Hmm.. Get pistons that dont overshoot the block? How else was I able to get 11.5:1 c/r out of my gsr with a LS rods/crank, and PR3 pistons? I never compared prelude pistons to CTR's, that was just the pic that popped up that compared the 2 domes and how ridiculously big, and unefficient those pistons are, unless built in a proper engine made to handle them, like the stock B16B that they originally came from.

just because one piston raises your compression more than the other doesnt mean its better if your engine wasnt built to handle that high of a c/r.

look what happens when you drop B16B pistons in a STOCK B20 block, with a B16 head, and use this calculator for proof.
http://www.zealautowerks.com/bseries.html

14.8:1 c/r doesnt look to good on a stock block unless you like detonation. That doesnt include decking the block, or shaving the head.

And the moly coating can be done to most pistons, so thats an invalid topic. Thanks for trying tho...
I never once compared Prelude pistons to CTR pistons, I was just comparing the DOME of the piston, If you quote in my older posts where I specifically told the op to drop a set of H22 pistons in his B16, then Ill admit fail, and leave this thread.

I did a lot of research before I built my last engine. I was also going to buy a new set of CTR's to drop into my GSR, and call it a day. I spent HOURS on the N/a section in this forum, and all the educated guys that knew what they were doing, told me to stay away from CTR's. CTR pistons do not equally distribute the combustion in the cylinder because of that dome. It splits the expanded gasses in the cylinder after the spark has been ignited, and run less efficiently unless built in a proper engine, and I cant stress that enough. CTR's are **** in a street engine not built to handle them! They are awesome If in the correct application!

 

 

¿QUE PASO AQUI VATO LOCO?

 

Bored.

Stop calling me crazy!

 

ctr pistons, since it will yield you a higher cr. And it's brand new, used pistons off craigslist. Not saying it's trash, but 50/50 chance it's useable or junk. Just my .2

 

OP, Whats your set up like?

 

How the hell are you gonna fit B16B pistons with a 81mm bore in a B20 block with 84mm bore? You're retarded.

Also, if you really want to make power, you're gonna need big cams with big duration and lift which will overlap. Only way to make power with these cams is to have higher compression as the overlap bleeds the combustion mixture.

What does the "stock block" have to do with detonation? You can run 15:1 compression in a block without detonation if it's tuned right.

You seem to have read some catch phrases in the all-motor forums, but you still have a **** TON to learn.

 

yew went to jhot i always go there. they have awesome prices.

/thread derail(ish)

 

Hes the one asking about the pistons, not me. Re-read the whole thread before you come in here looking like a jackass. oh, too late

Not only is it common sense that if youre going to boost your stock compression in a block thats used to seeing 9.x:1 to ****ing 14+:1, youre going to need a serious build. Bigger cams are OBVIOUSLY in need, as well as supporting mods. now, onto your fail..

1. I'm telling him to stay away from CTR pistons. If you could actually read, you would have caught this instead of running your mouth (in this case fingers ).

2. Who in their right mind would run 15:1 C/R in a street car???!?!? Are you High??

3. IF, and thats a really big IF, he found someone who could tune his stock block, with no ARP rod bolts, or head studs, how ****ing long do you think its going to last before the block and head seperate from the huge compression boost?

4. #3 continued, He would have to run on race gas, or possibly something with a higher octane to NOT get detonation. You cant tune that out if youre running 14:1 c/r and on street fuel (correct me if im wrong, but im pretty damne sure), detonation is fuels inability to hold the compression, thus firing off before you reach TDC.

5. You obviously dont know **** about anything, so please, leave this thread. Im trying to help OP out. If you want to convince him that running CTR's is a good idea, then I'll be waiting for the "MY BLOCK JUST BLEW UP ON START UP" thread.

Seriously, OP, go to the N/a section to ask questions about your build.... too much bad information here, and im not saying everything I said is true either, Its just from what I have learned over the years of building my car. If you want to listen to someone whos Screenname is 'toadfart' then you probably deserve whats coming to you...

 

i remember my ctr piston b18c1 block/ b16 head JUN III cam setup....9000+rpms of goodness. made 221whp with that setup. the good ol days of racking up 1000s of dollars on my credit card

I daily drove that setup on 94 octane. never detonated due to over 12:1 compression at all

 

^^^
I bet your block wasn't stock either.

