Login  /  Register  
  Home  -  Forum  -  Classifieds  -  Photos  -  Links     

  << Previous Topic | Next Topic >>Return to Index  

Building a 390 for MPG's

February 23 2014 at 12:52 PM
nandoz  (Login nandoz)

I am acquiring a 76 F-150 4wd with a 390/auto in it. This truck will be a daily driver, wood hauler, work truck. I have done a couple of FE builds before, but never cared about fuel mileage. I want to build this one so that I can afford to drive it a lot. My plans include 33" tires, headers, dual exhaust, and some engine work. The lower end is in good shape, so I won't be pulling the motor any time soon (hopefully). It needs a boat load of torque, and maximum fuel mileage.

 Respond to this message   

Blair Patrick
(Login CaptCobrajet)

You gotta do the bottom end too..................

February 23 2014, 1:00 PM 

to make it right. Tight quench (which the stock shortblock won't have), hydro roller 194/204 on a 112, .520 lift. D2 heads, Performer manifold, 112 Autolite, MSD 5 box. Light rings, Napier 2nd. Tight clearances and 5/20 oil. I'm doing one right now. Basically a 2014 model FE!

Blair Patrick

 Respond to this message   
Bill Ballinger
(Login blue65gal)

I like it! What sort of hydro roller lifters would you reccomend?

February 23 2014, 1:42 PM 

My wife and I have a 2011 Mustang, and nothing to haul anything with. I have a lot of FE parts, and I was thinking we could find an older truck rolling chassis that she finds "cute" and driveable and build an FE just that way, get cast pistons .002 out of the hole and a rebuilder set of Fel-Pro 8554PT head gaskets, D2 or C8 heads. Keep it about 9:1 so it will run nice on regular with a auto, I would really like to do a 352 with an FX Cruiso that I could take the bell and fit to an AOD, I have a ported Performer I did 10 years ago and is very balanced and has great velocity and flow for what it is. I would need a nice roller and lifters. I also have a bunch of 2100's and 4100's , I had a 1.12 4100 off of a 352, but I would like to go with 1.08 primaries and 1.12 secondaries by using the thinner boosters in the, or putting the 1.08s in the front. I have a set Morels, but I am kind of saving them for bigger Bullet roller in a 428 I want to build down the road.

That is neat project! Maybe a '50's Ranchero, we need something to haul things in that we can make nice enough that she likes to drive it around. If you had an exact copy of the 390 2V regular fuel cam in a roller that gets up into the .480's that is the best I have had for mileage. We could get 25 mpg on the highway out of '69 Galaxie 4dr land yacht when we first got married and it was a 390, the same the same 390 that is my "394" I built that is in my '65 Galaxie with the same C6 and 4.33s w/ a Spartan locker.

It would be really cool to be able to match a 302 for mileage and make close to 300 hp.

This message has been edited by blue65gal on Feb 23, 2014 1:47 PM

 Respond to this message   
Tom P
(Login tomposthuma)

If you don't pull the motor you won't be getting much gain.

February 23 2014, 2:41 PM 

The factory pistons are way down the hole. Huck 'em away. Get some pistons that make tight quench while keeping the compression in check. No sense getting 20mpg if it means $12 a gallon race gas.

The KB Hyper pistons are what i'd choose, or get forged custom ones if you are floating in dough.

I'd go for a bigger cam than Blair, still need power too, after all what is gas mileage, miles per gallon. The faster you do those miles on the same amount of gas the farther you go.

Proper headers, not those silly shorties. I'd also use the RPM intake and a 4180 carb from a 83-85 Mustang 5.0.

AND******* A vacuum gauge. Drive while watching it, never mind what's out the windshield, keep the reading high and the fuel level stays high too.

 Respond to this message   
(Login country63sedan)

Tell me more Blair

February 23 2014, 5:06 PM 

How tight are the clearances? How much compression? Valve size? I've been thinking pretty hard about a Fuel Efficient FE, but I have no real world experience to make decisions from. I had much different ideas for the intake system (6v TBI). I'm having a hard time finding the line between performance and fuel efficiency. Later, Travis

 Respond to this message   

Blair Patrick
(Login CaptCobrajet)

Here we go..........

