Quote Originally Posted by Aevus View Post
Bytheway, with my 2nd (stock) engine but with all bolt-ons, tune and headers+custom exhaust, I already have 6,050rpm peak power. An extra 600 rpm shouldnt be a problem with that aggressive cam, ported heads and completely upgraded valvetrain, not to mention the forged internals. In fact it's very possible that engine will be 7,000rpm capable, but educated-guesses here of the bottlenecks:

- Oil system = 6,800 rpm max
- Prefix's hydraulic lifters (1/8 turn) = 7,000 rpm max
- Custom cam = 6,900-7,100 rpm max
- Stock crank but machined (oil passage) and balanced = 7,000-7,200 rpm max
- Ported heads = ???
- Fuel system = ???
- All the valvetrain except hyd lifters = 8,000rpm+
- Forged internals = 8,000 rpm+

All educated-guesses because nobody really knows about the real limits of a combination. That makes the engine topic so fascinating!

Take the hydraulic lifters. Nobody in their right mind would dare pushing a hyd above 7krpm, right? WRONG.

and compounded the combination with a set of short-travel hydraulic roller lifters, stud-mounted 1.6:1 ratio roller rockers, titanium retainers, and triple valve springs, and wound the thing up to 7,700 rpm without a hint of valve float.

That wasn't a typo. We revved this thing almost to 8,000 rpm with hydraulic lifters in the block. And it worked.
https://www.motortrend.com/news/rpm-...ic-roller-cam/

So maybe my hyd lifters with 1/8 turn adjust will start to do troubles at 6,800, maybe 7,000 or maybe only 7,500... Almost impossible to know without testing it with all the other parts. Maybe the whole valvetrain will not be the bottleneck at all. Maybe it will be the flow of the heads, or even the camshaft, or the crank, or the oil system (most likely)...

What's kind of crazy is: there is almost always a solution to push the limits even farther. Even though it would seem ''impossible'' at first. Someone somewhere did some tests, trial and errors, and found a solution for a particular problem.