Highest RPM reached?

[ganma_ca]

So I'm assuming with like dual valvesprings some TI retainers and some solid lifters and cams you could probably hit 10-13K rpm on a CA head? WHY????? I want to over-protect my CA! (from myself and missed shifts!).... Not to mention I want F1 speed lmao JKJK Sounds like everyone is building heads right now lol figured I'd join the band wagon. After seeing that there is no such thing as rockers in a CA head I figure the sky's the limit with a good set of cams/springs/valves/guides/retainers/massive porting lol!

[asoomal]

Theoretically, a stroke of 3.29" will get you 9118.54103343465 RPM's at a mean piston speed of 5000 fpm.

[srt4monster]

Theoretically, a stroke of 3.29" will get you 9118.54103343465 RPM's at a mean piston speed of 5000 fpm.

but the can easily be fixed with some longer rods and shorter pistons.

[asoomal]

The stroke is still gonna be the same, sure there will be less stress due to less side loading with a higher rod to stroke ratio, but you're still hitting 5000FPM, which is considered a reasonable limit for a fully built, balanced and dampened rotating parts.

[r34 gtr]

The head will be fine, but you will be spinning bearings and slangin' rods and whatnot at that speed. Then your loosed parts in the bottom end will make a mess of the head, making its ability to rev to 13k kind of moot. Get a billet full counterweight crank, build the head, and you can rev it to 9k if you must.

Side note, I am sitting in the office right now, and people are moving some pallets of stuff in the attic/upstairs storage area. I just heard this:

Guy 1: f***!
Guy 2: f***?
Guy 1: f***.
Guy 2: f***.
Guy 1 and 2: fuuuu***************kkkkk (sung in a melodious manner)
then I hear them moving stuff again. Good times.

[mdb4879]

What about big block chevy's? I've seen 632's shift at 9300 rpm before, capable of going faster there just isn't any more usable power, and they have a 4.750" stroke. Granted these motors are rebuilt at least once every season and only make about 5-second passes, plus the components are larger and have more meat on them so they can probably take more stress. But I think it's possible to rev well past 9K in a CA. I'm sure some people are going to say it's better to make power from boost rather than revs, which I agree with to an extent, unless you just want to rev, then it's just personal preference.

But then again, it seems your reason is for protection. I've heard of people dropping from third to 2nd at 8k rpm and the motor live through the experience. So however not good it may be, the bottom end can handle immediate bursts without instant failure. So on to the head. This all depends on your components within. The stronger the valve springs, lower the lift, and longer the duration, the higher the point at which you'll float the valves. With greater lift and less duration the valve spring has to move a greater distance in a lesser amount of time to keep up with the cam lobe, and the rpm at which the spring and lobe lose contact is lower. So if you have high lift cams, then more duration will give the spring more time to lift up. Idk what math would be involved to figure out the exact point where float would occur, but this gives a general idea about what affects it. Also I'm sure the material of the valve may have an affect on engine safety. I would think a stronger valve could hold up to more shock from closing faster before it breaks (although if the lash is adjusted correctly this shock should be minimal).

I think the 5000FPM thing is a generalization. It really all depends on the materials used, and the dimensions. So if someone had the cash, they could have larger wrist pins made and pistons and rods with more meat around the wrist pins, rods with more meat around the journals, and even a crankshaft with larger journals. Yeah, it's a LOT of money, but anything can be made for someone with pockets deep enough.

I'm sure Supertech valve springs, both single and dual, can handle any revs any of Tomei's cams could reach while making any little bit of power, but your concern is mis-shifting which could result in much higher revs than you'd ever comfortably reach from flooring it alone.

[ganma_ca]

I plan on making a usable powerband all the way up to about 8k, and want the extra room in case of a mis-shift. Why not go sequential shifter you might ask???? Because Ikeya formula wants like $1,800+ for one lmao. So am I correct in thinking lighter and stronger materials would be ideal for building something that can rev high? I am doing the supertech duals as I have seen what they can handle, guide wise I want to know should I stick with oem or go with the brass from Tomei?

[asoomal]

What about big block chevy's? I've seen 632's shift at 9300 rpm before, capable of going faster there just isn't any more usable power, and they have a 4.750" stroke. Granted these motors are rebuilt at least once every season and only make about 5-second passes, plus the components are larger and have more meat on them so they can probably take more stress. But I think it's possible to rev well past 9K in a CA. I'm sure some people are going to say it's better to make power from boost rather than revs, which I agree with to an extent, unless you just want to rev, then it's just personal preference.

But then again, it seems your reason is for protection. I've heard of people dropping from third to 2nd at 8k rpm and the motor live through the experience. So however not good it may be, the bottom end can handle immediate bursts without instant failure. So on to the head. This all depends on your components within. The stronger the valve springs, lower the lift, and longer the duration, the higher the point at which you'll float the valves. With greater lift and less duration the valve spring has to move a greater distance in a lesser amount of time to keep up with the cam lobe, and the rpm at which the spring and lobe lose contact is lower. So if you have high lift cams, then more duration will give the spring more time to lift up. Idk what math would be involved to figure out the exact point where float would occur, but this gives a general idea about what affects it. Also I'm sure the material of the valve may have an affect on engine safety. I would think a stronger valve could hold up to more shock from closing faster before it breaks (although if the lash is adjusted correctly this shock should be minimal).

