gotrice16

Ok, since i have no money for a vtec head for this LS block that i'm typing on right now, i am going to spend 100 bucks to get a stock LS head. I'm trying to get this motor swap done as cheaply as possible, but also done properly. This LS block has PCT pistons(Ctr for the laymen), and a newly rebuilt setup on stock rods. I am going to take it apart to check the dude's work, but i am confident that things will pan out well.

now, i want to use nitrous because i can't find a JRSC at all that will fit on my motor. Also, i don't want to turbocharge because i'll end up spending money that i don't have. Plus, i have other priorities right now that take money to facilitate. So, nitrous is the cheapest option, and is a fairly reliable system in my experience.

I'm only going to use a wet kit for now with 50 shot jets. my question is, are these CTR pistons going to be an issue at all? I know they are cast, and make sizeably more compression. But it's only a 50 shot. I'll also be monitoring A/F with a wideband o2 and tuning it with hondata so i can keep it from leaning out. I also have a 255 lb/hr walbro to be on the safe side. Plus, i heard that nitrous likes high compression. i also have an Accel ignition coil but i want to grab an MSD digital ignition.

also, i'd probably be looking at 170 whp, right? I'm not concerned about power off the bottle, because i don't actually need to mash on the throttle too often. I'll probably burn through a bottle at first fairly quickly, but i am also not all that crazy a driver.

gotrice16

not a single reply. going on 40 views.
bump.

ghostofnyc

iTrader: (3)

what are you using for fuel

Jackalope

From what I understand, Nitrous is just like using a Turbo.
Higher Compression will just give you a smaller margin of error when tuning.
You'll want to make sure that you have all the necessary precautions.

And 170whp seems reasonable.

gotrice16

what do you mean about what am i using for fuel? Do you mean octane? 93 octane.

with a small 50 shot, though, isn't there a somewhat large margin of error?

i agree about air/fuel playing a key part in nitrous tuning. That junk is crucial to keep rich in all circumstances.

My key concern is the integrity of the pistons and rods. As long as i can keep the motor rich and prevent pinging, cast pistons aren't a problem, are they? what about the stock rods? are they strong enough to handle a 50 shot?

I'm going to use a MSD, like i said, to keep timing somewhat low, and i'm going to use a button arming and button activation system mounted on my shifter. So i don't have to worry about WOT activation or the WOT switch getting stuck open.

jasons9594

unlike what the other guy said nitrous is nothing like a turbo except its a a form of power adder thats it...and yes nitrous loves higher compression..if im not mistaken the ctr pistons put u at like 12to 1 or higher?but on that note i wouldnt waste the money on a nitrous kit if ur only ganna spray a 50shot...rule of thumb on nitrous id u can spray 50% of ur base hp all day long without any probs what so ever. (if jetted right of course)i have 3 civics and everyone of them are on spray and have been for the past 5 years (give or take the time ive owned them) i have a gsr on a 100shot fogger going to direct port and ganna up it to 150shot i have a stroked 12to1 h22 on a 100shot fogger and am ganna direct port it to a 150 shot also and i have a sohc vitara build on 15psi and a 50shot(wich makes a extra 74hp on spray)ive ran prob over 250lbs of nitrous threw them and never once had a issue that was nitrous related.......o and all are on pump gas.

ghostofnyc

iTrader: (3)

PCT's dont like detonation at all it's heaviest of all oem pistons tend to crumble under pressure. P30's would be a better choice. Nitrous doesn't love or hate compression. But if you can get a flat top high cr piston it would be ideal cause it will give you a better burn of the mixture. Your compression on your motor will limit the amount of n20 you can spray before detonation. The question alot of people should have is how much n20 will my fuel allow me to run not how big of a shot I can run. And the that depends on the octane you are using.

ghostofnyc

iTrader: (3)

OEM pistons and rods are capable of handling big shots how big depends on fuel like I said before. Shot peening rods is added insurance along arp head studs. If you are going pull alot of timing dont waste your time. I run all my shots off the button also

gotrice16

well, my question is, why would it make any difference if i had higher compression, thus, more power and a smaller shot for 170 whp, or flat pistons and a bigger shot? wouldn't it be less likely to pop with the smaller shot? because, what i am reading is that detonation is more prone with a bigger shot. Or am i misunderstanding? I think it would be better especially because i wouldn't have to use as much fuel to keep it running safely. plus, i'd have enough power off the bottle and still be able to use the nitrous to get some good gains when i need them. It wouldn't be a slug off the bottle and also wouldn't need a ton of fuel to keep rich.

am i mistaken with this assumption? i just don't want to have to buy different pistons if the ones i have are just fine. i figure lower shot on more all-motor power to start with is better than less all-motor power and a bigger shot. Plus, i have that 255lb/hr pump, so i'm not concerned with maxing it out.

oh, and over 12:1 on PCTs are only on ls motors with vtec heads. i've seen a clayed LS with these same pistons and the motor was calculated with 11.4-1 compression

ghostofnyc

iTrader: (3)

You are misunderstanding what im saying PCT is not the best piston to spray on period can it be done yes would I no I have seen this piston fail time and time again NA. I'm assuming you want to run this setup on 93 octane. Do you know what the cr would be on the P30's compaired to the PCT 11.0:1 cr vs 11.4:1 cr. Which would have a higher detonation point on pump gas? 11.0:1 cr vs 11.4:1 cr your not gonna notice that big of a difference in NA hp. Now even that I said flat top piston I said flat top high compression, I am a firm believer in making the most NA hp and then spraying but I use better fuel if it was a pump gas motor I would opt for the lower cr motor so I would have a higher detonation point. Why would you want to retard the timing taking away power to make power? When you could run lower cr motor and not have to take away anything.

gotrice16

that makes sense. So, b16 pistons are high compression flat top?

ok. so the rods for ls will be fine? will they have to be modified to accomidate b16 pistons?

gotrice16

Just broke down the Ls motor a little ways. I took the oil pan, oil pickup, and windage tray off. Imagine my surprise when i found the GSR block girdle bolted down. I am glowing right now, this saves me tons of cash. Also, when i removed it, the main bearings are still shiny silver and new. This motor is so cherry! The cylinder walls still have crosshatch on them, and they are shiny and reflective.

I might get around to pulling the flywheel and crank off and removing rear and front main. We'll see how far i get tonight.

gotrice16

I knew it would only get better! I have ARP rod bolts, the block is tapped for oil squirters, the rod bearings are all silver and nice. Best of all, there are no ridges or chomps in the cylinder walls, they are smooth as silk!

I'm going to post some pics tomorrow, but here's my question for now. Is it a big deal that the rod bearings are a tad cloudy? also, some have very minor scratches that are only seen in certain light, but can't be felt with the finger. Is this an issue? should i replace the rod bearings? i know i'm replacing the water pump, but i'm going to take the oil pump apart and clean it well. The oil pan part of the block looks good. The sending unit is still fairly light in color and shiny.

I got this motor for 400 bucks from manhattan. not too shabby at all, considering what it has on it!!!