I run a stock, points type, 1 piece cap with brass terminals & small diameter msw type resistence plug wires. I run right at 350 miles with 79- 21 gallon fueltank.

That's 17 mpg, way I see it. I have had a few Bowtie Blowhards fill my tank by losing a bet I could top 2X their mpg. It doesn't matter whether they got a 350 SBc or a 454 BBc, although I can almost triple up on a dually 454 Bowtie mpg.

I guess I'm just lucky or somethin', huh?
FBp

 

These 2 things jump out at me as the reason for your 460 success. Even my plane jane (custom) 1987 Crew 4x4 weighs 6000 lbs. Guys with electrical components, air bag systems, air conditioning, etc ect ect sometimes weigh 7200 or more . I have the zf-5 speed and 3.55 gears and can sometimes get 15 and over. If you would put a 5 speed overdrive in it, you might see 20 mpg. At 62 mph you'd be turning 1500 rpms. Think you have enough motor?

Tony

 

I was getting about 8.9 mpg. I did some jet changes and timing changes and now get over 10 mpg. I have C6 auto w/2000-2200 stall converter, 8:1 compression RV cam, dual exhaust, 2:73 rear end. I dont understand why I dont have 15 mpg. I do alot of 80 mpg driving which should be fine for the gears I have. ?????? OH Well. I'll keep playing around to make it better.

 

I've got an F-250, 460 with 3.54 gears and 35" Mud Terrain tires with a C-6 with towing shift kit. I get 13-14 miles per Imperial Gal. (1.20 US Gal.) when I take it easy. Best I've heard of is 16 per Imp. gal. Running light with a tailwind.

If you're getting 15 mpg on a US Gal. you're doing really, really well. Especially with 4.10's in it. Good on you, wish I could do it.

Pat
78 F-150 2WD 351M
79 F0250 4WD 460