MUSTANGEATER

iTrader: (10)

All things being equal which one would get you down the track faster? Which would be a better setup for a medium sized shot of Nitrous, say 200?

The Iron 408 4.030x4.00 or the Aluminum 393 4.100x3.700?



Thanks for the help

Floyd

D Rock

iTrader: (7)

I would have to say the 408, they extra stroke will equal more torque, which will get you off the line quicker, and should make up for the weight gain of the iron block. And if I had to pick a engine for handling, it has to go to the Alum. engine(along with better weight transfer).

IMO i would pick the iron block for the 200 shot also.

sr71bb

iTrader: (3)

NO NO No.A iron block weighs 112lb MORE than a aluminaum block.Thats on the front of the car.The 393(are you sure your not reffering to a 395 ,4.125 stroke)has the longer stroke.Which=more low end t,better 60fts,funner car to drive ect.There is no dout that a iron block is stronger,but for a 200 shot the A. block is a much better choice.

PS:I'm building a 395 with a direct port 300 shot.And I am confidant that with the right
tune It wil hold.No matter what choice you make know that no motor lives for ever.I know that I will prob. blow this thing up and then I will build another stronger,faster and better motor for the following race season.The never edning cycle of racing.You got to love it.

MUSTANGEATER

iTrader: (10)

No I am not reffering to the 395 all stroke. I already listed the dimensions of each motor above.

Chicago Crew UnderBoss

iTrader: (1)

If your going with a resleeved motor then for the alum. block with the bore you reference then i would go for the bigger cubed 408 as it will make more power N/A (should offset the 100lbs) and on spray it will be 100% more reliable and durable then the resleeved alum. motor in my humble opinon!

Black Sunshine/ 00SS

iTrader: (1)

I will say the 393, but I'm biased. I have one. A 200 shot is a walk in the park for this motor. I'd say if it's set up right, you'll be better off with the 393, because of the weight & because it will handle the juice.

The times in the sig are with a 200 shot, but with a crappy posi, & not set up properly suspension. It ran an 11.1@122 on motor, right off the trailer & 3550 raceweight, WITH a nitrous tune!!

It's actually a 4.100 x 3.72.

badls1

iTrader: (1)

how about 383 on DP, save that 100lbs from the front. I had iron block, now i am going back to aluminum to save that extra 100lbs. what ever you do it will always be 100lbs heavier vs aluminum block.

steve2001sh

Aluminum is a lot lighter, but iron makes more power (less heat transfer = more efficiency). If you want to do autocross, go aluminum for sure. Aluminum means less weight for better handeling and better cooling for long grueling drives. If you want to do 1/4s, you'll have to do the math. You'll get more power out of the larger 408 (I plan on building an aluminum 408 out of the LS2 block when it comes out), you can abuse iron more, and iron makes more power to begin with. Will all that make up for the extra 100lbs? Probably, look up some dynos to be sure.

badls1

iTrader: (1)

all the fast cars are aluminum by the way. its the same casting except the matrial why would iron make mre power?

steve2001sh

It's a matter of thermal transfer efficiency. We all know that a sizable chunk of an engine's power is totally wasted as heat. From a physics standpoint, waist=heat. When your air/fuel combusts, it does 2 things. It heats itself and it heats your piston and your cylinders. Heating your air/fuel is good, because that causes it to expand thereby push your piston, thereby make you go. Heating your cylinder is bad. That heat does no one any good, and it means that you need a cooling system to keep your engine from melting. More heating the cylinder means less pushing the piston. How can you make it heat your cylinder less? There are two ways: make the temperature of the cylinder closer to the temperature of your air/fuel, or make your cylinder out of a less conductive material. Playing with the temperature isn't always a good option. Raising the temperature of the block could damage it. Option 2 is to use a less conductive material like iron. Iron still gets hot, but not as quickly as aluminum. Iron drinks less heat, meaning more heat is pushing your pistons. This is why iron blocks are more efficient. This is also one reason why aluminum blocks usually have iron sleeves.

Now, is the extra power worth the extra weight? It just depends on the application.

VINCE

iTrader: (1)

I am sure there are some iron blocks on that FAST list.

Mike K.

I hope so. IRON block seems to be stronger and much cheaper than a sleeved block. I'm no professional racer so I can live with the extra lbs

MUSTANGEATER

iTrader: (10)

Man I am really impressed with that. I'm still unsure about sleeving the block. Any more info?

Black Sunshine/ 00SS

iTrader: (1)

The more I think about it, the more I realize how great a run that was. The car has a nitrous convertor, and nitrous tune. 60' was 1.6 something.

The additional weight is not worth it, although I have thought of building an iron block for a spare, because it would be cheaper. But not better overall, IMO.

Chuck@

iTrader: (1)

Actually the reason aluminum blocks have iron sleeves is because aluminum is not strong enough to last any extended duration at all as a cylinder wall. And aluminum actually dissipates heat better than iron.


Chuck

1QWIKZ

iTrader: (6)

CVponYKillER

Im thinking about ordering a 408 w/ forged pistons ect. How much power you think i'd be running w/ a good cam and s2 heads?

Chuck@

iTrader: (1)

That would depend on many other factors involved, and what the car is going to be used for... What are your goals and budget involved?

Chuck