347 Stroket VS. 357W (.030 over)?

jst6 · May 6, 2004

Any advantage other than reliability for going with the 357W over the stroker? i've seen short blocks priced higher for the sroker motor than the 357 from the same company. I'd rather go with the 357 but if the 347 can make the same power and use my stock hood, mores the better.

any thoughts?

2bav8 · May 6, 2004

The 351W block has the potential for more cubic inches should you need more in the future. It also has stronger main webbing than a 302 block.

I came across the same cross roads with Kingsford and went with a 347.
I prefer the lighter weight and smaller block for improved handling and additional hood clearence. If drag racing is more your tune, a 351W might be better suited for you.

10secgoal · May 6, 2004

That is true. But the 351 needs all new gear too. So I would go with the 342.

Edbert · May 6, 2004

10secgoal said:
That is true. But the 351 needs all new gear too. So I would go with the 342.

Only intake and distro are different. If this is a 65-66 then you might need different headers but heads and accessories (possible braket change) are the same. I'd say go with the 357 (in fact I DID when I had to choose). The block is MUCH stronger, makes more torque, is able to take higher revs, both due to bigger bearings and that the 347 has a long stroke for high rev applications. Add to that the ability to turn it into a 427 when you get the urge and the lower cost makes it pretty much a no-brainer to me.

Pakrat · May 6, 2004

2bav8 said:
The 351W block has the potential for more cubic inches should you need more in the future. It also has stronger main webbing than a 302 block.

I'll give ya the "more cubes" part uncontested, but IF it were a Mexican 302, wouldn't the main webbings be as beefy?

How do you like the 347 performance wise BTW 2bav? When the time comes to rebuild my motor one day I have been toying with the idea of stroking it, but for a cruiser I was thinking 331 might be more than enough unless I'm talking chump change to go up to 347.

2bav8 · May 6, 2004

is able to take higher revs, both due to bigger bearings and that the 347 has a long stroke for high rev applications

Actually, last time I checked a 347 has a 3.4" stroke and the 351W has a 3.5" stroke. I think that gives the advantage to the stroker motor for higher revs.

Also, the smaller bearings of the stroker are also an advantage over the larger ones, yet again advantage goes to the stroker.

Pak,

The 347 performs very well. Personally I would build a 347 over a 331 anyday unless you're going to go with a lot of boost. I mean for both builds you really should be upgrading your cylinder heads anyways so why not maximize them with extra cubic inches.

Thustlewhumber · May 6, 2004

I have a 66 fastback that had a 289 in it and I went to a 351w. The difference is night and day. I went from squealing my tires when I take off to smoking my tires by flooring it at 40mph. You are going to spend way too much time and effort trying to get something out of a 302 that is already there with the 351w (and thats not counting stroking the 351w).

There are 2 things you need: A water pump from a 70 mach 1, and some headers from Hedman Headers. Other than that, the 351w drops right in with no other modifications and can bolt up to your existing equipment. I loved my 289, but I think that the 351w is a much better engine overall (design, power, reliability). Personally, I think everyone should ditch the 289/302 and put in 351's But some people like to be purists....

LMan · May 6, 2004

Most of the early horror stories about 347/331 strokers have long since been rectified, but the rumors still persist that they are ticking time bombs, for some reason....

A properly-built 331 or 347 will last as long as a 351 or 351-based stroker, IMO. Whether you get a 351-based or a 302-based stroker, the point is that with todays quality and prices, it makes no sense to rebuild a stock-stroke motor when a stroker is so easily done.

The 331/47 will be lighter, if thats important to you, plus you get to keep your front dress and bracketry, headers/exhaust, etc (if you want to keep them). If you want lots of growing room later (392, 427, etc), get the 351 as the 302 is maxed out at 347 already.

Edbert · May 6, 2004

2bav8 said:
Actually, last time I checked a 347 has a 3.4" stroke and the 351W has a 3.5" stroke. I think that gives the advantage to the stroker motor for higher revs.

Also, the smaller bearings of the stroker are also an advantage over the larger ones, yet again advantage goes to the stroker.

Correct me if I am wrong but I thought the part of the stroker that makes them less stable at high RPMs than a stock-stroke setup is not the total stroke or length of the rods but the actual throw of the crank itself. I mean that the 351W gets its longer stroke via a taller deck, meaning the bottom of the heads are actually farther from the centerline of the crank. In a 347 the centerline of the crank is the exact same distance from the bottom of the heads as it is in the 2.87 (IIRC?) inch stroke of the 289 (and the even shorter 260 right?). That means that from 2.87 to 3.4 inch difference is all made up by a longer throw on the crank. The 347 gets its 3.4 inch stoke by making the lower portion of the rods travel in a larger circle around the centerline of the crank resulting in more stresses than the 3.5 inch stroke of the 351/357.

Please correct me if I am wrong here.

jst6 · May 6, 2004

either way i decide, it's going to be a full build up (crank, rods, heads, cam etc.). The extra torque of the 357 really makes me want to go that route.

I've called a few machine shops today, locally and internet. it seams its going to cost nearly the same (+ or - $400 depending on the shop) to go the 347 or the 357. which in my eyes seals the deal on going the 357w route. not only can it go HUGE later on but the crank trhow was one of the burning questions in my mind.

I appreciate all your responses.

btw Edbert, you have all the stuff i'm trying to get now!! except i'm looking at a much more radical cam setup with dif heads.

Edbert · May 6, 2004

jst6 said:
btw Edbert, you have all the stuff i'm trying to get now!! except i'm looking at a much more radical cam setup with dif heads.

