Looking for 400+ horse and a torque curve from hell, <6500 RPM redline. Truck is 70 F250 4x4 6500 lb daily driver, has NV4500 5 speed, 4.10 gears, 35" tires. Want it to out perform anything new and get 15+ MPG. Going with Electromotive TEC3 injection/spark for sure, but everything else is in the air. This is what I was thinking: shelby aluminum block, forged (scat?) crank, Crower rods, JE pistons, RPM heads, modify RPM intake for injectors, Custom ground comp hydr. roller (comp has excellent custom cam dept.). I need some help with cubic inches, bore/stroke and rod length. I do alot of heavy towing with the truck as well as cruising at 70 on the freeway (2200 rpm). I want to keep the cubic inches down for the sake of gas mileage. Thinking between 406 and 428. That leaves alot of bore and stroke combinations, well as long as shelby's willing to make a block with 4.13" bore. Thanks for the help.

Dustin

 

My 2 cents,

Build a mild-medium 10:1 CR 410 using a Ford 390 block. Put the rest of the money into a gas savings account. I don't think you can get 15MPG in 6500lb 4x4 without going to diesel.

Sure, saving a 100lbs or so with the Aluminum shelby block will help with, mileage....but $5000 buys a lot of gas :-)

The 400 crank HP is pretty easy to get to with most FE combinations.

 

Mileage is the hardest part. The only way would be build a good grunt motor and put a good overdrive in it. Make it idle going down the highway. Make a long stroke motor and don't turn it hard. It's easier to make big torque that way.

My '69 F100 has a 428CJ motor, it turns 3000 rpm at 60-62 mph. I never have to move my foot to make it go up a hill on any highway. It stays constant no matter what. Now, you need to do the same thing, only make it idle along at 1700 rpm like most late model trucks do. A Shelby block would be nice, but not a necessity. A nice torque induced roller cam, Ebok heads with some mild port work. Hey.....sounds like you need Scouder's motor.... . Heck, Greg's would do you good too...

I think the fuel injection would be a plus. You could keep it tuned to max efficiency for mileage. I think it could be done...........with enough money

Good Luck

 

Larry, What an overdrive unit goes for about $2200+......but there nice! Russ

 

I guess I was a little negative in my first repsonse. I think you could get 15 MPG with a well tuned Fuel Injection setup and an OD tranny. Is the NV4500 an OD, or just a HD 5 speed?

My motor would be close to accomplshing your goals. But consider I've already got $10k invested and I don't have a $5k block!

I think you could get that kind of power from a more stock 410-428. And save a lot of gas money.

So, a 410 with the Holley Projection system. Then get that OD effective gear ratio into the low 3s or upper 2s.

 

hey average did you have to get an adapter for your truck to put that 5 speed in?

 

Ya, I've looked at GV units before when I still had my '00 PSD. The cost is just prohibitive for what I was going to get out of it.

If you get either a late model 5 spd or maybe a Richmond 5-6 spd you would be ahead.

 

yes i like the 6 speeds richmonds however I dont know if it is truckworthy and can take towing.

 

The NV4500 is an OD tranny. 4th gear is 1:1 and 5th gear is 0.73. This is actually a great tranny for the FE family...if you are in the market for an OD tranny. Keep in mind an adapter is needed.

 

If my Nash 5 spd can put up with 5500 rpm launches with a 4100 lb car....then I think it could handle towing duties!!!

My friend just bought 6 spd last year for a project car he is building. Man, those things are HEAVY!!! My 5 spd is bad enough for one person to move around, the 6 spd is even worse. The extra gearset hanging on the back really add to the weight.

I would use it just about anywhere without worry.

 

Yes the NV4500 is a 27% OD. An adapter is required and I did some mixing and matching between dodge and chevy tranny parts to get the tranny I wanted. The richmonds are a tough unit, But even though thier first gear is very low for a car it's not a granny gear which is almost a requirement if you do a lot of towing. I also like the tight, crisp feel of a good toploader truck tranny. Also TEC3 injection is, to my knowledge, the best injection you can buy period. It's alot of fabrication to make it work on a V8 since the company mainly caters to the rice rocket community, but it's distributorless, 1 coil per cylinder and the only limitation is the engine can't accelerate more than 16,000 RPM/second. I shouldn't have a problem there. I first used TEC3 on my dad's twin turbo 65 stang stroker 302. For an engine with a 5-9000 powerband it has amazing low end torque and driveablity that I contribute to the TEC3. Also, if you look closely at the engine compartment pictures in half million dollar custom hot rods in magazines you can usually make out a little black box with "TEC3" on it. I realize there are cheaper ways to do things than aluminum and forged parts and I may be spending more money than I need to. The reason I have is I'm deployed in the navy right now and upon return I'll have enough saved up to buy a new truck if I wanted to. I like my old F-250 and want to try to make it perform like the new truck that I'm not going to buy.

 

Good luck with the build! Keep us informed on the progress...