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-   1973 - 1979 F-100 & Larger F-Series Trucks (https://www.ford-trucks.com/forums/forum38/)
-   -   390 Crankshaft (https://www.ford-trucks.com/forums/1314980-390-crankshaft.html)

redroad 05-25-2014 08:12 AM

Good job ! I have a special place in my heart for the FE motors my first Ford truck had a 390 4 barrel and it was the 1st motor I ever built :-X04 and I still run a 390 in one of my 1976 highboys but when fuel went above $3.50 a gal. for 87 octane I started playing with the 300 six motor .. I have had for a number of years a 300 that I run on propane for a stationary electrical backup generator ..

Here's some 300's in F100's to listen to



blue04.5 05-25-2014 09:44 AM

Mckoloum I'm looking forward to your project. I suggest you do what you've been wanting to for a long time and build the 390. An American V8 sings a sweet tune that no straight six can replicate. I'm not bashing the six because it's a good motor just saying you can't help wanting what you want. Good luck bud.

mikeo0o0o0 05-25-2014 09:58 AM

I haven't been following this thread until now. Welcome to FTE mckoloum, lots of good people here.
Nice looking truck and a good start to a project.
Where in "sunny Florida" are you located?

redroad 05-25-2014 10:04 AM


Originally Posted by blue04.5 (Post 14376958)
Mckoloum I'm looking forward to your project. I suggest you do what you've been wanting to for a long time and build the 390. An American V8 sings a sweet tune that no straight six can replicate. I'm not bashing the six because it's a good motor just saying you can't help wanting what you want. Good luck bud.

You can't want MPG and a 390 at the same time :-X04 unless you get both

Rogue_Wulff 05-25-2014 12:13 PM

There is an option for an "off-the-shelf" 5 speed, but it's not cheap.
New Process (Chrysler) and Muncie (GM) formed New Venture Gear in the early 90's, and made several 5 speed truck transmissions that found their way into both GM and Dodge pickups.
The most common, is the NV4500. As one of the few 5 speed truck transmissions ever built (for a production truck) with a separate bellhousing, it can be adapted to fit nearly any engine, in 2wd or 4wd configuration. This is accomplished with either a custom bellhousing, or a spacer/adapter to bolt the NV trans to the stock bellhousing.
The NV4500 is a rather robust trans, as the HD version was used in Dodge trucks behind both the V10 and Cummins diesel. However, they do have one weakness, the nut holding the 5th gear on the back of the mainshaft can back off, and if this happens, the gears can be damaged, and 5th gear can become unusable. There are fixes for this issue, so they should be considered if one decides to try this conversion.

Link to one (of many) sites that offer info on conversions. It specifically mentions the FE about 1/2 down the page.
New Page 1

mckoloum 05-25-2014 12:18 PM

You are right Blue,
I know it is going to hurt my wallet with the MPG but for me the V8 is a part of the American history! When you are a kid and you see all those movies like Bullit, Two Lane Blacktop or Vanishing Point, like me you need to have a V8.
I had a 1995 Bronco, with the 5.8L. engine, it was my daily driver and it really hurt me driving 45 miles/day! Now I missed it...

mckoloum 05-25-2014 12:20 PM

Thanks Mike,
I am in the West Palm Beach area.
You are right I find some help in here really quick, it help a lot to have all of you guys ready to share your knowledge, Thanks to all of you.

mckoloum 05-25-2014 12:25 PM

Thanks for the info Rogue,
I just looked at the link, this will be a nice modification.
My budget is really low, trying to keep the cost as low as I can, I might stick with my 3 speed for now.
I also read you can improve the mileage by putting the right part in the engine, what you guys think will be best combination, for low budget!

redroad 05-25-2014 12:41 PM

The FE motor is the most expensive of Ford motors to rebuild but it was worth it to me .. You will have to decide whether your budget can hold up ..
For example on a budget but still wanting the motor to perform I might choose these heads http://www.ebay.com/itm/Ford-Heads-390-428-GT-6-B-14-6-B15-C6AE-6090-R-/191189063008?hash=item2c83c19560&item=191189063008&pt=Motors_Automotive_Tools&vxp=mtr
Do you want it to be able to use 87 octane fuel?

Do you have kids ? :-X04

Rogue_Wulff 05-25-2014 12:46 PM


Originally Posted by mckoloum (Post 14377256)
I also read you can improve the mileage by putting the right part in the engine, what you guys think will be best combination, for low budget!

There's not much you do to improve the MPG with an FE. But, there's also not much you can do to hurt the MPG either, so you might as well make it run good.

