I have a B18A1 and im looking to for some horsepower. what brand and size cams can i use without changing out my valve springs and retainers.

 

crower 62402-2 is on sale right now factory direct for $324. i just looked at the valve lift vs stock and i'm 99% sure you won't have any problems with those cams and your stock valve springs. factory LS duration is 194/196@.50 the crowers are 203/208@.50 also the valve lift goes from 395/380 to 417/399

 

do you have any other internal engine mods done?

I could hardly recommend any aftermarket cam with stock pistons. It doesn't make sense.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SuzukaBlueAP2 &raquo;</TD></TR><TR><TD CLASS="quote">do you have any other internal engine mods done?

I could hardly recommend any aftermarket cam with stock pistons. It doesn't make sense.</TD></TR></TABLE>

explain in detail.

are you saying more compression is needed to increase duration and receive benefit?

 

I'm saying a camshaft isn't something you just bolt in and gain power. You need to take the piston geometry into consideration at the same time.

We will take the B18 engine that is in question here for example. Because the pistons in the B18 don't spent a lot of time at Top Dead Center you need a cam that has a longer duration and more overlap. This allows you to cram as much as as possible into that cylinder in such a short amount of time. At the same time you don't want that intake valve staying open too long because you will eventually start to lose cylinder pressure because of this.

So, that's the long of the short really. Did I help you understand that any better?

I am not certain, but, I believe the Crower 403's and 404's are really the only way you are going to unleash some ponies in the B18A/B engines.

 

you said a b18a1 leading me to assume the engine has quite a few miles on it. why cheap out and risk your engine with stock springs that have seen better days?

 

4 cycle engines all operate the same way. i have no idea what the talk about pistons not spending a lot of time at TDC has to do with this but it is a true fact. i also do agree the 403s and 404s are the way to go on the engine in question. problem is they require more spring and really should have more compression. along with ecu work since the redline needs to go up from stock. the 402s are a nice increase in duration from stock that work with his existing springs and probably his stock fuel map. of course the HP gains are hard to say. especially with a high mile bottom end. sometimes there is no gain at all by increasing duration with high mile bottom ends since more duration bleeds cylinder pressure. i don't know if i would personally spend the money on them without knowing the shape of the engine in question but the OP did ask what would work with his factory springs.

btw...piston geometry? LOL where did that come from?


Modified by idrivesideways at 9:31 PM 9/1/2008


Modified by idrivesideways at 9:33 PM 9/1/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by idrivesideways &raquo;</TD></TR><TR><TD CLASS="quote">
btw...piston geometry? LOL where did that come from?
</TD></TR></TABLE>

The behavior of the piston as it travels up and down in the cylinder based on its rod/stroke ratio = piston geometry

 

true it is, but it still doesn't help this guy in his choices.

i totally know what people are getting at here and i tend to side with them. that is dropping in a set of slightly larger cams like the 402s might not make as big of difference as you expect. now if you have a high mile motor and want to pep it up here's what i would do

1. buy piston rings & a hone for your drill
2. get a 3 angle valve job and new valve seals
3. buy a head gasket for when you put the head back on, new pan gasket is also probably smart

all 3 of the above will run you under $300 and will really pep up your ride if it has some miles under it.





Modified by idrivesideways at 10:05 PM 9/1/2008

 

IIRC Buddy Club III+

do a search on buddy club cams on here, i member it mentions in the thread.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by __oversea &raquo;</TD></TR><TR><TD CLASS="quote">IIRC Buddy Club III+

do a search on buddy club cams on here, i member it mentions in the thread.</TD></TR></TABLE>

those are vtec cams. the OP has a b18a.

 

oh my bad.lol

 

i whouldnt recommend beefing up the top end without the bottom..i put a new itr head on my ride with 140k lasted three days before i threw a rod into my pan..no very appealing to say the least. just my experience but make sure you make a good choice and run a compression test.

 

stuff like tossing rods is common with low oil pressure from worn out bearings. when you bring the power up it finally goes. well, that and stock LS bottom ends are famous for breaking rod bolts when you strap on vtec heads and bring up the HP and the RPM.

 

i learned some stuff just now =]