Ok this isn't a 355 or 383 which one is better thread.

Couple nights ago a few guys tried telling me that a 383 is horrible for the street and that a 355 would be better.

I don't get this, wouldn't a 383 be better because you don't have to keep in high in the powerband to make good power and a 383 would have good torque pretty much anywhere?

I am goign to be building a 383 with either the AI 200cc head kit or the LE3 kit.

What do you guys think?

 

Okay, so what is the question then?

 

In general, a 383 will produce more torque throughout the RPM range. That being said, if you're going with a LE3 or equivalent heads and cam package, it won't be very good on the street... Those setups are really designed for the drag strip...

 

Everyone will say that the 383 is as streetable as the 355, by and large I would agree that this is true. However this topic has been beat to death.
I think it comes down to pros, cons and goals. I will speak to the 355 since that was my choice for a new motor.

355 Pros:

• Cheaper to build (reuse LT1 crank)

• More friendly to hit your desired compression ratio

• Better fuel economy (this speaks for itself)

• More reliable (slower reciprocating pistons and rods per revolution reduces chance for failure compared to the faster 383 RA) with RPM's being equal.

• More reliable at very high RPM's (6.5K+)

• Needs no block clearancing

355 cons:

• Less TQ across the board compared to the 383

• May be too small for very big heads and cams

I think the only real advantage of the 383 is the fact it will make a good bit more torque across the powerband than the 355.

If you require the maximum amount of power, then go 383. I am very happy with my 355 and have no regrets.

 

thanks thats all i need to know.

 

I am going to disagree with the reliability portion of your thread as I have 12 plus years on my 383...My experience has been that when built right the 383 usually will last longer because of the lower rpms the motor needs to make similar power than the 355, plus it usually takes a bit more cam with a higher rpm power band to equal the 383...I take my car to 6300 and thats all I need to run what I run...

I will agree that it can be pricey, but any well built motor will be..I run Oliver 5.85" rods which greatly help the rod angle in the bores added by the longer stroke Callies crank. What I have seen on here are wayyy too many mismatched poorly built set ups in both 355 and 383 form.

It all comes down to preference and goals...I run 11.30s with a 383 with a small cam, ported LT1 heads, 3600 Vig and get 20 mpg highway..I'm going into my 13th year of racing/street driving, etc with no failures...

No matter which route you choose your success depends on proper parts selection and attention to details...

--Alan

 

whats a callies crank cost? sorry to steal this thread but i was j/w i was planning on using an eagle crank with eagle 6" rods with kb pistons...what was the price on your full bottom end?

 

I am getting a rotating assembly from Advanced Induction. The budget 355 one has forged Compstar h beam rods with forged mahle pistons. and it is 1096. If you step up to the kit with the forged crank it jumps up to 2096 whether you go with 355 or 383

 

The LS7 has a 4.0" stroke and turns 7K from the factory so I don't see a 3.75" stroke being a problem...

 

Very wrong comparison.

LS7 is very strong block and also bigger than LT1/LS1 5.7 block.

The problem with 383 LT1 is thin walls because of extra bore. I think 7000rpm is too much for 383cid if its a daily car.

 

Just FYI, the 355 and the 383 have the same bore in most cases. They are just .030 over pistons. Sometimes you'll even see them .040 over, which isn't technically a 383, but is normally refered to as one. It all depends on the condition of the cylinder walls of the block they are working with. The reliability factor that was brought up before is due to piston velocity. It doesn't have anything to do with thin cylinder walls. Since you're going to a 3.75" stroke, the piston is traveling farther with each rotation of the crank. So at the same RPM, the 383's pistons are moving faster than the 355's.

 

Piston speed has to do with stroke and RPM, not bore or block strength. And a 383 and 355 have the same bore.

 

It should be referred to as a 385 CI engine. 0.060" over is a 388 CI with the same stroke.

 

Depends on your setup.
The bigger in cubic inches you go the more duration you will need.
If you stay with a kind of a tame cam, you will get decent fuel economy and have all the torque you will ever need on the street. This will be a very streetable setup.
Now, if you go with a wild cam in either one you will be not very streetable in either.
What are you trying to achieve, all Street car, Street/Strip or all out Drag Car?
Then everybody can give you the right answer.
BTW either one should work, how much are you looking to spend?

 

Alan, roughly how many miles are on that engine setup?