February 24 2014, 6:25 PM 

Main bearing clearance about .0015. Rods at .002 vertical, spreading some at the part line. If you run clearances like this, there are some things that must be confirmed. The main bores must be consistent. They can't pinch in the "X". Alot of re-hones pinch in the X. I prefer the vertical measure on the housing bore to be on the low spec, and gradually growing as you check out toward the parting line. You also need a full groove bearing for tight clearances. Oiling the groove all the way around lubricates the bottom half of the bearing better when the clearance is tight. It also will see less wear on start up from both the thin oil and the full groove bearing. Running down the road, the thin oil will have less drag on the oil pump, and I also would use a regular M57 Melling pump. Housing bores on both mains and rods need to have minimal to zero taper, as this will effect bearing wear when you go tighter. Straight bores, good eccentricity, and careful measurement will make the tight clearance work for you. It will also keep idle oil pressure more stable in a streeter. The rockers need to have .0015 to the shafts also, and run the drip tins. If the rockers bleed bad, it will really pump the oil to the top. I prefer to restrict the oil in the deck, and do the oil mods to the main galley and 1,2, and 4 main holes. I like a good supply and control the bleed with the clearance and the restrictors. Oil mods to the main galley will make it send too much to the top if not cut back at the deck. I do it there so the head gasket does not have to hold back the pressure, and the head bolt cavity isn't pressurized as much as if you put the restrictor under the rocker stand.

I like a 2.09 intake and either the 1.57 or the 1.65 exhaust valve. The bigger intake valve will flow more at low lift in an equal port. A really good valve job is paramount. Then you can ease up on camshaft and still fill the cylinder....efficiently. I went small on the cam to give it more bottom end response, so you don't have to floor it to pull off in normal driving. It does need a good curve in the distributor, and 9 to 9.2 C/R if iron headed. I think 135-140 cc intake runner is best, which is where the C8/D2's and the C6-R and C4-G heads will be. I said D2 because they are hard enough for unleaded gas without putting exhaust seats in them. Edelbrock or other alums will be too big for the small cam/390 cube idea.

I like the 4100 for the annular boosters. I think one of the guys mentioned the 302 HO carb, which is also a super choice for the same reason. The primaries in those are annular also. Actually, that is a better idea than the 4100. I owned an 85 GT with a carb, and an 86 with EFI. The '85 would run and hide from the '86, and the mileage was no better with EFI, if as good. The ONLY benefit of the EFI is the cold start. A well-tuned annular carb can get great fuel mileage. The downside is that about once a year, you should change the power valve, needles, and accelerator pump. You can change alot of those for the cost of EFI. JMO.

A really good fit on the intake manifold, and viton seals will keep better control of oil trying to contaminate the cylinder charge. LOTS of manifolds leak oil in the ports unnoticed, and umbrellas will also let too much oil in. Create a closed PCV system with a PCV valve and also a hose to the air cleaner(a check valve in the hose is a plus). Again, the PCV will only benefit you if it can pull a vacuum, which means you MUST have really good ring seal, which is a book of it's own. It is a package to get where you are trying to go, and it all works together for your benefit or your detriment.

Blair Patrick

 Respond to this message   
(Login nandoz)

That is a lot to digest

February 24 2014, 7:27 PM 

I won't be building the engine tomorrow. I have some time to read, research, read some more, ask questions. I really like the idea of a a modern FE. I am trying to keep the build cost down, I have problem with spending money on car/truck projects. I want to keep it simple, build a nice truck motor, and not burn up the grocery money on gas.

 Respond to this message   
(Login country63sedan)

Thank you very much

February 25 2014, 3:56 PM 

I appreciate the details Blair.

I don't want to hijack this thread, but I have been thinking about fuel mileage for quite awhile. I've built it in my head a thousand times, and will probably do it a few more times before I decide on everything. Later, Travis

 Respond to this message   

(Login HolmanMoodyStroppeVet)

We did similar builds for and with Ford

February 25 2014, 9:17 PM 

Hi Blair

As always, you are doing great work here and in the shop. I appreciate all of the guys you help and guys, Blair can do heads, porting,machine work and a lot more for you. He is a trusted resource for us.

