Pistons=speed

[SniperXr2]

If I go with pistons that have a nice compression, something like 12:1, am i going to get a nice horsepower gain. I was thinkin of going with some high comp pistons and new rods, new cams, all the good stuff. I know if i run 12:1 then turbo would be out of the question, but I still think she would smile over a 50-75 shot. I dont think I wanna go turbo, I might though. I have one week to figure it out. I need to order parts SOON. I am open to any, and all sugestions. Thanks guys..
-Rob

 

[workin_on_it]

i have been pondering the same question lately. i have a 91 n/t and i'm thinking of running 10.5 or 11:1 compression. in order to do this though, i will have to do alot of uprgading thruoghout the engine. here is a little list i have made.
Pistons, rods, rod bolts, maybe knife edge the crank, cams (probably hks because ive heard good things), headwork ei:bigger valves and higher lift springs and better retainers, intake manifold, probably a bigger and better radiator and high performance waterpump, cam gears, probably a copper head gasket, headbolts,
thats just the basic hardware.
then you need the fuel to supply it. i think i would go with a gm mass and translator.....heard lotsa good things about these too. i would also need bigger injectors and a bigger fuel pump.
to support this, i would need an intake and header(which i already have) and exhaust, clutch, underdrive pulleys wouldn't be a bad idea, remove the balance shaft, maybe even the flywheel(could just get my stock one lightened) but as you see it takes alot of work! i'm a muscle car fan and i have worked on a lot of 302's and 360's, so thats why i would rather go the non turbo route.
is anyone on this site running high compression and non turbo? I'm sure there are but lets here your set ups and how it runs etc.

 

[Defiant]

12:1 is just about out of the question with modern [whatever that crap is instead of] gasoline. 10½:1 is pushing it.
You might be able to work some magic with water, alcohol or propane injection.
If you can get it to run, and with supporting mods, higher compression could give you another 20-50 hp on a 2-liter motor.

 

[workin_on_it]

20-50? 10.5:1 with all the supporting mods im guessing would give you over 200 whp! plus alot more torque! and if you upgraded the whole valvetrain, you would be able to rev to 9 grand i'm sure! i'm not trying to start an argument i just can't wait to see people who have done higher compression and what kind of results they get.

 

[Boosh]

ok, it is safe to run 12:1 on the streets. its just all about the tuning. find a place that has good people, and you can run your car on 93 octane all day and have no trouble. Or you could just pour in some octane boost everytime you fill up.

If you want to highcomp./nitrous, get flat top pistons. i believe they come in like 10.5:1 and maybe a little higher, ut then you get into tuning and stuff... You can run a much larger shot with them like 150 or so and not blow anything up. something about the domed pistons makes them bad for nitrous... i never figured out why its just what i heard.

Now from past experience with hondas, i have noticed that fully reuilt high comp. motors have put down a good amount of HP. i say do it.

 

[SniperXr2]

Ok, I have a little over two grand, is that going to be enough to get a nice high compression piston, and all the supporting mods to make it safe? I am not going to run with nitrous anytime soon, but I would like to in the future(within 6 months). What would be the highest compression I would wanna run? I always fill up with 93 level gas, but I wouldnt wanna run any crazy propain injection or anything, and I do have to drive this every day, so 103 level is out of the question, that is way to freakin expensive. What compression pistons do we run stock? Would I wanna bore out my block at all? As you can see I do have alot of questions, I have a mechanic helpin me with the install of all of the parts, he works with neons, and I am under the impression they are about the same car. Thanks for all of the help guys.
-Rob

 

[workin_on_it]

well theres the cost of the pistons, which are the heart of the beast.... they will set you back at least 500. you might not have to the rods, but if your going to be running nitrous, then you probably should get some good billet rods, like the crowers...thats 700! you'd want to run more aggresive cams for sure to feed these pistons enough air.... thats another 4-500. you'd want cam gears to tune everythiong properly, and those will be another 300. your already at the 2000 mark and theres more to go. good headwork with all new valve, springs and retainers will set you back another 500 at the least! 2500. this is just the basics. you will definately need bigger injectors if your goin 12:1, thats gonna be at least 250. 2750. now you need the walbro fuel pump. thats 120 for the 190 lph. now your at 2870. then the fuel computer....gm maf and translator.300 bucks. now its over three grand.
my point is if you want to do it right, its gonna cost you. you can probably get cheaper prices than this, but do it right the first time!
im saving up some mad cash before i get in over my head on this.

