Update on project 13 second LS..

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S

SleEPeR_CRX

Senior Member
Hello ladies... well theres some new idea's for my 13 second all motor LS project.

as many of u know im working on making my 1992 B18a CRX into a 13 second all motor car on a low ass budget. i just got my 13 lb clutch in, and my act pressure plate and disc. and now im starting to work on the head.I have crower 403's with titanium springs and retainers ready to go in after i take the head to the shop. a new plan has come up, to raise the compression by milling the head. i have to get new vavle seals and guides, and 3 angle valve grind with a mild PnP, and i thought a nice head milling would raise compression to around 10-10.5:1. any1 see any problem with this? can the head get milled this much? im keeping stock Pistons and rod's for price sake. im also possible getting a JDM 4-1 header with a 2.5" collector for 350 canadian, and a real mugen ECU, with 3 chips for 300 canadian. just depends on my $$ situation. right now ive spent the follow which are ALL IN CANADIAN DOLLERS

$400- 2.25" cat back exhaust with arospeed genII muffler( yes eww arospeed)
$80 - short ram intake with K&N filter
$5 - dryer tubing running from bumper to intake cone.
$80 - lightened integra flywheel ( 13lbs)
$650 - ACT clutch and pressure plate
$1300 - crower 403 cams with titanium springs and retainers
$150- Block Guard.

In shop, is my head
$400- new valve seals and guides, mild PnP, 3 angle valve grind, and MAYBE deck it to raise compression

coming soon
JDM 4-1 header
Mugen ECU with 3 different chips

Ill keep ya'll posted after i take her to the track


also, my question was. how far can i mill the head to get max compression ( would like 10-10.5:1)

Thanks
 
ditch the "mugen" ECU. It's not from Mugen. Second of all, use pistons to raise your compression. I would reccomend b16 pistons. They aren't even that expensive, and you can save money by ---> Also, you have abosolutely no need for a block guard, all it has the potential to do is cause problems. Your valvetrain seems good to me, but im not an n/a guy, so someone else might be able to give more input on that.
 
im thinking of going n2o later on down the road, thats y the block guard, and while the head is off i may as well do it. i also dont have the knowledge to lower the block to get b16 pistions ineither.
 
i agree with what liquidmeth said, and if you're thinking of spraying later, then get forged pistons, honda oem cast pistons are not a good choice for spray, really depends on how much you want to spray. but the blockguard will not help you with that, ditch the blockguard.
 
im only wanting a 35-50 shot, nothing higher than 55. but that is after i hit 13's N/A then i try to spray for 12's or low 13's.

and eventho i dont NEED blockguard i think it would just be safer and more friendly on me later if i did it now. i didnt think u had any problems with them.
 
if your that stuck on it just have a machine shop "post" your cylinder walls.

posting>blockguards.

are you doing a complete rebuild with new piston rings? cause if you are just get a set of b16 pistons, they fit the stock ls rods and will give you a very nice 10.8:1 compression.

that setup should easily get you into the low 13's on a cool day at sea level.
 
no, im just redoing the head, i dont wanna get into the block cause i dont have the $$ or the skill yet. so i wanna do what i can with raising compression on the head, so milling seemed the best option.

also

Blockguards are alot cheaper than posting.
 
seems i can mill it 20 thousands giving me 9.8:1 compression maybe 10.0:1, which is good enough for what ill be doing with it.
 
eh, i still say throw the b16 pistons in there, do it right the first time :)
 
I did the math on the shoddy little B series compression calculator- milling will only raise you about 0.2:1 per ten thousandths of an inch. That's it. If you want to go from your stock 9.2:1 to 9.8:1, you would have to mill 0.030 inches off, and that's quite a bit of material. Going to 10.5:1 would require 0.065 inches...

Even if the math is off, milling to raise compression really isn't how you should approach the problem. I'm sure you can find a set of B16 pistons for pretty cheap and drop those in on top of your stock rods. It's not too too difficult.
 
PIstons are the way to go. I have a set of JDM B16 Pistons on LS rods I would sell you for a reasonable price. The JDM pistons yield a slightly high compression ratio than the USDM.
 
hmm, i have a friend who has been racing and building honda's since he was 10, and he is building an LS b/c he is bored of everything else ( has build a b18c1 b16a and h22a) and he went with Je pistions then milled the head the same amount i want to do mine, and his comp went from 10.6:1-10.8:1, so i should get .2 more compression.
 
There you go- and he still used custom pistons. He should have just spec'd out the pistons to be 10.8:1 instead of milling to gain extra compression. Go buy yourself the B16 pistons.
 
a block guard has a greater chance of distorting your block than it does saving your motor. You have to know that blockguards aren't a harmless addition to saftey. They have the potential to cause pretty serious problems.
 
Not if you weld them in and then rebore your sleeves so they're shaped correctly, but yeah- block guards aren't the best solution.

:lol:
 
ya well i took my head in today, 270 bucks canadian to get it ALL Done, valve seals guides, 3 angle valve grind, 20 thou mill, install crower springs and retainers. i am going to say no to the blockguard too, cause it will take another week to get here and i wanna get my car on the road asap. i hate borrowing my sisters 93 tercel:(
 
If you plan on reving higher than 6.8K with your 403's than I would suggest maybe getting your rods Shotpened and resized. ( $150 US ) I think LS rods are really being pushed around 8k! And while they are at the machine shop get the B16 pistons pressed on. I would wait a week or so now, so you have no reason to tear it back down later..........Do it right the first time. Good Luck!
 
LS rods are good to about 7500 rpm, after that its iffy, and i will only take it about 7300 right now, until i can get a new ECU. after that i might take them a bit higher like 7400, but probably still well below 8000
 
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