347 Stroker - Explorer EFI

[Casey4wd]

Originally I thought I would build a fairly stock 5.0 out of a '96 Explorer for my Bronco, but my engine shop was suggesting a 347 stroker. Curious what others thoughts are on this. I have heard the build a 351 instead plenty, but not looking to go that route. The Bronco will be 95%+ on the road, around town with some highway miles. I want to use it as a daily driver for about 50% of the time. My job dictates that I have something else for the other 50%.

Who has done this with an explorer EFI set-up. Any recommendations or things not to do?

Thanks in advance!

 

[NYLES]

you already have the explorer stuff?

 

[Jdgephar]

Honestly, for just the street, and mild off road on the sand dunes, my 5.0 (non-EFI) works great in my '68. I have a 347 in my '72, and yes, it has more power, but I don't need that for tooling around on the highway or in town. Plus, it sucks more gas.

More power is always more fun...if the cost isn't that much different, go for it.

 

[sykanr0ng]

Most stroker kits are 28 ounce imbalance.
You will need the harmonic damper from the Explorer front dress rebalanced for that.
Also need a 28 ounce flywheel.

 

[76Bronco302]

damper dudes will be the place to go for the rebalanced HB. A good stroker kit will come with the proper flex plate. I went 347 on my explorer swap and once I hit that throttle for the first time I couldn't remove the smile from my face. My bronco is 99% street. I wasted that tank pretty quick. The next tank Im still on and driving like a normal person with the occasional blow your doors off move with about a 1/4 left after 2 weeks of driving. I might drive it 5-10 times a week so that may not be saying much.

 

[sykanr0ng]

damper dudes will be the place to go for the rebalanced HB. A good stroker kit will come with the proper flex plate. I went 347 on my explorer swap and once I hit that throttle for the first time I couldn't remove the smile from my face. My bronco is 99% street. I wasted that tank pretty quick. The next tank Im still on and driving like a normal person with the occasional blow your doors off move with about a 1/4 left after 2 weeks of driving. I might drive it 5-10 times a week so that may not be saying much.

Won't help him much, he's running with a ZF5.

I have not seen a single kit with a truck flywheel.

Most of the kits are sold for Mustangs so do the flexplates even have the right tooth count?

But, Damper Dudes is where I would get an Explorer balancer done as well.

 

[Joe473]

Won't help him much, he's running with a ZF5.

I have not seen a single kit with a truck flywheel.

Most of the kits are sold for Mustangs so do the flexplates even have the right tooth count?

But, Damper Dudes is where I would get an Explorer balancer done as well.

Just went through this. Jegs sold me a kit that they confirmed from scat would come with truck flywheel and ship out next week. Rep called scat while on phone with me to confirm.

They took the order charged the card and it took like 6 weeks to get the kit. Best thing when the kit arrived it had the 157 tooth flywheel!! Wait another 2 weeks then when I assembled it one of the brand new connecting rods had a bolt siezed in it from the factory. Another 2 week delay. Not happy with jegs customer support and ethics. I'm sure if you call summit they can get. SCAT or eagle to do the truck flywheel

Just got it together and taking it easy for break in. So far so good. I did it based on 96 explorer with gt 40 heads and early bronco front dress. Painted weiand intake and autolite 4100...It's a sleeper until you get into the skinny pedal a little.

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[Broncobowsher]

Built a 330" stroker with Eagle parts a decade ago. Simple check box for the 50 oz-in instead of the 28. No change in price.

They mistakenly sent a 3.40" crank that was exchanged without drama.

This was before the Explorer EFI was a viable option so I used a Mustang EFI. That still took upgraded injectors to feed it. A bigger MAF that wouldn't max out. And since that blew the tune so far out (injectors, MAF, added displacement, better flowing heads...) it would run on a stock tune but was crap. Took a custom tune to make it drive. Used the Explorer intake and accessory drive.

In the end the RPM was limited by the accessory drive speed. I spent way more building the engine then the other engine I was running (the 351W). The chassis dyno said both made the same HP in the end. 250 to the ground either way. The 351 was so much more fun to drive. It gave the low end torque that was on right away where the smaller stroker needed to spin a lot more to make the same HP.

 

[Casey4wd]

Thanks for the replies. A lot of good points for me to consider.

you already have the explorer stuff?

Yes. I pulled all the EFI stuff and block from a 1996 Ford Explorer.

 

[JSmall]

Thanks for the replies. A lot of good points for me to consider.