You probably built that thing to handle the compression, and revs. OP never mentioned any mods, which is why I'm assuming his engine is a stock B20 with some stock Vtec head.

 

im actually learning from this thread

 

Has there been any mention of what rods are to be used?

 

lolz at a CA resident that still thinks they can get away with running that kind of a motor. Enjoy the BAR ticket.

 

x2.

but what i dont get is how can the air/fuel mixture be seperated unevenly if the gases will move within the combustion chamber?
so naturally, the fuel will be evenly split

 

actually my block was stock, of course i used arp head studs. I also had jun valvesprings and cryotreated titanium retainers.

 

fatpride111

 

You still haven't answered my question about putting B16B pistons in a B20B block. All you did was call me names in your post.

Let me explain why you're wrong in so many levels.
1) Your ONLY reason for telling the OP to stay away from CTR pistons is because of the dome on the piston. Again, he's got a B20VTEC. How the hell is he going to fit B16 or CTR pistons in his B20 block? B16 pistons = 81mm bore. B20 block = 3mm bore.

2) Where are you pulling 15:1 ratio from?

3) You don't even know what the OP has in his motor. You're only assuming it is not built. Again, you can tune the motor to run all sorts of compression even on a stock block. Rod bolts are needed if he's going to rev over 7500 or so, but not necessary if he's staying within the factory redline. Since he's already swapped heads, he should have used aftermarket head studs as it's cheap insurance and if he didn't there's a chance he cut other corners and his motor will probably fail. Again, his head is not going to separate from the block due to the bump in compression. It's all in the tuning. Add more fuel and run less ignition timing.

4) OP would not have to run race fuel if he somehow magically installed B16B pistons in a B20 block. You asked to correct you if you're wrong. Here it is. YOU'RE WRONG. Detonation is caused by too much heat inside the compression chamber. The heat will cause the mixture to ignite without the need of a spark plug, and instead of the slow burn of the mixture like normal, it "detonates" or explodes. So what do you do to cool the chamber down? You add more fuel. If you light gasoline, does it explode? No, it burns slowly. So add a couple percent more fuel to the mix, retard the ignition timing, and you can run your random compression ratio of 15:1 with 91 octane gas. Is it dumb to do this? I would say so, but it is possible even on a stock block.

5) You've already made it clear that you're immature with all this name calling. Just grow up and learn to communicate like an adult if you're at adult age.

By the way, here's the specs of the motor I built myself and street tuned myself.

B20B block STOCK sleeves
ARP rod bolts
CP Forged pistons 11.5:1 compression
AEBS head studs
AEBS intake manifold
Stock B16 head with Rocket Motorsports valve springs and retainers
ITR oil pump
Piece of crap Greddy 4-2-1 header with factory cat
Stock airbox
RS*R exhaust
Stock GSR cams

Motor put down 189 to the wheels and 128 ft/lbs torque.

With cams, header and a bigger exhaust, this motor would put down close to 220 hp to the wheels.

EDIT:: Do you even know the reason why "splitting the mixture" from the dome is bad? It's because it doesn't promote swirling of the mixture as it enters the chamber. Which means atomizing of the fuel is not happening, which means you wont get a complete burn during ignition. Nothing to do with blowing up a motor. Did you also know that if you drill small dimples in the intake runners in the path of the fuel and intake air, this promotes atomization before the fuel gets to the combustion chamber? Yeah it does.

 

CLIFF!! do not post that shiet here only warning you will get slammed on the interwebz

 

seriously, read the posts

Here, maybe capital letters in bold will do the trick...

1. I NEVER ONCE TOLD OP TO USE CTR PISTONS IN A B20 BLOCK. Get that through your head, man. He was asking what the difference between PR3, and CTR pistons was, I simply said CTR's are **** compared to PR3's, unless youre running a race engine with super high compression, and mods to support it. OP never said anything about his block being built, which is why I assumed it was stock. If he would have came in here with some more info, I wouldnt have too assume so much valueable information that could actually help us/him.

As to why he wants to know is beyond me, maybe he has another build? maybe he wants to get over-sized CTR's? who knows, who cares.