In about 1969, Ford began pre testing unleaded builds for California. Remember, we were the 'assholes'..oops....environmentally eager...folks...ie assholes...oops.... who mandated it first .....but the Federal Law compelled such. So, we were in Calif, Holman was down South,and Shelby and Gurney were out here, but we got the EPA CARB Cert work. And unleaded work, cat convertor work, and more.

What a weird time. Being paid millions to build winning Race Cars with and for Ford, and then transitioning into building unleaded mileage production engines. Two pathes we did, Ford rejected early on, but DID adopt later,,,,turbos......and propane.....and turbo'd propane. It was too much too soon for Ford in the early 70's.

One hindrance was also, those single, restrictive, pellet convertors. We hug duals, there is the light off issue, cured, by later high flow convertors.

Imagine, we had this huge race parts retail deal, and warehouse, tons of FE race parts, and here comes unleaded and all of these California smog prototype parts. We had the induction heat treated, D2 heads, maybe 2 years early. But nobody really gave a hoot, why? Every Rat head, the L88 or LS7 big block heads, the hi perf stuff, had induction hardened seats.....

And we yawned, since we brought hardened press fit 427 seats to the Vanguard...which remains.....until .... today,,,,,thanks Ford...

BUT.......we got to do valve seat and valve testing builds too. And we used stainless valves...bronze guides...which was not at all common in 70,71,72.

Imagine,,,,,,just the 351W piece, was 150 engines. Pull the engine from brand new cars, do basically what you are doing Blair, then reassemble, test....pull apart again, and measure,describe,photo,and tell Ford.

FE's were built and built to squeaze out mileage, and there are even more tricks

Can't say most of us were happy to see,,,retarded low overlap wider lobe center smog grinds....we ground a lot of test cams....nobody liked seeing the compression go away, but it had to be done. The early stuff relied a lot on, you all remember,,,,higher coolant temp, much more ignition retard,much leaner.

We proved otherwise, as your work does Blair, and as many many figured out them and since. I replied because your term, modern FE caught my imagination too.

Once the gas crisis really squeazed a lot of FE guys by the figs, our best engine builder, had his 390 Ranchero, I helped.....2.73 gears, 2 V High velocity set up....vacuum gauge, and 70 degrees total mechanical and vacuum...

The deal was, drive it like you had an egg below your bare foot, ie, maintain max vacuum....and also, special high velocity exhaust...and low temp

And we learned.....4 spd helped over an auto, on mileage builds,,,sometime 1 or 2 MPG.....and this is why later auto's have lock up convertors....we used 2.73'2 3.00's......Detroit went over drive auto...

A Nash 5 speed can help a lot of mileage projects....get her to bog in 4th and 5th.

Your build is awesome, and if we had port EFI and programmable ignition, knock sensor, O2 sensor and all, I bet you and me and friends, could get 20 MPG or more, pussy footing it...and more in a lighter platform,,,

No doubt, me, and many customers, built high mile per G FE's, I ran the life out of 3 in Mustangs. Same deal....on mine, small high velocity headers, street master ported, very similar custom cams...we also used the 1-131....that is the tiny Holley....390 CFM 4V.

Mileage FE's were so common, Isky,Engle,Crower and Crane, sold a lot of mileage cams......

And I wish you had been there with us because I am sure we would have all benefitted....

As I said when I first joined, we did test builds, and also used the small combustion chamber heart heads, modified, with good results as well. And I laugh, we milled in, reflector recesses,in the piston,to maintain quench but lower CR, oh....like you do these days,,,,say...43 or 4 years ago.

Now, a 2014, smog legal, 390-428....injected, probably just durasparked, not 8 coils, that would be fun,,,full roller valvetrain, optimized aluminum heads, very doable....HA HA.......prove why FORD could have and should have kept the FE in production a lot longer ! We sure believed that !! Using Yates style, fast burn heads, and developing relevant ignition and fuel curve maps,say, in a light Mustang, would be fun. Bet we might squeak out 25 MPG under ideal conditions...maybe...(No..not a long, mild, down hill coast)

But they killed our FE....yet she had so much more to give.....

You know, we all got to be real pissed off, as Chevy just continued with the 454. The Gen 5, the one piece rear mains, and so on. Always wanted to see similar FE evolution. Same deal...Dodge kept the 440 wedge going and going too.

