Forged vs. Cast

[waverider]

Forged parts, atleast with Guns it makes a difference. Much stronger and longer lasting product. Instead of Arguing ove which product is superior
why not look at the actual materials and processes used to constuct these
Japanese wonders.

Now I am Not sure of lawn blowers, edgers,weedeaters, your basic 2 stroke engines.

Stihl - German- from what I have read does not use forged parts, except is some chain saws. However Shindiwa does use forged Connecting rods and cranks.

None seem to use forged pistons, Redmax >>>the Superior Japanese>>>
product does not use forged parts. However Husqvana does use
forged cranks and connecting rods. No one on this site respects Husqvana
and most worship at the Japanese Redmax product. Funny my dealer
here thinks Redmax makes a inferior, crap product, and says they always
break down, bad parts and hard to work on. I have an edger, by Redmax
is ok, nothing great in my opinion. The 4mix Stihl is far superior in my opinion.

Does it make any difference????

Many people buy Hondas Accords,BMWs, etc because they are the only Mfg to use forged Cranks and and rods. But honda is not into the 2 stroke yard equipment. Most of the stuff now if you go to China is made there for Honda,
I know I saw it.

[TRANSMAN]

Is Not Required...

Forged parts, atleast with Guns it makes a difference. Much stronger and longer lasting product. Instead of Arguing ove which product is superior
why not look at the actual materials and processes used to constuct these
Japanese wonders.

Now I am Not sure of lawn blowers, edgers,weedeaters, your basic 2 stroke engines.

Stihl - German- from what I have read does not use forged parts, except is some chain saws. However Shindiwa does use forged Connecting rods and cranks.

None seem to use forged pistons, Redmax >>>the Superior Japanese>>>
product does not use forged parts. However Husqvana does use
forged cranks and connecting rods. No one on this site respects Husqvana
and most worship at the Japanese Redmax product. Funny my dealer
here thinks Redmax makes a inferior, crap product, and says they always
break down, bad parts and hard to work on. I have an edger, by Redmax
is ok, nothing great in my opinion. The 4mix Stihl is far superior in my opinion.

Does it make any difference????

Many people buy Hondas Accords,BMWs, etc because they are the only Mfg to use forged Cranks and and rods. But honda is not into the 2 stroke yard equipment. Most of the stuff now if you go to China is made there for Honda,
I know I saw it.

You would not really need to have forged pistons in your basic small engine for lawnmower use.....There are reasons you would not even want forged pistons in anything except a raceing engine ...

*Cast Pistons:

1.. Can be fit with tighter /closer tolerances, less clearance between cylinder wall, which means longer engine life.....

A tighter cast piston will not wobble in the cylinder as much as a forged piston ....Less wobble means better ring / oil control, rings dont twist in their grooves when cylinder clearance is tight... Better compression,less blowby, longer ring life..... Tighter piston clearance means the engine is quieter, because the piston is not slapping around in the cylinder ,especially when cold....

Under extreme conditions the cast piston is less dence/porous ,and can burn through, crack, or break if exposed to excessive knock or ping.....Engines should not be exposed to these extreme conditions under normal usage....

Best for normal opperateing conditions, and cheap in price...

*Forged Pistons:

1..Used for very heavy duty use such as supercharged ,or turbocharged engines that may experience knock or ping... Forged is much more expensive,and must be fitted with more clearance, which creates more noise especially at startup...Alluminum is forged from molten alluminum makeing them denser, heavier, stronger but they expand by a factor of 2X that of cast, requireing double the installed clearance....

Piston and rings fit more sloppy in cylinder increasing chance for blowby, less oil control, more oil consumption, less cylinder compression,increased oil contamination, and increased ring wear /shorter ring life due to more twisting in the groves....... ....

Will not burn through under severe knock/ping conditions but may crack on the skirts because they tend to slap against the cylinder wall even after reaching opperateing tempeture....


*Forged Crank:

Stronger for raceing or heavy duty engines but usually the forged cranks are hard to find perfectly straight and increase main bearing wear.....EXPENSIVE!!! but most mower engines are forged anyway because they are small and easy to make....

*Cast Crank:

Fine for general use and cheap to make....Cast cranks are much straighter, lighter, and will actually flex under load...The granular structure dampans torsional vibration when run at high rpm helping eliminate frequency vibrations....

When you take a few hundred engines apart you realise saying the engine has forged this and 4 bolt main that really is meaningless and more for romantic thoughts of the engine owner....

If you have a supercharged/turbocharged engine then the forged pistons are a must....but,

I never saw a crankshaft drop out the bottom of a 2 bolt main bearing block...If some exploseive force was imposed to push the crank out of a 2 bolt block the crank or somthing else would break in the 4 bolt block anyway....