Yes. I pulled all the EFI stuff and block from a 1996 Ford Explorer.

Are you keeping it OBDII with the Explorer computer?

 

[NYLES]

Heres another problem your gonna run into is 302 efi running 347 inches a whole nother box a worms.

I am about to abort Ford efi and try Fitech, 302, 331, 347, 357, 351, 393, 408 itll run on em all. NO harness mess!

Not trying to influence that but a lot less complicated than Ford efi.

A good set of heads, cam and fuel system of your choice a 302 will make enough power to scare you! And if its 95% street hwy........Speed Demon 575 carb aint bad either!

 

[Casey4wd]

Are you keeping it OBDII with the Explorer computer?

That was my original plan. Starting to think the 347 stroker is more work than it is worth. I think my worn out, carbed 302 in it now (with at least 2 cylinders that have very little compression) is pretty fun. Explorer EFI with a fresh block, BC Bronco Headers and Magnaflow exhaust is going to be a whole new world of power.

 

[sykanr0ng]

If the OBD2 computer can run a 351W (which EFI Guy says it can) then why would it not be able to run a 347 stroker?

 

[gambling209]

Most stroker kits are 28 ounce imbalance.
You will need the harmonic damper from the Explorer front dress rebalanced for that.
Also need a 28 ounce flywheel.

they make a pulley that bolts onto a flat 28 balancer and matches up with the explorer front dress. driven 4x4 sells it. also think wild horses do to. I also was thinking about a 347. after machining the 302 parts, it is about break even money wise. here is where I was thinking:http://www.ebay.com/itm/331524280093?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT for my kit

 

[JSmall]

If the OBD2 computer can run a 351W (which EFI Guy says it can) then why would it not be able to run a 347 stroker?

I'm not sure, but I thought I read somewhere that Gary said the tune would need to be tweaked for a 347...it could have been in reference to a cam choice though.

 

[sykanr0ng]

they make a pulley that bolts onto a flat 28 balancer and matches up with the explorer front dress. driven 4x4 sells it. also think wild horses do to. I also was thinking about a 347. after machining the 302 parts, it is about break even money wise. here is where I was thinking:http://www.ebay.com/itm/331524280093?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT for my kit

I'd rather have an Explorer balancer re-worked by Damper Dudes.
The 'adapter' pulley is made of aluminum which has more of a reputation for squealing than the iron/steel OEM factory pulleys.

Break even on money is what I came up with too.
That and the Lightning intake keeps getting harder to find and more expensive all the time.

 

[sykanr0ng]

I'm not sure, but I thought I read somewhere that Gary said the tune would need to be tweaked for a 347...it could have been in reference to a cam choice though.

Which ever way I go I'm going to have him reprogram the PCM anyway, so having him change it for more cubes is no big deal.

 

[Casey4wd]

I have a fresh 28 oz flywheel currently. Having the harmonic balancer changed for 28 oz is not that big of a deal since I would get to keep the flywheel (cost is off set). Garry is going to be doing the wiring for me and the programming (need to buy an A9L computer), so there is not much additional cost in there. I was considering replacing the fuel injectors anyway, so I had already planned on that cost. The only area where it is potentially more expensive is anything to do with the intake... which I am unsure of right now. I would prefer to re-use the explorer stuff for that if possible.

 

[BanditBronco]

I am at the point of choking out an explorer intake set up on a stock bore original block roller converted 302, at most the cylinders are opened up to 306 just for wear during the rebuild. running stock internals, a lunati cam, and flotech aluminum heads with 19# injectors I am at the limit of the stock maf, throttle body, intake and injectors to make more power. Running a tweeker piggy back on an a9l computer with a mustang harness. on the dyno I put down 209hp 233 torque, talking with the dyno tech that spent most of the week with my rig on the dyno I am pretty maxed out on air and fuel. So I would plan on going aftermarket for intakes and injectors. Do some research on the mustang forums those guys have probably been there done that.

 

[englewoodcowboy]

Stroking the motor is not too expensive to do to add cubes however, with being on the road more than off, the explorer motor is a good start. I am building 2 of them right now for 2 customers and if you ditch the explorer cam in favor of an HO cam you will have around 310HP and 350TQ. You have to upgrade the valve springs as the explorer cam had such a low lift the HO cam exceeds it. I am running the FiTech on all builds so far and it has been fantastic. My personal bronco is a built 347, aluminum heads etc. and it is 400HP 450TQ with all torque in at 2500 RPM. I have not dared enough to go wide open throttle with it yet...


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