8500-9000 rpm

[niswiz]

with uprated valve springs, 270 8.8 tomei cams and a fully built engine running a t3/t67 h.o bb, is 8500-9000 rpm possible or is it a waste of time?

[float_6969]

IIRC, peak HP is rated at about 7500rpm with those cams. IDK how the power falls off after that though. I would imagine that if you've got a turbo big enough to breath up that high, and you're confident in the bottom end holding together, the run it up on the dyno and see if it makes power up there. If it does, good! If not, set the redline to 8K and call it a day.

[Spawn_CA18]

for over 8500rpm your crank is has to be balanced . also with this cams and turbo no need for 8500-9000

[r34 gtr]

Also, I probably wouldnt want to be running stock hydraulic lifters at that kind of engine speed. Solid type procams, solid lifters, and stiffer valve springs for sure. Oh, and rods are necessary, or at least ARP rod bolts.

[blownhemi]

Maybe there should be a sticky reminding people that this engine is not built for revs, not in the least. What it lacks in revs in comparison to other engines, though, it makes up for in boost-ability.

[boost_boy]

Maybe there should be a sticky reminding people that this engine is not built for revs, not in the least. What it lacks in revs in comparison to other engines, though, it makes up for in boost-ability.

Semi-perfectly put in the fact that it is a boost and load friendly little engine. However, it really is designed to rev pretty good and high, but the point of nissan designing it this way was possibly so that you can have a little fun after the T2crap turbocharger runs out of puff. It truly is a revver, but it can use a little help to do it effectively (ie solid lifters, serious cams, etc). One must remember, the head is the hottest part of this engine that allows you to rev the crap out of this motor, but realistically float is right in the fact that 8000rpm is all you guys really need.

[niswiz]

i was checking because i was trying to decide if to purchase some aftermarket valve springs to complete the engine. so the next question is do i need aftermarket springs for 7500 rpm at 8.8mm lift? springs are rated at 11mm lift.

[boost_boy]

i was checking because i was trying to decide if to purchase some aftermarket valve springs to complete the engine. so the next question is do i need aftermarket springs for 7500 rpm at 8.8mm lift? springs are rated at 11mm lift.

it woudn't hurt any. Those stock valve springs wear-out after about 100,000 miles or so>

[s13drifter88]

i will say it will rev but i think mine revved a little more than it should. i think somebody back in jdm-land might have done a little tinkering with the ecu before i got it. after i ran it for about 2 weeks i pulled the ever loving sh*t out it for 2 gears (2ed and 3ed) and when it buried the tach i set my safc to hold the peak values acheived and did it again. 2 times i hit 9300 before it started bouncing. lemme tell you, it made VERY scary noises revving that high.

[dash]

revving is a waste of time, especially with this motor. I find the CA18 to be the worst refined of the 1.8L motors of the day imo. Is it the half counterweighted crank..... or nissan balance tolerances ? I dunno, but by comparison, it ain't no smooth free-revver
Hard to imagine, that Mobnes' 260/8.8 SP61 monster wouldn't satisfy 99.9999% hardcore CA18 enthusiasts

as a contrast, a few corolla clubmembers spin & shift their 4AGs past 10,500rpms, with relatively "simple" cam/lifter mods.
Thing is, they ET no quicker than the cars with more traditional 8000rpm redlines..... and most of them split the cylinder bores, as a bonus - lol.

[float_6969]

Just a friendly reminder here ppl, we're not dealing with 90's Honda vtec technology here. We're dealing with a motor that began development in the EARLY 80's. In a few years, this motor will be working on 30 year old technology. That fact that it's capable of competing at all with more modern and advanced technology is a feat in and of itself.

Really, the 4AG is the only thing (IMHO) from that era that even comes close, and as dash has pointed out, the 4AG has it's flaws as well (When is the last time you ever heard of a CA18 splitting a cylinder?)

