Has anyone out there stroked their 302 motor to either a 331 or a 347? Have you done it and kept the vehicle fuel injected? I have a 1995 Ford F-150 and I am thinking about buying a 302 block and building a stroker and then swapping the manifolds when i throw it in. Has anyone made this work? would I have to change anything other than the injectors? Any info is appreciated. And if you have stroked your engine, what kind of power gains did you get. Thanks
-John

 

From what I have seen it can be done with other mods. You will need to switch to mass air or have a chip programmed so the computer can run more efficiently with the increased displacement.

 

The truck is already equipped with Mass Air from the factory, so will I need to change anything at all?

 

Go to the Stang forums. There are lots of injected strokers. All are high rpm, but all you're talking about is a cam change to make it suitable for the weight of a truck.

 

I THINK you will need a chip for the MAF or computer to make the right air/fuel mix, so check into that.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!

 

A EFI331, or EFI347 sounds like a cool idea to put into a late-model pickup,or Bronco.I'm kinda undecided on what to put into my 1990 Bronco when the time comes : a EFI460 big block/E4OD, or rebuild my current 302 into a 331,and upgrade the Bronco's AOD to handle the extra power.I've "built" a few EFI331 engines with Desktop Dynos,and I'm impressed with the results.Never tried "building" a 347 inch 302, but I'll try that next.With either,MAF is a wise choice.I doubt Speed Density will like the extra cubes.If you're gonna go with a full tilt 331,or 347, you'll need computer & fuel delivery upgrades.A custom module("chip")might also be something to consider,as stated before.

 

You have MAF, but speed density would handle it no problem if you programmed a chip for it.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!

 

My 1990 is Speed Density,not MAF.I also have Speed Density on my '94 pickup's 460,with a bunch of mods done to it,including a supercharger & chip, so it seems to be okay.It also has a mild cam in it,but I was always told anytime you go big on a cam,and add stuff like better-breathing heads, MAF would be better.Sometimes my 460 has an erratic idle,but other than that it seems to have taken to the changes in stride.

 

Thats a misconception about speed density, you can program the chip with the mods you make, it works just as well and is muhc cheaper than swapping to MAF if you don't already have it.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!

 

Hey, you should summon the user "Lightning2fast", and tell him that you want to switch to MAF and ditch speed density. That's his favorite topic, he'll talk you into keeping it in 1 post! TK

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

Look for my posts here, so that he doesn't have to explain things twice.


https://www.ford-trucks.com/dcforum/perf/1018.html

https://www.ford-trucks.com/dcforum/DCForumID18/1286.html

https://www.ford-trucks.com/dcforum/DCForumID39/4674.html



Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster American Thunder Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.

Then theres:
99' Mustang GT 4.6L
88' F-250 Heavyduty 4x4 351/c6
95' Mercury Cougar 4.6L V-8
80' E-350 300/6 with a
3 spd column shifter. Weighs around 7,000lbs w. 65mph top speed, who wants to race me!

 

[updated:LAST EDITED ON 23-Aug-02 AT 11:20 AM (EST)]Here is an Explorer running a 347 Stroker, MAF, etc. Over 600hp and running around 11.5 or lower quarters...

[link:www.speedfreak.cc|www.speedfreak.cc]


It can be done...

 

[updated:LAST EDITED ON 23-Aug-02 AT 01:33 PM (EST)]basically changing the MAF is one of the "common" bolt-on mods when souping up a 'stang, for 2 reasons. one is that a bigger MAF will let more air into the motor. the other reason is that aftermarket MAF's come calibrated for whatever size injectors you want, so no computer reprogramming or custom chip burning or anything like that is needed.

for example, i have 24# injectors and a C&L MAF with the 24# "sample tube". if i port the heads & intake, make it a 347, and put in a bigger cam, then i'll need bigger injectors again - no problem, i'll just swap the injectors and change the sample tube (about $30).

347's aren't necessarily high-rpm. with everything else the same, a 347 will make it's power at lower rpm's than a 302 - the extra cubes will "max out" the whatever flow the heads & intake are capable of, because they will suck more air through than a smaller motor at the same rpm. so if you left everything completely stock EXCEPT changing it to a 347, then it would have a big increase in low-rpm torque & mid-range power. it would "run out of steam" at a lower rpm than the 302 - it wouldn't "scream" on the top-end, it would pull harder without having to scream!

if you put the explorer 5.0L heads & intake on a mustang, and swap the cam to an E303 or a split-pattern aftermarket cam that favors the exhaust, then you'll see a nice gain across the whole powerband. if you put those parts on a 347, you'd have bigger gains in the low-end and midrange, and still be pulling strong up to somewhere between 5500 and 6000rpm. a setup like that, with the appropriate bolt-ons, should get you up to about 300HP at the rear wheels!

but to JUST make it a 347, the "special" parts you need are the crank, rods & pistons. looking on ebay, you can find the crank for $180 shipped. I-beam rods are about $250. for pistons, i'm planning to use the keith black hypereutectics. if you're not going to run NOS or a blower, then they should be fine.

the only other parts you have to change are the harmonic balancer and the flywhel or flexplate. i THINK earlier 28oz. 302 parts will work, but not sure.

everything else CAN stay the same - the late 70's 302's and 351W's had the same heads and most likely the same exhaust and very similar intakes, and they apparantly ran just fine (relatively speaking). but if you improve the intake, exhaust, cam, and fuel delivery, then it can EASILY put out 1.5x the power it has stock, with great gas mileage and good street manners. with some aftermarket heads and a more high-rpm approach (but still hydraulic) it can double the stock power levels, and still be fairly decent at the gas pump and in traffic...

it might be more cost-efective to just put in a 351W. all the EFI stuff is the same - in fact, everything is the same except the intake and the balancer and flywheel, and some of the accessory brackets on the front of the motor.

 

Is this going to be a daily driver or a play toy.I would not recomend a 347 for a daily driver.There are issues with oil consumption and rod ratios etc.Also the longevity of these strokers is questionable.If you do build it have a machinist who builds race motors assemble the motor and check ALL clearances.I'm not sure but the skirt may have to be notched to clear the rod bolts.The rotaing asembly will have to be balanced.If you add 45 cubic inches you will need bigger injectors a larger mass air meter calibrated to your injectors.A new cam to take advantage of the larger displacement.If it's in the budget some bigger heads would help.IMO for a daily driver swapiing in a 351 would be alot easier.You could take the money you would spend on a stroker assembly and buy some good heads and intake for the 351.

Billy