Ok so I read and seen a lot of full engine builds for 1000hp + and they look and run great. Ive also read a bunch of forums speculating on how much HP a stock motor can handle. Where I get confused and limited on info is what actually fails on these motors and WHAT actually needs built. I've had my s2000 for almost 15 years and have gone through 3 motors with spun rod bearings on a stock f20. I was then supercharged for 150k + at 14psi before spinning a rod bearing. My latest motor i pulled an f22 from a salvage yard and overhauled my entire setup and ran 34 psi at 9500rpm on a bone stock(I swapped ap1 intake cam) f22 before lifting the head and blowing a head gasket.

My question is now that im pulling the head to put ARP headstuds in, what are the critical weak points in these motors. Do I just slap the studs in and call it a day or do I add in a set of ACL race bearings to the rods because it's only a matter of time before one of those spin. Should I add a little ring gap to the pistons? Are rods even necessary? Are aftermarket pistons just shiny accessory's that you'll never see lol. My point is why are we doing full builds when majority of these stock parts hold up to some pretty extreme environments.

I can answer any questions about my setup, but im more curious to here from anyone with actual engine failures and experiences. Maybe some mods they've done to get more life out of the factory parts. We've seen 900+ on a "stock" motor, but do we actually need a full engine build to get to the 1000hp mark safely(ish). Thanks.

 

From what I read on here 9500rpm on a F22C is not gonna last, you will need a lighter rotating assembly

 

I've read the same thing, and while the car only makes approximately 10-12 passes down the quarter mile a month. Im just curious as to why. What part fails. Do the pistons sieze do to high piston speed, is it valve float, etc. We have a lot of info on the motor as a whole, what it can and can't do. It would be nice to break down exactly what starts to fail and why. Someone has pushed the limits and broke something. Id like to hear what that was.

 

While it would indeed be nice to know which parts fail, we already know enough to rule some things out.

If an ap2 can't survive 9.5k rpm without lighter rotating assembly, we can rule out piston speed, as that would still be the same with lightened assembly.

Valve float too would be unaffected by lightening rotating assembly.

What a lighter rotating assembly would do is reduce momentum. So likely culprits are rods, rod bolts, possibly wrist pins. Most likely I think though is rod bearings (and maybe crank bearings too). The momentum overcomes the oil film, allowing metal to metal contact.

High rpm is more difficult for an engine to withstand than FI. You are better off power wise adding more boost but keeping redline at or below stock levels. Especially if quarter mile is your goal.

Bigger engines (all else equal) make more power. There are two ways to make a smaller engine act bigger. Power adders or spin it faster (or a bit of both). Honda chose to spin this one faster, as it fit the cars intended purpose.

You are changing its purpose for your needs. No longer any need to stick to Honda's formula.

 

That all makes great sense, bringing the rpms down and changing pulleys is no big deal. But bringing the focus to oil and bearings as being the the first contributing factors to high rpm engine failure is a nice place to start.

So if RPMs are kept into check, and lets say you start crossing into the 35 - 40psi realm what's next. Wrist pin falure, rods start giving? I've managed to push 32 psi with the blower now, and im not sure how much more it has in it, but I wouldn't mind pushing some more limits.