Eagle H beams vs. prepared O.E. connecting Rods

[ka-J]

I can have my stock rods prepared by my machinest for $50. That includes flash grinding the casting imperfections and at the same time "laying over the metal fibers in a specifac direction" - as it was explained to me, then shot peened, and finally polished. Then I can Cryo-Treat them for $7.50 a rod witch increases the strength 30%-50%. Or shopuld I just buy some suspect Eagle H beams for $350? I don't plan on exceeding the 350 hp & tq. range, but I would like a solid engine that can turn a few more rpm's then the O.E. cams powerband deems necassary.

[s13sr20chris]

shotpeening is good, cryo is not worth 30%-50%, and $350 is pretty cheap for a set of h beam rods. at that price i would get the eagles. otherwise just have yours shotpeened.

[Ludeykrus]

I have seen cryo'd and shotpeened KA rods take hell; but for the price, it's your call.

[sil80drifter]

get h beams and cryotreat them

sil80

[ka-J]

It's a difficult choice to make, but I think I'am going to save up for some forged rods. I have heard how adicting boost is, and I doubt I would be able to resist turning it up. Has anyone ever used eagle rods in there ka before? If so how much power did they withstand?

[sil80drifter]

What kills rods (and pistons) is usually detonation. With good tuning you can probably get away with stock rods, up until certain HP numbers. If you overboost, or lean out, the engine is gonna blow anyway, no matter what rods/pistons you have. Yeh, sure the forged rods can withstand a few mild bangs, but if you're detonating really badly, you shouldn't be relying on rods to save you, but on the dyno and some engine management.

sil80

[s13sr20chris]

an excellent point

[marshun]

What kills rods (and pistons) is usually detonation. With good tuning you can probably get away with stock rods, up until certain HP numbers. If you overboost, or lean out, the engine is gonna blow anyway, no matter what rods/pistons you have. Yeh, sure the forged rods can withstand a few mild bangs, but if you're detonating really badly, you shouldn't be relying on rods to save you, but on the dyno and some engine management.

sil80

true. but if he were have good rods and pistson and it predetonated wouldnt he only need to resurface the head and block, and put a new head gasket? since the block should be fine.

im not sure how strong a KA block is. but im just curious about that too. i've seen some built honda motors get blown and they just resurface heads and the block and put another head gasket. of course they inspected the block.

i dont know if this was a one of a kind event or not.

well im just curious and just wanted to know

[ka-J]

Forged rods can also withstand higher rpm's. But, Theres a guy in oregon thats spinning an na ka up to 7,200 with s prepared O.E Rods. He says at 7,400 rpm's they snap. (12.5:1 compression and producing around 230 rwhp) I think the vendor that offered me the Eagle Rods for my car was smoking something, becuase Eagle does not make a connecting rod for the KA. looks like I'am back where I started. O.E. rods it is!

[sil80drifter]

if you melt a piston, you melt a piston, yeah maybe you won't completely melt the super forged one, but u'll do it enough damage to need a new piston.

i know some other peoepl who were getting Eagle rods for the KA, maybe not normally, but a custom job, they can certainly do.i dunno why people are all that crazy about slightly higher revvs in the KA, 7200 aint' that much better than the 6500-6700 I can get out of it stock... yes the NISMO cars with high performance upgrades and a completely rebuilt block did 12k redline, but that's a completely different story.

sil80

[s13sr20chris]

12k? do you have any info on this?

[sil80drifter]

i used to now i can't dig it up... i'm sure c-quik or someone else knows too, sorry i'm not doing good backup on this.

sil80

[ka-J]

I'am sure an sr20 can rev up to 12,000 rpm's, but not a ka. The Sr's crank is fully counter wieghted, and I think the stroke is better for high rpm's. The Nasport gt3 ka's take the cake when it comes to high rpm ka's. Some of them are spinning a little past 8,000, but With the high rod angles of the ka, the side forces on the rods are comprarable to the forces on a rod in a f1 car at red line.