[D_Stirls]

Really, the 4AG is the only thing (IMHO) from that era that even comes close, and as dash has pointed out, the 4AG has it's flaws as well (When is the last time you ever heard of a CA18 splitting a cylinder?)

4G-63

[NUTCSE]

Really, the 4AG is the only thing (IMHO) from that era that even comes close, and as dash has pointed out, the 4AG has it's flaws as well (When is the last time you ever heard of a CA18 splitting a cylinder?)

4G-63

FJ20.............

[D_Stirls]

FJ20.............

Cosworth YB series

[s13drifter88]

DSM ladies and gentlemen oh and its a fully balanced crank


btw dash, the 7m isnt no revver either and ive seen them turn past 8 and 8.5k and they feel like they were balanced on a bathroom scale


revving isnt over rated, the ability to broaden your rev band and scream to the stratosphere is nice. 10.5k, now thats pointless (unless your an Yamaha R1 or a CBR1000RR cause thats where they make their power) Smaller displacement engine have to get moving and build their rotaional energy to make their power (B18C5 8.?k rev limit). They dont have the benefit like a chevrolet 454 does, inhaling almost our engines entire displacement per cylinder (speaking sarcasticly) and churning out gobs of wtq's even at idle (not speaking sarcasticly). Since we lack 75% of said displacement we make up by spinning really fast, thus inhaling and exhaling more making our power. 8-9k isnt a bad thing, isnt it drift star syndicate the revs their rb25 to 9.5? with a 35 r it prob doesnt see boost till 4 so why not go to 9.5 and have 5.5k rpm worth of useable power. with larger cams the power band is going to shift upwards so why not use the upwards area.

[float_6969]

The 4G is a good motor too, but the rest of drivetrain and the vehicle it was used in, weren't great IMHO. The FJ is older technology than the CA or 4G, so I wasn't considering it. Although given the 3, the FJ is better than both. If it were an option, The CA would be gone and I'd have an FJ24 in the S14.

[dash]

revving isnt over rated, the ability to broaden your rev band and scream to the stratosphere is nice. 10.5k, now thats pointless

how can 9500rpm make sense to you, but 10,500 doesn't? Neither will be quicker than a 8000rpm combo. That's "nice" ?

Smaller displacement engine have to get moving and build their rotaional energy to make their power (B18C5 8.?k rev limit). They dont have the benefit like a chevrolet 454 does

example; two valve 1.8L SOHC, full weight, factory motor, factory transmission.... goes 9.1sec, no spray. He needs revs??

so why not go to 9.5 and have 5.5k rpm worth of useable power

no magical cam & turbo combo gonna make gobs of torque at 4k and hold it to 9.5. That's a fantasy.
Everything has compromises. More revs = more cam = peakier powerplant, not simply broader.
Why would anyone need "5.5k rpm worth of useable power" anyway..... when u have a gearbox ?

Wringing a ca18 into a zone of questionable reliability & longevity is risky business imo.
most of our goals can be accomplished with the "right" setup. Enough successful hot ca18 examples out there to copy

[themadscientist]

The 4G is a good motor too, but the rest of drivetrain and the vehicle it was used in, weren't great IMHO. The FJ is older technology than the CA or 4G, so I wasn't considering it. Although given the 3, the FJ is better than both. If it were an option, The CA would be gone and I'd have an FJ24 in the S14.

FJ head next to CA

[float_6969]

Interesting. I've never seen them side-by-side like that. I thought the FJ ports were bigger than that, but after you attach the sub-manifold, I'll bet they're the same size, and the FJ has MUCH better port entry angle than the CA does.

The bore spacing on the FJ looks huge! I didn't realize they put that much meat in the cylinders.

