lets have a serious discussion about a 351w swap in a 2nd gen

i would like to strike up a new conversation about the infamous 351w swap in a 2nd gen. not some hack shoehorn full of compromises. i mean a no/low compomise build that can look factory. can drive factory. can maintain cruise control and air conditioning. and emissions legal too!

it has been tried by few and i don't know of any sucesses. i may have gotten the closest, as i drove mine on the highway for about 4 minutes.

due to a house that needs work, a 2 week old baby and 2 other kids needing attention, a full time job, a part time job and a wife who wants some of my time too, my project is over with. there's nothing i hate more than unfinished projects, so thats where you come in! if you become the first to daily drive a 351w explorer, my job is complete.

so, i am going to use some free time over the next few weeks to see to it that everyone has access to the knowledge to perform this swap. this is also a discussion for ideas and experience.

TO EVERYONE OUT THERE THAT TOLD ME AND OTHERS "IT CAN'T BE DONE", I REJECT YOUR REALITY AND SUBSTITUTE MY OWN!

let the games begin!

 

[OffTrac]

I have a spare 351W 4v from a parts '69 Cougar for mine and my dad's '69 cats. Not yet sure of it's good enough to use, but I'd love to follow this. I definitely want to go V8 when the 4.0 gives up.

 

[pufferfish]

CHAPTER I: its all about torque

when you are dealing with a 4300+lb vehicle trying to bulldoze its way through the airstream, the more torque you have the better. got taller tires? you just lost rear wheel torque. want to climb that hill? its torque that gets you there. want to tow 7000lbs up a hill? torque makes it seem effortless.

everyone talks about horsepower. horsepower is a calculation of torque (TQ x RPM / 5252=HP). torque determines horsepower. erase horsepower from your memory as the definition of performance. in any internal combustion engine, you have few factors of torque production. #1 engine size. #2 volumetric efficiency. #2 is the most complicated and dynamic factor in engine building. it can be as simple as high compression or forced induction and can get as complicated as variable valve geometry technology. for this discussion, we will stick with engine size.

in my experience, a general rule of thumb for relatively mild pump gas 16-valve pushrod engines is (CI x 1.15=TQ potential). so a 302 can produce roughly 350ftlbs. a 347 can produce roughly 400ftlbs. and a 408 can produce roughly 470ftlbs. again, this is a mild engine. no 8000rpm motors. no power adder engines. no 14:1 compression C16 fueled engines.

how much torque do you need? thats a great question and i don't have a formula for that. i cant tell you how much to have, but i can tell you its a compromise. more torque ALWAYS adds up to more build cost. from my research, a stroked 302 short block will add about $1000. you can add close to another $1000 more for the heads and intake. there is also marginal cost for the fact that the 302 in an explorer is 50oz imbalance and the stroker is going to have a 28oz imbalance.

next, the 351w block. whats not to like about it? it starts at 4more cubes than the biggest stroked 302 and can go up from there. the block is inherently much stronger. if you get a 96+ block, you can also use factory 302 hydraulic roller lifters and cams. if you don't have the luxury of a roller block, fear not. the cam selection is still good and is actually cheaper. here's the kicker...ready for it? a 351w short block costs the same as an equally equipped 302! a stroked 351w costs about $1000 more. the same as stroking the 302! now, heads and intake go up though. your 351ci needs to breathe the same amount of air as the 347, so plan on $1000 more than 302 stuff for that. the 351 stroker is going to need the top shelf stuff. plan on $500 above the 347/351 hardware.

so, speaking striktly of the engine cost alone:
rebuild the 302 @ 300ftlbs = $XXXX.XX
built 302 @ 350ftlbs = $1000 extra ($20 per ftlb)
347 @ 400ftlbs = $2000 extra ($20 per ftlb)
351 @ 400ftlbs = $1000 extra ($10 per ftlb)
408 @ 470ftlbs = $2500 extra ($15 per ftlb)

i think that clears up why we would discuss a 351w swap and that doesn't even account for the various uber cheap 351w engines out there running a meager 350ftlbs. no fancy aftermarket parts. rebuilt OEM style 351w long blocks are ridiculously cheap and will run forever!

so, the engine makes sense. the question is, does the investment in time and money make sense to do the swap. only you can make that decision, but in the following chapters, i am going to try to give you the information to make that decision for yourself. i promise its not as insurmountable as you think.

 

[Turdle]

I totally agree with you Steve. Now, how much is it worth to you guys to get this into your explorer? If you want over 450 hp ( doggone it here I go with the hp again), ok over 400 ft lbs, you will definitely want the stronger block.

 

[boominXplorer]

I am doing this swap come spring time. Prepare to make a custom oil pan, cut the crap out of the a/c box unless you want to do a body lift and the ignition system will be fun. Not to mention good luck finding a gt40 lower intake for a 351

 

[JCat]

Can the driveline handle it?
.
When I built a 302 engine for a Mustang I once owned, it broke everything behind it..
.
When I replaced my 351M with a 460 (F150), it broke and twisted everything behind it.
.
One thing I have experience with is . . . . I always learn things the hard way.

 

[boominXplorer]

Yeah, the stock trans will hold 500 hp with only a good shift kit in it. The 8.8 will be fine also. If your awd you WILL have issues with the t-case

 

[ssp.interceptor]

.

 

[Joe Dirt]

tmoss... There's a blast from the past in my old Mustang days!

 

[Scott B.]

I'll listen in.

I'm swapping a 302 (well, 306) with about 300 lb-ft of torque into my '93 Ranger (equivalent to a 1st gen Ex.) I don't have the deck height issues to worry about, but have the same electrical, cooling and emissions issues.

