355 vs. 383
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Launching!
Joined: Nov 2004
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From: Rochester, NY
355 vs. 383 Ok I am looking for suggestions as to which to build. Im going to be starting an engine project soon for my car where i hope to achieve mid 11's NA and spray 10's. I was thinking of going with a forged 355 with LT4 heads sent to lloyed for the LE2 setup but have heard that there is almost no price difference between building a 383 and 355 if you are going with a forged setup. What does everyone think is the price not going to be that much different and is the LE2 setup on these motors even going to get me to where i want to be ET wise. Also im going to be spraying this motor with around a 150 - 200 shot with my nitro daves plate kit to get into the 10's 
Go with the 383. They are not much more to build and are very streetable and have good longevity. Torque monster!! As far a heads.........the LE2 would work ok or even better get a stage 2 or 3 from Port Pros www.portpros.com . Port pros can also sell you a built 383.
I had this conundrum back 3 years ago. If you take a 355 forged motor which you will need, and a forged 383 motor, same rotating assemblies, just a difference in the machining and clearancing. 383's is about the same cost, maybe a couple of 100 more but you gain so much torque you cant deny it.
If you were building a boost motor, then maybe the ability to rev quicker may steer you toward the 355, but its a n2o motor, go 383. Dont mess around.
If you were building a boost motor, then maybe the ability to rev quicker may steer you toward the 355, but its a n2o motor, go 383. Dont mess around.
FWIW,
The real budget between a really good 355 and 383 is more than a few hundo.
A 383 puts limits on a lot of things, the heads need to be able to feed the motor and have enough valve in them so they don't choke the motor.
The valvetrain is more likely to be higher lift which requires better parts to make live.
The bottom end is going to have more piston speed and more TQ which is going to stress it more meaning you really need good parts.
Not to mention the intake being a restriction at high RPM as well.
On the other hand a 355....
Can use a stock crank or a cast steel crank without problems.
Can easily use stock head castings to get you were you want to go in terms of port sizes and valve sizes.
The stock intake is not as much of a restriction.
The best thing to do is go and look at inexpensive 355 setups that run really well. There are a lot of them out there, and not nearly as many 383 setups that match those numbers.
If you are shooting a 150-200 shot a 355 is going to be fine and get the job done for you easily.
Bret
The real budget between a really good 355 and 383 is more than a few hundo.
A 383 puts limits on a lot of things, the heads need to be able to feed the motor and have enough valve in them so they don't choke the motor.
The valvetrain is more likely to be higher lift which requires better parts to make live.
The bottom end is going to have more piston speed and more TQ which is going to stress it more meaning you really need good parts.
Not to mention the intake being a restriction at high RPM as well.
On the other hand a 355....
Can use a stock crank or a cast steel crank without problems.
Can easily use stock head castings to get you were you want to go in terms of port sizes and valve sizes.
The stock intake is not as much of a restriction.
The best thing to do is go and look at inexpensive 355 setups that run really well. There are a lot of them out there, and not nearly as many 383 setups that match those numbers.
If you are shooting a 150-200 shot a 355 is going to be fine and get the job done for you easily.
Bret
Bret I hear a lot of (old school motor builders) say that a 383 or 396 are short lived motors b/c of the long strokes but I have seen many 383's last for many many years even a decade or so. Why do these type of people believe stroker motors wont last???? Is it just in the way you build it????
Tony haven't seen anything from Portpros (not denying there talent) but an LE2 head is a pretty good head for our cars at a GREAT PRICE.
A buddy of mine has a pair and they are a work of art.
LE did my AFR's and from what he tells me they will feed my 396, single plain motor no problem to 7000 RPM shift points.
BTW any more updates on your beast, I never seen a dyno graph do you think you could post it for us.
Tony haven't seen anything from Portpros (not denying there talent) but an LE2 head is a pretty good head for our cars at a GREAT PRICE.
A buddy of mine has a pair and they are a work of art.
LE did my AFR's and from what he tells me they will feed my 396, single plain motor no problem to 7000 RPM shift points.
BTW any more updates on your beast, I never seen a dyno graph do you think you could post it for us.
Don't worry I'm sure Tony will come tell you everything you want to know about PortPros.
As for old school 383's and 396's, they usually had lots of piston to wall clearance, didn't use moly rings, shorter rods and probably couldn't machine cylinder bores as cylindrical. Old school guys who never learn new tricks also like OEM iron castings and big freaking cams.
Bret
As for old school 383's and 396's, they usually had lots of piston to wall clearance, didn't use moly rings, shorter rods and probably couldn't machine cylinder bores as cylindrical. Old school guys who never learn new tricks also like OEM iron castings and big freaking cams.
Bret
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Teching In
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Originally Posted by SStrokerAce
FWIW,
The real budget between a really good 355 and 383 is more than a few hundo.
...On the other hand a 355....
Can use a stock crank or a cast steel crank without problems.
Can easily use stock head castings to get you were you want to go in terms of port sizes and valve sizes.
The stock intake is not as much of a restriction...
Bret
The real budget between a really good 355 and 383 is more than a few hundo.
...On the other hand a 355....
Can use a stock crank or a cast steel crank without problems.
Can easily use stock head castings to get you were you want to go in terms of port sizes and valve sizes.