 

[SniperXr2]

What kind of WHP would I be lookin at after doing all of that? I am serious about doing it, but I want to do it right the first time.
-Rob

 

[91LaserRS]

ok, it is safe to run 12:1 on the streets. its just all about the tuning. find a place that has good people, and you can run your car on 93 octane all day and have no trouble. Or you could just pour in some octane boost everytime you fill up.

I wouldn't recommend building a high compression motor or having one built if you don't know how to tune. You can't realisticly have a 12 to 1 motor and run to a shop everytime you have a problem. Have you ever read the back of a bottle of Octane booster? It raises the octane rating up by .7. That means if you fill up with 93 octane gas and add a bottle of octane booster that would put you up to 93.7. WOOHOO.


Later,

 

[The1Bill]

Actually, if the stock horsepower is 140, 10.5 will net you 5.04 horsepower, for a grand total of 145.04. Each compression point is worth 4% more horsepower. With 12.5:1, 156HP can be expected, given the same volumetric effeciency.
There is a reason that it is said that "boost is more effecient then compression."
-=B-=

 

[workin_on_it]

but thats just for the pistons...if you do the 4% after doing intake, intake manifold, exhaust, header, upd's and headwork and lightening up the pistons, rods and valvetrain, you will see a larger gain. also when you run higer comp pistons and an aggressive cam, the gains are much greater! if i ever get around to doing all that i have planned, i will be hoping for 200 whp, which is alot for a non turbo and will take alota tuning and stuff.
and why has no one who is running higher compression posted yet? does no one do up nt's or somthing?

 

[The1Bill]

The problem is that a 2.0 that is making decent power just isn't streetable, without valve timing control or lift control. A VTEC motor would not be able to idle very well, and certainly not at 800RPM, if it had a cam that matched the upper lobes. The volumetric effeciency of a naturally aspirated motor is the limiting factor. There is just so much air that the motor can pull into the combustion chamber. at WOT, a well setup 2.0 might be able to pull in .55L of air each rotation. .55L just doesn't do much when it "only" happens 7200 times per minute. A motor setup to have greater then 100% VE would not do well at low RPM, though. So, you would need to rev the absolute piss out of the motor to get it to do anything, even with high compression. That's why a turbo works so well. It can push 1.0L or more per rotation in that same 2.0L motor. That's why it just isn't really worth it.
-=B-=

 

[SniperXr2]

If I have a little over two grand, could I build an engine that would like boost? I wanna do this soon, and I am not against turbo at all, I am trying to learn about alot of this as I go. A very good friend of mine is a mechanic, and I trust him, he is helpin me with all of this for dirt cheap. If I go with the Howell bottom end kit, and run like 8.6:1, how much slower would I be compaired to having stock internals? Would I need to buy anything else? If I ran low compression couldnt I boost the hell out of it and be better off? Sorry about all of these questions guys, I just dont wanna mess any of this stuff up, and I wanna have a faster car .
Thanks
-Rob

 

[E-CLIPS97]

Is it possible to have advanced timing and higher compression pistons at the same time??

 

[Defiant]

Originally posted by workin_on_it
20-50? 10.5:1 with all the supporting mods im guessing would give you over 200 whp! plus alot more torque! and if you upgraded the whole valvetrain, you would be able to rev to 9 grand i'm sure!

Read more slowly, I said "another 20-50", as in "additional" or "gain".

