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11.5 :1 compression?

2

200SVT

Guest
If I were to use 11.5:1 compression pistons in my csvt, would the stock injectors be to lean for the engine, and if so who makes injectors to fit a csvt? Also I know the hp would be higher in the rpm range than stock, do to higher compression, but about how many hp would I gain from jumping from 10.5:1 to 11.5:1 in a csvt at the wheels? One more thing would 93 octane gas be to low for this compression?
 
Needs more turbo kit. Not worth it for the money invested in pistons and machine work. Silly kids.
 
Ok where to start..Pump gas would be fine..Some same different but i believe its fine..As far as compression goes..Demon IIRC has some insane Compression in his SVT lets hope he will Chime in..He runs 24Lbs injectors..( Wedsite says )...But i do know he has a 3L...
Why are you wanting to put high Comp pistons in your Vehicle anyways?
 
why do what everyone else is doing, turbo, supercharger, or 3L. I see nothing wrong with these things, and I know these three things would bring bigger power than a stock csvt, but I would like to see the original motor going NA, and one part of a build would be pistons at a higher compression.
 
While being on a crusade to get the most out of the 2.5L is admirable, it's NOT cost-effective. Replacing pistons to get only a few ponies is lots of $$$ that would get a bigger hp yield elsewhere. Rhetorically: Is it worth $2000 to be different AND slower than the crowd?
 
You know why everyone is doing it?! Because everything else has been done and it works!!!!! Ever think of that? :idea: Demon has done the math with a 1 point bump in comp. Not worth the $. I'm sure ppl would be running it. Bolt the 2.5 heads with SVT cams to a 3L to bump it cheaply and gain the TQ. :idea:
 
ya the hp with high compression would not be right for the money
 
stock injectors will be more than sufficient with a bump in compression to 11.5:1. I dont really see gaining maybe 10 hp being worth $700 for a set of pistons though.
 
cowbell.jpg


substitute cowbell for turbo...
 
While being on a crusade to get the most out of the 2.5L is admirable, it's NOT cost-effective. Replacing pistons to get only a few ponies is lots of $$$ that would get a bigger hp yield elsewhere. Rhetorically: Is it worth $2000 to be different AND slower than the crowd?

More beneficial to use a 3L shortblock with SVT heads and cams. That will net you higher compression and cost less than a set of custom pistons along with the required hardware for replacing the pistons.
 
Yes, 3L block with SVT heads and cams would be much much cheaper, still be N/A, have more torque like todd said, and you would still be increasing your compression (11.25:1 [i believe that is correct compression for this setup]).
 
Rule of thumb 1 pt of compression will get you somewhere around 2% to 2.5% increase, or 5HP in your case.
 
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I understand where he is coming from. If my cash was right i be planning a 3L 12:1 to 13:1 compresson engine. I've heard of people tryin to get pistons made and what not. Like i said if the money was right. Turbo is a fast and cheap way to get horsepower. But is it really that much of a challenge. I am the kind of person that likes big things. It might be a hassle but in the end it all pays of. I have a homie who has a Civic. I know what you guys are going to say. But i'm using this to set a point. People with civics always go for the turbos as well. But my homie is just like me and loves all motor. He took a 2.0L had it bored and stroked to a 2.2L. Got his whole bottom end blueprinted. Forged Crank 13.1:1 compression pistons. And first it took him a while to get everything running right cause there werent that many people at the time using this setup. But when everything was right. He was putting down low 11sec 1/4 miles. And i bet that brought a bigger smile to his face. :laugh: . So all i have to say is dont be afraid to be different. If your money is right and got the time. I SAY GO ON AHEAD AND DO IT. I WISH YOU THE BEST. ALL MOTOR ALL DAY EVERYDAY. STILL LOVE TURBOS AND SUPERCHARGERS. WHATEVER GETS THAT POWER
why do what everyone else is doing, turbo, supercharger, or 3L. I see nothing wrong with these things, and I know these three things would bring bigger power than a stock csvt, but I would like to see the original motor going NA, and one part of a build would be pistons at a higher compression.
 
More beneficial to use a 3L shortblock with SVT heads and cams. That will net you higher compression and cost less than a set of custom pistons along with the required hardware for replacing the pistons.

I am still of the opinion that putting 2.5L heads on top of a 3L block isn't the best idea in the world. There are at least a couple negatives I can think of off the top of my head, and I've never even tried to build one. Heck, I'm having a hard enough time finding the time to bolt together my first 3L . . .
First, I am still firmly of the opinion that the plenum sizing on the 2.5L is BARELY adequate for the 2.5L as it is, and even a little short for the SVT. Second, I don't like the idea of putting a combustion chamber designed for the 2.5L bore over the top of the 3.0L bore. I'm no combustion technical specialist (but a good friend of mine is) but I hear that squish band design is pretty darn important . . . Plus, I'm sure there are other issues with it that become apparent once you spend some time with it. I know people have built them successfully, but I just think there are better ways to go.
 
Not to mention that a high compression engine on pump gas is pointless.

For perhaps a small bump in HP at the high end you'll have to cut a bunch of timing to keep from knocking on pump gas which will kill your torque throughout the rev range.

Not to mention that you won't be able to rev it high enough to take advantage of the high compression goodness either. Well unless you just wanna rev it to 8k like a few of us have done. Nothing lasts forever... right?
 
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Dyanamic compression will only change significantly if the cam timing (intake valve closing) is changed. Later closings require higher static CR's because the effective compression stroke is shorter. Higher static ratios are used to compemsate. The dynamic CR is what matters...

Pairing high compression pistons with a more aggressive cam will be more effective. IIRC, someone already used a 11.5:1 static ratio with the SVT camshaft.
 
Good thing here in vegas we can run over to REBELS Gas station and pump some 100 octane. :laugh: . The only problem is that it only costs 10.00 a gallon.:blackeye: . That would suck for a daily driver.
Not to mention that a high compression engine on pump gas is pointless.

For perhaps a small bump in HP at the high end you'll have to cut a bunch of timing to keep from knocking on pump gas which will kill your torque throughout the rev range.

Not to mention that you won't be able to rev it high enough to take advantage of the high compression goodness either. Well unless you just wanna rev it to 8k like a few of us have done. Nothing lasts forever... right?
 
Good thing here in vegas we can run over to REBELS Gas station and pump some 100 octane. :laugh: . The only problem is that it only costs 10.00 a gallon.:blackeye: . That would suck for a daily driver.

That sucks. I can get 110 around town for under 5 bucks a gallon :)
 
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