school me on stroker smallblocks

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prodart340

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pros,cons, do I have to bore the block out so far that it's beyond street stability? tips? thanks in advance,mike
 
Get the "Big Inch Mopar Small Blocks" book. They usually carry it at B&N or here on Amazon.

Should tell you what you need to know, very good book and current unlike most of the Mopar-specific books available.
 
The book the guys mentioned is a good one and explains in laymans terms about strokers.

ProDart to answer one of your questions. No you don't bore the block way out. In fact you don't even have to bore it at all if you don't want to. That's why their called strokers. You change the stroke length (crankshaft) to gain the extra cubic inches.

Pro's: lots of torque and more streetable than a radically cammed 340 or 360. That huge grin you'll get when dropping the hammer.:-D:-D

Con's: not alot except you really should run forged pistons cause the piston speed on a stroker is much more than on a 318/340 or 360. Depending on which rods you use you may have to notch the block for clearance. May also use more fuel cause your right foot will like to live on the floorboard. Can I get an amen 340Sfastback!!:cheers:
 
you only bore the block as much as needed....or to the size that is available for the engine you have...
 
Amen:cheers:
The other pro is that there are quite a few kit packages on the market for under $1500.
Andrew
 
The book the guys mentioned is a good one and explains in laymans terms about strokers.

ProDart to answer one of your questions. No you don't bore the block way out. In fact you don't even have to bore it at all if you don't want to. That's why their called strokers. You change the stroke length (crankshaft) to gain the extra cubic inches.

Pro's: lots of torque and more streetable than a radically cammed 340 or 360. That huge grin you'll get when dropping the hammer.:-D:-D

Con's: not alot except you really should run forged pistons cause the piston speed on a stroker is much more than on a 318/340 or 360. Depending on which rods you use you may have to notch the block for clearance. May also use more fuel cause your right foot will like to live on the floorboard. Can I get an amen 340Sfastback!!:cheers:

Amen.

The other draw back is you might get caught by the cops smoking the tires up like I did recently. Luckily the cop was cool and only gave me a 1 point ticket which the judge let me off on because of clean record. And you won't need to use the brake to smoke them up either; just push on the pedal at any speed under 25 mph and instant smoke show.
 
Fastback beat me to it.

Con: You have to buy a new set of rear tires a lot more often!!

Get the above mentioned book. It really is helpful. It explains the builds and even lists a bunch different combos. Lots of pictures and info!!
 
I just ordered my 408 Stroker rotating assembly a couple weeks back. Can't wait to get it =P~.

I believe that my 360 will be bored .030 to achieve the 408, coupled with the 4" crank. I will have to notch the bottom of the cylinders, but that's small potatoes. I upgraded to the forged pistons, forged crank and upgraded the rods, also. For the few extra bucks, it's better to be safe.

I've had big block cars before, but didn't want the weight in my Dart, so the Stroker seemed like a perfect fit.

Now when will it be here.
 
so i think i messed up the balancer threads in my 360 lol. maby im just lookin for an excuse to have to get a new crank lol. but its bored .30 or .40 over cant remember at the time but all i would need is a crank and bearings? or what? and how hard is it to do for someone that has never done it before? i have tore apart engines and put them together but never really done perf stuff lol
 
No, you would need to buy new pistons. The pins are located differently on stroker pistons. Stock pistons would hit the head.

Shouldn't be to hard to assemble it yourself. Or you could have your local machine shop assemble the short block for you.
 
What every you do don't buy a kit that is balanced. By the kit unbalanced and get a good reputable local shop to balance it correctly.
 
.......or buy a B&M plate, run a neutral converter and a 360 damper an run it externally balanced.

(You'll still need a piston assembly balance of course, but this way you can avoid filling the crank with mallory.)
 
What every you do don't buy a kit that is balanced. By the kit unbalanced and get a good reputable local shop to balance it correctly.

Exactly what Bill said... The balance job done buy the companies is marginal at best. Have a shop do the balance with everything matched up, not pulling weights off boxes... like at least one company does.

flexplate/balancer has nothing to do with 340Fastbacks comment. It's about sloppy work by the distributors. Many of the kits are internally balanced anyways.
 
flexplate/balancer has nothing to do with 340Fastbacks comment. .

No? If have thought it had everything to do with it?

Theres two ways to balance a crank -

1/ Internally through the use of Mallory metal slugs , or

2/ Use an external balance set up like a 360.

Or IF you are talking about "assembly balancing" (matching and weighted pistons) - then we're talking different processes..and I'm all ears.......
 
Exactly what Bill said... The balance job done buy the companies is marginal at best. Have a shop do the balance with everything matched up, not pulling weights off boxes... like at least one company does.

flexplate/balancer has nothing to do with 340Fastbacks comment. It's about sloppy work by the distributors. Many of the kits are internally balanced anyways.

Which company did that?

PM me if you want...
 
No? If have thought it had everything to do with it?

Theres two ways to balance a crank -

1/ Internally through the use of Mallory metal slugs , or

2/ Use an external balance set up like a 360.

Or IF you are talking about "assembly balancing" (matching and weighted pistons) - then we're talking different processes..and I'm all ears.......