Now that I think of it, the 4G63 looks like an inbred cousin of the FJ

[s13drifter88]

Revving to 10.5k is near pointless for any street car because the cam/turbo combo to make efficient power up that high wouldnt leave the vehicle very streetable so a street trim engine would more or less just be making racket up that high. Dont shoot for it.

two-valve 1.8... what? in what car? 1/8 or 1/4? what mods? saying factory engine and trans doesnt really mean much. factory ls's with factory trans do all kind of cool things a make all kind of cool noises when doing those cool things. factory 2j's with factory trans do all kind of neat things, make neat sounds, do big cool John Force smokies ect ect

Why not have 5.5k of usable power? are you a 1000rpm power band guy or something? i know the car has gears. thats what that 1-5/R lever thingy is for in the middle of the car. with such a broad power band why waste is with shifting constantly. Were I able to afford it would love to mate a z32tt trans to my CA with a Q45 dif. A broad power band with longer gears mean the car can keep pulling longer. if youre in 5th gear when you pass the traps at the track youre wasting to much shifting, when you hit the clutch the car isnt under power and youre not accelerating. Look at what Yamaha and Honda did with the YZF450 and the CRF450 moto bikes. both of them rev over 11k yet start hitting their band around 5k due to the head design and cam profiles. they dropped from a close ration 5spd trans to a wide ratio 4spd (My yamaha was a 4spd) and dropped 1 tooth on the rear sprocket. Now we have a machine with a fat-azz power band and gears that go for days. that bike pulled wayyyyyyy harder than my KX250 which had the 5spd close ratio and added a hinson rear sprocket with 1 more tooth oh and it only revved to about 10k. So why is revving over rated again?

[themadscientist]

Save bearings, turn up boost.

[s13drifter88]

lol

[dash]

Save bearings, turn up boost

exactly..... like most "monster" street CA18s have

drifter, u obviously prefer arguing senseless points, rather than trying to understand what we're getting at.

did u not read the 4AG comment ?
dash gave u real world examples of ridiculously quick street cars, that ripped, without high revs.
a couple street miata 1.8s hit hi 10s, stock BP cams
our quickest street 2.6 sohc 4cyl starion clubmember et 10.4, stock cam, 6300rpm redline.
1.8 sohc mentioned was Izusu, Gemini 4 door sedan.... yes, a staggering 9.1sec 1/4. Moded factory 1.8 & auto transmission.

Mobne's, Tones (20g), Ryso, MK II, etc... were all silly quick street CA18, that didn't "waste time" hi revving
....but what do those skilled veterans know, eh ?
build your CA18 like a normally aspirated street bike then.... since that foolish analogy somehow makes sense to u.
Good luck

4G63 looks like an inbred cousin of the FJ

from memory..... my 4-port ca18 head look like my 1st gen dsm twin

[themadscientist]

Handling the FJ I would describe the heft and over-engineering and simplicity of it as a "big block" four banger. It's like nothing I've encountered. The 4G63 is not fit to lovingly cup the FJ's balls.

This crank don't walk son. It swings with authority like a warhammer.

[float_6969]

Now THAT is a sexy crank.

[s13drifter88]

omg, more dsm and mazda comparisons. dash, i like you, you entertain me when im bored. i like revving, i like revving to the moon... to infinity and BEYOND! yes that analogy makes sense, not only does it make sense but its been proven. if were going to make "off manufacturer" comparisons ask yamaha or honda. as for nissan, if it will make power that high then rev it that high. spin till it has no more juice then grab the next gear. if turbo/cams can keep up keep going. is it necessary to rev that high, no... but now this is a 1.8l forum, not a big block forum. what does BMW's V10 indy motor rev to??? what does Honda's indy motor rev to? if you build it to make power up there then use it.

to the OP, is your car a daily or a play toy. will you be beating the snot out of it. i beat the piss out of mine, its a play toy. if it breaks oh well, thats drag/drifting/whatever you do. if your cam/turbo will continue making power to the limis you stated then by all means go for it.

Now to the FJ crank... PREEEEEETTTYYYYYYYYYYYYYYYY!!!!!!!!!!!

[themadscientist]

You know when you have a lot of FJ parts? When you walk into a respected tuning shop, they build 9 second GT-Rs, and the head mech sees you and says "sell me some FJ connecting rods, I know you got em." Sorry Charlie, I need all four sets.