jazzop
jazzop New Reader
9/26/17 1:37 p.m.

Not a 'murrican car guy.  In fact, this is my first V-8 powered vehicle ever (in 25 years of driving).  But when you need a heavy-duty truck, Detroit has the only game in town.  I recently acquired a 1995 F-350 4x4 with the 351 Windsor motor and ZF5 manual gearbox.  Its role in my fleet will be to haul stuff.  Therefore, a lot of 351W mods are not relevant because they are designed for cars with power gains at higher RPMs, sometimes at the expense of torque.  I rarely see over 3500 RPM on the tach unless I'm unloaded and trying to scoot through traffic.

Suggestions are welcome for any improvements that will give me more torque and/or lower-RPM power out of this motor.  Other tips and tricks are welcome, if you have experience with this generation of F-series and know of design/build shortcomings that can be improved.

rslifkin
rslifkin SuperDork
9/26/17 1:47 p.m.

You'll be able to gain some low end, but with a non-turbo gas motor in a truck, you pretty much have to be willing to sit in a low gear and let it rev when you need the power.  The only way you'll get tons of low rpm power where you never need to rev it past 4k to get what you want would be with a very large displacement engine or boost.  

Wayslow
Wayslow HalfDork
9/26/17 2:18 p.m.

Yup. I hate to say it but the only way to make bigger HP and torque numbers is by going up in RPMs. It takes a bit of getting used to but remember that the oil pressure and coolant flow increase with engine revs so you aren't doing any harm.

jazzop
jazzop New Reader
9/26/17 5:07 p.m.

In reply to rslifkin:

Not a fan of turbos in general (except on diesels), but I did pencil in a supercharger way down on the list of things to do to this motor.  At this point, however, I'm just looking for ideas that would fall into one of the following categories. (Yes, I should have been clearer in the OP)

1. Fixes for known deficiencies.  You know, those design flaws and failure-prone stuff that every marque enthusiast knows about but newcomers don't, such as a modified oil pick-up, reinforced motor mount, wiring hack, etc.

2. "Mandatory" simple performance enhancers.  Also typically common-knowledge among enthusiasts and usually junkyard-sourced from different years/models.  e.g., bigger throttle body, electrical hacks, brake caliper upgrade, better heads/cams...  Often this is the stuff that makes you scratch your head asking, "why did they put the crappy part on when they had this in the parts bin already?"

3. Aftermarket products that are well known to enhance performance/strength/reliability.

[EDIT-Addition] To further explain my rationale, it might help to know that as soon as I buy a vehicle, I like to build a detailed list of the planned and potential improvements so that I can research parts and keep my eyes open for stuff in the junkyard or on eBay/CL.  The list is consulted anytime I have to repair something so that I can seize the opportunity to make the improvement in conjunction with the repair.  Of course, if I ever find myself with surplus time and money, I can always pick something off the list to do; but with 7 cars, I don't really find myself in that position very often.

dean1484
dean1484 MegaDork
9/26/17 5:28 p.m.

I would think that an top end kit with a set of headers would wake it up.  Think cam intake heads and headers and probibly a new carb while you are there or spend some more and go efi.  I bet if you call edelbrock they could hook you up all in one box to your door.

jazzop
jazzop New Reader
9/26/17 5:49 p.m.

In reply to dean1484:

It already is EFI from the factory.

I spoke to Edelbrock and they are more than happy to sell me thousands of dollars worth of parts.  I'm not quite so enthusiastic about dropping thousands of dollars on parts for stuff that isn't broken, however.

Chadeux
Chadeux Dork
9/26/17 6:05 p.m.

In reply to jazzop :

All I've seen tells me that's basically how you make power with an old V8. You replace 50-80% of it or you perform witchcraft. If you want the big numbers you do both. 

dean1484
dean1484 MegaDork
9/26/17 6:48 p.m.

Performance cost $$$$$. You are stuck with heads and an intake and a cam that are limiting you.  The only other option is to piece together used parts and then go at it.  

Forced induction is the other route and in the end will probibly cost you the same amount. 

dean1484
dean1484 MegaDork
9/26/17 6:52 p.m.

Another option is a rear end gear change.   To better apply the power you have to the type of driving you typically do.   This will potentially can cause you problems if your usage changes.  

snailmont5oh
snailmont5oh HalfDork
9/26/17 7:15 p.m.

Explorer 5.0 heads probably wouldn't hurt, if you can find manifolds that will work. You'll have to open up the bolt holes a little. Better flow and more compression. Or, you could do a little exhaust port work and mill the heads that are on the truck. They're probably E7TE, so they're one of the better castings.

I've heard that you can cheaply build a 393 stroker with clever use of stock parts from other engines, and a little machine work. 

rslifkin
rslifkin SuperDork
9/26/17 7:23 p.m.