And , the FE went obsolete, and they handed us the 400 M.................and the 351M...and zero performance parts...and we said thanks...as most handed these guttless wonders to the scrap heap..... I can't forget how many I saw just smelted. Sad

Yes I know Jack did a stout one 40 years hence...who cares. We hauled ass with 429 Bosses and 351C's.

Always fun

Thanks as always

This message has been edited by HolmanMoodyStroppeVet on Feb 26, 2014 9:04 AM

 Respond to this message   

Blair Patrick
(Login CaptCobrajet)

Hey Tom!.................

February 26 2014, 10:44 AM 

Glad to know I'm not crazy! I like the D2 head, small manifold, 390-ish mileage mizer idea. I also have some small cc CNC raised ports that we use on 352 Super Stock Edelbrocks that I think could be killer. I think I will dyno one soon and report. It might surprise us all to see what a 2014 FE endurance/street mill will do. I am leaning toward EFI, even as much as I love a Holley.........that stuff can learn and tune itself!!

Blair Patrick

 Respond to this message   
(Login country63sedan)

I'd love to see dyno results with iron heads

February 26 2014, 4:26 PM 

I think it would make enough torque by accident. I've been thinking of building a 410 with D2 heads,cast iron shorties, 6v TBI with a manual overdrive for the wagon. I was also thinking CJ size valves and 5/20 oil (wasn't sure it would work). I keep wanting near 10 to 1 compression, but know that would just make a rattler. I figured it would be all done by 4000 rpm, but would probably never see north of 3200. A big engine turning slow and steady should have enough torque for the job, and get decent mileage.

I appreciate any info you guys will share on the mileage master subject. I really want to have a 50+ year old engine that gets comparable mileage to new plastic junk. With my commute (about 90 miles a day) a gas hog will never get driven. Later, Travis

 Respond to this message   
Wreckless Warren
(Login pcode390)

1976 F-150 4X4, 390/C-6, 33" Tall Tires, Heavy Hauling, Good MPG?

February 23 2014, 5:02 PM 

I'm not quite sure how you could get there from here. I't damn hard to get decent milage out of a 390/C-6 when it's just pushing around a Fairlane with 3.0 rear gear and just one person in it. jmo. ww

[linked image] [linked image] [linked image] [linked image] [linked image]

1965 Galaxie 500XL 445ci Stroker C-6
1965 Galaxie 500XL 390ci P-Code, 4-Speed
2001 Ford F-150 SuperCrew 5.4L
2006 John Deer X320 Garden Tractor

 Respond to this message   
(Login nandoz)

Part of my interest is the challenge.

February 24 2014, 5:37 PM 

I know 25mpg can be done with an FE. My 64 Marauder had a cam, intake, exhaust, 750 Holley, and got 25 on the highway. That car was 5000lbs, and had all the aerodynamics of a barn door.

 Respond to this message   

(Login Bad427stang)

If not going inside, you won't get as much benefit, but

February 23 2014, 5:08 PM 

If you are serious and want to try, you can do better, but eventually its an 8:1 motor with over .130 of quench distance

- Duals and an H pipe
- I'd go custom cam, stay under 268 advertised, spread to 112, and index on 104 (for that matter, take the stock cam and advance it to 102-104 whatever a gear set will allow) Check intake valve clearance...
- Run as thin as a head gasket as you can find, but to be honest, don't spend any extra money or time looking too hard, you'll never get to a real tight quench because that motor is already WAY below deck
- Performer 390 and a 600 Edelbrock or a 4100 as someone else mentioned
- Recurve the distributor to allow more initial (12 or so in a truck IMHO) without passing 38 or so total

The best way to do it would be very similar but get the compression up and quench tight and a real nice valve job. IMHO valve sizes wont mean much, it's more important to just optimize the D2 head in the bowl and seat area with a light clean up here and there

Maybe consider a low gear set in the C-6, the tall tires won't be your friends

[linked image]
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM intake, 3310, 4 speed

This message has been edited by Bad427stang on Feb 23, 2014 5:24 PM

 Respond to this message   

(Login Cobrabill)

You should be looking at

February 23 2014, 5:20 PM 

EFI for the route you want to take.