I think the stock valvetrain would live at 9K, at least for awhile. But I don't know if the rest of the fuel system and engine management could keep up, and breathing would be weird: if you were set up to run 9K, your powerband would likely be so narrow that you'd not be able to move off from a stop without killing it.

 

[Defiant]

Originally posted by E-CLIPS97
Is it possible to have advanced timing and higher compression pistons at the same time??

Just a matter of having enough knock resistance. But in the real world, we're fairly limited, mostly by the fuels readily available.

 

[SxyStrtRcr]

that octane booster doesnt say ".7". it says "7 points". i was just at the parts store b4 reading this and i bought some.

 

[91LaserRS]

that octane booster doesnt say ".7". it says "7 points". i was just at the parts store b4 reading this and i bought some.

Read the fine print.



Later,
Frank

 

[workin_on_it]

defiant - i thought you meant with all the mods an extra 20-50.
the1bill - obviousely you know a bit about n/t because you are a wiseman. do you know of people who are running high compression adn supporting mods? i want to learn as much as i can before i decide to do this. pretty much all of my motor buildups have been on older muscle cars like ford 289's and 302's and i helped my friend with high compression on his 360, so all my knowledge is on bigger engines. i know that my friends 360 stock had under 200 hp stock and by the time weer done with it, he should be around 350...thats a mild cam, pistons,(8:1-9.8:1), mild head work, bigger carb, headers, and a few other peices. i know this is starting with a bigger engine but he will almost be doubling the power output.
my main goal if i go this route is to get 200whp(about 250 at the crank), which wont be doubling the power, since i figure that the 1gnt has about 110-115 whp to start with.
still no one has posted with high compression experience

 

[The1Bill]

Doubling the power of a fairly (sorry) ineffecient large pushrod V8 with a rediculously mild cam is not as tough as it is to double the power output of a fairly well tuned small displacement motor with an advanced valvetrain and a high VE from the factory. It is easy enough to make a large displacement motor have plenty of power all around, as there is that much more air and fuel being burned. Increasing the VE with a cam will reduce the low end slightly, but when you are working with almost three times the displacement, a shallower low end is not a kiss of death for streetability. Increasing the VE on a small motor that does not have a ton of torque to spare would shallow out the bottom end enough to make a good idle dificult, and streetability flies out of the window. So, for the total possible power that you can make with high compression and a crazy cam, you must decide what level of streetability you want. You can run high compression with a bit of timing retard and premium fuel only, and that is not too much of a loss in streetability. Are you willing to have a really lumpy idle, though? Do you want to need to have a 1200+ RPM idle? Would a car that does nothing until 7500RPMs be too much to ask? This is entirely up to you, and defines the most power that you will be able to make. In a state like Californi, though, that has only 91 octane, a turbo would be ideal, as you can turn down the compression (the boost) when you are running the piss-like substance that they call gas, and run higher boost at the track when you can get some 110+ octane racing fuel into it.
So, is it possible to make a ton of power with a 2.0 naturally aspirated. Will it be a friendly and easily driven street machine? Probably not.
-=B-=

 

[workin_on_it]

thanx man and i live where theres 94 octane and no emmissions laws! i have been doing alot of resaerch on it the past few weeks and i'm not sure i'd want to do it with my everyday street car....
what about stroker kits? do they make them for th 4g63? since they have a longer stroke, that would help low end torque alot more would it not? and do you know of people on this site that are running high comp with supporting mods?

 

[SniperXr2]

The1Bill, I was looking at your mods, and was wondering, was the AT to MT swap hard, I have been looking into it, and havent seen someone who did it. How much was the approx cost? Thanks man.
-Rob

 

[Kirby]

I would just like to point out a few things. Workin is talking about the NT 4g63 so you would not need and could not use some of the stuff he is talking about. Secondly I just want to say that the only way a 420a would be seeing 9k is with a standalone strapped to it. The car is not capable of raising the rev limit, so that is another issue when trying to make power from compression.