Other option is to swap a 460.  It came stock in some of those trucks, so it should be a pretty easy swap. 

jazzop
jazzop New Reader
9/27/17 2:16 a.m.

To respond to a bunch of points above:

Based on my research, the GT40 heads are the gold standard for that motor.

An engine swap is only a consideration if my engine grenades or I am offered a free/cheap motor that is superior.  I have run across some stroker builds online, but unfortunately they are not documented rigorously enough to know everything that was done.

This truck is only used for utilitarian purposes, so it will be loaded down >=50% of the time and driving habits are fairly consistent.

Don't forget that I know nothing about American makes and nothing about V8 motors.  The only other American vehicle I've owned was a 1987 Dodge D250 with a slant 6.  So this is actually the first "V" motor I've ever owned in 25 years of driving.  So please don't assume that I know some things that are probably second-nature to owners of Detroit iron.

snailmont5oh
snailmont5oh HalfDork
9/27/17 4:21 p.m.

There is plenty of material available for research on the 351 Windsor/5.8 Liter engine, in print as well as online. If you know that little about it and want to know more, I'd suggest starting there, if for no other reason than to bring yourself up to speed on what people mean when they talk about certain parts or build options. 

Dirtydog
Dirtydog Reader
9/27/17 9:02 p.m.

You can look at massaging the heads, custom grind cam for low end grunt, better injectors to match, better air intake, and for seat of the pants performance, different rear gears.  Better ignition.  Also a set of headers.   More air in more air out.

Rodan
Rodan Reader
9/28/17 12:03 a.m.

I've had an F150 with the 5.0, an F250 with the 460, and currently own a Bronco with the 351W.

#1, most cost-effective route to better torque and fuel mileage:  sell it, and buy the exact same truck with a 460.  They're dirt cheap, it'll have more torque and will get the same or slightly better mileage.  Upgrade the exhaust on the 460 for 1-2 more mpgs.  When I had my F250/460, I was getting better mileage than anyone I knew with a similar truck with the 351.  And our Bronco gets 8-10mpg.  351s just get crappy mileage.

Otherwise, it's like any other engine:  more air in, more air out, and more fuel to match.  I don't recall off the top of my head, but if your '95 is speed density, you're going to be severely limited on what you can change with the stock ECU.  Easy enough to check for a MAF meter in the inlet tract.  If it is Mass-Flow, you can do a little more before you'll run into the limitations of the stock computer.  Probably the best option for low end torque is a stroker crank as mentioned above, and a slight compression bump.  Remember, even a motor that makes more power at higher rpms will likely still have more torque than stock at low rpms.   Another option is a relatively stock engine with two small, quick spooling turbos... but you'll need aftermarket EFI to make it live.

I'm planning an engine for the Bronco in the future, and it will most likely be a ~392 stroker, with a carb style manifold, better heads and Megasquirt EFI.  IMHO the truck heads/manifolds and stock EFI are the biggest choke points on the 351.

ddavidv
ddavidv PowerDork
9/28/17 4:46 a.m.

I own a '93 Lightning which was the pinnacle of factory performance for the 351W of that era. It has the best HP and torque numbers of any of the small block Windsor engines and is comparable to the later 'modular' Triton engines used in the F-series. Though the Lightning uses a lot of specific parts most of what makes its power are the heads (GT40), intake (GT40) and exhaust (factory tubular manifolds). It has decent torque which is helped by the (I think) 4:11 gears.

If you could find a Lightning engine--they are out there--it would be mostly plug and play. You won't have the L computer but I'd tell you to move to a mass air system anyway. If you could just score the intake and heads you can pick any cam you want at that point. Speed density severely limits modifying that aspect.

Beyond that I'd concur with the suggestion to just get a 460 powered truck. Fuel mileage will be abysmal but you will have all the torque you could ever want. When I shopped for a truck to tow my race car I would not have taken any of the SBF's of that vintage other than the L. The 460 is the way to go, but I bought my L for the price of a 302 powered truck and liked the 'odd' factor of it.

jazzop
jazzop New Reader
9/29/17 1:03 p.m.

Selling the truck and getting a 460 is not as easy as it sounds.  I looked for a truck with a manual gearbox for 2 years and finally found one.  A slushbox is totally out of the question.  If the 460 will mate to my driveline, it would probably be easier to find just a motor than a complete truck.

Rodan
Rodan Reader
9/29/17 1:49 p.m.

I guess it depends on where you are.  I cruise CL regularly looking for an F250 for an axle donor for my bronco... rarely see 351 manuals here in AZ, but lots of 460s.

Kramer
Kramer Dork
9/29/17 7:25 p.m.

Look for a "towing cam." It will make all the difference in the world.  I had a stock SBC with a Melling towing cam and two barrel.  Very torquey and powerful, for what it was.  

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