That said, building a 390 with ~9.5:1 CR and a mild-ish cam (like comp H268) can net better MPG than a stock (dog) 360/390. This obviously requires driving with a bit of throttle restraint........
Easy way to get that CR range, is use stock 360 pistons (in the correct overbore as needed) on 390 rods/crank. The 360 used a piston that was originally built for the 390, but since it stopped more .100 away from the head, the CR (in the 360) was in the low 8:1 range. The same piston on 390 rod/crank, gives 9.3-10:1 CR depending on head CC.

redroad 05-25-2014 12:53 PM


Originally Posted by Rogue_Wulff (Post 14377289)
There's not much you do to improve the MPG with an FE. But, there's also not much you can do to hurt the MPG either, so you might as well make it run good.

That said, building a 390 with ~9.5:1 CR and a mild-ish cam (like comp H268) can net better MPG than a stock (dog) 360/390. This obviously requires driving with a bit of throttle restraint........
Easy way to get that CR range, is use stock 360 pistons (in the correct overbore as needed) on 390 rods/crank. The 360 used a piston that was originally built for the 390, but since it stopped more .100 away from the head, the CR (in the 360) was in the low 8:1 range. The same piston on 390 rod/crank, gives 9.3-10:1 CR depending on head CC.

So what money you would be saving on building a higher compression ratio motor for MPG? you immediately lose on the added price of 91 octane fuel or at least part of it.. Now that sounds reasonable :-X04 I'd go with 9.0:1 max

mckoloum 05-25-2014 01:23 PM

Redroad, funny you show me this link, I saw those but the description said it will not fit the 8 bolt manifold without drilling 4 new holes? And those are with the CJ valve.
Does having the CJ valve or stock valve will change anything in MPG?
No I don't have kid, why?
Being able to put 87 will be a nice thing.

Rogue if I understand I should stay below the 9.5:1 compression ratio. And the compression ratio is one of those thing I can't figure out yet, I understand the CC from the head and cylinder chamber play a role in it, but does the camshaft have an incidence on the CR?

redroad 05-25-2014 01:38 PM


Originally Posted by mckoloum (Post 14377355)
Redroad, funny you show me this link, I saw those but the description said it will not fit the 8 bolt manifold without drilling 4 new holes? And those are with the CJ valve.
Does having the CJ valve or stock valve will change anything in MPG?
No I don't have kid, why?
Being able to put 87 will be a nice thing.

Rogue if I understand I should stay below the 9.5:1 compression ratio. And the compression ratio is one of those thing I can't figure out yet, I understand the CC from the head and cylinder chamber play a role in it, but does the camshaft have an incidence on the CR?

Will the CJ size valve give better mpg ? Not to much I would say but it will make the engine breath better and run more efficiently .. Where you will notice it is when you step on the accelerator .. The 12 bolt pattern for exhaust will only matter if you are going to try and use a stock exhaust manifold .. You can get headers for the 390 with a 12 bolt flange .. Kids means no money for toys .. My kids grown and out of the house .. now the grandkids are almost driving age .. I've been working on a F250 for/with Grandson number 1 so it's ready when he's old enough ..

Rogue_Wulff 05-25-2014 01:43 PM


Originally Posted by redroad (Post 14377302)
So what money you would be saving on building a higher compression ratio motor for MPG? you immediately lose on the added price of 91 octane fuel or at least part of it.. Now that sounds reasonable :-X04 I'd go with 9.0:1 max

With proper ignition timing, you can still run 87 octane in a 390 with 9.5:1 CR. Of course, much higher than that, and 91 can become required.

The 74 I have, has a 390 with 360 pistons, a factory 390GT/428CJ camshaft, with D2 heads (9.3-9.5:1 CR), and it runs fine on 87 octane with the timing set a couple degrees back from optimal. Optimal timing, it prefers 89 octane, but can still handle the cheaper stuff. It's been this way since Dad built the engine some 25 years ago...... About 3 years before my youngest kid was born.

redroad 05-25-2014 01:58 PM


Originally Posted by Rogue_Wulff (Post 14377385)
With proper ignition timing, you can still run 87 octane in a 390 with 9.5:1 CR. Of course, much higher than that, and 91 can become required.

The 74 I have, has a 390 with 360 pistons, a factory 390GT/428CJ camshaft, with D2 heads (9.3-9.5:1 CR), and it runs fine on 87 octane with the timing set a couple degrees back from optimal. Optimal timing, it prefers 89 octane, but can still handle the cheaper stuff. It's been this way since Dad built the engine some 25 years ago...... About 3 years before my youngest kid was born.

That sounds good .. On my 76 highboy I still tow with it on occasion so I needed to keep the CR down but the heads were reworked for CJ size valves keeps exh. temps motor temps down when it's workin .. It still has truck duties :-X04


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