Performance difference: 351W vs 354 stroker?

[Unique 289_FIA]

I've wondered this for awhile. How would a 351W's performance compare to a 302W stroked to 354 (Southern Automotive's kit), assuming similar heads, intake, carb, etc? Would there be a significant difference? Would the stroker make more torque? Which has more potential? Why would one choose one versus the other?

Robert

[blykins]

I'd say the only difference if any is the torque curves and powerband ranges....I'd say the 351W would make a little more torque.....and the power bands would be down a little lower.

[Excaliber]

I would think the 342 would also shave a 100 pounds or so off the weight. That alone may give it an "advantage".

Ernie

[auto10x]

The 351 will make the power easier and likely last longer.
auto10x
Bill

[DAVID GAGNARD]

I agree with Bill,the 351 based motor will not have to "work" as hard or turn as many rpms to produce the same as the stroker..... If you are using "similar" heads/intake (aluminum) I would think the weight difference alone would be just the block,which I do not think would be near 100 pounds....The strokers are great,but in this case especially if it is going to be a "street" engine, I would go with the 351.....

Just my .02 cents---and that and .75 cents might or might not get you a cup of coffee in downtown Marksville,La., saturday morning......

David

[Pete Munroe]

I went through the Ford SVO catalogue last year and posted a few weights about 302/351 stock block, Sportsman, SVO versions, aluminum version, etc...should have printed it out somewhere, I guess its in the archives but don't remember the title to find it.

I have a 289...302 block for all practical purposes, that is stroked to 347...everything that can be replaced with aluminum is on the engine and my goal, as the car was a ERA 289, was a stock appearing engine, low 8.2 inch deck height with the lowest weight possible short of an aluminum block...( which is a dry sump engine so all the monkey motion of a remote tank, lines and dry sump pump may negate that advantage...although you could relocate it to the right side of the trunk area for balance).

Anyway, if you aren't going to stroke the 351, do the small block and save at least 40 to 50 pounds and have a lower c.g...if you are looking for a good handling track car with more power than 90% of us "wanna-be drivers" can use anyway in anything but a straight line.

Engine life???...is this a daily commuter???...most of these cars never see more than 5000 a year, and thats the first wildly enthusiastic year.

The really serious 351 engines seem to have main bearing spacers to decrease the diameter of the main bearings for lower rotational speed on the crank to...~289/302 speed.

So, other than rod angularity, side loads on the cylinders and pistons, rings in the oil pack, all related to the shorter deck height, who cares?...if you aren't doing serious racing in endurance events, looking to be smog legal for 50K+...the lighter weight seems worth it for a street or track car...

If you are a power guy, stroke the 351 to 400+, and forget the weight...have fun, but why run a 351 when you can run a lighter 347...stroke the 351 for lots of torque and power, or skew the car to lower weight for quicker handling with the small block.

Whatever you do you will have fun, just think it out to maximize your configuration...stoker kits are pretty cheap...you want easy low rpm POWER and TORQUE, go for the big cubes...stroke the 351.

Pete

[Keithc8]

Just build a 351W stroker and be done with it. These engines will all cost within a few hundred dollars of each other. You can build a 408 Windsor for about the same money as a 351W any more. Good luck and I say the cubic inches has it. Thanks Keith c

[Doug I]

Robert ....... what you have now works, and works well. It also looks damn good sitting in there. The power difference probably couldn't be noticed in daily driving anyway.

The 351 has more potential as the 354 Stroker has already had a major modification done in going from 302 to 354. The 351 is very close to the stroker in pretty much stock form and you can go up from there.

My opinion is ........ if it isn't broken it doesn't need fixing.

Enjoy that fine car, and was last weekend some good cruising' weather or what ?

[klayfish]

I'm not a mechanic, and I don't play one on TV, so I'll not even try the technical end of it.

But as others said, the stroker is a 302 already stretched pretty far. If you start with a 351W, you have more potential. It can be stroked to 400+ and make gobs of power. I went from a 302 to a 351 and the power difference is huge. I think the weight difference you give up with the 351, unless you are a hard core racer, would be more than offset by the added power.