I think the 5000FPM thing is a generalization. It really all depends on the materials used, and the dimensions. So if someone had the cash, they could have larger wrist pins made and pistons and rods with more meat around the wrist pins, rods with more meat around the journals, and even a crankshaft with larger journals. Yeah, it's a LOT of money, but anything can be made for someone with pockets deep enough.

I'm sure Supertech valve springs, both single and dual, can handle any revs any of Tomei's cams could reach while making any little bit of power, but your concern is mis-shifting which could result in much higher revs than you'd ever comfortably reach from flooring it alone.

F1 engines just reach 5000 btw.

[mdb4879]

Why not go sequential shifter you might ask???? Because Ikeya formula wants like $1,800+ for one

That cheap? lol

F1 engines just reach 5000 btw.

Yeah, but they sustain their high revs for hours at a time. Those BBC's only do so for 4-7 second bursts depending on the length of the track. Plus the motors are much more massive, and can have more "meat" on the internals to handle it better. I'm not saying they can sustain that for extended periods of time, but for short bursts like a mis-shift like we're talking about, he should be in the clear to exceed that limit.

B18's have an even longer stroke than CA's, and people rev those things to 9k repeatedly. As much as I hate using youtube for reference, there are videos with people free revving to 10k. As much as I disagree with abusing any motor like that, especially without any load on it, a higher limit is achievable. I'm not trying to get in a pissing contest. I agree with what you're saying, but for his purposes (a safeguard) the limit is higher.

Now in all seriousness, maybe $1800 for a sequential transmission isn't too bad of an idea. You could easily spend more than that to make a head "bullet-proof." Idk how much has changed in this time, but 20 years ago my boss was having a 632 built for a Chevelle and just his valves alone were $100 a piece (probably some titanium sodium-filled thing, and they're about twice the size of any CA valve). Again, that is a totally different beast from a CA, but the principle is a LOT of money could be going into this. So if it's just a bullet-proofing measure then $1800 for a transmission isn't too bad.

[mdb4879]

I just looked into that thing a realized it's just a shifter. I thought it was a transmission, lol. How much would a sequential transmission cost?

*EDIT: And that would put you at the $10k mark. Well I think that one just shot out the window, lol

[srt4monster]

What about big block chevy's? I've seen 632's shift at 9300 rpm before, capable of going faster there just isn't any more usable power, and they have a 4.750" stroke. Granted these motors are rebuilt at least once every season and only make about 5-second passes, plus the components are larger and have more meat on them so they can probably take more stress. But I think it's possible to rev well past 9K in a CA. I'm sure some people are going to say it's better to make power from boost rather than revs, which I agree with to an extent, unless you just want to rev, then it's just personal preference.

But then again, it seems your reason is for protection. I've heard of people dropping from third to 2nd at 8k rpm and the motor live through the experience. So however not good it may be, the bottom end can handle immediate bursts without instant failure. So on to the head. This all depends on your components within. The stronger the valve springs, lower the lift, and longer the duration, the higher the point at which you'll float the valves. With greater lift and less duration the valve spring has to move a greater distance in a lesser amount of time to keep up with the cam lobe, and the rpm at which the spring and lobe lose contact is lower. So if you have high lift cams, then more duration will give the spring more time to lift up. Idk what math would be involved to figure out the exact point where float would occur, but this gives a general idea about what affects it. Also I'm sure the material of the valve may have an affect on engine safety. I would think a stronger valve could hold up to more shock from closing faster before it breaks (although if the lash is adjusted correctly this shock should be minimal).

I think the 5000FPM thing is a generalization. It really all depends on the materials used, and the dimensions. So if someone had the cash, they could have larger wrist pins made and pistons and rods with more meat around the wrist pins, rods with more meat around the journals, and even a crankshaft with larger journals. Yeah, it's a LOT of money, but anything can be made for someone with pockets deep enough.

I'm sure Supertech valve springs, both single and dual, can handle any revs any of Tomei's cams could reach while making any little bit of power, but your concern is mis-shifting which could result in much higher revs than you'd ever comfortably reach from flooring it alone.

F1 engines just reach 5000 btw.

do you know what the MPS is for a top fuel drag car? 9500 is more then safe with a built bottom end. you are only at 5177FPM. rod ratio also plays a good part in it as well same with bore. my neon has a stroke of 101mm at 8k rpms it has a mean piston speed of 5295FPM and that is done all the time. our shop car revs to 8800rpms and that is 5826FPM. the CA18DET will have no problems going to 9500rpms or even 10000rpms.

[ganma_ca]

Yeah lmao no dog gear boxes for me. I'm not that baller! I'm not dropping a ton on the head either.For around $1800 I'll have it built enough. I mean I'm not going all out but I've got some Tomei solid cams already. I'll do the solid lifters, supertech duals/retainers/stainless valves, rb26 valve shims, some porting and call it a day. And I'm pretty sure have a nice buffer in case the unexpected happens lol.

[asoomal]

Well yeah, you can spin it beyond 5000, it just won't be as reliable.