 Respond to this message   

Wes Adams Ford428CJ
(Select Login ford428cj)

A well tuned carb is within~

February 24 2014, 7:40 AM 

1 - 2 mpg of a EFI set up. Like the guys have said... 4100 carb, Performer intake, a small cam on a 114 lsa. 9.5 to 1 CR would be perfect..... Zero deck, total timing 36~38, dizzy with an adjustable vaccum advanced, hot ignition set up (Mallory or MSD 6AL box) and a set of headers with 2.5" exhaust. JMHO

"The F.E. Wiki Home"

[linked image]
Wes Adams FORD428CJ
Built Ford Tuff With Good Ford Stuff
03 F-250 Crew Cab 4x4 6.0 and 35's
64 Falcon 428FE
55 FORD Truck 4-link Rides on air with 428FE



 Respond to this message   

Rory McNeil
(Login RM428)

Re: A well tuned carb is within~

February 24 2014, 10:18 AM 

Maybe even closer than that Wes. I have the March 2014 issue of Car Craft, and they have a big article where they took a 590 HP BB Chevy Nova, and compared 4 aftermarket EFI systems, as well as the cars existing Holley 950 carb. The EFI systems tested were MSD Atomic, Edelbrock E Street, Holley Terminator, and FAST EZ-EFI 2.0, and the kits ranged in price from $2000. to$2200. After all the systems were tested, the mileage results were all extremely similar, the FAST system was the highest, at 14.5 MPG, the "worst" were the Holley and Edelbrock, which produced 14.2 MPG, which is exactly what the 950 Holley carburator accomplished. I don`t know about you, but spending over 2 grand for 1/4 MPG improvementis not very cost effective.
Also, a buddy bought a new 24 foot motorhome, with a carburated 460 Ford in 1985, and several years later, traded it in, and bought another 24footer, with a 460 EFI. He assumed that the EFI on the newer engine would give considerably better mileage, in reality, it was virtually identical. Sure, in stop and go bumper to bumper traffic, in a smaller car, the EFI would likely show decent gains in mileage, but most motorhome mileage is on the open road, where a properly working carb can do a very good job. The low compression 390 4 barrel in my 74 F350 car hauler, averaged 10.5 MPG on my 2500 mile round trip trek to California a few years ago, weighing well over 10,000 lbs, with 4.10 gears, and a 450 cfm Holley 4 barrel, which I thought was pretty decent. Thats about 2 MPG better than my buddys 98 Chevy 3500 (454 Vortec with OD automatic) did when we towed his Chevelle race car to California several years earlier.

428 powered Fairmont drag car, Best ET:9.97 @132.56MPH, best 60 ft: 1.29
59 Meteor 2 dr. sedan 332, Ford O Matic
74 F350 ramp truck 390 4speed
1985 Mustang 331 4 speed Best ET10.29at 128.7mph, 1.40 69 foot

 Respond to this message   
Chris McAlpine
(Login chris401)

Question I Have Asked

February 23 2014, 5:24 PM 

A member suggested having a pair of C8 or D2 heads and choice intake milled to fit lower end on a 360 and make decent compression. I had concerns about quench but have yet to test anything yet. On your build a 265DEH dialed straight up will put intake valve closing at 57 deg +/-, wont be desired quench but will help dynamic compression a little.

 Respond to this message   

Mike U.
(Login mtrain)

Look for a cam with a wide LSA around 114-116 degs......

February 23 2014, 5:42 PM 

That way you won't be pulling as much gas into the exhaust on the valve overlap.

That, and a good 5 speed OD tranny would be a good bet.

 Respond to this message   

Sam M
(Login Rusty_Old_F250)

Port velocity is your friend

February 23 2014, 7:51 PM 

Think small, stock D2 or C8 heads, maybe just a bit of cleanup, remove the thermactor bumps etc. No big port work. Stock iron or a Performer intake (not an RPM) and a small cam. Like everyone else has said keep quench tight but compression fairly low.



"Zero to Sixty in 3 to 4 minutes"

 Respond to this message   
< Previous Page 1 2 Next >
  << Previous Topic | Next Topic >>Return to Index