 

[ssp.interceptor]

.

 

[tmsoko]

Boomin - you need to work out a deal with Steve! He has the hard parts done, you just need to buy them from him and finish it off!

No need to modify the airbox.

I have had my 351W mocked up in my engine compartment several times. I have all the required custom parts done, except the ac line extensions. As I am also doing a custom intercooler manifold, I am still nowhere close to being done. So, the 302 will go back in the truck this Christmas (for the first time in 6 years... lots of cobwebs to get out of this thing!)

So, buy steve's parts and give me a challenge so I get off my butt and complete mine! (Please).

 

[ssp.interceptor]

.

 

[pufferfish]

i may have been overzealous with my idea of posting a comprehensive how-to on this swap. babies are really friggin' needy! i just don't have enough time to go through it all from memory without missing info.

to address the concerns above:
the fact is that the 351w is used in full size trucks with the 4r70w behind it and an 8.8 rear. i have talked with numerous tranny builders and they all say it is plenty stout, but there are simple items to make it better. first is a shift kit. second is kevlar bands. third is a good torque convertor.

the ac box doesn't need to be hacked up or even touched. it does require thought in designing headers and you're not running tall valvecovers with rocker stud girdles underneath. a body lift will definitely make this easier, but is absolutely not required.

there is absolutely no reason you cant utilize the stock 2nd gen 5.0 ECU and harness. the cam sensor and balancer with the trigger wheel have been done without spending much money. everything else is exactly the same to control the 2 engines.

i don't know why you would get hung up on a 351w gt-40 lower intake? there are better options out there. but if you insist, $400 gets you a good lower and any old upper will do. its going to cost $600+ for an aftermarket long runner intake.

i really can't speak to the strength of the transfer case. there are options out there if you like, but then the front diff and half shafts will be the weak link. but, my bet is a well rebuilt awd transfer case and front diff/half shafts, will be fine for street duty. offroad may be a different story, but you don't want an awd setup for that anyhow!

 

[snoranger]

puffer... What was your solution to the balancer?

 

[tmsoko]

Some info from my side:

Absolutely agree with the valve covers and clearance to the HVAC. Plenty of clearance with stock or tight aftermarket covers. I have fabricated Moroso covers and clearance is fine.

I did do a 5/8" lift to the engine and a 1" lift of the body. This was done to provide adequate clearance of the oil pump to the steering rack. The 351W oil pump was ~1/2 - 3/4" taller than the 302 pump. The engine lift was min to give me comfortable clearance. The body lift was min "puck" size I could get.

For the cam sensor, I did similar to Steve. I took a 351W distributor and cut off the bottom of the shaft. I took an explorer cam sensor and cut off the bottom of that too. Then bored a hole in one, turned down the other, slipped together, and welded. I need to make a similar bushing to what Steve did, so I may end up getting a 3.8L sensor and starting over...

for the crank pulley / damper / trigger wheel, I took the easy way out. When I had my engine balanced for the new pistons / h-beam rods, I had them balance with a 28 oz flywheel and the 50oz damper. A strange setup, but perfectly balanced regardless.

Headers are interesting to say the least. Took plenty of time, but done.

This link has most of the pictures / detail from years gone by. You can see it has been a while. Heck, I have done nothing on this for 2-3 years now.

http://www.rangerpowersports.com/forum/f402/1999-awd-kenne-bell-351w-swap-233918.html

I need some motivation!

 

[pufferfish]

my balancer came from Turdle, so i am not entirely sure how it was made to be a 28oz. but, i can tell you it is a stock balancer and it has extra holes in it to rebalance it. i spoke with an engine builder and he said he could rebalance it.

i went with a 1/4" engine lift. i paid extra attention to getting the oil pan tucked up to the bottom oil pump bolts. i had about 3/8" clearance from pan to steering rack. i can't be certain that was enough, but i felt it was going to work. keep in mind that if you plan to use the stock clutch fan, your fan is on the engine and the fan shroud is attached to the body. there is play in the opening, but be careful.

 

[boominXplorer]

Yeah I am in the collecting parts phase now. I will be using the stock explorer balancer that has been drilled and rebalanced to 28oz. I will be using the flexplate off the 351 just as long as the teeth match up. I also have a cam sensor built but need new brass bushings for it.

The engine I am using is from a 96 F250. I am going to keep the bottom end stock and got a set of ported gt40p's that I need to get drilled out for the head bolts. I also already have roller rockers, just need lifters and pushrods. I am attempting to keep this swap somewhat cheap but not cut corners.

I am 2wd so no worries of the oil pan clearing a front diff, but the steering rack and a/c box are a big concern. I want to lift the engine as little as possible, I even thought of shaving the steering rack bushings to gain a about 1/4" - 3/8" clearance.

I really want to keep my gt40 upper setup since my upper is already highly ported to match a 75mm tb and to keep it mostly factory on the top half.

Steve - I cant find any pics of your oil pan, can you post one?

 

[ssp.interceptor]

.

 

[pufferfish]

oil pan buildup

take 1 stamped steel explorer pan, 1 stamped steel 351w pan, measure twice, cut, weld, grind and paint.

the oil pickup is an explorer version with a few cuts and welds to position it, orient the flange for the 351w pump and lengthen the vertical portion for the deeper sump wit hproper clearances.

take a look at the dipstick. the explorer tube and dipstick tube are shown. the dipstick hit the side of the main cap, so i had to bend the tube where it sits below the oil pan mounting surface on the block, so it would steer the dipstick down to clear the cap and bolt. it still didn't work very well. i could hear the dipstick hitting the crank when it ran. not sure how a 351w dipstick and tube work around this issue, but it is worth looking at.