I am in the middle of a 383 build from the ground up. My order got mixed up somehow and I ended up with an Eagle forged rotating assembly with forged rods instead of the H beams that I wanted. I am putting this in new 4 bolt LT1 block that has been bored .030. How much of a difference will this make in the long run? Realistically, I see the motor putting out around the 375-400rwhp mark. I want to build a strong bottom end that I could do a better H/C to in a few years if I wanted to, which by the way, does anyone know what the specs are for a stock cam in a 95Z w/ T-56 trans? Any help would be great. Thanks.

 

H-Beam Vs. I-Beam

http://www.hotrod.com/techarticles/c...ds/index3.html

Stock cam specs:

http://www.grandsportregistry.com/lt1vslt4.htm

I really hope you're not putting stock H/C on a 383...

 

thanks for the info and no, I am not putting stock heads back on. Just want to get an idea of how much more cam I will be going with. Thanks again.

 

I've almost got 12 years on my 383 built with Oliver 5.85" Billet steel I beams...I make 400rwhp and they've never let me down...

--Alan

 

Thanks for the vote of confidence Alan. If you don't mind my asking, what are your basic engine specs? I don't want all the secrets just a basic idea. Thanks again.

Troy

 

Big difference between billet I beams and forged I beams.. Billet I beams are stronger than forged Hbeams.

 

One thing to consider with the Eagle "I" beams is that they are made from 5140 steel. The H-beam Eagles are made from 4340 steel.

That being said I have the 5140 rods in my present shortblock, and they handle the power levels you are describing with ease.

I am building a new shortblock for my car (different pistons and forged crank) and am using the Scat pro mod rods that are an I beam design and made from 4340 steel.

Eagle rates their 5140 rods to 500 hp.

 

The quality of the rod and the fasteners is much more important than H vs. I beam. Except in the most extreme applications, primary rod failures are quite rare anyway.

Rich

 

Hey guys, thanks for the input. I really appreciate it. I want to build a pretty strong bottom end motor. I dont mind doing heads/cam later if I have to because I don't have to pull the motor for that.

 

I suppose it depends on what I-beams you are refering to.

Firstly in your post you say you wanted h-beams and got forged rods instead. The h-beams are forged 4340 material, its the i-beams that are sub-par material. This is within the Eagle line-up. What brand are we talking about. Carillo I-beams are some the nicest and strongest rods available, but they're also $1500 a set.

 

The rods are made by Eagle, SIR 5.7". Will this make much of a difference? I guess the next obvious question would be are SIR rods any good and what does "bushed" mean when talking about pins? Sorry to keep hitting all these questions, I just don't want to do this bottom in a year or two.

 

I don't keep too many secrets as this is supposed to be fun..Anyway, the motor was originally an LPE 383 engine package built almost 12 years ago. The bottom end remains untouched as they built it with a Callies crank, Oliver billet 5.85" rods and JE pistons all in a Corvette 4 bolt block...11.2:1 comp ratio...Heads are LT1 castings with 2.00/1.56 valves originally CNC'd/hand done by LPE and re-ported by E.B. Porting in 2005 along with a Joe Overton spec'd 226/234 cam to replace the LPE 211/219 it came with...Intake was ported by LPE and its got an LPE 58mm TB...I never had any failures at all, I just wanted to go a bit faster which is why I had the heads re-ported and went with a bit bigger (yet still fairly weenie) cam...I only have to go to 6300 to make peak hp which is also easier on the rotating parts...

I realize the billet rods are stronger than the regular forged...Was just saying that these I beams are very durable and have proven themselves over time...

--Alan

 

Alan, thanks for the baseline. I am not looking to go out and beat a bunch of ricers, just nice to know that I could if I wanted to. I am like you, I don't need to go fast, just faster than the guy next to me

Thanks again. I really appreciate the info.

Troy

 

You're welcome..I'm actually going to try for 11 teens with this little cam next year...Going to 3" true duals with an X, Edelbrock 304's, dumped at the axle and switching the 3.73s to 4.10s...I think there's .2 there somewhere...

--Alan

 

Good luck with it. Please let us know how you make out. Any time an F-body makes it big, I think we smile

Mind if I PM you a few specs in the coming days?