Thanks, I made many compromises with my car. It is for street driving mainly. I wanted rock-solid reliability and easy driveability. I also wanted NO issues with pump gas (now or future green blends), as well as enough vacuum for power discs and automatic transmission. DSS told me my bottom end was good for 7500RPM but my cam will crap out just over 6K.

SandSprite · May 6, 2004

I thought the oil pans were different too....

BAD67FUN · May 6, 2004

Stroke the little guy.... Aluminum heads, get the weight down. Balance the car. Make it fun to drive. Especially if you already have the 289/302 block.

Unless you intend be a drag queen. Then go cubes all day.

I like to carve corners. Be different. 95% of the classics around here are drag queens. They slap big cube engines in with a nice paint job and are done. It's like a bunch of meat heads struttin at the local gym.

My granny can run the quarter mile...

SadbutTrue · May 7, 2004

351ws are only 40 lbs heavier than 302s, and the differential drops more if you add aluminum intake and heads (351w intake is a bit bigger, and I think the heads might have more meat on them too... ) to both. An aluminum headed/intaked 302 might only weight 20-25 lbs less than an aluminum headed/intake 351. This could be made up dozens of ways. The extra torque and durability of the 351w make it more than worth 20 lbs to me.

And although I eventually see my car having some cornering ability... classics aren't really meant for corner carving. Even with all the mods in the books, they still aren't going to handle with a modern car thats designed for handling. They will, however, plaster you to the rear of your seat, smoke the tires, sound rediculously mean and look the part at the same time better than just about any modern car.

Mosse · May 7, 2004

I got to drive my -66, which was a 7-year project (lazy?), and now it on the streets again. It used to have 289 with 280 cam and headers, now it has mild 351-w .030 over with crower mechanical cam (212/216), performer intake, 600 cfm carter, hedmann swap headers and -69 heads. There is lot more to come, but I can all ready tell you I like this engine. It pulls hard from idle (700 rpm), and is fun to drive... I just can´t wait to get in tuned right..

I´ll post dyno numbers and pics later... (They propably aren´t so impressive, but these kind of dyno numbers are hard to find as a reference)

I´d say go for 351, but I doubt you can do it with 400 buckos ...

Nice point about deck height, hadn´t thought of that, Edbert

Thustlewhumber · May 7, 2004

Mosse, you seem to have pretty much the same setup as I do. I have a Thunder Series 650, but other than that its almost the same. Keep us posted since I havent made my way to the dyno yet.

brianj5600 · May 7, 2004

BAD67FUN said:
Stroke the little guy.... Aluminum heads, get the weight down. Balance the car. Make it fun to drive. Especially if you already have the 289/302 block.

Unless you intend be a drag queen. Then go cubes all day.

I like to carve corners. Be different. 95% of the classics around here are drag queens. They slap big cube engines in with a nice paint job and are done. It's like a bunch of meat heads struttin at the local gym.

My granny can run the quarter mile...

Your web site shows the battery all the way up behind the headlight. Wouldn't the balance be better if it were closer to the taillight? I don't know I'm just a meat head. He could do a 351, move his battery, and still be better off than you. I don't think he is seriously racing this car, and the extra weight should not make a noticable difference in handling. Most guys with slow car brag about the handling.

Like it or not a 347 makes comprimises to fit a 3.4 stroke into an 8.2 block. No piston designer would make a ring package like that on their own, but that is what you have to do. I also doubt that an engine builder would build such a short rodded motor unless he had to. Piston to cylinder friction/wear is on the wrong end of the scale. I'm not a long rod freak, but it is easy to find them, and there are advantages to longer rods. I'm not saying that a 347 can't be powerful or reliable, just no engine designer would make these comprimises if he had a choice. I'll keep my 9.5 block! Sincerly, Meat Head

BAD67FUN · May 7, 2004

Hey man... send me the cash for the battery/trunk kit and I'll get right on that. It's on the list...

I didn't say do as I've been able to do so far... I said this is what I'd do if I were to do it... CASH IS KING, BABY!!

I suppose you're gonna pick on my bungee cord holding the battery down too...

Go for it... I got nothing to hide!

Hey, while you're at it... I'm taking donations for my 5speed swap.

My point was not to alienate the big cube crowd... more to add option. Don't give up on the little block. I think there's alot to be accomplished by making what you have run well as opposed to just throwing cubes at it.

That's just me... I sometimes do things the hard way.... what I feel is the right way.

brianj5600 · May 7, 2004

I missed the bungee cord. I just had to do it, I am a former straight liner. I live in middle Tn. and there are not any straight roads around here, so handling in on my list of improvements too. I am building my car to drive and enjoy, not to drag race or park it for people to look at, though it will see a strip and cruise night on occasion. The clincher for me was block strength because next winter it gets a turbo. I was a little concerned with the pistons too. My brother has a 347 and likes it, and it's fast, but would struggle with a turbo.

Mosse · May 8, 2004

I will, if I just jhad the time... Today I got my new plates (they made pretty carefull examination to my baby ,but let it pass...) They didn´t notice my Negative wedge kit and near 2" drop on A-arms

Car handles great, allthough I have little slack on the wheel... So maybe next winter I´ll mget some Rack&Pinion there.. these are never ready...

I´d still vote for 351w .. Mine weighted 1325 kg (2900lbs), with alu-intake, headers, full takn of gas, but without rear seat... and I have 30 kg of sound deadening in my car...

Front was 720 and rear 600 .. So there is a little too much weight in front. And this car is n´t really built for racetrack, allthough it see´s some track time.

347 Stroket VS. 357W (.030 over)?

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