The stock intake is not as much of a restriction...
Bret
Bret does make a good point. You can build a good 355 using a stock crank and heads with out breaking the bank.
Getting it to run mid to low 11's, no problem. 10's are with in reach with out the spray.
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Originally Posted by SStrokerAce
Don't worry I'm sure Tony will come tell you everything you want to know about PortPros.
Bret
Bret
Like Neil said......Port Pros has been around a while but has not advertised on big boards like this one until now. Many people on here (including StrokerAce) push the LE heads which is fine. I have seen decent work from him. Nothing wrong with pushing someone else who I think does better work. I have seen, installed, tuned, and driven cars that has had both LE and PP heads. Port Pros wins my vote.......thats why I direct people to him. Look at his credentials on his website..........the man has worked for Winston, Busch, Indy RL, Cosworth, and Shafiroff Racing. Graduated from S.A.M (School of Automotive Machinist) and completed the high performance cylinder head program at University of Colorado. He knows his stuff and has some ofthe best equipment on the market.
Originally Posted by T/A KID
Bret I hear a lot of (old school motor builders) say that a 383 or 396 are short lived motors b/c of the long strokes but I have seen many 383's last for many many years even a decade or so. Why do these type of people believe stroker motors wont last???? Is it just in the way you build it????
Tony haven't seen anything from Portpros (not denying there talent) but an LE2 head is a pretty good head for our cars at a GREAT PRICE.
A buddy of mine has a pair and they are a work of art.
LE did my AFR's and from what he tells me they will feed my 396, single plain motor no problem to 7000 RPM shift points.
BTW any more updates on your beast, I never seen a dyno graph do you think you could post it for us.
Tony haven't seen anything from Portpros (not denying there talent) but an LE2 head is a pretty good head for our cars at a GREAT PRICE.
A buddy of mine has a pair and they are a work of art.
LE did my AFR's and from what he tells me they will feed my 396, single plain motor no problem to 7000 RPM shift points.
BTW any more updates on your beast, I never seen a dyno graph do you think you could post it for us.
My vote goes for the 355 also. If you have a huge budget then go 383 and aftermarket heads fully ported will be quicker. I like the a 355 esp. with ported LT1 heads b/c LT1 heads usually don't flow enough for a 383. My 355 has run low 11's N/A and low 10's@134mph on 200HP n2o with factory ported LT1 castings. Now I put some Trickflows ported by Lloyd elliott and it will run 10's N/A and 9's on the spray once it's tuned. later Clint
My app is a little different from the topic, but only because I'm going FI instead of nitrous or N/A. In my situation, a forged rotating assembly and splayed 4-bolt mains are a necessity wether I went 355 or 383. Because of this, the difference in cost is minimal...
Because of my budget, my choice was a 383 because the extra inches made it cheaper to get the power level I want. I can get my numbers with Port Pros stg2 heads on a 383. But if I went with a 355, I'd spend more on the heads to get the same power levels.
My Vote goes to 383!
Oh yeah, Tony! Thanks for that hookup!
Because of my budget, my choice was a 383 because the extra inches made it cheaper to get the power level I want. I can get my numbers with Port Pros stg2 heads on a 383. But if I went with a 355, I'd spend more on the heads to get the same power levels.
My Vote goes to 383!
Oh yeah, Tony! Thanks for that hookup!
Lloyd just had a guy get off the dyno today with some good results in a Imp
"95 impala ss with 3.73 gears and a edge 3500 stall.
438 hp 419lbs of torque with the converter locked
423 hp 407lbs of torque with the converter unlocked.
intake also ported, this is on a 383."
The more I work with Lloyd the better I see him getting. He has some VERY GOOD LT1 heads out there now that are making some very good numbers.
Bret
"95 impala ss with 3.73 gears and a edge 3500 stall.
438 hp 419lbs of torque with the converter locked
423 hp 407lbs of torque with the converter unlocked.
intake also ported, this is on a 383."
The more I work with Lloyd the better I see him getting. He has some VERY GOOD LT1 heads out there now that are making some very good numbers.
Bret
i have a 357 with le2 heads and cam...everything is forged and new cept stock crank....puttin down 389 hopin to put down 425 with the tune...plus i have a 155 shot..my compression is 12 to 1 and im hoping to either get a new motor soon or change this one around....wantin a supercharger now
TECH Apprentice
Joined: May 2005
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From: Boise Idaho
Originally Posted by T/A KID
Bret I hear a lot of (old school motor builders) say that a 383 or 396 are short lived motors b/c of the long strokes but I have seen many 383's last for many many years even a decade or so. Why do these type of people believe stroker motors wont last???? Is it just in the way you build it????
3.48 to 3.75 = 0.27" per stroke = 0.54" per rotation
0.54" X 1000 rpm's = 540" = 45' per minute
100000 miles on a car with 3.23 gears, and .70 overdrive
100000 X 3.23 = 323000 X .70 = 226100 rotations
355ci 226100 rotations X (3.48X2) = 1573656" = 131138' = 24.84 miles of piston travel
383ci 226100 rotations X (3.75X2) = 1695750" = 141312' = 26.76 miles of piston travel
so in theory a 383 would have 1.0775 times the wear of a 355
but then again how many of us are building them to go for the long road, not me
