1 2
yupididit
yupididit GRM+ Memberand Reader
12/6/14 12:54 p.m.

Curious,

Is there any advantage of having a 351W over a 302? Both being ran through a t5 with EFI.

All things being equal as far as $$$.

Mr_Clutch42
Mr_Clutch42 Dork
12/6/14 1:31 p.m.

I'm a Chevy guy so all I know is that you get to tell people that you have a 351 Windsor, not many Ford car owners seem to swap them.

stuart in mn
stuart in mn PowerDork
12/6/14 1:33 p.m.

All things being equal, except for 49 additional cubic inches. A 351 has a taller deck, which can make it more difficult to fit in your car, depending on what car it is. I would imagine 302 parts are more common and less expensive. You can also use a stroker kit in a 302 to get more cubic inches if desired.

oldtin
oldtin UberDork
12/6/14 1:57 p.m.

About an inch and a half taller. Off road crowd prefers the 351 over 302. More torque more volume. There's also stroker kits. However big the 302 goes, the 351 can go a little bigger.

dropstep
dropstep Reader
12/6/14 2:00 p.m.

if budget isnt a concern the 351 is a better option because of the taller deckheight. i prefer the 302 because parts are cheaper, theres alot more used performance parts available for budget prices.

yupididit
yupididit GRM+ Memberand Reader
12/6/14 2:18 p.m.

How about the parts interchangeability between the two.

novaderrik
novaderrik PowerDork
12/6/14 2:51 p.m.

go with the bigger one, you can never have too many torques at your disposal. i can tell you from personal experience that a nothing 70's 351W with a mild cam is a ton of fun in a 79 Mustang with 3.42 gears and an automatic trans..

if you get a later model one with a roller cam, then any roller cam for a 302 HO will slide right in... heads interchange with maybe a little drilling out of the head bolt holes for bigger fasteners, so you have a lot of options there.. intakes are different due to the higher deck height, but anything available for the 302 has an equivalent for the 351W. headers may or may not fit a particular chassis due to the taller deck height and resulting wider engine.

regarding stroking them: you can get 347 kits for the 302, but you can find kits to make a 351W into a 427..

Knurled
Knurled PowerDork
12/6/14 5:03 p.m.

The 351W block is physically stronger, too. It weighs a lot more than just the deck height change would indicate because there's a lot more beef-metal in it. You'd have to step up to an aftermarket 302 block to get something as strong, at which point it weighs as much as a 351W anyway.

None of this matters if you're putting it in front of a T5. The trans will probably break before you get a chance to split a 302 block.

aussiesmg
aussiesmg MegaDork
12/6/14 5:08 p.m.

If you have the height clearance covered, go 351 every time.

More power, stronger, reliable, just better.

heads are interchangable, only the intake is significantly different as far as bolt ons go

jimbbski
jimbbski HalfDork
12/6/14 5:08 p.m.

I agree with "novaderrik" above. Except for the intake and some header fitment issues there is no reason to go with a 302 instead of a 351 if the goal is torque! If you have a Mustang then a 302 based engine is going to be cheaper to build and you can gear it to gain performance. But if the vehicle is something heavier then go 351! The only down side is that a T5 behind a 351 is near it's torque limit with only mild mods. Ford never used the T5 behind a 351. Trucks got a truck trans and the rare 1995 Cobra R used a Tremac 5 speed.

Will
Will SuperDork
12/6/14 7:39 p.m.
jimbbski wrote: The only down side is that a T5 behind a 351 is near it's torque limit with only mild mods. Ford never used the T5 behind a 351. Trucks got a truck trans and the rare 1995 Cobra R used a Tremac 5 speed.

The Fox body-spec T5 was only rated to 300 lb-ft. Ford installed the M5R2 in the Supercoupe because even it was making more torque than that.

The_Jed
The_Jed UltraDork
12/6/14 8:10 p.m.

302w uses 7/16" head bolts, 351w uses 1/2" head bolts.

One of my many bench builds for my Mark VII is a roller cam 5.8 (351) with gt40p heads(drilled for 1/2" studs, milled for 10:1 compression and ported), stock h.o. cam, 1.7 roller rockers and o.e. truck intake. All of the torques!!

curtis73
curtis73 GRM+ Memberand UberDork
12/6/14 10:24 p.m.

Are we talking street? Cubes are king. If we're talking race, HP is king.

They are the same basic engine except for deck height... The short windsor (289/302) is much more common, so parts are cheap. You can build a stroked and bored 347 from a 302 often times for the same price as a 351 at the same power level.

So for equal money, a 351 will have more cubes, more low end torque, and a lower RPM peak. A 302 will have the same HP, but a slightly higher tq peak with lower tq numbers.

In almost any situation, cubes are better. Unless you can make your goals cheaper with the super-cheap 302.

