ive been working on building a 383 stroker for the past couple months now..i need some help with making a decision on some rods..i want a fast revving engine, but at the same time i want it to be strong..
so far the build is consisting of the following:

383 stroker(completely forged)
LE2 heads/ le2.2 cam
6.000 rods
-4cc flat top pistons
comp cam 1.6 pro mags
4 bolt billet splayed caps
ls7 lifters(good to 7k rpm)
double roller timing chain
if you need anymore info, just let me know

anyways, i plan on looking at around 12:1 compression and turning around 6800 rpm. im unsure on what weight of rods i want and h-beam or i-beam. ive found some scat q-lite h-beam rods weighing 565g, found some eagle rods weighing 640g and they have some going clear up to 680g. i know the lighter the better, but i dont want to go to light w/ my compression level and rpm and im afraid they might be too weak. Any advice or help would be great..thanks

 

First off look at the cam specs to see where power will be produced. No reason to buy Ti rods made for 900hp+ or revving at 9k rpm. I think best thing to do is call the manufactures for strength and material ratings to compare with weight. 6in rods are common so I'm sure you'll find lots of options.

 

Just go with a standard scat I beam rod with 7/16 cap screw. Plenty strong for any n/a lt1 and one of the best budget rods for a stroker because it will require the least grinding on the block and to clear the cam. The h beam design is actually more problematic as far as clearance, and is no better in terms of strength, its even weaker depending on the manufacturer/design.

Don't spend a wad of money in the short block, it doesn't really get you anywhere power wise. You're not doing anything crazy and 6800rpm is nothing for a small block with decent parts. You will get more of the 'fast reving' improvement from a really light weight clutch and flywheel setup than you will from spending thousands on the crank rods and pistons. If you don't believe me fire up an automatic car with no converter behind it sometime, the throttle response is insane.

 

yea i actually did start my engine w/ just flexplate when i did my a4 to t56 swap..it was indeed very responsive..i was told to stay away from i-beam because they were weaker..idk

 

Scat Pro I Beam 7/16 Capscrew - best deal going. You will need to have the big end bores checked and the pin bushings may need to be opened up some just like with any performance part. Nice thing is that Scat always errors to the low side so the engine builder can open the clearances to their desired #'s.

 

If you take the actual rods you're planning on using and do the engineering stress calculations based on different loads and geometry that it will actually see, the I beam is generally speaking stronger. It has a higher moment of inertia (second moment of area) and will resist bending better. It also generally speaking has a larger cross section than the H beam rods and can therefore stand compressive and tensile loads better as well.

All calculations aside 99 times out of 100 the rod bolts will fail before the rod itself does, and the time the rod fails is likely due to a defect like an inclusion or a stress riser or sometimes even a void in the rod rather than a design or material strength issue. You're not going to make enough power n/a to worry about either rod imo.