H/C/I 347 stroker vs 302 H/C/I(?)

[American_Muscle]

I have a question...

I've been reading up on the 347 and was leaning towards it but....

It doesn't seem to me that an H/C/I 347 puts out much more than an H/C/I 302.

I understand you can't use the same 302 H/C/I parts on a 347 but is it worth it?
If you don't get much more power..what's the justification for doing it?
More torque?
Horsepower the naturally aspirated way?

Are the H/C/I parts I need for a 347 more expensive than those for a 302?
At first I was thinking about getting the trickflow kit for my 302...which dynos at about 310 rwhp.

Am I missing the point of a stroker?

 

[dirtysohc]

What do you mean you can't use the same parts?

 

[90mustangGT]

An engine being a vacuum pump, being larger in displacment will pull more air at the same RPM, making more power. However you may not be able to feed the larger displacment with enough air at higher rpm so the power will just level off. However you most likley will still make more HP.

Lets say you have a decent mild H/C/I setup on a 302 and you do nothing but swap out shortblocks to a 347. You would see some HP increase but not that much but there would be much more torque, and a wider powerband. So if you raced another car that you were dead even with before on the highway, the stroker wouldn't really show up, but if you went from a stop and had traction there would be a big difference.

Lets say you had a larger H/C/I setup for a 302 and did a 347, you would see huge gains everywhere.

Cubes are only good if you can feed them.

 

[BlownFiveLiter]

You can use all the same parts on a 347 that you could on a 302, but with greater potential from the stroker. Stroker engines are ideal for anyone wanting more cubic inches and power from the 302, instead of stepping up to a 351 based engine, not to mention the weight savings over doing so. Plus, no one is any wiser if you say it's a 302, but you're really packin' 45 more cubes!

 

[American_Muscle]

I guess I worded my post wrong.
You can obviously use the same parts on a 347..but it wouldn't make sense to get the stroker.

My question is really.....is it worth it to get the stroker, pay the extra money if you might see 40 whp more...plus I'm sure the better flowing heads, intake etc are more expensive than what a 302/306 would need.

I've read several times that a stroker build is not a budget build.
I'm not really on a budget but I don't want to throw money out the window.

 

[90mustangGT]

I guess I worded my post wrong.
You can obviously use the same parts on a 347..but it wouldn't make sense to get the stroker.

My question is really.....is it worth it to get the stroker, pay the extra money if you might see 40 whp more...plus I'm sure the better flowing heads, intake etc are more expensive than what a 302/306 would need.

I've read several times that a stroker build is not a budget build.
I'm not really on a budget but I don't want to throw money out the window.

Bigger heads, intakes, and cams don't cost much if any more, until you start stepping up to 205cc heads and Victor style intakes and such. No a 347 isn't a budget build, but then again to rebuild a stock motor isn't that much less. If you get a stroker kit, wich is usually around a grand, then you need a flywheel and balancer which is going to cost you around $300-600 more. Machine work on the blocks is about the same. However getting new pistons, rings, berrings, bolts, machining the stock crank and prepping the rods won't exactly be that cheap.

 

[dirtysohc]

Why would you need a flywheel and balancer if you get it balanced for 50oz.

 

[Rick 91GT]

Why would you need a flywheel and balancer if you get it balanced for 50oz.

You shouldn't go 50oz on a stroker, makes the crank like a piece of swiss cheese?

 

[dirtysohc]

Swiss cheese? Never heard that one. The only time you need to go to a lighter balancer is if you plan on turning higher RPM's. I've had many engine combos over the years turning between 6500 and 7000 RPM and always with a 50oz balance. I would say if you were to go above 7000 Rpm's I would go with a 28oz or 0oz internal balance at that point. But just switching to a stroker set up doesn't nessecitate changing the 50oz set up.

 

[90mustangGT]

Your right dirtysohc, but most kits come as 28oz and to have them balanced to 50oz takes a lot of cutting on the crank and unless you "got the hookup" then it is quite expensive so it's almost cheaper to go 28oz and it does have it's advantages. I don't understand why the companies that make strokers dont' do 50oz because most of what it's going into is 50oz setups. They would sell more of them.

I went with a SFI balancer (pioneer) with a Alumimum Flywheel (spec) so of course mine cost a little more.

 

[Rick 91GT]

Yes you can go 50oz but it takes a lot of material out of the counter weights, to do it properly it should be taken off radially which is expensive. Going to the lighter inblance in better on parts and bearings.

Is it preference maybe, but I think you'll find most builders prefer the 28oz or internal balance over the 50oz on stroker combos, cast or forged crank.

 

[dirtysohc]

I work in a machine shop part time that my best friend owns and he sells them mostly in 50oz balance because most customers cars are 50 oz from the factory and the kits are initially cheaper. There's no great need or benefit from a lighter balance if the car won't see elevated Rpm's. I'm not saying that's the best, HP wise or for parts longevity, but it's the cheapest. I'm doing my 347 with an internal balance because this engine combo will be seeing over 7000 RPM's with the combo I'll be assembling. My friend is selling me a 347 kit at his cost for around $800 or so with forged crank, H-Beams and domed pistons. I couldn't pass that up!