As far as parts interchanging, they mostly all do. The 351 is a taller deck, so intakes, pushrods, etc will all be different, but they are both windors. Its just that one has a taller deck. Extrapolate from that what makes sense.

novaderrik
novaderrik PowerDork
12/6/14 11:57 p.m.

whatever you do, keep in mind that the later (84 and up?) HO 302 used the 351W firing order, and i think they all went to that firing order sometime in the late 80's.. just something to keep in mind when looking at cams and when you are trying to figure out why it runs like crap despite having all the wires on the cap in the order that it shows in the Chilton's manual for the year of the engine..

Kenny_McCormic
Kenny_McCormic PowerDork
12/7/14 12:20 a.m.

I theory you just need to spin the 302 faster to keep up, in practice displacement is the cheapest power adder.

Nitroracer
Nitroracer SuperDork
12/7/14 6:10 p.m.

Having built a 351, there are enough differences that for the money I would have rather built a 302. I guess it all depends on your budget and intentions with the engine. There are fewer intake choices for the 351, both EFI and carb, a cheap T5 may not survive as long behind one, roller cams didn't appear until 1994. But I was building on a budget with mostly OEM parts. Easier to find parts for a 302 as well.

Keep in mind if you want to modify a 351 you'll want some nice heads and an intake for that extra air flow from the additional displacement. I have GT40 heads on mine and wish I went with something aftermarket.

oldopelguy
oldopelguy SuperDork
12/7/14 9:00 p.m.

My dad dropped a valve in his 351 bus 1000 miles from home and could only find a set of 302 heads quickly and cheaply. Local machine shop drilled out the holes and he put it back together and drove home.

Somehow the compression ratio ended up super high and he had to run premium and octane booster to keep it from pinging but it sure seemed to make good power.

novaderrik
novaderrik PowerDork
12/7/14 10:02 p.m.
Nitroracer wrote: Having built a 351, there are enough differences that for the money I would have rather built a 302. I guess it all depends on your budget and intentions with the engine. There are fewer intake choices for the 351, both EFI and carb, a cheap T5 may not survive as long behind one, roller cams didn't appear until 1994. But I was building on a budget with mostly OEM parts. Easier to find parts for a 302 as well. Keep in mind if you want to modify a 351 you'll want some nice heads and an intake for that extra air flow from the additional displacement. I have GT40 heads on mine and wish I went with something aftermarket.

from what i understand, it's not too hard to put a factory style roller cam and lifters in pretty much any Windsor block ever made.. just a little drilling and tapping of a few holes in the lifter valley for the spider.. i saw a buildup online somewhere a number of years ago where they did this, but i haven't looked at an actual Windsor block in person since i built a 302 out of an 88 Marquis for a friend's 89 Mustang about a decade ago..

HappyAndy
HappyAndy UltraDork
12/7/14 10:42 p.m.

If the $$ is more important than the total tq, go with the 302. More stuff is available, and a lot of it can be had for pennies on the dollar as used parts, even top shelf stuff.

If total torque is more important than the $$, and room allows it, then go with the 351w.

The fact is that both choices are good, and can be built up strong enough to overwhelm a T-5 without spending a ton.

yupididit
yupididit GRM+ Memberand Reader
12/8/14 12:38 a.m.

This is all good info. I guess they aren't as alike as I would hope. It's a bummer the t5 isn't up for the task.

I was thinking auto too. Just looking at affordable v8 engines that can make good torque. To eventually replace the m117 in the 450sel. LT1 and 351W are my top choices, unless i can find a 4.8 or 5.3 for a steal. Which is least likely.

yupididit
yupididit GRM+ Memberand Reader
12/8/14 12:44 a.m.

Actually scrap the manual transmission. I just thought about how hard it would be to find a w116 3 pedal assembly

bgkast
bgkast GRM+ Memberand SuperDork
12/8/14 12:48 a.m.

I think a w123 assembly fits, but an automatic suits the W116's personality.

Trans_Maro
Trans_Maro UberDork
12/8/14 1:04 a.m.

I like Ford trucks.

The Ford guys in my town are idiots.

I had a good running 351W out of a police interceptor and I couldn't give the damn thing away.

Ended up getting scrap value for it.

yupididit
yupididit GRM+ Memberand Reader
12/8/14 1:07 a.m.

Thought that too but I think it's the assemblies from the r107 that can be used.

Either way, you're right about the personality of the car.

ddavidv
ddavidv PowerDork
12/8/14 4:16 a.m.

A4OD bolts up behind a 351w and it's what we run in the first gen Lightning. Add a Punisher brand valve body and it will shift with authority. I like my 351w; it still spins freely much like a 302 but has much better torque characteristics.

1 2
Our Preferred Partners
Y0u5A4EHveegUtCehrGO3UHxLzf3sLL1GRTIVMKWeVa7yoP5B8UWAKxEgbw5hQPU