No, your flexplate comment has NOTHING to do with 340's comment. Different issue all together. He's talking about the final balance whether internal or external and you made a blanket statement about slap a B&M flexplate on it... which is misleading at best to the uninformed. Slap an external balance B&M plate on an engine intended to be internal balanced and see what you get.

You can buy kits that are set up for internal or external balance in most cases. The final balance should be done by a reputable shop. It's a why pay twice for the same alleged work.

I won't keep at this because I've seen some of your thread killing prose with george and others. It's like trying to read "war and peace."

Scat was the company with the sloppy balance procedures.
 
All manufacturers skew the "balanced" vs "weight matched" numbers. For some assemblers it's important to get it RIGHT. For some, it's not. That's all I can ad to these answers...
 
A professional balance job will come with a sheet showing starting and ending balance in grams and the progression to get there. I wish I had a scanner. It's amazing how far a factory stroke, KB pistons, Eagle I-beams, aftermarket harmonic damper and B&M flexplate was off balance. Never trust a kit manufacturer to have the balance right on the money. This is even more critical on engines with a longer stroke.
 
Slap an external balance B&M plate on an engine intended to be internal balanced and see what you get.

You can buy kits that are set up for internal or external balance in most cases. The final balance should be done by a reputable shop.

Exactly, and we didn't even mention the variances in harmonic dampers and torque converters.

I brought everything to the shop, including the harmonic dampner, the correct B&M flexplate for an externaly balanced engine, the Hughes nuetrally balanced torque converter, crank, rods, pistons, pins, spirolocks, rings, etc.
 
Slap an external balance B&M plate on an engine intended to be internal balanced and see what you get.

So before you turn blue - maybe you can tell me where I said to "slap a flex plate on it".

YOUR WORDS, not mine.

CrackedBack/ Ram charger - If both of you you want to throw a hysterical little tantrum every time YOU missunderstand the point of a post - feel free to rant on and waste everyones time.

My point was specific to crank balancing only - If the crank balance from the company couldn't be trusted - consider an unbalanced kit and balance it externally as per the externally balanced 360.

Maybe more reading _
Or IF you are talking about "assembly balancing" (matching and weighted pistons) - then we're talking different processes..and I'm all ears.......

and less assumption is required?

Of course in both cases(internal or external crank balancing) the total assembly still needs balancing -Fine, fill yer boots - get your favourite shop to do it, no argument.

but Im not talking about that process.


Oh and BTW Cracked Back - if my posts are a struggle for you, that says way more about your intellect than it does about me for writing them.
 
A cheaper cast crank will have heavier and lightter areas throughout them. It's the casting process. Forging helps even that all out, and it makes the whole crank uniform density. That's one reason they are stronger. When one talks about "weight matched" parts, you have to understand what parts play what roles in the balancing of a V-type engine. Another thing is we are talking about rotation of the crank in the mains, and reciprocation (up and down) of the pistons, plus the mixed directions of the rod (both around and up and down).
The crank can be heavy or light in most areas because they are close to the mains and for the most part, the stresses are all different. It's all pretty much rotation. The crank also has torsional stress, which is twist as one cylinder fires, another compresses, etc. Torsional stress is what the harmonic dampner is designed to take care of. It just happens to be a good place to add counterweight for the factory desiners when the crank's counterweights are not big (heavy) enough. Forged cranks have more dense steel and therefore are heavier in the same physical volume than cast. This comes in when the cast cheaper cranks are used. Cranks are not balanced as part of manufacture.
The pistons have to be weight matched. They simply go up and down as part of the reciprocating assembly. Same with the rigns, piston pins and locks, and a little oil. The better forged pistons are close to matched. But there are always exceptions and errors. Cheaper forged or hyper or cast tend to be more wide in terms of weights individually. There's a reason they are less money. Wider tolerances, manufacturing, and lack of matching are part of the reason.
Rods are all over for a variety of reasons. I can show you set of "weight matched" Eagle or Scat or 440Source that weight the same. The issue is the piston pin end and the crank pin ends of the rods are considered different in the balancing process. The pin end is part of the reciprocating weight. The big end is part of bith the reciprocating and the rotating masses. So the overall weights are matched. but the ends can be all over the place (and ALWAYS are). Factory rods are that way too.
Factory assemblies can be internally balanced (with forged cranks and non-6pac rods) because the cranks are heavier and the strokes are shorter, so there is enough weight present to easilly bring things into balance within 30-50grams of so. Cast cranks need some extra mass just for the stock stuff, nevermind the longer strokes. So the factory used counterweights on the hamonic dampner, and the torque convertor. Again, it's a wide spec for "in balance". The B&M flexplate replaces the weight on the factory convertors so the aftermarket convertors can be run. No aftermarket performance convertor comes counterweighted for a factory engine assembly. Some will do it for you for extra cash.
I only internally balance because i want better than factory. Modern equipment can get the assemblies balanced to within .1 gram. One tenth of one gram. At 6K rpm that factory 30 grams of out-of-balance is pounds of force on the crank and mains of the block. The idea is to reduce the stress on the parts and allow more power to be made and available at the crank.
Costs will vary shop to shop. I pay $350 plus any heavy metal that's needed which can be pricey again, depending on your shop..
 
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