BsGreenZ

Ok so my friend spun a main bearing in hsi last motor and cracked the block ... so we found another block for him and he's doing a 383 stroker set up... .3o dished pistons, 6" rods and a balanced eagle crank... he's running it with a LT4 hot cam, stock un-ported heads, not sure if he'll have the money to get them done yet... long tubes, flowmaster super 40 and some 3.73's in the rear... besides that its going to stay pretty much stock except for maybe a TH350 swap in stead of the 4L60E... i'm not sure what to really expect from this cumbo but he had asked me if i think that he could keep up with me or take me after it's ready??? I have no idea since i have alot more bolt ons and head work.... what you guys think we can expect from this new motor, and will it take me???

94Z396

Umm question, you don't use a 6 inch rod on a 383 you'll use a 5.7 inch rod! I'd suggest a custom cam for a 383. The hot cam is to little for a 383. The heads will choke it! A set of LE heads or Trick Flows would be alot better than the stock heads. Personally yall would probably side by side. More than likely an even race!

Built LT1

iTrader: (3)

Both my 383's were built using 6 inch rods. They offer less sidewall loading over the 5.7 inch and improve combustion as well.

BsGreenZ

i'm not really sure on the rod length i know its just a LT1 383 kit that he ordered... i think that he's going to get his heads ported and polished and i'm trying to get a bigger cam but im not sure if its going to happen... but i guess we'll see, and my motor will probably going to a 383 later this summer, and i'll probably run a bigger cam than what im running now.. but thanks..

Built LT1

iTrader: (3)

I would not build a 383 using stock un-ported heads. 212 CFM (LT1 stock head flow) is not enough to support a 383 with a cam.

BsGreenZ

i'll let him know, and i guess they will be getting ported lol... thanks man...

Built LT1

iTrader: (3)

I am not an expert on engines so I can't intelligently defend either rod choice, I just know that both sizes will work. I don't think it's that big of a deal so whatever rod comes in your kit should work fine.

BsGreenZ

i just checked out the package and they are 6" rods ...

Ed Wright

iTrader: (1)

Guess I used a lot of wrong parts.

94Z396

The 383 i took apart had 5.7 inch rods, didnt know you could use a 6" rod in a 383! My bad. I aint going against your judgment Ed.

94Z396

Ok it seems to be Smartass 101, i just asked a ?!

BsGreenZ

ok come on i was just asking what people thought.. its cool i dont know every thing to just leave it be... thanks guys..

LT1MAN

iTrader: (6)

why would you put stock heads on a 383? with a little hotcam? i think i will be a low compression sloppy waste of money personally.

95FbFormula

iTrader: (25)

It seems like he is building a motor without really knowing what to use. Why use the dished pistons is he building for boost??. Also what other things does he plan for the heads RRs ect.. porting is also a must and not just the cheapest porting you can get something like an LE3 or AI200cc job is needed if you want to really see any gain from a 383 also some work to the stock intake manifold would be good. There are many other factors to a 383 build and if he was worried about not having the money to port the heads i wouldn't even attempt a 383.

~>SweetSS<~

I think it will be really close. I have a 383 LT1 - used LE heads as well, and a CC306 cam. Don't go with stock heads!

BsGreenZ

At this point its getting built so he can have his car back and the heads are getting ported and polished as much as possible and the intake manifold is getting ported a little.. he wants to put a bigger cam in it just not sure which one at this moment and it has the 1.6 rollers from the LT4 hot cam kit... its not a unlimited budget build but its not a really tight one either, but i'm sure we'll figure out some more stuff on it, he was thinking about the Trick Flow LT-1 headers, but at this point the block hasnt even been to the machine shop..

WHITEBIRD

get the heads ported if not he is wasting time the cubic inches will not make that much of a differance in HP without good flowing heads.

OutlawZ

iTrader: (4)

Damn me and Ed used the wrong rods.. damnit better call my engine guy and tell him to start over....

Alright since nobody else cared to drop some tech on how this works i guess i'll get in educate mode to tell people how it works with rod length vs piston used....

Okay basically you can use a 5.7" rod, 5.85 rod, or a 6" rod with your 383. you might even be able to use longer/shorter combos but these are the norm. If you use a 5.7" rod your piston will have the area for the wristpin at a certain height in the piston. If you use a 6" rod the reason you can't use the same piston is because with that rod the piston would come out of the block .3 of an inch..... SOOOOO To make up the difference the 6" rod piston will have the wristpin moved up .3" higher in the piston than the 5.7" rod/piston.... get it..... you are increasing rod length but sacraficing wristpin depth down in the piston. This has multiple effects on the motor. Rod to piston ratio, sidewall loading, dwell time at TDC, friction in the bore (ie sidewall loads), etc..... Those are all good things. The bad thing is that sometimes you move the wristpin up in to the ring lands sacraficing piston strength.... it's a tradeoff..... but seeing as how the guys with crazy 383 builds are all mostly using 6" rods it's probably a good thing.....

hope this clears up some fuzzy ideas about this topic...

plaf713

iTrader: (8)

if he wants to stroke it then stroke it, dont listen to these guys, everyone has different goals, a 383 is a good building block, hell you are already 33 c.i.'s better than you were before and the motor is fresh. it is a great start, then when you get an itching to go faster, throw some le's on em or whichever heads, and a cam to go with it. just do whatever you want. i have a 383 with the lt4 hot cam and im happy, my heads are ported though, and when i get sick of this h/c package ill get a bigger one.

moserman

iTrader: (7)

its all about combos for a 383, i have a 510 horse 383 using 6 inch rods (6 inch rods make more torque) and have ported heads, btu i had stock heads on my motor until i put the new ones on and it ran strong with the old 224/230 cam but there is a solid amount of combos so just do some research to find what u want and it will pay off.