331 or 347 Stroker?

[68torinogt]

what kind of difference is your cylinder walls making (just for future reference)?

 

[R2D2]

Hmm whats so thin about the cylinders on a 347? No different than a 306

 

[5spd GT]

Cylinder walls are the same, but the approach of the assembly is steeper against the sidewalls. Rod ratio that is. That is greater "sideloading", that is what he is referring to. Did I say it is devestating to the engine, nope, so don't go off

More force equals more likely to "not be good"

 

[R2D2]

Cylinder walls are the same, but the approach of the assembly is steeper against the sidewalls. Rod ratio that is. That is greater "sideloading", that is what he is referring to. Did I say it is devestating to the engine, nope, so don't go off

More force equals more likely to "not be good"

more mythical rod ratio nonsense from 1983 in the sbc circles. Carry on

 

[5spd GT]

It isn't mythical. It has a steeper rod ratio. I didn't say it would kill the motor. What is so "mythical". Does the 3.4" stroke have less stress on the sidewalls than a 3" stroke?

 

[R2D2]

are you the same guy on corral?

 

[nosmatt]

of course he is, read the post.


anyhoo, IMHO, if your planning a s/c, dont build a stroker UNLESS you use a good (read: r302, dart, world, boss) block. it is just more wasted money.


aftermarket .030 pistons with reliefs, and stock crank/rods is the most cost effective way.
if you buy good top end parts, you will still be able to outpower the stock block on pump gas.



again, MHO!



good luck either way.

 

[5spd GT]

Yes sir

Just some one tell me that a 3.4" stroke with a 5.315/5.4" rod has less pressure applied to the outer cylinder walls than a 3" stroke with a 5.090" rod. Tell me which ones you see last longer. In any shortblock. Yes, there are even steeper rod ratios than a 3.4" stroker, but do you see them lasting 200,000 or 250,000 on a regular basis compared to those with a steeper condition.

 

[giddyup306]

Their have been some pretty informative responces in this thread.

I've built both. I don't have any experience with a boosted 331 or 347 so I am of no use there. I can tell you that a 500fwhp streetable 347 is very dooable. I have a combo in the works that with 260cfm heads and 11.5:1 CR will make that kind of power. That's before "the big shot". For a daily driven or even a weekend warrior their is not a dout in my mind that the best way to make big hp is to have a lot of the power on throttle and have the rest of the power on tap.


Blocks....

As mentioned get a quality block. I opted for a 69-70 boss block and it cost 1100. Not only are they a hi po part they are highly sought after by the boss people. I'm sure that most of the people on the forum have heard the myth of the Mexican block. In std bore or .010 it will take 600. I don't believe it. I've heard too many people say that it won't hold up. Keep in mind that just comes from what people told me. Not personal experence.

 

[R2D2]

There really is no myth to the mexican block, they are by far stronger when compared to a late model block, all it takes is one visual look at the main webbing to see. The other higher nickel content theory is mythical. The mexican block will handle some serious power. I have 1 member running a 306 all motor, 2860lbs, car goes 10 teens. Do the math on that one. Will go 9.90's very shortly with a few small changes.

 

[giddyup306]

I won't confirm or deny it untill I see it for myeslf. Like I said I have no experence with the mexican block.

 

[R2D2]

I won't confirm or deny it untill I see it for myeslf. Like I said I have no experence with the mexican block.

look at the main webbing, its glaring

 

[1991vert]

i went with a 347 and im slapping on a novi2000 @ about 10psi. compression is very important when going boosted so make sure to keep it low if you decide on a supercharger.

a dart block is always nice too

 

[tkolstad]

Thanks you guys have been big time helpfull, gave me a bunch of new ideas!