On my 383, I got a cast steel eagle crank (1 pc RMS), eagle SIR I beam rods (rated at 500hp), sealed power forged flat tops (appx. 10.5-10.75:1 CR), vortecs (ported exhaust for better nitrous flow, stock intake runners), come xe274. All that being said, Im "guesstimating", I should say hoping, that I can get about 400hp at the flywheel. IF that were the case, and I used a 100 shot of nitrous, how long do you think my rods would last, being "rated at 500hp"? the car will be seeing a good but f street and strip, and I doubt id even use the nitrous a lot. I just wondered if they rated rods at "maximum, thats it, no more power whatsoever", or "500hp, gve or take. Go ahead and juice it up ".

 

I have heard that eagles tend to perform poorly near there limits, though it may be a rumor. Also, you say you ported for exhaust flow on your heads, and vortecs have extremely good flow on the exhaust side as it is, so a 100 shot will probably deliver considerably more then 100 hp. You never really know what will happen, if you feel the risk is worth the reward, and you have money to fix a blown motor, go for it.

Just a personal story I have about people modding motors, one of my friends installed a turbo kit on his integra and ran 6 psi of boost, and he called a performance shop and they told him that it might last a while but the stock bottom end cant really handle any more hp then comes from the factory. He went to some forums, and talked to some friends, and everyone said that hondas can handle 10 psi no problem, they've seen people running them for years. 2 days after he installed the kit, a ring land on his piston gave out and the block was damaged beyond repair.

 

You have it a bit backwards... Vortecs exhaust flow is pretty bad - probably the worst thing about the heads in general. Anyway, I have just about the exact same shortblock: esp cast crank, trw forged pistons, and a set of mystery-brand 5.7 I-beam rods (they're supposed to be C&A but have no identifable marks on them). ARP wavlock bolts and main studs for some extra safety.

Just as soon as I work some bugs out I'll be working my way up to the 200 shot... I want 11.0's and I'm pretty confident the shortblock will handle it as long as the tune is good. With your 383 and XE274 you wont be reving high, especially on nitrous. You figure low RPM's + short bursts of "too much" power it'll probably take it forever. I have quite a few friends with low-buck nitrous motors and when they've blown up its never been because of rod failure. It always seems to be either burned up pistons or the crank snapping.

 

Have you ever seen flow-bench tests of vortec heads? Their exhaust flow is admirable compared to other stock castings, and with porting they show significantly more gains on the exhaust side then the intake.

 

We have all seen PLENTY of flow-bench tests of Vortec heads. Gotta be the single biggest buzzword topic in the hot-rod mags these days.

Their exhaust flow is the same typical crappy stock exhaust port flow we've become accustomed to in stock SBC heads. I don't know what flow test you saw; but in reality they usually test in the 140-150 CFM range at their max valve lift (which is only .475" or so), about like nearly all other stock iron heads. And like other stock heads, adding more lift without porting doesn't do much if any good, even after the guides are cut down to allow it.

But you're right, you can gain a great deal by porting on the exhaust side, but relatively little on the intake. About all you can do that helps on the intake, is the usual bowl smoothing and casting flash removal; leaving the port shape ALONE.

 

Porting the vortecs generally yeilds minimal gains, the port shapes are pretty good for a stock head.

As for the N20, if the motor was built to be run N/A then it's got the wrong ring package, wrong end gaps, and probalbly a set of pistons that aren't nitrous friendly. The ringlands are probably a litte to high. You may be able to get away with it, but you better pray it doesn't detonate.

 

as for the rings, your right. They're standard "street/strip" gaps. Pistons are forged TRWs flat tops w/ VR.I forget exactly what the ring gap was, and again about the ring land height. Im sure I got the specs somewhere.

Im just wanting to add like a 100 shot if I could for whenever, not everytime I get in it. It would be, sorry to say, more to look at than I would actually use it.

 

According to a flowbench test down by david vizard, vortec heads flow around 165 cfm on the exhaust side at .450 and up with a 1.6" exhaust valve. Compared to other stock cylinder heads and even some aftermarket ones, this is quite good(most stock style heads only flow about 120cfm, better ones like corvette aluminum heads flow about 150cfm). And, on the same flow bench test he got the heads to flow over 200 cfm on the exhaust side at .600 with a fair amount of porting.