So I've become very interested in these all-motor b18b builds here on honda-tech, and had a few questions.

- Is the valvetrain/cams the only thing limiting an LS from revving to 9000+?
-Or will it simply not make power up that high because of lack of vtec or compression?
-Does the LS head suck for high rpm power?

People always compare b16's to b18b's heads up, saying they are about the same speed. But if you were to add simple cams and valvetrain to an LS, and increase the redline, wouldn't you be on par with a GSR if not more?

tia.

 

1. The stock rods/rod bolts are also a weak point in addition to the stock valvetrain.
2. VTEC is all about the 2 cam profiles...if you can find a non-VTEC cam that will make power @ 9K rpms like VTEC does remember you don't have a smaller primary lobe so it will idle like crap, if at all. And yes, the B18B has only 9:1 c/r which is way too low for those monstrous types of cams.
3. Yes the head has small ports and valves so it does suck for extreme high rpms.

Someone correct me if I'm wrong but aren't the Crower 405's the biggest non-VTEC cams out there? They don't rev to 9K either and push the rockers to their limit.

 

so whats the reason for revving to 9k again?

 

I'd worry about valvetrain stability with the ball and socket style rocker setup of the LS heads. No personal experience @ 9ooorpm here, just thinking out loud.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by klungemonger &raquo;</TD></TR><TR><TD CLASS="quote">1. The stock rods/rod bolts are also a weak point in addition to the stock valvetrain.
2. VTEC is all about the 2 cam profiles...if you can find a non-VTEC cam that will make power @ 9K rpms like VTEC does remember you don't have a smaller primary lobe so it will idle like crap, if at all. And yes, the B18B has only 9:1 c/r which is way too low for those monstrous types of cams.
3. Yes the head has small ports and valves so it does suck for extreme high rpms.

Someone correct me if I'm wrong but aren't the Crower 405's the biggest non-VTEC cams out there? They don't rev to 9K either and push the rockers to their limit.</TD></TR></TABLE>
I'm prett sure you are correct about the 405s but yes I agree to your 3 points.

Oversizing vavles may help a bit but still 9k is a ton, people think its only 800 rpm more then a b16. Heck even the 8200 is alot, we Honda guys take RPM forgranted at times.

If only my SBC reved to 9k.

 

9k is a bit high.your going to need to up the compression and also have nice built head

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by marcusgnf &raquo;</TD></TR><TR><TD CLASS="quote">so whats the reason for revving to 9k again?</TD></TR></TABLE>That's the real point here. If there was a benefit or purpose to taking an LS that high it would definitely have been done or at least there would be some parts available to support a build like that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ChokeOnMySmoke &raquo;</TD></TR><TR><TD CLASS="quote">9k is a bit high.your going to need to up the compression and also have nice built head</TD></TR></TABLE>


Even with 'upping' the compression, it all comes down to what the cams stop making power at.
I've generally seen built NON-Vtec b18's running max of 8k rpm and around there. Usually you'd see 7500-7800rpm's on a street motor depending on what cams you go with.

 

I see no reason to wind a B18B to 9,000. My 85mm LS motor with BC 2's (=Crower 403's) peaks at 7,200 with a GSR intake manifold. I will be testing the motor with 405a's soon; both with the GSR intake manifold and a Blox intake manifold. I suspect that all of the setups that I am going to test are going to peak prior to 8,000 RPM. I have some doubts about the B18B rocker setup with the big cams and high RPM-we will find out soon enough.

 

http://www.nonvtec.com/forums/viewtopic.php?t=444

 

Or:
https://honda-tech.com/zerothread?id=1877372

 

my bad

 

The stock rods/rod bolts are too weak?

Ok maybe I don't need to goto 9k, but 8k would be decent. The only reason I ask is because torque x rpm = hp. and we all love hp.

 

Yes, torque x rpm = horsepower. But it doesn't matter how much rpm you throw at it if the torque isn't there.

 

to the ppl that went all motor for the b18b, what kind of power did you make?

 

i rev'd a bone stock ls motor up to 8~8500, that was the biggest waste of time ever, if actualy felt like i was de-celerating around 8k.

i only tried that once by putting a different ecu in, the ls just stops making power around 74 or 7500 max

going with a b16 or a b18b really is a toss up, the ls head, compression and rod bolts suck, but the b16 is a 1.6 lt and it costs more but it does rev higher, an ls with arp rod bolts, new pistons and a vtec head would be your best bet if you want to take the cheap way to somewhat quick