Best to concentrate on the quality of the rings, valves, gaskets, lubrication, etc etc, and make sure the parts are fitted properly with the proper clearances, and built in a clean area by someone who knows what their doing.....

Now i`m Tired,TRANS..............

[Tuttaz]

You would not really need to have forged pistons in your basic small engine for lawnmower use.....There are reasons you would not even want forged pistons in anything except a raceing engine ...

*Cast Pistons:

1.. Can be fit with tighter /closer tolerances, less clearance between cylinder wall, which means longer engine life.....

A tighter cast piston will not wobble in the cylinder as much as a forged piston ....Less wobble means better ring / oil control, rings dont twist in their grooves when cylinder clearance is tight... Better compression,less blowby, longer ring life..... Tighter piston clearance means the engine is quieter, because the piston is not slapping around in the cylinder ,especially when cold....

Under extreme conditions the cast piston is less dence/porous ,and can burn through, crack, or break if exposed to excessive knock or ping.....Engines should not be exposed to these extreme conditions under normal usage....

Best for normal opperateing conditions, and cheap in price...

*Forged Pistons:

1..Used for very heavy duty use such as supercharged ,or turbocharged engines that may experience knock or ping... Forged is much more expensive,and must be fitted with more clearance, which creates more noise especially at startup...Alluminum is forged from molten alluminum makeing them denser, heavier, stronger but they expand by a factor of 2X that of cast, requireing double the installed clearance....

Piston and rings fit more sloppy in cylinder increasing chance for blowby, less oil control, more oil consumption, less cylinder compression,increased oil contamination, and increased ring wear /shorter ring life due to more twisting in the groves....... ....

Will not burn through under severe knock/ping conditions but may crack on the skirts because they tend to slap against the cylinder wall even after reaching opperateing tempeture....


*Forged Crank:

Stronger for raceing or heavy duty engines but usually the forged cranks are hard to find perfectly straight and increase main bearing wear.....EXPENSIVE!!! but most mower engines are forged anyway because they are small and easy to make....

*Cast Crank:

Fine for general use and cheap to make....Cast cranks are much straighter, lighter, and will actually flex under load...The granular structure dampans torsional vibration when run at high rpm helping eliminate frequency vibrations....

When you take a few hundred engines apart you realise saying the engine has forged this and 4 bolt main that really is meaningless and more for romantic thoughts of the engine owner....

If you have a supercharged/turbocharged engine then the forged pistons are a must....but,

I never saw a crankshaft drop out the bottom of a 2 bolt main bearing block...If some exploseive force was imposed to push the crank out of a 2 bolt block the crank or somthing else would break in the 4 bolt block anyway....

Best to concentrate on the quality of the rings, valves, gaskets, lubrication, etc etc, and make sure the parts are fitted properly with the proper clearances, and built in a clean area by someone who knows what their doing.....

Now i`m Tired,TRANS..............

What he said...

Forged in heavy racing apps = Good
Cast in Regular use = good

IE I can put forged crank, rods, and pistons in a Yugo and you still got a Yugo.

[Woody]

Ditto what Transman said (thanks for posting it first Trans and saving me all the typing).

In firearms, forged is not necessarily better either. Have a look at what Ruger has done with investment castings, and you will see for yourself. Hell, look at what Glock has done with injection molded polymers. The casting process of today is a far cry from what it used to be. Investment casting can turn out parts with outstanding tolerances, strength, and service life without the associated costs of forging.

As far as the Stihl 4-Mix edger, I have one as well. I'll most likely purchase a RedMax next time. No valves to adjust, and a bit lighter. The Zenoah Strato-Charged engines have proven themselves to be top-notch in my books. Nothing against the Stihl, I use it and like it. It IS, by design, a more complicated engine, with more moving parts. A bit more finicky as well. At least that is my experience. Oh, and I thought nearly all Stihl products sold in the USA were manufactured in Virginia.

Tuttaz:

You would have a yugo that burns more oil, has more blowby (especially when cold), has more piston slap, reciprocates more weight, and would most likely last just as long.

Woody

[Tuttaz]

Tuttaz:

You would have a yugo that burns more oil, has more blowby (especially when cold), has more piston slap, reciprocates more weight, and would most likely last just as long.

Woody

ROFL

So true...Another point is you use parts that are as strong as they need to be....Or we would have FORGED Windshield Wiper arms....hey thats an idea

[waverider]

Thanks Transman,
What an education. Your the man...I will now disregard the forged
advertising of these manufactures.

[waverider]

Thanks Transman,
What an education. Your the man...I will now disregard the forged
advertising claims of these manufactures. Cast is better for me.