Steve

[Unique 289_FIA]

Stroking the 351 seems to be the popular answer I've been getting. Of course a 4xx c.i. motor has more potential. But what I'm asking is given a stroked 302W and a non-stroked 351W, is there any performance benefit of one over the other? In other words, will the 351 inherently make more torque or will the stroker? Are the power bands going to be different (given same setup)?

I already have the 354 stroker from S.A. and am quite pleased with it, but I'm new to Ford small blocks and this was a question I've been pondering.

Thanks, guys!

R.

[DAVID GAGNARD]

Unique 289;

I no engine expert by any stretch,but I would think given two engines of similar cubic inches (351 vs. 354),and similar hp and torque numbers,I would guess the non- stroked engine would probably make it's power at a lower rpm level than the stroked engine,mainly because of the rod ratio and length.....this is just a guess,I really do not have any hard data to back this up,just what I've seen with stroked vs. non stroked engines in the past...

Hopefully some of the enigne builders on this site could shed some light on this with actual hard data (dyno results).. Later on,I'm going to try to "run" two similar engines on my Desk Top Dyno and see the results and will post them....

David

[Unique 289_FIA]

David,

Mind running my setup on your desktop dyno? You can find most of the specs at Southern Automotive's website, but there have been a few changes:

354 stroker (3.470 stroke)
Trick flow heads, ported
Holley 750 DP
Edelbrock Air Gap intake
Mallory ignition
Tremec 3550, 4.10 rear

What else do you need?

R.

[Unique 289_FIA]

A related question: What comprised the 351's extra 49 c.i. of displacement? Bore, stroke or a bit of both? The stroke of the 354 is 3.470 in. How's that compare to the 351W? I guess the answers to these questions would prolly answer my performance questions.

Thanks again!

R.

[DAVID GAGNARD]

Unique 289;

Need all the specs on your cam card,bore,stroke (have),compression ratio,intake (single plane or dual plane manifold),carb we have ,heads we have,mufflers or no mufflers,header tube size,that should about do it.....cam type,hydraulic,solid lifter,hydraulic roller,or solid roller????

351-W--bore 4.00 inches,stroke 3.5 inches

David

[blykins]

A 351W & C has a 4.000" bore and a 3.500" stroke. Also, I can run Desktop Dyno for you too....need cam specs and compression ratio.

[Unique 289_FIA]

Ahhh, so the 354 actually has less stroke and a little more bore. Hmmm, so theoretically it should be able to rev a little higher with less low end grunt (an area which it does not lack, can't imagine more ). It will pull all the way to 6800.

Doh, of course cam specs. It's a custom grind from Elgin, I'll have to get the card when I get home. Solid lifter, flat tappet. Compression ratio is about 10:1. Mufflers (don't know what type), 1 3/4" headers. I think the Edelbrock Air Gap is a dual plane intake, but I'm new to that terminology as well (used to be a turbo import guy... I know, I know ), perhaps someone else can confirm?

R.

[DAVID GAGNARD]

Unique 289;

Yes,with bigger bore and shorter stoke it should rev quicker....Low end grunt is probably not lacking in your case especially with a light car....Just checked Summit,the Air Gap you have is most likely a dual plane manifold,although you can get an air gap in single plane.....When I mentioned mufflers,you can run the dyno numbers with or without mufflers.....

If that thing of yours pulls to 6800 rpm,you have a well built motor and a pretty healthy cam,how is it on the street at low rpms???? What length rods does it have????

David

[Unique 289_FIA]

Cam specs:
Advertised duration: I-298 E-308
Duration at 0.050: I-238 E-248
Lift: I-0.512 E-0.536
112* of lobe separation

Don't know the rod length. I intend to eventually call S.A. up and ask them if they can tell me all the in's and out's that I don't have the paperwork for. As for how it runs on the street, I have noticed no lag in power of anykind at any rpm, but then I don't punch in 4th if I'm chugging along at 1500. Of course, with 4.10's it's usually above 2000 anyway.

[DAVID GAGNARD]

Unique 289;

I'm running a tremec and 3.00 rear gears in a 9" rear end,first gear is pretty "short",your running a tremec with 4.10's???? Do you actually use first gear????If so, it must be realllllllll short.......

David

[Unique 289_FIA]

It also gets reeaallly good gas mileage.