2. You stated that you can run 15:1 compression in a STOCK block, which I call Bullshit on unless you have proof. B20's weren't made with the intention to be raced or run on that high of a compression. You cant bump a 9:1 c/r to 15:1 and not expect to have problems. I know about the bore size, you dont have to keep bringing it up, All I was showing were examples of how much of an increase CTR's bring to an engine not made to support it.

3. You cant tune how your head studs are going to hold..

I'm saying from personal experience about my last build. My last gsr blew the rings, so I decided to rebuild it and bump the compression up to 11.8:1 with p30 pistons, LS crank/rods (as calculated before shaving the head, after it was like 12:1 or close, dont remember exactly, been too long), and I used the stock torqueing sequence (65ft/lbs final step) with brand new ARP head studs. Guess what happened? Turned it on, started burning oil, and had LOW compression numbers. After awhile the car wouldnt even turn on, and showed like 10psi compression. I did some research, went on Team-Integra, and low and behold, I was told since I bumped my compression, I had to tighten the head-studs more for it to hold the much higher pressure in the cylinder. I swapped the head gasket, tightened it to a torque sequence I was given on their, final step being like 75ft/lbs, and car started up and ran just fine. Had no issues after that. If going to 12:1 c/r affected it that much, just imagine 15:1. where NO street car should be. I'm not saying it wont hold it, youre just going to be breaking **** all the time IF you can get it to work.

4. Not just heat that causes detonation, Its pressure too. CTR's=higher c/r=higher pressure= detonation.

Basically what I got from that, is the only way to reduce detonation, is to add more 91 octane fuel (not even 93...) to a 15:1 engine? lol. Yeah, build one, and let me know how many times your engine blows up just pulling out of your drive way.

here, brush up on your engine building 101.

I doubt OP is running alcohol injection in his stock B20

5. I never once started calling anyone named untill you guys started flamming me with no input, or proof of any sort. This is GDD, dont get butthurt cause someone calls you a retard after you make a stupid statement like "running 15:1 c/r in a block is possible". I was just giving my .02, I dont start calling names unless its a '10, or someone who deserves it.

quoted for proof.

But after this post, Im kinda starting to wonder if im wasting my time posting here...

Im glad you can build and tune your own engine, but I dont really care to be honest with you..

 

Useless post

 

One last post. I see your logic, but pressure causes heat. For example, turbochargers build pressure and that's why you need an intercooler to lower intake temperatures. Pressure builds heat. Plain and simple.

Pressure builds heat, heat causes the mixture to ignite prematurely, this causes detonation.

With your logic, all pressure will result in detonation? How about those drag cars running 42psi of boost? What's their pressure like? Why do turbo'd cars need way bigger injectors and retarded ignition timing? To keep the heat under control. Same basic idea.


I absolutely agree with you that it is stupid to run super high compression in a street car, but the example you used using that calculator, you used a B20 block (which has a longer crank and rods yielding a higher compression ratio). CTR pistons in a B16 block or a standard GSR block with shorter crank and rods would not yield such high compression and would be streetable.

PEaCe oUT

 

Yes, they do run high psi, but they also dont exceed their limit. Thats why they use lower compression pistons, because with as much air thats being forced in there, that 9:1 c/r quickly raises to 13:1 (+/-), and takes hours and hours of tuning. They dont exceed their limitations, just because their boosted doesn't mean their c/r jumps to 15:1+. The people that build them know what their doing, and know how to work with what their given.

Even when they boost the fck out of a drag car, they still add liquids to cool it off the AIT (i.e. meth-injection) other wise, like you said, the pressure/heat will build up, and you'll start blowing parts.

CTR's in a stock GSR would yeild compression ratios of about 13:1 give or take. ITR pistons are easier to work with, and would only boost your c/r to 11:1 or so, which is why I perfer them over CTR's. Like I've been saying the whole thread, CTR's are good pistons to work with if the engine builder knows what hes doing, If someone went and built any old engine their had with those pistons, chances are theyre going to run into some trouble. The way OP worded his question lead me to believe he didnt what the mother**** he was talking about it, which is why I told him to stay away. If he came in here with more info, and more research, then of course maybe the CTR's would have worked for him.